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189-477: Sequoia sempervirens ( / s ə ˈ k w ɔɪ . ə ˌ s ɛ m p ər ˈ v aɪ r ən z / ) is the sole living species of the genus Sequoia in the cypress family Cupressaceae (formerly treated in Taxodiaceae ). Common names include coast redwood , coastal redwood and California redwood . It is an evergreen , long-lived, monoecious tree living 1,200–2,200 years or more. This species includes
378-429: A helical structure (i.e., shaped like a corkscrew). Their double-helix model had two strands of DNA with the nucleotides pointing inward, each matching a complementary nucleotide on the other strand to form what look like rungs on a twisted ladder. This structure showed that genetic information exists in the sequence of nucleotides on each strand of DNA. The structure also suggested a simple method for replication : if
567-423: A mutation–selection balance . It is predicted that a viral quasispecies at a low but evolutionarily neutral and highly connected (that is, flat) region in the fitness landscape will outcompete a quasispecies located at a higher but narrower fitness peak in which the surrounding mutants are unfit, "the quasispecies effect" or the "survival of the flattest". There is no suggestion that a viral quasispecies resembles
756-405: A ring species . Also, among organisms that reproduce only asexually , the concept of a reproductive species breaks down, and each clone is potentially a microspecies. Although none of these are entirely satisfactory definitions, and while the concept of species may not be a perfect model of life, it is still a useful tool to scientists and conservationists for studying life on Earth, regardless of
945-534: A sexual process for transferring DNA from one cell to another cell (usually of the same species). Transformation requires the action of numerous bacterial gene products , and its primary adaptive function appears to be repair of DNA damages in the recipient cell. The diploid nature of chromosomes allows for genes on different chromosomes to assort independently or be separated from their homologous pair during sexual reproduction wherein haploid gametes are formed. In this way new combinations of genes can occur in
1134-400: A "classical" method of determining species, such as with Linnaeus, early in evolutionary theory. However, different phenotypes are not necessarily different species (e.g. a four-winged Drosophila born to a two-winged mother is not a different species). Species named in this manner are called morphospecies . In the 1970s, Robert R. Sokal , Theodore J. Crovello and Peter Sneath proposed
1323-424: A 'smallest clade' idea" (a phylogenetic species concept). Mishler and Wilkins and others concur with this approach, even though this would raise difficulties in biological nomenclature. Wilkins cited the ichthyologist Charles Tate Regan 's early 20th century remark that "a species is whatever a suitably qualified biologist chooses to call a species". Wilkins noted that the philosopher Philip Kitcher called this
1512-582: A DNA molecule. In 1983, Kary Banks Mullis developed the polymerase chain reaction , providing a quick way to isolate and amplify a specific section of DNA from a mixture. The efforts of the Human Genome Project , Department of Energy, NIH, and parallel private efforts by Celera Genomics led to the sequencing of the human genome in 2003. At its most fundamental level, inheritance in organisms occurs by passing discrete heritable units, called genes , from parents to offspring. This property
1701-493: A complex trait is called heritability . Measurement of the heritability of a trait is relative—in a more variable environment, the environment has a bigger influence on the total variation of the trait. For example, human height is a trait with complex causes. It has a heritability of 89% in the United States. In Nigeria, however, where people experience a more variable access to good nutrition and health care , height has
1890-620: A conical crown , with horizontal to slightly drooping branches. The trunk is remarkably straight. The bark can be very thick, up to 35 cm (1.15 ft), and quite soft and fibrous, with a bright red-brown color when freshly exposed (hence the name redwood), weathering darker. The root system is composed of shallow, wide-spreading lateral roots . The leaves are variable, being 15–25 mm ( 5 ⁄ 8 –1 in) long and flat on young trees and shaded lower branches in older trees. The leaves are scalelike, 5–10 mm ( 1 ⁄ 4 – 3 ⁄ 8 in) long on shoots in full sun in
2079-428: A connected series of neighbouring populations, each of which can sexually interbreed with adjacent related populations, but for which there exist at least two "end" populations in the series, which are too distantly related to interbreed, though there is a potential gene flow between each "linked" population. Such non-breeding, though genetically connected, "end" populations may co-exist in the same region thus closing
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#17327760849892268-621: A considerable part of the trees' water needs. Fog in the 21st century is, however, reduced from what it was in the prior century, which is a problem that may be compounded by climate change . The northern boundary of its range is marked by two groves on mountain slopes along the north side of the Chetco River , which is on the western fringe of the Klamath Mountains , near the California–Oregon border. The northernmost grove
2457-483: A different parent. Many species have so-called sex chromosomes that determine the sex of each organism. In humans and many other animals, the Y chromosome contains the gene that triggers the development of the specifically male characteristics. In evolution, this chromosome has lost most of its content and also most of its genes, while the X chromosome is similar to the other chromosomes and contains many genes. This being said, Mary Frances Lyon discovered that there
2646-432: A different species from its ancestors. Viruses have enormous populations, are doubtfully living since they consist of little more than a string of DNA or RNA in a protein coat, and mutate rapidly. All of these factors make conventional species concepts largely inapplicable. A viral quasispecies is a group of genotypes related by similar mutations, competing within a highly mutagenic environment, and hence governed by
2835-546: A diploid cell with paired chromosomes. Diploid organisms form haploids by dividing, without replicating their DNA, to create daughter cells that randomly inherit one of each pair of chromosomes. Most animals and many plants are diploid for most of their lifespan, with the haploid form reduced to single cell gametes such as sperm or eggs . Although they do not use the haploid/diploid method of sexual reproduction, bacteria have many methods of acquiring new genetic information. Some bacteria can undergo conjugation , transferring
3024-429: A gene is used to produce a specific amino acid sequence . This process begins with the production of an RNA molecule with a sequence matching the gene's DNA sequence, a process called transcription . This messenger RNA molecule then serves to produce a corresponding amino acid sequence through a process called translation . Each group of three nucleotides in the sequence, called a codon , corresponds either to one of
3213-508: A genetic boundary suitable for defining a species concept is present. DNA barcoding has been proposed as a way to distinguish species suitable even for non-specialists to use. One of the barcodes is a region of mitochondrial DNA within the gene for cytochrome c oxidase . A database, Barcode of Life Data System , contains DNA barcode sequences from over 190,000 species. However, scientists such as Rob DeSalle have expressed concern that classical taxonomy and DNA barcoding, which they consider
3402-449: A healthy tree. Bark is so thick on the bole that bark beetles cannot enter there. However, the canopy branches have thin bark (see photo at right) that native bark beetles are able to bore into for egg-laying and larval growth via tunnels. Redwoods also face herbivory from mammals: black bears are reported to consume the inner bark of small redwoods, and black-tailed deer are known to eat redwood sprouts. The oldest known coast redwood
3591-482: A heritability of only 62%. The molecular basis for genes is deoxyribonucleic acid (DNA). DNA is composed of deoxyribose (sugar molecule), a phosphate group, and a base (amine group). There are four types of bases: adenine (A), cytosine (C), guanine (G), and thymine (T). The phosphates make phosphodiester bonds with the sugars to make long phosphate-sugar backbones. Bases specifically pair together (T&A, C&G) between two backbones and make like rungs on
3780-435: A higher body temperature. In a low-temperature environment, however, the protein's structure is stable and produces dark-hair pigment normally. The protein remains functional in areas of skin that are colder—such as its legs, ears, tail, and face—so the cat has dark hair at its extremities. Environment plays a major role in effects of the human genetic disease phenylketonuria . The mutation that causes phenylketonuria disrupts
3969-530: A lack of lowland passages through the Oregon Coast Range north of the Chetco River , coupled with the absence of coastal landscapes beyond storm salt-spray and tsunami inundation — for which this conifer species is highly intolerant. The native area provides a unique environment with heavy seasonal rains up to 2,500 mm (100 in) annually. Cool coastal air and fog drip keep the forest consistently damp year round. Several factors, including
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#17327760849894158-506: A ladder. The bases, phosphates, and sugars together make a nucleotide that connects to make long chains of DNA. Genetic information exists in the sequence of these nucleotides, and genes exist as stretches of sequence along the DNA chain. These chains coil into a double a-helix structure and wrap around proteins called Histones which provide the structural support. DNA wrapped around these histones are called chromosomes. Viruses sometimes use
4347-505: A living cell or organism may increase or decrease gene transcription. A classic example is two seeds of genetically identical corn, one placed in a temperate climate and one in an arid climate (lacking sufficient waterfall or rain). While the average height the two corn stalks could grow to is genetically determined, the one in the arid climate only grows to half the height of the one in the temperate climate due to lack of water and nutrients in its environment. The word genetics stems from
4536-808: A main trunk volume of 1,033 m (36,470 cu ft), and the Lost Monarch , with a main trunk volume of 988.7 m (34,914 cu ft). Albino redwoods are mutants that cannot manufacture chlorophyll . About 230 examples (including growths and sprouts) are known to exist, reaching heights of up to 20 m (66 ft). These trees survive like parasites , obtaining food from green parent trees. While similar mutations occur sporadically in other conifers, no cases are known of such individuals surviving to maturity in any other conifer species. Recent research news reports that albino redwoods can store higher concentrations of toxic metals, going so far as comparing them to organs or "waste dumps". Heights of
4725-492: A misnomer, need to be reconciled, as they delimit species differently. Genetic introgression mediated by endosymbionts and other vectors can further make barcodes ineffective in the identification of species. A phylogenetic or cladistic species is "the smallest aggregation of populations (sexual) or lineages (asexual) diagnosable by a unique combination of character states in comparable individuals (semaphoronts)". The empirical basis – observed character states – provides
4914-581: A more storied role than the Pacific Lumber Company (1863–2008) of Humboldt County, California, where it owned and managed over 810 km (200,000 acres) of forests, primarily redwood. Coast redwood lumber is highly valued for its beauty, light weight, and resistance to decay. Its lack of resin makes it absorb water and resist fire. P. H. Shaughnessy, Chief Engineer of the San Francisco Fire Department wrote: In
5103-597: A narrow strip of land approximately 750 km (470 mi) in length and 8–75 km (5–47 mi) in width along the Pacific coast of North America; the most southerly native grove is in Monterey County, California , and the most northerly groves are in extreme southwestern Oregon. The aforementioned qualification of "native" is because the species was introduced to various locations in Victoria, Australia , in
5292-502: A national news outlet published a lengthy article that cast a favorable light on their efforts. The New York Times Magazine wrote: Not wanting to cause ecological problems by planting the trees across the Pacific Northwest, [Philip] Stielstra would eventually contact one of the foremost experts on the coast redwood, a botanist and forest ecologist named Stephen Sillett , at Cal Poly Humboldt, and ask if moving redwoods north
5481-449: A particular species, including which genus (and higher taxa) it is placed in, is a hypothesis about the evolutionary relationships and distinguishability of that group of organisms. As further information comes to hand, the hypothesis may be corroborated or refuted. Sometimes, especially in the past when communication was more difficult, taxonomists working in isolation have given two distinct names to individual organisms later identified as
5670-456: A phenotype involves studying identical and fraternal twins , or other siblings of multiple births . Identical siblings are genetically the same since they come from the same zygote. Meanwhile, fraternal twins are as genetically different from one another as normal siblings. By comparing how often a certain disorder occurs in a pair of identical twins to how often it occurs in a pair of fraternal twins, scientists can determine whether that disorder
5859-433: A redwood tree below the soil line, though usually within 3 m (10 ft) in depth from the soil surface. Coast redwoods develop burls as seedlings from the axils of their cotyledon , a trait that is extremely rare in conifers. When provoked by damage, dormant buds in the burls sprout new shoots and roots. Burls are also capable of sprouting into new trees when detached from the parent tree, though exactly how this happens
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6048-589: A regional news article that, once again, showed strong support as well as bold statements by the group's founder. Even before the controversy developed in Washington state, professionals in Canada were documenting horticultural plantings of the California species already in place in southwestern British Columbia . In 2022 a Canadian Forestry Service publication used northward horticultural plantings, along with
6237-466: A review of research detailing redwood's paleobiogeography and current range conditions, as grounds for proposing that Canada's Vancouver Island already offered "narrow strips of optimal habitat" for extending the range of coast redwood. The authors point to a topographical "bottleneck" north of the California border that could have impeded northward migration during the Holocene. The bottleneck entails
6426-403: A series of genes can be combined to form a linear linkage map that roughly describes the arrangement of the genes along the chromosome. Genes express their functional effect through the production of proteins, which are molecules responsible for most functions in the cell. Proteins are made up of one or more polypeptide chains, each composed of a sequence of amino acids . The DNA sequence of
6615-400: A short way of saying that something applies to many species within a genus, but not to all. If scientists mean that something applies to all species within a genus, they use the genus name without the specific name or epithet. The names of genera and species are usually printed in italics . However, abbreviations such as "sp." should not be italicised. When a species' identity is not clear,
6804-560: A sign of reticulate evolution (in which two species hybridize and give rise to a third) among the three genera. However, the long evolutionary history of the three genera (the earliest fossil remains being from the Jurassic ) make resolving the specifics of when and how Sequoia originated once and for all a difficult matter—especially since it in part depends on an incomplete fossil record. The species name "sempervirens" means "evergreen", thought to be because of its previous placement in
6993-457: A single parent. Offspring that are genetically identical to their parents are called clones . Eukaryotic organisms often use sexual reproduction to generate offspring that contain a mixture of genetic material inherited from two different parents. The process of sexual reproduction alternates between forms that contain single copies of the genome ( haploid ) and double copies ( diploid ). Haploid cells fuse and combine genetic material to create
7182-448: A small circular piece of DNA to another bacterium. Bacteria can also take up raw DNA fragments found in the environment and integrate them into their genomes, a phenomenon known as transformation . These processes result in horizontal gene transfer , transmitting fragments of genetic information between organisms that would be otherwise unrelated. Natural bacterial transformation occurs in many bacterial species, and can be regarded as
7371-400: A smooth blend of traits from their parents. Mendel's work provided examples where traits were definitely not blended after hybridization, showing that traits are produced by combinations of distinct genes rather than a continuous blend. Blending of traits in the progeny is now explained by the action of multiple genes with quantitative effects . Another theory that had some support at that time
7560-404: A specialist may use "cf." before the epithet to indicate that confirmation is required. The abbreviations "nr." (near) or "aff." (affine) may be used when the identity is unclear but when the species appears to be similar to the species mentioned after. With the rise of online databases, codes have been devised to provide identifiers for species that are already defined, including: The naming of
7749-523: A species as groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other such groups. It has been argued that this definition is a natural consequence of the effect of sexual reproduction on the dynamics of natural selection. Mayr's use of the adjective "potentially" has been a point of debate; some interpretations exclude unusual or artificial matings that occur only in captivity, or that involve animals capable of mating but that do not normally do so in
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7938-400: A species as determined by a taxonomist. A typological species is a group of organisms in which individuals conform to certain fixed properties (a type), so that even pre-literate people often recognise the same taxon as do modern taxonomists. The clusters of variations or phenotypes within specimens (such as longer or shorter tails) would differentiate the species. This method was used as
8127-491: A species. All species definitions assume that an organism acquires its genes from one or two parents very like the "daughter" organism, but that is not what happens in HGT. There is strong evidence of HGT between very dissimilar groups of prokaryotes , and at least occasionally between dissimilar groups of eukaryotes , including some crustaceans and echinoderms . The evolutionary biologist James Mallet concludes that there
8316-685: A species. Generally the term includes the unknown element of a distinct act of creation. Many authors have argued that a simple textbook definition, following Mayr's concept, works well for most multi-celled organisms , but breaks down in several situations: Species identification is made difficult by discordance between molecular and morphological investigations; these can be categorised as two types: (i) one morphology, multiple lineages (e.g. morphological convergence , cryptic species ) and (ii) one lineage, multiple morphologies (e.g. phenotypic plasticity , multiple life-cycle stages). In addition, horizontal gene transfer (HGT) makes it difficult to define
8505-528: A taxonomic decision at the discretion of cognizant specialists, is not governed by the Codes of Zoological or Botanical Nomenclature, in contrast to the PhyloCode , and contrary to what is done in several other fields, in which the definitions of technical terms, like geochronological units and geopolitical entities, are explicitly delimited. The nomenclatural codes that guide the naming of species, including
8694-517: A traditional biological species. The International Committee on Taxonomy of Viruses has since 1962 developed a universal taxonomic scheme for viruses; this has stabilised viral taxonomy. Most modern textbooks make use of Ernst Mayr 's 1942 definition, known as the Biological Species Concept as a basis for further discussion on the definition of species. It is also called a reproductive or isolation concept. This defines
8883-452: A transition of heredity from its status as myth to that of a scientific discipline, by providing a fundamental theoretical basis for genetics in the twentieth century. Other theories of inheritance preceded Mendel's work. A popular theory during the 19th century, and implied by Charles Darwin 's 1859 On the Origin of Species , was blending inheritance : the idea that individuals inherit
9072-412: A unique three-dimensional structure for that protein, and the three-dimensional structures of proteins are related to their functions. Some are simple structural molecules, like the fibers formed by the protein collagen . Proteins can bind to other proteins and simple molecules, sometimes acting as enzymes by facilitating chemical reactions within the bound molecules (without changing the structure of
9261-447: A variation on the morphological species concept, a phenetic species, defined as a set of organisms with a similar phenotype to each other, but a different phenotype from other sets of organisms. It differs from the morphological species concept in including a numerical measure of distance or similarity to cluster entities based on multivariate comparisons of a reasonably large number of phenotypic traits. A mate-recognition species
9450-493: A variety of amphibians, birds, mammals, and reptiles. Old-growth redwood stands provide habitat for the federally threatened spotted owl and the California-endangered marbled murrelet . The height of S. sempervirens is closely tied to fog availability; taller trees become less frequent as fog becomes less frequent. As S. sempervirens ' height increases, transporting water via water potential to
9639-400: A variety of hereditary characteristics that replicate and remain active throughout generations. While haploid organisms have only one copy of each chromosome, most animals and many plants are diploid , containing two of each chromosome and thus two copies of every gene. The two alleles for a gene are located on identical loci of the two homologous chromosomes , each allele inherited from
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#17327760849899828-515: A variety of reasons. Viruses are a special case, driven by a balance of mutation and selection , and can be treated as quasispecies . Biologists and taxonomists have made many attempts to define species, beginning from morphology and moving towards genetics . Early taxonomists such as Linnaeus had no option but to describe what they saw: this was later formalised as the typological or morphological species concept. Ernst Mayr emphasised reproductive isolation, but this, like other species concepts,
10017-671: A viability of about 1%, and do not generally reach the highest levels of viability until age 250. The rates decrease as the tree starts to get very old, with trees over 1,200 not reaching viability rates over 3%. The low viability may discourage seed predators, which do not want to waste time sorting chaff (empty seeds) from edible seeds. Successful germination often requires a fire or flood, reducing competition for seedlings. The winged seeds are small and light, weighing 3.3–5.0 mg (200–300 seeds/g; 5,600–8,500/ounce). The wings are not effective for wide dispersal, and seeds are dispersed by wind an average of only 60–120 m (200–390 ft) from
10206-438: Is "an entity composed of organisms which maintains its identity from other such entities through time and over space, and which has its own independent evolutionary fate and historical tendencies". This differs from the biological species concept in embodying persistence over time. Wiley and Mayden stated that they see the evolutionary species concept as "identical" to Willi Hennig 's species-as-lineages concept, and asserted that
10395-488: Is X-chromosome inactivation during reproduction to avoid passing on twice as many genes to the offspring. Lyon's discovery led to the discovery of X-linked diseases. When cells divide, their full genome is copied and each daughter cell inherits one copy. This process, called mitosis , is the simplest form of reproduction and is the basis for asexual reproduction. Asexual reproduction can also occur in multicellular organisms, producing offspring that inherit their genome from
10584-400: Is a group of sexually reproducing organisms that recognise one another as potential mates. Expanding on this to allow for post-mating isolation, a cohesion species is the most inclusive population of individuals having the potential for phenotypic cohesion through intrinsic cohesion mechanisms; no matter whether populations can hybridise successfully, they are still distinct cohesion species if
10773-458: Is a set of organisms adapted to a particular set of resources, called a niche, in the environment. According to this concept, populations form the discrete phenetic clusters that we recognise as species because the ecological and evolutionary processes controlling how resources are divided up tend to produce those clusters. A genetic species as defined by Robert Baker and Robert Bradley is a set of genetically isolated interbreeding populations. This
10962-425: Is a somewhat ambiguous definition of what is referred to as a gene. Trait inheritance and molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the cell , the organism (e.g. dominance ), and within
11151-477: Is about 2,200 years old; many others in the wild exceed 600 years. The numerous claims of older redwoods are incorrect. Because of their seemingly timeless lifespans, coast redwoods were deemed the "everlasting redwood" at the turn of the century; in Latin , sempervirens means "ever green" or "everlasting". Redwoods must endure various environmental disturbances to attain such great ages. In response to forest fires,
11340-451: Is absorbed through multiple pathways. Leaves directly take in fog from the surrounding air through the epidermal tissue , bypassing the xylem . Coast redwoods also absorb water directly through their bark. The uptake of water through leaves and bark repairs and reduces the severity of xylem embolisms, which occur when cavitations form in the xylem preventing the transport of water and nutrients. Fog may also collect on redwood leaves, drip to
11529-518: Is an important branch in biology because heredity is vital to organisms' evolution . Gregor Mendel , a Moravian Augustinian friar working in the 19th century in Brno , was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today,
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#173277608498911718-414: Is between 8 and 8.7 million. About 14% of these had been described by 2011. All species (except viruses ) are given a two-part name , called a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature , also sometimes in zoological nomenclature ). For example, Boa constrictor
11907-414: Is called speciation . Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book The Origin of Species . Speciation depends on a measure of reproductive isolation , a reduced gene flow. This occurs most easily in allopatric speciation, where populations are separated geographically and can diverge gradually as mutations accumulate. Reproductive isolation
12096-482: Is caused by genetic or postnatal environmental factors. One famous example involved the study of the Genain quadruplets , who were identical quadruplets all diagnosed with schizophrenia . The genome of a given organism contains thousands of genes, but not all these genes need to be active at any given moment. A gene is expressed when it is being transcribed into mRNA and there exist many cellular methods of controlling
12285-403: Is described formally, in a publication that assigns it a unique scientific name. The description typically provides means for identifying the new species, which may not be based solely on morphology (see cryptic species ), differentiating it from other previously described and related or confusable species and provides a validly published name (in botany) or an available name (in zoology) when
12474-671: Is further weakened by the existence of microspecies , groups of organisms, including many plants, with very little genetic variability, usually forming species aggregates . For example, the dandelion Taraxacum officinale and the blackberry Rubus fruticosus are aggregates with many microspecies—perhaps 400 in the case of the blackberry and over 200 in the dandelion, complicated by hybridisation , apomixis and polyploidy , making gene flow between populations difficult to determine, and their taxonomy debatable. Species complexes occur in insects such as Heliconius butterflies, vertebrates such as Hypsiboas treefrogs, and fungi such as
12663-726: Is hard or even impossible to test. Later biologists have tried to refine Mayr's definition with the recognition and cohesion concepts, among others. Many of the concepts are quite similar or overlap, so they are not easy to count: the biologist R. L. Mayden recorded about 24 concepts, and the philosopher of science John Wilkins counted 26. Wilkins further grouped the species concepts into seven basic kinds of concepts: (1) agamospecies for asexual organisms (2) biospecies for reproductively isolated sexual organisms (3) ecospecies based on ecological niches (4) evolutionary species based on lineage (5) genetic species based on gene pool (6) morphospecies based on form or phenotype and (7) taxonomic species,
12852-473: Is in late winter with maturation about 8–9 months after. Each cone scale bears three to seven seeds , each seed 3–4 mm ( 1 ⁄ 8 – 3 ⁄ 16 in) long and 0.5 mm ( 1 ⁄ 32 in) broad, with two wings 1 mm ( 1 ⁄ 16 in) wide. The seeds are released when the cone scales dry and open at maturity. The pollen cones are ovular and 4–6 mm ( 3 ⁄ 16 – 1 ⁄ 4 in) long. Its genetic makeup
13041-530: Is insufficient to transport water to leaves beyond this range. Further studies have indicated that this maximum requires fog, which is prevalent in these trees' natural environment. A tree reportedly 114.3 m (375 ft) in length was felled in Sonoma County by the Murphy Brothers saw mill in the 1870s, another claimed to be 115.8 m (380 ft) and 7.9 m (26 ft) in diameter
13230-793: Is located within Alfred A. Loeb State Park and Siskiyou National Forest at the approximate coordinates 42°07'36"N 124°12'17"W. The southern boundary of its range is the Los Padres National Forest 's Silver Peak Wilderness in the Santa Lucia Mountains of the Big Sur area of Monterey County, California. The southernmost grove is in the Southern Redwood Botanical Area , just north of the national forest's Salmon Creek trailhead and near
13419-403: Is no easy way to tell whether related geographic or temporal forms belong to the same or different species. Species gaps can be verified only locally and at a point of time. One is forced to admit that Darwin's insight is correct: any local reality or integrity of species is greatly reduced over large geographic ranges and time periods. The botanist Brent Mishler argued that the species concept
13608-497: Is not sufficient) and the southwestern corner of coastal Oregon within the United States. Being the tallest tree species, with a small range and an extremely long lifespan, many redwoods are preserved in various state and national parks; many of the largest specimens have their own official names. The name sequoia sometimes refers to the subfamily Sequoioideae , which includes S. sempervirens along with Sequoiadendron (giant sequoia) and Metasequoia (dawn redwood). Here,
13797-478: Is not valid, notably because gene flux decreases gradually rather than in discrete steps, which hampers objective delimitation of species. Indeed, complex and unstable patterns of gene flux have been observed in cichlid teleosts of the East African Great Lakes . Wilkins argued that "if we were being true to evolution and the consequent phylogenetic approach to taxa, we should replace it with
13986-400: Is one of the species of the genus Boa , with constrictor being the species' epithet. While the definitions given above may seem adequate at first glance, when looked at more closely they represent problematic species concepts. For example, the boundaries between closely related species become unclear with hybridisation , in a species complex of hundreds of similar microspecies , and in
14175-477: Is regular. The terrain also made it harder for loggers to get to the trees and to get them out after felling . The trees above the fog layer, above about 700 m (2,300 ft), are shorter and smaller due to the drier, windier, and colder conditions. In addition, Douglas-fir , pine , and tanoak often crowd out redwoods at these elevations. Few redwoods grow close to the ocean, due to intense salt spray, sand, and wind. Coalescence of coastal fog accounts for
14364-441: Is responsible for the development of structures within multicellular organisms, these patterns arise from the complex interactions between many cells. Within eukaryotes , there exist structural features of chromatin that influence the transcription of genes, often in the form of modifications to DNA and chromatin that are stably inherited by daughter cells. These features are called " epigenetic " because they exist "on top" of
14553-586: Is similar to Mayr's Biological Species Concept, but stresses genetic rather than reproductive isolation. In the 21st century, a genetic species could be established by comparing DNA sequences. Earlier, other methods were available, such as comparing karyotypes (sets of chromosomes ) and allozymes ( enzyme variants). An evolutionarily significant unit (ESU) or "wildlife species" is a population of organisms considered distinct for purposes of conservation. In palaeontology , with only comparative anatomy (morphology) and histology from fossils as evidence,
14742-472: Is sometimes an important source of genetic variation. Viruses can transfer genes between species. Bacteria can exchange plasmids with bacteria of other species, including some apparently distantly related ones in different phylogenetic domains , making analysis of their relationships difficult, and weakening the concept of a bacterial species. Genetics Genetics is the study of genes , genetic variation , and heredity in organisms . It
14931-751: Is the Hyperion tree , measuring 115.61 m (379.3 ft). The tree was discovered in Redwood National Park during mid-2006 by Chris Atkins and Michael Taylor , and is thought to be the world's tallest living organism. The previous record holder was the Stratosphere Giant in Humboldt Redwoods State Park at 112.84 m (370.2 ft) (as measured in 2004). Until it fell in March 1991, the "Dyerville Giant"
15120-434: Is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity . Other ways of defining species include their karyotype , DNA sequence, morphology , behaviour, or ecological niche . In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes
15309-497: Is the physical basis for inheritance: DNA replication duplicates the genetic information by splitting the strands and using each strand as a template for synthesis of a new partner strand. Genes are arranged linearly along long chains of DNA base-pair sequences. In bacteria , each cell usually contains a single circular genophore , while eukaryotic organisms (such as plants and animals) have their DNA arranged in multiple linear chromosomes. These DNA strands are often extremely long;
15498-694: Is the same as that which Mendel published. In his third law, he developed the basic principles of mutation (he can be considered a forerunner of Hugo de Vries ). Festetics argued that changes observed in the generation of farm animals, plants, and humans are the result of scientific laws. Festetics empirically deduced that organisms inherit their characteristics, not acquire them. He recognized recessive traits and inherent variation by postulating that traits of past generations could reappear later, and organisms could produce progeny with different attributes. These observations represent an important prelude to Mendel's theory of particulate inheritance insofar as it features
15687-594: Is threatened by hybridisation, but this can be selected against once a pair of populations have incompatible alleles of the same gene, as described in the Bateson–Dobzhansky–Muller model . A different mechanism, phyletic speciation, involves one lineage gradually changing over time into a new and distinct form (a chronospecies ), without increasing the number of resultant species. Horizontal gene transfer between organisms of different species, either through hybridisation , antigenic shift , or reassortment ,
15876-431: Is unusual among conifers, being a hexaploid (6n) and possibly allopolyploid (AAAABB). Both the mitochondrial and chloroplast genomes of the redwood are paternally inherited . Scottish botanist David Don described the redwood as Taxodium sempervirens , the "evergreen Taxodium ", in his colleague Aylmer Bourke Lambert 's 1824 work A description of the genus Pinus . Austrian botanist Stephan Endlicher erected
16065-423: Is yet to be studied. Shoot clones commonly sprout from burls and are often turned into decorative hedges when found in suburbia. Coast redwood is one of the most valuable timber species in the lumbering industry. In California, 3,640 km (899,000 acres) of redwood forest are logged, virtually all of it second growth. Though many entities have existed in the cutting and management of redwoods, perhaps none has had
16254-486: The Blue-eyed Mary ( Omphalodes verna ), for example, there exists a gene with alleles that determine the color of flowers: blue or magenta. Another gene, however, controls whether the flowers have color at all or are white. When a plant has two copies of this white allele, its flowers are white—regardless of whether the first gene has blue or magenta alleles. This interaction between genes is called epistasis , with
16443-545: The California Academy of Sciences , William P. Gibbons (1812-1897) described in 1893 the hollow shell of a coast redwood in the Oakland Hills of Alameda County with diameter of 9.9 metres (32 ft) at breast height. This tree's girth is rivalled by the " Fieldbrook Stump" of Humboldt County with a diameter of 9.8 metres (32 ft) at 1.5 metres (4.9 ft) from the ground. Coast redwoods have
16632-530: The ICZN for animals and the ICN for plants, do not make rules for defining the boundaries of the species. Research can change the boundaries, also known as circumscription, based on new evidence. Species may then need to be distinguished by the boundary definitions used, and in such cases the names may be qualified with sensu stricto ("in the narrow sense") to denote usage in the exact meaning given by an author such as
16821-539: The Pacific Northwest , led to the formation of a citizen group in Seattle, Washington undertaking assisted migration of this species hundreds of miles north of its native range . In contrast to cautionary statements made by forestry professionals assessing other tree species for assisted migration, the citizens involved with the group known as PropagationNation had met with little controversy until in 2023
17010-478: The Royal Horticultural Society 's Award of Garden Merit . Fairly solid evidence indicates that coast redwoods were the world's largest trees before logging, with numerous historical specimens reportedly over 122 m (400 ft). The theoretical maximum potential height of coast redwoods is thought to be limited to between 122 and 130 m (400 and 427 ft), as evapotranspiration
17199-677: The San Luis Obispo County line. The largest and tallest populations are in California's Redwood National and State Parks ( Del Norte and Humboldt counties) and Humboldt Redwoods State Park , with the overall majority located in the large Humboldt County. The ancient range of the genus is considerably greater, with relatives of the coast redwood living in Europe and Asia prior to the Quaternary geologic period. In recent geologic time there have been considerable shifts in
17388-413: The ancient Greek γενετικός genetikos meaning "genitive"/"generative", which in turn derives from γένεσις genesis meaning "origin". The observation that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding . The modern science of genetics, seeking to understand this process, began with
17577-399: The fly agaric . Natural hybridisation presents a challenge to the concept of a reproductively isolated species, as fertile hybrids permit gene flow between two populations. For example, the carrion crow Corvus corone and the hooded crow Corvus cornix appear and are classified as separate species, yet they can hybridise where their geographical ranges overlap. A ring species is
17766-507: The jaguar ( Panthera onca ) of Latin America or the leopard ( Panthera pardus ) of Africa and Asia. In contrast, the scientific names of species are chosen to be unique and universal (except for some inter-code homonyms ); they are in two parts used together : the genus as in Puma , and the specific epithet as in concolor . A species is given a taxonomic name when a type specimen
17955-415: The neutral theory of molecular evolution through publishing the nearly neutral theory of molecular evolution . In this theory, Ohta stressed the importance of natural selection and the environment to the rate at which genetic evolution occurs. One important development was chain-termination DNA sequencing in 1977 by Frederick Sanger . This technology allows scientists to read the nucleotide sequence of
18144-469: The tallest living trees on Earth, reaching up to 115.9 m (380.1 ft) in height (without the roots ) and up to 8.9 m (29 ft) in diameter at breast height . These trees are also among the longest-living trees on Earth . Before commercial logging and clearing began by the 1850s, this massive tree occurred naturally in an estimated 810,000 ha (2,000,000 acres) along much of coastal California (excluding southern California where rainfall
18333-406: The "cynical species concept", and arguing that far from being cynical, it usefully leads to an empirical taxonomy for any given group, based on taxonomists' experience. Other biologists have gone further and argued that we should abandon species entirely, and refer to the "Least Inclusive Taxonomic Units" (LITUs), a view that would be coherent with current evolutionary theory. The species concept
18522-444: The 1930s for experimental reasons and have since flourished. The prevailing native elevation range is 30–750 m (100–2,460 ft) above sea level, occasionally down to 0 and up to about 900 m (3,000 ft). They usually grow in the mountains where precipitation from the incoming moisture off the ocean is greater. The tallest and oldest trees are found in deep valleys and gullies, where year-round streams can flow, and fog drip
18711-421: The DNA sequence and retain inheritance from one cell generation to the next. Because of epigenetic features, different cell types grown within the same medium can retain very different properties. Although epigenetic features are generally dynamic over the course of development, some, like the phenomenon of paramutation , have multigenerational inheritance and exist as rare exceptions to the general rule of DNA as
18900-632: The F1 offspring mate with each other, the offspring are called the "F2" (second filial) generation. One of the common diagrams used to predict the result of cross-breeding is the Punnett square . When studying human genetic diseases, geneticists often use pedigree charts to represent the inheritance of traits. These charts map the inheritance of a trait in a family tree. Organisms have thousands of genes, and in sexually reproducing organisms these genes generally assort independently of each other. This means that
19089-504: The Greek word genesis —γένεσις, "origin", predates the noun and was first used in a biological sense in 1860. Bateson both acted as a mentor and was aided significantly by the work of other scientists from Newnham College at Cambridge, specifically the work of Becky Saunders , Nora Darwin Barlow , and Muriel Wheldale Onslow . Bateson popularized the usage of the word genetics to describe
19278-405: The abbreviation "sp." in the singular or "spp." (standing for species pluralis , Latin for "multiple species") in the plural in place of the specific name or epithet (e.g. Canis sp.). This commonly occurs when authors are confident that some individuals belong to a particular genus but are not sure to which exact species they belong, as is common in paleontology . Authors may also use "spp." as
19467-448: The ability of the body to break down the amino acid phenylalanine , causing a toxic build-up of an intermediate molecule that, in turn, causes severe symptoms of progressive intellectual disability and seizures. However, if someone with the phenylketonuria mutation follows a strict diet that avoids this amino acid, they remain normal and healthy. A common method for determining how genes and environment ("nature and nurture") contribute to
19656-415: The accumulation of dense undergrowth and woody debris. Thus, even a naturally occurring ground fire could threaten to spread upwards and become a canopy fire spreading uncontrollably over a widening area. Coast redwood reproduces both sexually by seed and asexually by sprouting of buds, layering, or lignotubers . Seed production begins at 10–15 years of age. Cones develop in the winter and mature by fall. In
19845-444: The adaptive function of repair of DNA damages. The first cytological demonstration of crossing over was performed by Harriet Creighton and Barbara McClintock in 1931. Their research and experiments on corn provided cytological evidence for the genetic theory that linked genes on paired chromosomes do in fact exchange places from one homolog to the other. The probability of chromosomal crossover occurring between two given points on
20034-570: The amount of hybridisation is insufficient to completely mix their respective gene pools . A further development of the recognition concept is provided by the biosemiotic concept of species. In microbiology , genes can move freely even between distantly related bacteria, possibly extending to the whole bacterial domain. As a rule of thumb, microbiologists have assumed that members of Bacteria or Archaea with 16S ribosomal RNA gene sequences more similar than 97% to each other need to be checked by DNA–DNA hybridisation to decide if they belong to
20223-440: The basis for inheritance. During the process of DNA replication, errors occasionally occur in the polymerization of the second strand. These errors, called mutations, can affect the phenotype of an organism, especially if they occur within the protein coding sequence of a gene. Error rates are usually very low—1 error in every 10–100 million bases—due to the "proofreading" ability of DNA polymerases . Processes that increase
20412-474: The biological species concept, "the several versions" of the phylogenetic species concept, and the idea that species are of the same kind as higher taxa are not suitable for biodiversity studies (with the intention of estimating the number of species accurately). They further suggested that the concept works for both asexual and sexually-reproducing species. A version of the concept is Kevin de Queiroz 's "General Lineage Concept of Species". An ecological species
20601-505: The biological species concept, a cladistic species does not rely on reproductive isolation – its criteria are independent of processes that are integral in other concepts. Therefore, it applies to asexual lineages. However, it does not always provide clear cut and intuitively satisfying boundaries between taxa, and may require multiple sources of evidence, such as more than one polymorphic locus, to give plausible results. An evolutionary species, suggested by George Gaylord Simpson in 1951,
20790-502: The canopy, where branch bark is thin and leaves are vulnerable. In the millions of years that predated human evolution, this level of protection worked well against natural fires originating from lightning strikes. When the first humans arrived in North America, redwoods thrived in regions where ground fires were intentionally set by indigenous populations on a seasonal basis. However, when peoples arrived from other continents in
20979-404: The cat plays the role of the environment. The cat's genes code for dark hair, thus the hair-producing cells in the cat make cellular proteins resulting in dark hair. But these dark hair-producing proteins are sensitive to temperature (i.e. have a mutation causing temperature-sensitivity) and denature in higher-temperature environments, failing to produce dark-hair pigment in areas where the cat has
21168-429: The cell, these genes for tryptophan synthesis are no longer needed. The presence of tryptophan directly affects the activity of the genes—tryptophan molecules bind to the tryptophan repressor (a transcription factor), changing the repressor's structure such that the repressor binds to the genes. The tryptophan repressor blocks the transcription and expression of the genes, thereby creating negative feedback regulation of
21357-421: The chromosome is related to the distance between the points. For an arbitrarily long distance, the probability of crossover is high enough that the inheritance of the genes is effectively uncorrelated. For genes that are closer together, however, the lower probability of crossover means that the genes demonstrate genetic linkage; alleles for the two genes tend to be inherited together. The amounts of linkage between
21546-444: The circumference of the tree trunk. Within a short period after sprouting, each sprout develops its own root system, with the dominant sprouts forming a ring of trees around the parent root crown or stump. This ring of trees is called a "fairy ring". Sprouts can achieve heights of 2.3 m (7 ft 7 in) in a single growing season. Redwoods may also reproduce using burls . A burl is a woody lignotuber that commonly appears on
21735-564: The coast redwood's range in North America. Coast redwood bark has been found in the La Brea Tar Pits , showing that 25,000–40,000 years before the present redwood trees grew as far south as the Los Angeles during the last ice age . The authors of a 2022 paper suggest, "Were it not for the remarkable ability to sprout after fire, many southern forests may have lost their Sequoia component long ago." As to previous redwood range to
21924-422: The combined DNA sequences of all chromosomes) is called the genome . DNA is most often found in the nucleus of cells, but Ruth Sager helped in the discovery of nonchromosomal genes found outside of the nucleus. In plants, these are often found in the chloroplasts and in other organisms, in the mitochondria. These nonchromosomal genes can still be passed on by either partner in sexual reproduction and they control
22113-433: The concept of a chronospecies can be applied. During anagenesis (evolution, not necessarily involving branching), some palaeontologists seek to identify a sequence of species, each one derived from the phyletically extinct one before through continuous, slow and more or less uniform change. In such a time sequence, some palaeontologists assess how much change is required for a morphologically distinct form to be considered
22302-486: The context of a population. Genetics has given rise to a number of subfields, including molecular genetics , epigenetics , and population genetics . Organisms studied within the broad field span the domains of life ( archaea , bacteria , and eukarya ). Genetic processes work in combination with an organism's environment and experiences to influence development and behavior , often referred to as nature versus nurture . The intracellular or extracellular environment of
22491-512: The early nineteenth century. The trees were felled by ax and saw onto beds of tree limbs and shrubs to cushion their fall. Stripped of their bark, the logs were transported to mills or waterways by oxen or horse. Loggers then burned the accumulated tree limbs, shrubs, and bark. The repeated fires favored secondary forests of primarily redwoods as redwood seedlings sprout readily in burned areas. The introduction of steam engines let crews drag logs through long skid trails to nearby railroads, furthering
22680-463: The early stages, the cones look like flowers , and are commonly called "flowers" by professional foresters, although this is not strictly correct. Coast redwoods produce many cones, with redwoods in new forests producing thousands per year. The cones themselves hold 90–150 seeds, but viability of seed is low, typically well below 15% with one estimate of average rates being 3 to 10 percent. The viability does increase with age, trees under 20 years old have
22869-435: The evidence to support hypotheses about evolutionarily divergent lineages that have maintained their hereditary integrity through time and space. Molecular markers may be used to determine diagnostic genetic differences in the nuclear or mitochondrial DNA of various species. For example, in a study done on fungi , studying the nucleotide characters using cladistic species produced the most accurate results in recognising
23058-417: The expression of genes such that proteins are produced only when needed by the cell. Transcription factors are regulatory proteins that bind to DNA, either promoting or inhibiting the transcription of a gene. Within the genome of Escherichia coli bacteria, for example, there exists a series of genes necessary for the synthesis of the amino acid tryptophan . However, when tryptophan is already available to
23247-539: The forest floor, and be absorbed by the tree's roots. This fog drip may form 30% of the total water used by a tree in a year. Redwoods often grow in flood-prone areas. Sediment deposits can form impermeable barriers that suffocate tree roots, and unstable soil in flooded areas often causes trees to lean to one side, increasing the risk of the wind toppling them. Immediately after a flood, redwoods grow their existing roots upwards into recently deposited sediment layers. A second root system then develops from adventitious buds on
23436-412: The genus Sequoia in his 1847 work Synopsis coniferarum , giving the redwood its current binomial name of Sequoia sempervirens . It is unknown how Endlicher derived the name Sequoia. See Sequoia Etymology . The redwood is one of three living species, each in its own genus, in the subfamily Sequoioideae . Molecular studies have shown that the three are each other's closest relatives, generally with
23625-455: The heavy rainfall, create a soil with fewer nutrients than the trees need, causing them to depend heavily on the entire biotic community of the forest, and making efficient recycling of dead trees especially important. This forest community includes coast Douglas-fir , Pacific madrone , tanoak , western hemlock , and other trees, along with a wide variety of ferns , mosses , mushrooms , and redwood sorrel . Redwood forests provide habitat for
23814-469: The information an organism uses to function, the environment plays an important role in determining the ultimate phenotypes an organism displays. The phrase " nature and nurture " refers to this complementary relationship. The phenotype of an organism depends on the interaction of genes and the environment. An interesting example is the coat coloration of the Siamese cat . In this case, the body temperature of
24003-406: The inheritance of an allele for yellow or green pea color is unrelated to the inheritance of alleles for white or purple flowers. This phenomenon, known as " Mendel's second law " or the "law of independent assortment," means that the alleles of different genes get shuffled between parents to form offspring with many different combinations. Different genes often interact to influence the same trait. In
24192-427: The largest human chromosome, for example, is about 247 million base pairs in length. The DNA of a chromosome is associated with structural proteins that organize, compact, and control access to the DNA, forming a material called chromatin ; in eukaryotes, chromatin is usually composed of nucleosomes , segments of DNA wound around cores of histone proteins. The full set of hereditary material in an organism (usually
24381-485: The leaves becomes increasingly difficult due to gravity. Despite the high rainfall that the region receives (up to 100 cm), the leaves in the upper canopy are perpetually stressed for water. This water stress is exacerbated by long droughts in the summer. Water stress is believed to cause the morphological changes in the leaves, stimulating reduced leaf length and increased leaf succulence. To supplement their water needs, redwoods use frequent summer fog events. Fog water
24570-523: The magnificent trees regain lost territory. In December 2023, the Associated Press exclusively reported criticism from professionals in the region and nationally: While beginning to favor experiments in assisted population migration of more southerly genetics of the main native timber tree, Douglas-fir , professionals were united against large-scale plantings of California redwoods into the Pacific Northwest. The next month, January 2024, carried
24759-571: The nature of inheritance in plants. In his paper " Versuche über Pflanzenhybriden " (" Experiments on Plant Hybridization "), presented in 1865 to the Naturforschender Verein (Society for Research in Nature) in Brno , Mendel traced the inheritance patterns of certain traits in pea plants and described them mathematically. Although this pattern of inheritance could only be observed for a few traits, Mendel's work suggested that heredity
24948-575: The newly buried trunk and the old root system dies. To counter lean, redwoods increase wood production on the vulnerable side, creating a supporting buttress. These adaptations create forests of almost exclusively redwood trees in flood-prone regions. Coast redwoods are resistant to insect attack, fungal infection, and rot. These properties are conferred by concentrations of terpenoids and tannic acid in redwood leaves, roots, bark, and wood. Despite these chemical defenses, redwoods are still subject to insect infestations; none, however, are capable of killing
25137-529: The north, an upright fossil stump of a coast redwood on a beach in central Oregon was documented 257 km (160 mi) north of the current range. The ability of Coast Redwood to live for more than a thousand years, along with its unusual capacity to resprout from its root crown when felled by natural or human causes, have earned this species the label of "carbon-sequestration champion." Its potential to contribute toward climate change mitigation , as well as its demonstrated ability to thrive in coastal regions of
25326-483: The numerous fungi species of all the concepts studied. Versions of the phylogenetic species concept that emphasise monophyly or diagnosability may lead to splitting of existing species, for example in Bovidae , by recognising old subspecies as species, despite the fact that there are no reproductive barriers, and populations may intergrade morphologically. Others have called this approach taxonomic inflation , diluting
25515-500: The offspring of a mating pair. Genes on the same chromosome would theoretically never recombine. However, they do, via the cellular process of chromosomal crossover . During crossover, chromosomes exchange stretches of DNA, effectively shuffling the gene alleles between the chromosomes. This process of chromosomal crossover generally occurs during meiosis , a series of cell divisions that creates haploid cells. Meiotic recombination , particularly in microbial eukaryotes , appears to serve
25704-435: The original sequence. A particularly important source of DNA damages appears to be reactive oxygen species produced by cellular aerobic respiration , and these can lead to mutations. In organisms that use chromosomal crossover to exchange DNA and recombine genes, errors in alignment during meiosis can also cause mutations. Errors in crossover are especially likely when similar sequences cause partner chromosomes to adopt
25893-593: The paper is accepted for publication. The type material is usually held in a permanent repository, often the research collection of a major museum or university, that allows independent verification and the means to compare specimens. Describers of new species are asked to choose names that, in the words of the International Code of Zoological Nomenclature , are "appropriate, compact, euphonious, memorable, and do not cause offence". Books and articles sometimes intentionally do not identify species fully, using
26082-515: The parent tree. Seedlings are susceptible to fungal infection and predation by banana slugs , brush rabbits , and nematodes . Most seedlings do not survive their first three years. However, those that become established grow rapidly, with young trees known to reach 20 m (66 ft) tall in 20 years. When canopy space is not available, small trees can remain suppressed for up to 400 years before accelerating their growth rate. Coast redwoods can also reproduce asexually by layering or sprouting from
26271-410: The past few centuries, indigenous fire practices were disallowed — even in the few places where the first peoples were permitted to continue living. Flammable brush and young trees thus accumulated. Clearcut logging further hampered a return to a fire-resistant tall canopy. Governmental policies aimed at suppressing all natural and human-caused fires, even in parks and wilderness areas, amplified
26460-674: The person who named the species, while the antonym sensu lato ("in the broad sense") denotes a wider usage, for instance including other subspecies. Other abbreviations such as "auct." ("author"), and qualifiers such as "non" ("not") may be used to further clarify the sense in which the specified authors delineated or described the species. Species are subject to change, whether by evolving into new species, exchanging genes with other species, merging with other species or by becoming extinct. The evolutionary process by which biological populations of sexually-reproducing organisms evolve to become distinct or reproductively isolated as species
26649-470: The phenotype of the organism, while the other allele is called recessive as its qualities recede and are not observed. Some alleles do not have complete dominance and instead have incomplete dominance by expressing an intermediate phenotype, or codominance by expressing both alleles at once. When a pair of organisms reproduce sexually , their offspring randomly inherit one of the two alleles from each parent. These observations of discrete inheritance and
26838-543: The process of protein production . It was discovered that the cell uses DNA as a template to create matching messenger RNA , molecules with nucleotides very similar to DNA. The nucleotide sequence of a messenger RNA is used to create an amino acid sequence in protein; this translation between nucleotide sequences and amino acid sequences is known as the genetic code . With the newfound molecular understanding of inheritance came an explosion of research. A notable theory arose from Tomoko Ohta in 1973 with her amendment to
27027-435: The product rule, the sum rule, and more. Geneticists use diagrams and symbols to describe inheritance. A gene is represented by one or a few letters. Often a "+" symbol is used to mark the usual, non-mutant allele for a gene. In fertilization and breeding experiments (and especially when discussing Mendel's laws) the parents are referred to as the "P" generation and the offspring as the "F1" (first filial) generation. When
27216-519: The properties of a protein by destabilizing the structure or changing the surface of the protein in a way that changes its interaction with other proteins and molecules. For example, sickle-cell anemia is a human genetic disease that results from a single base difference within the coding region for the β-globin section of hemoglobin, causing a single amino acid change that changes hemoglobin's physical properties. Sickle-cell versions of hemoglobin stick to themselves, stacking to form fibers that distort
27405-426: The protein itself). Protein structure is dynamic; the protein hemoglobin bends into slightly different forms as it facilitates the capture, transport, and release of oxygen molecules within mammalian blood. A single nucleotide difference within DNA can cause a change in the amino acid sequence of a protein. Because protein structures are the result of their amino acid sequences, some changes can dramatically change
27594-406: The rate of changes in DNA are called mutagenic : mutagenic chemicals promote errors in DNA replication, often by interfering with the structure of base-pairing, while UV radiation induces mutations by causing damage to the DNA structure. Chemical damage to DNA occurs naturally as well and cells use DNA repair mechanisms to repair mismatches and breaks. The repair does not, however, always restore
27783-464: The reach of loggers beyond the land near rivers previously used to transport trees. This method of harvesting, however, disturbed large amounts of soil, producing secondary-growth forests of species other than redwood such as Douglas-fir, grand fir , and western hemlock. After World War II, trucks and tractors gradually replaced steam engines, giving rise to two harvesting approaches: clearcutting and selection harvesting. Clearcutting involved felling all
27972-424: The recent great fire of San Francisco, that began April 18th, 1906, we succeeded in finally stopping it in nearly all directions where the unburned buildings were almost entirely of frame construction, and if the exterior finish of these buildings had not been of redwood lumber, I am satisfied that the area of the burned district would have been greatly extended. Because of its impressive resistance to decay, redwood
28161-436: The redwood and giant sequoia ( Sequoiadendron giganteum ) as each other's closest relatives. However, Yang and colleagues in 2010 queried the polyploid state of the redwood and speculate that it may have arisen as an ancient hybrid between ancestors of the giant sequoia and dawn redwood ( Metasequoia ). Using two different single copy nuclear genes , LFY and NLY, to generate phylogenetic trees , they found that Sequoia
28350-487: The result of misclassification leading to questions on whether there really are any ring species. The commonly used names for kinds of organisms are often ambiguous: "cat" could mean the domestic cat, Felis catus , or the cat family, Felidae . Another problem with common names is that they often vary from place to place, so that puma, cougar, catamount, panther, painter and mountain lion all mean Puma concolor in various parts of America, while "panther" may also mean
28539-586: The ring. Ring species thus present a difficulty for any species concept that relies on reproductive isolation. However, ring species are at best rare. Proposed examples include the herring gull – lesser black-backed gull complex around the North pole, the Ensatina eschscholtzii group of 19 populations of salamanders in America, and the greenish warbler in Asia, but many so-called ring species have turned out to be
28728-399: The root crown, stump, or even fallen branches; if a tree falls over, it generates a row of new trees along the trunk, so many trees naturally grow in a straight line. Sprouts originate from dormant or adventitious buds at or under the surface of the bark. The dormant sprouts are stimulated when the main adult stem gets damaged or starts to die. Many sprouts spontaneously erupt and develop around
28917-408: The same allele of a given gene are called homozygous at that gene locus , while organisms with two different alleles of a given gene are called heterozygous . The set of alleles for a given organism is called its genotype , while the observable traits of the organism are called its phenotype . When organisms are heterozygous at a gene, often one allele is called dominant as its qualities dominate
29106-446: The same genus as Taxodium distichum (baldcypress) of the southeastern USA. Unlike coast redwood, baldcypress loses its leaves in winter. The common name "redwood", applied to both the coast redwood and the giant redwood, is a reference to the red heartwood of the trees. Common names that refer to Sequoia sempervirens alone include "California redwood", "coastal redwood", "coastal sequoia", and "coast redwood". Coast redwoods occupy
29295-508: The same species. This concept was narrowed in 2006 to a similarity of 98.7%. The average nucleotide identity (ANI) method quantifies genetic distance between entire genomes , using regions of about 10,000 base pairs . With enough data from genomes of one genus, algorithms can be used to categorize species, as for Pseudomonas avellanae in 2013, and for all sequenced bacteria and archaea since 2020. Observed ANI values among sequences appear to have an "ANI gap" at 85–95%, suggesting that
29484-529: The same species. When two species names are discovered to apply to the same species, the older species name is given priority and usually retained, and the newer name considered as a junior synonym, a process called synonymy . Dividing a taxon into multiple, often new, taxa is called splitting . Taxonomists are often referred to as "lumpers" or "splitters" by their colleagues, depending on their personal approach to recognising differences or commonalities between organisms. The circumscription of taxa, considered
29673-401: The second gene epistatic to the first. Many traits are not discrete features (e.g. purple or white flowers) but are instead continuous features (e.g. human height and skin color ). These complex traits are products of many genes. The influence of these genes is mediated, to varying degrees, by the environment an organism has experienced. The degree to which an organism's genes contribute to
29862-509: The segregation of alleles are collectively known as Mendel's first law or the Law of Segregation. However, the probability of getting one gene over the other can change due to dominant, recessive, homozygous, or heterozygous genes. For example, Mendel found that if you cross heterozygous organisms your odds of getting the dominant trait is 3:1. Real geneticist study and calculate probabilities by using theoretical probabilities, empirical probabilities,
30051-653: The shape of red blood cells carrying the protein. These sickle-shaped cells no longer flow smoothly through blood vessels , having a tendency to clog or degrade, causing the medical problems associated with this disease. Some DNA sequences are transcribed into RNA but are not translated into protein products—such RNA molecules are called non-coding RNA . In some cases, these products fold into structures which are involved in critical cell functions (e.g. ribosomal RNA and transfer RNA ). RNA can also have regulatory effects through hybridization interactions with other RNA molecules (such as microRNA ). Although genes contain all
30240-446: The similar molecule RNA instead of DNA as their genetic material. DNA normally exists as a double-stranded molecule, coiled into the shape of a double helix . Each nucleotide in DNA preferentially pairs with its partner nucleotide on the opposite strand: A pairs with T, and C pairs with G. Thus, in its two-stranded form, each strand effectively contains all necessary information, redundant with its partner strand. This structure of DNA
30429-500: The single celled alga Acetabularia . The Hershey–Chase experiment in 1952 confirmed that DNA (rather than protein) is the genetic material of the viruses that infect bacteria, providing further evidence that DNA is the molecule responsible for inheritance. James Watson and Francis Crick determined the structure of DNA in 1953, using the X-ray crystallography work of Rosalind Franklin and Maurice Wilkins that indicated DNA has
30618-673: The southeastern United States from eastern Texas to Maryland. It also does well in the Pacific Northwest (Oregon, Washington, and British Columbia), far north of its northernmost native range in southwestern Oregon. Coast redwood trees were used in a display at Rockefeller Center and then given to Longhouse Reserve in East Hampton, Long Island, New York, and these have now been living there for over twenty years and have survived at 2 °F (−17 °C). This fast-growing tree can be grown as an ornamental specimen in those large parks and gardens that can accommodate its massive size. It has gained
30807-506: The species concept and making taxonomy unstable. Yet others defend this approach, considering "taxonomic inflation" pejorative and labelling the opposing view as "taxonomic conservatism"; claiming it is politically expedient to split species and recognise smaller populations at the species level, because this means they can more easily be included as endangered in the IUCN red list and can attract conservation legislation and funding. Unlike
30996-441: The strands are separated, new partner strands can be reconstructed for each based on the sequence of the old strand. This property is what gives DNA its semi-conservative nature where one strand of new DNA is from an original parent strand. Although the structure of DNA showed how inheritance works, it was still not known how DNA influences the behavior of cells. In the following years, scientists tried to understand how DNA controls
31185-580: The study of inheritance in his inaugural address to the Third International Conference on Plant Hybridization in London in 1906. After the rediscovery of Mendel's work, scientists tried to determine which molecules in the cell were responsible for inheritance. In 1900, Nettie Stevens began studying the mealworm. Over the next 11 years, she discovered that females only had the X chromosome and males had both X and Y chromosomes. She
31374-423: The successful germination of redwood seeds. A study published in 2010, the first to compare post-wildfire survival and regeneration of redwood and associated species, concluded that fires of all severity increase the relative abundance of redwood, and higher-severity fires provide the greatest benefit. Self-pruning of its lower limbs as height is gained is a crucial adaptation to prevent ground fires from rising into
31563-429: The tallest coast redwoods are measured yearly by experts. Even with recent discoveries of tall coast redwoods above 100 m (330 ft), it is likely that no taller trees will be discovered. Species A species ( pl. : species) is a population of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring , typically by sexual reproduction . It
31752-456: The term redwood on its own refers to the species covered in this article but not to the other two species. The coast redwood normally reaches a height of 60 to 100 m (200 to 330 ft), but will be more than 110 m (360 ft) in extraordinary circumstances, with a trunk diameter of 9 m (30 ft). Historically, the American naturalist , physician and founder member of
31941-485: The theoretical difficulties. If species were fixed and clearly distinct from one another, there would be no problem, but evolutionary processes cause species to change. This obliges taxonomists to decide, for example, when enough change has occurred to declare that a lineage should be divided into multiple chronospecies , or when populations have diverged to have enough distinct character states to be described as cladistic species. Species and higher taxa were seen from
32130-824: The time of Aristotle until the 18th century as categories that could be arranged in a hierarchy, the great chain of being . In the 19th century, biologists grasped that species could evolve given sufficient time. Charles Darwin 's 1859 book On the Origin of Species explained how species could arise by natural selection . That understanding was greatly extended in the 20th century through genetics and population ecology . Genetic variability arises from mutations and recombination , while organisms themselves are mobile, leading to geographical isolation and genetic drift with varying selection pressures . Genes can sometimes be exchanged between species by horizontal gene transfer ; new species can arise rapidly through hybridisation and polyploidy ; and species may become extinct for
32319-446: The trees have developed various adaptations. The thick, fibrous bark of coast redwoods is extremely fire-resistant; it grows to at least a foot thick and protects mature trees from fire damage. In addition, the redwoods contain little flammable pitch or resin . Fires, moreover, appear to actually benefit redwoods by causing substantial mortality in competing species, while having only minor effects on redwood. Burned areas are favorable to
32508-497: The trees in a particular area. It was encouraged by tax laws that exempted all standing timber from taxation if 70% of trees in the area were harvested. Selection logging, by contrast, called for the removal 25% to 50% of mature trees in the hopes that the remaining trees would allow for future growth and reseeding. This method, however, encouraged growth of other tree species, converting redwood forests into mixed forests of redwood, grand fir, Sitka spruce , and western hemlock. Moreover,
32697-477: The trees left standing were often felled by windthrow ; that is, they were often blown over by the wind. The coast redwood is naturalized in New Zealand, notably at Whakarewarewa Forest, Rotorua . Redwood has been grown in New Zealand plantations for more than 100 years, and those planted in New Zealand have higher growth rates than those in California, mainly because of even rainfall distribution through
32886-536: The tryptophan synthesis process. Differences in gene expression are especially clear within multicellular organisms , where cells all contain the same genome but have very different structures and behaviors due to the expression of different sets of genes. All the cells in a multicellular organism derive from a single cell, differentiating into variant cell types in response to external and intercellular signals and gradually establishing different patterns of gene expression to create different behaviors. As no single gene
33075-482: The twenty possible amino acids in a protein or an instruction to end the amino acid sequence ; this correspondence is called the genetic code . The flow of information is unidirectional: information is transferred from nucleotide sequences into the amino acid sequence of proteins, but it never transfers from protein back into the sequence of DNA—a phenomenon Francis Crick called the central dogma of molecular biology . The specific sequence of amino acids results in
33264-545: The two is responsible for inheritance. In 1928 , Frederick Griffith discovered the phenomenon of transformation : dead bacteria could transfer genetic material to "transform" other still-living bacteria. Sixteen years later, in 1944, the Avery–MacLeod–McCarty experiment identified DNA as the molecule responsible for transformation. The role of the nucleus as the repository of genetic information in eukaryotes had been established by Hämmerling in 1943 in his work on
33453-517: The upper crown of older trees, with a full range of transition between the two extremes. They are dark green above and have two blue-white stomatal bands below. Leaf arrangement is spiral, but the larger shade leaves are twisted at the base to lie in a flat plane for maximum light capture. The species is monoecious , with pollen and seed cones on the same plant. The seed cones are ovoid, 15–32 mm ( 9 ⁄ 16 – 1 + 1 ⁄ 4 in) long, with 15–25 spirally arranged scales; pollination
33642-540: The wild. It is difficult to define a species in a way that applies to all organisms. The debate about species concepts is called the species problem. The problem was recognised even in 1859, when Darwin wrote in On the Origin of Species : I was much struck how entirely vague and arbitrary is the distinction between species and varieties. He went on to write: No one definition has satisfied all naturalists; yet every naturalist knows vaguely what he means when he speaks of
33831-538: The work of the Augustinian friar Gregor Mendel in the mid-19th century. Prior to Mendel, Imre Festetics , a Hungarian noble, who lived in Kőszeg before Mendel, was the first who used the word "genetic" in hereditarian context, and is considered the first geneticist. He described several rules of biological inheritance in his work The genetic laws of nature (Die genetischen Gesetze der Natur, 1819). His second law
34020-680: The year. Other areas of successful cultivation outside of the native range include Great Britain, Italy, France, Haida Gwaii , middle elevations of Hawaii, Hogsback in South Africa, the Knysna Afromontane forests in the Western Cape, Grootvadersbosch Forest Reserve near Swellendam, South Africa and the Tokai Arboretum on the slopes of Table Mountain above Cape Town, a small area in central Mexico ( Jilotepec ), and
34209-518: Was able to conclude that sex is a chromosomal factor and is determined by the male. In 1911, Thomas Hunt Morgan argued that genes are on chromosomes , based on observations of a sex-linked white eye mutation in fruit flies . In 1913, his student Alfred Sturtevant used the phenomenon of genetic linkage to show that genes are arranged linearly on the chromosome. Although genes were known to exist on chromosomes, chromosomes are composed of both protein and DNA, and scientists did not know which of
34398-529: Was clustered with Metasequoia in the tree generated using the LFY gene, but with Sequoiadendron in the tree generated with the NLY gene. Further analysis strongly supported the hypothesis that Sequoia was the result of a hybridization event involving Metasequoia and Sequoiadendron . Thus, Yang and colleagues hypothesize that the inconsistent relationships among Metasequoia , Sequoia, and Sequoiadendron could be
34587-1023: Was cut down near Eureka in 1914, and the Lindsay Creek Tree was documented to have a height of 120 m (390 ft) when it was uprooted and felled by a storm in 1905. A tree reportedly 129.2 m (424 ft) tall was felled in November 1886 by the Elk River Mill and Lumber Company in Humboldt County, yielding 79,736 marketable board feet from 21 cuts. In 1893, a Redwood cut at the Eel River , near Scotia , reportedly measured 130.1 m (427 ft) in length, and 23.5 m (77 ft) in girth. However, limited evidence corroborates these historical measurements. Today, trees over 60 m (200 ft) are common, and many are over 90 m (300 ft). The current tallest tree
34776-609: Was extensively used for railroad ties and trestles throughout California. Many of the old ties have been recycled for use in gardens as borders, steps, house beams, etc. Redwood burls are used in the production of table tops, veneers, and turned goods. The Yurok people, who occupied the region before European settlement, regularly burned ground cover in redwood forests to bolster tanoak populations from which they harvested acorns, to maintain forest openings, and to boost populations of useful plant species such as those for medicine or basketmaking. Extensive logging of redwoods began in
34965-591: Was first observed by Gregor Mendel, who studied the segregation of heritable traits in pea plants, showing for example that flowers on a single plant were either purple or white—but never an intermediate between the two colors. The discrete versions of the same gene controlling the inherited appearance (phenotypes) are called alleles . In the case of the pea, which is a diploid species, each individual plant has two copies of each gene, one copy inherited from each parent. Many species, including humans, have this pattern of inheritance. Diploid organisms with two copies of
35154-421: Was particulate, not acquired, and that the inheritance patterns of many traits could be explained through simple rules and ratios. The importance of Mendel's work did not gain wide understanding until 1900, after his death, when Hugo de Vries and other scientists rediscovered his research. William Bateson , a proponent of Mendel's work, coined the word genetics in 1905. The adjective genetic , derived from
35343-402: Was safe. Sillett thought planting redwoods around Seattle was a fantastic idea. ("It's not like it's going to escape and become a nuisance species," Sillett told me, before adding, "it just has so many benefits.") Another factor encouraged Stielstra too: Millions of years ago, redwoods — or their close relatives — grew across the Pacific Northwest. By moving them, Stielstra reasoned, he was helping
35532-529: Was the inheritance of acquired characteristics : the belief that individuals inherit traits strengthened by their parents. This theory (commonly associated with Jean-Baptiste Lamarck ) is now known to be wrong—the experiences of individuals do not affect the genes they pass to their children. Other theories included Darwin's pangenesis (which had both acquired and inherited aspects) and Francis Galton 's reformulation of pangenesis as both particulate and inherited. Modern genetics started with Mendel's studies of
35721-479: Was the record holder. It, too, stood in Humboldt Redwoods State Park and was 113.4 m (372 ft) high and estimated to be 1,600 years old. This fallen giant has been preserved in the park. The largest known living coast redwood is Grogan's Fault, discovered in 2014 by Chris Atkins and Mario Vaden in Redwood National Park, with a main trunk volume of at least 1,084.5 cubic meters (38,299 cu ft) Other high-volume coast redwoods include Iluvatar , with
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