67-470: [REDACTED] Look up pignolo in Wiktionary, the free dictionary. Pignolo (plural pignoli ; also pinolo and pinoli ) may refer to: Pine nut , seed from trees of the genus Pinus Any cookie with pine nuts: Biscotto , twice baked cookie (biscuit), when made with pine nuts Pignolo (macaroon) , typical of Sicily Pignolo (grape) ,
134-629: A 100-gram ( 3 + 1 ⁄ 2 -ounce) reference serving, dried pine nuts supply 2,815 kilojoules (673 kilocalories) of food energy and are a rich source (20% or more of the Daily Value , DV) of numerous micronutrients , particularly manganese (419% DV), phosphorus (82% DV), magnesium (71% DV), zinc (67% DV), copper (65% DV), vitamin E (62% DV), vitamin K (51% DV), and the B vitamins , thiamin and niacin (29–35% DV), among others (table). Pine nuts have been eaten in Europe and Asia since
201-444: A Brownian motion model of trait evolution along a phylogeny. More recent methods also quantify the strength of convergence. One drawback to keep in mind is that these methods can confuse long-term stasis with convergence due to phenotypic similarities. Stasis occurs when there is little evolutionary change among taxa. Distance-based measures assess the degree of similarity between lineages over time. Frequency-based measures assess
268-428: A nucleophile . In order to activate that nucleophile, they orient an acidic and a basic residue in a catalytic triad . The chemical and physical constraints on enzyme catalysis have caused identical triad arrangements to evolve independently more than 20 times in different enzyme superfamilies . Threonine proteases use the amino acid threonine as their catalytic nucleophile . Unlike cysteine and serine, threonine
335-422: A common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution , where related species evolve different traits. Convergent evolution is similar to parallel evolution , which occurs when two independent species evolve in
402-602: A diverse range of dishes such as kibbeh , sambusak , fatayer , and Maqluba , desserts such as baklava , meghli , and many others. Throughout Europe, the Levant , and West Asia , the pine nuts used are traditionally from Pinus pinea (stone pine). They are easily distinguished from the Asian pine nuts by their more slender shape and more homogeneous flesh. Because of the lower price, Asian pine nuts are also often used, especially in cheaper preparations. Pine nut oil
469-562: A dough similar to that of a macaroon and then topped with pine nuts. In Catalonia , a sweet is made of small marzipan balls covered with pine nuts, painted with egg, and lightly cooked, and those are called "panellets". Pine nuts are also featured in the salade landaise of southwestern France . Nevada, or Great Basin, pine nut has a sweet fruity flavor and is promoted for its large size, sweet flavor, and ease of peeling. Pine nuts are also widely used in Levantine cuisine , reflected in
536-413: A gene has simply been switched off and then re-enabled later. Such a re-emerged trait is called an atavism . From a mathematical standpoint, an unused gene ( selectively neutral ) has a steadily decreasing probability of retaining potential functionality over time. The time scale of this process varies greatly in different phylogenies; in mammals and birds, there is a reasonable probability of remaining in
603-411: A heat source such as the sun to begin drying. It takes about 20 days until the cone fully opens. Once it is fully open and dry, the seed can be easily extracted in various ways. The most common and practical extraction method used is the repeated striking of the burlap bag containing the cone(s) against a rough surface to cause the cone(s) to shatter, leaving just the job of separating by hand the seed from
670-575: A high concentration of cerebrosides in the skin of their wings. This improves skin flexibility, a trait useful for flying animals; other mammals have a far lower concentration. The extinct pterosaurs independently evolved wings from their fore- and hindlimbs, while insects have wings that evolved separately from different organs. Flying squirrels and sugar gliders are much alike in their mammalian body plans, with gliding wings stretched between their limbs, but flying squirrels are placentals while sugar gliders are marsupials, widely separated within
737-496: A lesser extent. Russia is the largest producer of P. sibirica nuts in the world, followed by either Mongolia or Afghanistan . They each produce over 10,000 metric tons (9,800 long tons; 11,000 short tons) annually, most of it exported to China . Pine nuts produced in Europe mostly come from the stone pine ( P. pinea ), which has been cultivated for its nuts for over 5,000 years. Pine nuts have been harvested from wild trees for far longer. The Swiss pine ( P. cembra )
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#1732787346657804-468: A long evolutionary history prior to the extinction of the dinosaurs under which to accumulate relevant differences. The enzymology of proteases provides some of the clearest examples of convergent evolution. These examples reflect the intrinsic chemical constraints on enzymes, leading evolution to converge on equivalent solutions independently and repeatedly. Serine and cysteine proteases use different amino acid functional groups (alcohol or thiol) as
871-643: A molecular level to toxins. One well-characterized example is the evolution of resistance to cardiotonic steroids (CTSs) via amino acid substitutions at well-defined positions of the α-subunit of Na ,K -ATPase (ATPalpha). Variation in ATPalpha has been surveyed in various CTS-adapted species spanning six insect orders. Among 21 CTS-adapted species, 58 (76%) of 76 amino acid substitutions at sites implicated in CTS resistance occur in parallel in at least two lineages. 30 of these substitutions (40%) occur at just two sites in
938-568: A phylogenetic reconstruction, and are sometimes explicitly sought by investigators. The methods applied to infer convergent evolution depend on whether pattern-based or process-based convergence is expected. Pattern-based convergence is the broader term, for when two or more lineages independently evolve patterns of similar traits. Process-based convergence is when the convergence is due to similar forces of natural selection . Earlier methods for measuring convergence incorporate ratios of phenotypic and phylogenetic distance by simulating evolution with
1005-445: A similar environment, and so face the same environmental factors. When occupying similar ecological niches (that is, a distinctive way of life) similar problems can lead to similar solutions. The British anatomist Richard Owen was the first to identify the fundamental difference between analogies and homologies . In biochemistry, physical and chemical constraints on mechanisms have caused some active site arrangements such as
1072-634: A sought-after species due to the trading post system and the Navajo people who used the nuts as a means of commerce. The Italian pine nut ( P. pinea ) was brought to the United States by immigrants and became a favored treat along the East Coast in the early 1930s, when bumper crops of American pine nuts were readily available at low prices. When dried for eating, pine nuts are 2% water, 13% carbohydrates , 14% protein , and 68% fat (table). In
1139-413: A wine grape typical of Friuli Ribolla Gialla , another Italian/Slovenian wine grape that is also known as Pignolo Bianchetta Trevigiana , Italian wine grape known as Pignolo bianco Pignolo , a heritage variety of maize; see Italian traditional maize varieties See also [ edit ] Pignola , a town in southern Italy and a variety of wine grape grown there Pinole , maize that
1206-427: Is a secondary alcohol (i.e. has a methyl group). The methyl group of threonine greatly restricts the possible orientations of triad and substrate, as the methyl clashes with either the enzyme backbone or the histidine base. Consequently, most threonine proteases use an N-terminal threonine in order to avoid such steric clashes . Several evolutionarily independent enzyme superfamilies with different protein folds use
1273-463: Is a membrane stretched across four extremely elongated fingers and the legs. The airfoil of the bird wing is made of feathers , strongly attached to the forearm (the ulna) and the highly fused bones of the wrist and hand (the carpometacarpus ), with only tiny remnants of two fingers remaining, each anchoring a single feather. So, while the wings of bats and birds are functionally convergent, they are not anatomically convergent. Birds and bats also share
1340-553: Is added to foods for flavor. Some raw pine nuts can cause pine mouth syndrome, a taste disturbance lasting from a few days to a few weeks after consumption. A bitter, metallic, unpleasant taste is reported. There are no known lasting effects, with the United States Food and Drug Administration reporting that there are "no apparent adverse clinical side effects". Raw nuts from Pinus armandii , mainly in China, may be
1407-456: Is also used, to a very small extent. In North America, the main species are three of the pinyon pines : Colorado pinyon ( P. edulis ), single-leaf pinyon ( P. monophylla ), and Mexican pinyon ( P. cembroides ). The other eight pinyon species are used to a small extent, as is gray pine ( P. sabineana ), Coulter pine ( P. coulteri ), Torrey pine ( P. torreyana ), sugar pine ( P. lambertiana ) and Parry pinyon ( P. quadrifolia ). Here,
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#17327873466571474-452: Is an example of convergent evolution . In Asia, two species, in particular, are widely harvested: Korean pine ( Pinus koraiensis ) in northeast Asia (the most important species in international trade) and chilgoza pine ( P. gerardiana ) in the western Himalaya . Four other species, Siberian pine ( P. sibirica ), Siberian dwarf pine ( P. pumila ), Chinese white pine ( P. armandii ) and lacebark pine ( P. bungeana ), are also used to
1541-591: Is different from Wikidata All article disambiguation pages All disambiguation pages Pine nut Pine nuts , also called piñón ( Spanish: [piˈɲon] ), pinoli ( Italian: [piˈnɔːli] ), or pignoli , are the edible seeds of pines (family Pinaceae , genus Pinus ). According to the Food and Agriculture Organization , only 29 species provide edible nuts, while 20 are traded locally or internationally owing to their seed size being large enough to be worth harvesting; in other pines,
1608-482: Is dried, toasted, ground, and cooked in liquid Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Pignolo . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Pignolo&oldid=604766676 " Category : Disambiguation pages Hidden categories: Short description
1675-593: Is due to higher temperatures at elevations lower than 1,800 m (6,000 ft) during the spring, which dry up humidity and moisture content (particularly snow packs) that provide for the tree throughout the spring and summer, causing little nourishment for pine cone maturity. Although several other environmental factors determine the conditions of the ecosystem (such as clouds and rain), the trees tend to abort cones without sufficient water. High humidity encourages cone development. There are certain topographical areas found in lower elevations, such as shaded canyons, where
1742-542: Is responsible, say with brown dominant to blue eye colour . However, a single locus is responsible for about 80% of the variation. In lemurs, the differences between blue and brown eyes are not completely known, but the same gene locus is not involved. While most plant species are perennial , about 6% follow an annual life cycle, living for only one growing season. The annual life cycle independently emerged in over 120 plant families of angiosperms. The prevalence of annual species increases under hot-dry summer conditions in
1809-424: Is stunted, and the seeds deteriorate. When first extracted from the pine cone , they are covered with a hard shell (seed coat), thin in some species and thick in others. The nutrition is stored in the embryo ( sporophyte ) in the center. Although a nut in the culinary sense, in the botanical sense, pine nuts are seeds; being a gymnosperm , they lack a carpel (fruit) outside. The shell must be removed before
1876-409: Is the camera eye of cephalopods (such as squid and octopus), vertebrates (including mammals) and cnidarians (such as jellyfish). Their last common ancestor had at most a simple photoreceptive spot, but a range of processes led to the progressive refinement of camera eyes —with one sharp difference: the cephalopod eye is "wired" in the opposite direction, with blood and nerve vessels entering from
1943-536: The Chenopodiaceae and the Amaranthaceae . Fruits with a wide variety of structural origins have converged to become edible. Apples are pomes with five carpels ; their accessory tissues form the apple's core, surrounded by structures from outside the botanical fruit, the receptacle or hypanthium . Other edible fruits include other plant tissues; the fleshy part of a tomato is the walls of
2010-572: The Paleolithic period. They are frequently added to meat, fish, salads, and vegetable dishes or baked into bread. In Italian, they are called pinoli (in the US, they are often called pignoli , but in Italy, pignolo is actually a word far more commonly used to describe a fussy, overly fastidious or extremely meticulous person) and are an essential component of Italian pesto sauce; the upsurge in
2077-411: The catalytic triad to evolve independently in separate enzyme superfamilies . In his 1989 book Wonderful Life , Stephen Jay Gould argued that if one could "rewind the tape of life [and] the same conditions were encountered again, evolution could take a very different course." Simon Conway Morris disputes this conclusion, arguing that convergence is a dominant force in evolution, and given that
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2144-417: The last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy . The recurrent evolution of flight is a classic example, as flying insects , birds , pterosaurs , and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are analogous , whereas homologous structures or traits have
2211-619: The pericarp . This implies convergent evolution under selective pressure, in this case the competition for seed dispersal by animals through consumption of fleshy fruits. Seed dispersal by ants ( myrmecochory ) has evolved independently more than 100 times, and is present in more than 11,000 plant species. It is one of the most dramatic examples of convergent evolution in biology. Carnivory has evolved multiple times independently in plants in widely separated groups. In three species studied, Cephalotus follicularis , Nepenthes alata and Sarracenia purpurea , there has been convergence at
2278-446: The proboscis of flower-visiting insects such as bees and flower beetles , or the biting-sucking mouthparts of blood-sucking insects such as fleas and mosquitos . Opposable thumbs allowing the grasping of objects are most often associated with primates , like humans and other apes, monkeys, and lemurs. Opposable thumbs also evolved in giant pandas , but these are completely different in structure, having six fingers including
2345-576: The FDA found that some manufacturers substituted a non-food species of pine nuts in place of more expensive edible pine nut species as a form of food fraud . Some Native American tribes use the hard outer shell of the pine nut as a bead for decorative purposes in traditional regalia and jewelry. In the Great Basin area of the US, collecting pine nuts is a protected right through state law and treaty. In northern California, pine nuts are collected from
2412-575: The Mesozoic ) all converged on the same streamlined shape. A similar shape and swimming adaptations are even present in molluscs, such as Phylliroe . The fusiform bodyshape (a tube tapered at both ends) adopted by many aquatic animals is an adaptation to enable them to travel at high speed in a high drag environment. Similar body shapes are found in the earless seals and the eared seals : they still have four legs, but these are strongly modified for swimming. The marsupial fauna of Australia and
2479-523: The N-terminal residue as a nucleophile. This commonality of active site but difference of protein fold indicates that the active site evolved convergently in those families. Conus geographus produces a distinct form of insulin that is more similar to fish insulin protein sequences than to insulin from more closely related molluscs, suggesting convergent evolution, though with the possibility of horizontal gene transfer . Distant homologues of
2546-471: The back of the retina, rather than the front as in vertebrates. As a result, vertebrates have a blind spot . Birds and bats have homologous limbs because they are both ultimately derived from terrestrial tetrapods , but their flight mechanisms are only analogous, so their wings are examples of functional convergence. The two groups have independently evolved their own means of powered flight. Their wings differ substantially in construction. The bat wing
2613-420: The cause of the problem. Metallic taste disturbance is typically reported 1–3 days after ingestion, being worse on day two and typically lasting up to two weeks. Cases are self-limited and resolve without treatment. In the United States, from 2008 to 2012, some people reported a bitter metallic taste ("pine mouth") that sometimes lasted for weeks after they ate pine nuts. After an international investigation,
2680-437: The dolphin; among marine mammals; between giant and red pandas; and between the thylacine and canids. Convergence has also been detected in a type of non-coding DNA , cis-regulatory elements , such as in their rates of evolution; this could indicate either positive selection or relaxed purifying selection . Swimming animals including fish such as herrings , marine mammals such as dolphins , and ichthyosaurs ( of
2747-413: The early 21st century with increased culinary uses for pine nuts. In the United States, millions of hectares of productive pinyon pine woods have been destroyed due to conversion of lands, and in China and Russia, destructive harvesting techniques (such as breaking off whole branches to harvest the cones) and removal of trees for timber have led to losses in production capacity. Some growers claim that
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2814-505: The elevation of the pinyon pine is an important determinant of the quantity of pine cone production and, therefore, will largely determine the number of pine nuts the tree will yield. The US Department of Agriculture notes that variation in cone production between trees growing on identical sites is often observed. American pinyon pine cone production is most commonly found at an elevation between 1,800 and 2,600 m (6,000 and 8,500 ft), and ideally at 2,100 m (7,000 ft). This
2881-617: The exposed surfaces of the proteins, where they might interact with other components of the cell or the digestive fluid. The authors also found that homologous genes in the non-carnivorous plant Arabidopsis thaliana tend to have their expression increased when the plant is stressed, leading the authors to suggest that stress-responsive proteins have often been co-opted in the repeated evolution of carnivory. Phylogenetic reconstruction and ancestral state reconstruction proceed by assuming that evolution has occurred without convergence. Convergent patterns may, however, appear at higher levels in
2948-480: The four species-rich families of annuals ( Asteraceae , Brassicaceae , Fabaceae , and Poaceae ), indicating that the annual life cycle is adaptive. C 4 photosynthesis , one of the three major carbon-fixing biochemical processes, has arisen independently up to 40 times . About 7,600 plant species of angiosperms use C 4 carbon fixation, with many monocots including 46% of grasses such as maize and sugar cane , and dicots including several species in
3015-431: The genome in a potentially functional state for around 6 million years. When two species are similar in a particular character, evolution is defined as parallel if the ancestors were also similar, and convergent if they were not. Some scientists have argued that there is a continuum between parallel and convergent evolution, while others maintain that despite some overlap, there are still important distinctions between
3082-503: The grey pine or bull pine. Tribes burn designs into the hard shell, reflecting the same design they use in baskets; however, they are often left blank or burned to blacken. These are more often used in women's regalia and jewelry. Convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in
3149-443: The humidity remains constant throughout the spring and summer, allowing pine cones to fully mature and produce seed. At elevations above 2,600 m (8,500 ft), the temperature substantially drops, drastically affecting the state of the dormant cone. During the winter, frequent dramatic changes in temperature, drying, and gusty winds make the cones susceptible to freeze-drying that permanently damages them; in this case, growth
3216-407: The lineages diverged and became genetically isolated, the skin of both groups lightened more, and that additional lightening was due to different genetic changes. Lemurs and humans are both primates. Ancestral primates had brown eyes, as most primates do today. The genetic basis of blue eyes in humans has been studied in detail and much is known about it. It is not the case that one gene locus
3283-516: The mammal lineage from the placentals. Hummingbird hawk-moths and hummingbirds have evolved similar flight and feeding patterns. Insect mouthparts show many examples of convergent evolution. The mouthparts of different insect groups consist of a set of homologous organs, specialised for the dietary intake of that insect group. Convergent evolution of many groups of insects led from original biting-chewing mouthparts to different, more specialised, derived function types. These include, for example,
3350-454: The metal ion transporters ZIP in land plants and chlorophytes have converged in structure, likely to take up Fe efficiently. The IRT1 proteins from Arabidopsis thaliana and rice have extremely different amino acid sequences from Chlamydomonas ' s IRT1, but their three-dimensional structures are similar, suggesting convergent evolution. Many examples of convergent evolution exist in insects in terms of developing resistance at
3417-405: The molecular level. Carnivorous plants secrete enzymes into the digestive fluid they produce. By studying phosphatase , glycoside hydrolase , glucanase , RNAse and chitinase enzymes as well as a pathogenesis-related protein and a thaumatin -related protein, the authors found many convergent amino acid substitutions. These changes were not at the enzymes' catalytic sites, but rather on
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#17327873466573484-730: The nuts themselves are known by the Spanish name for the pinyon pine, piñón (plural: piñones ). In the United States, pine nuts are mainly harvested by Native American and Hispano communities, particularly in the Western United States and Southwestern United States , by the Shoshone , Paiute , Navajo , Pueblo , Hopi , Washoe , and Hispanos of New Mexico . Certain treaties negotiated by tribes and laws in Nevada guarantee Native Americans' right to harvest pine nuts, and
3551-424: The pine nut can be eaten. Unshelled pine nuts have a long shelf life if kept dry and refrigerated (−5 to 2 °C or 23 to 36 °F); shelled nuts (and unshelled nuts in warm conditions) deteriorate rapidly, becoming rancid within a few weeks or even days in warm, humid conditions. Pine nuts are commercially available in the shelled form, but due to poor storage, they can have poor flavor and may already be rancid at
3618-479: The placental mammals of the Old World have several strikingly similar forms, developed in two clades, isolated from each other. The body, and especially the skull shape, of the thylacine (Tasmanian tiger or Tasmanian wolf) converged with those of Canidae such as the red fox, Vulpes vulpes . As a sensory adaptation, echolocation has evolved separately in cetaceans (dolphins and whales) and bats, but from
3685-666: The popularity of this sauce since the 1990s has increased the visibility of the nut in America, primarily on the West Coast. Torta della nonna (literally "granny's cake") is a generic Italian dish name that in most families indicates an old family recipe for any cake but often is used for a tart or a pie filled with custard, topped with pine nuts and optionally dusted with icing sugar . Pignoli cookies , an Italian American specialty confection (in Italy, these would be called biscotti ai pinoli ), are made of almond flour formed into
3752-404: The protein (positions 111 and 122). CTS-adapted species have also recurrently evolved neo-functionalized duplications of ATPalpha, with convergent tissue-specific expression patterns. Convergence occurs at the level of DNA and the amino acid sequences produced by translating structural genes into proteins . Studies have found convergence in amino acid sequences in echolocating bats and
3819-425: The residue within the bag. Another option for harvesting is to wait until the cone opens on the tree (as it naturally will) and harvest the cone from the piñon pine, followed by the extracting process mentioned above. Fallen seeds can also be gathered beneath the trees. Because pine nuts are an important food source for many animals, overharvesting of pine nuts threatens local ecosystems, an effect occurring during
3886-399: The same clade ; cladistics seeks to arrange them according to their degree of relatedness to describe their phylogeny . Homoplastic traits caused by convergence are therefore, from the point of view of cladistics, confounding factors which could lead to an incorrect analysis. In some cases, it is difficult to tell whether a trait has been lost and then re-evolved convergently, or whether
3953-468: The same direction and thus independently acquire similar characteristics; for instance, gliding frogs have evolved in parallel from multiple types of tree frog . Many instances of convergent evolution are known in plants , including the repeated development of C 4 photosynthesis , seed dispersal by fleshy fruits adapted to be eaten by animals, and carnivory . In morphology, analogous traits arise when different species live in similar ways and/or
4020-442: The same environmental and physical constraints are at work, life will inevitably evolve toward an "optimum" body plan, and at some point, evolution is bound to stumble upon intelligence, a trait presently identified with at least primates , corvids , and cetaceans . In cladistics, a homoplasy is a trait shared by two or more taxa for any reason other than that they share a common ancestry. Taxa which do share ancestry are part of
4087-473: The same genetic mutations. The Gymnotiformes of South America and the Mormyridae of Africa independently evolved passive electroreception (around 119 and 110 million years ago, respectively). Around 20 million years after acquiring that ability, both groups evolved active electrogenesis , producing weak electric fields to help them detect prey. One of the best-known examples of convergent evolution
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#17327873466574154-666: The seeds are also edible but are too small to be of notable value as human food. The biggest producers of pine nuts are China , Russia , North Korea , Pakistan and Afghanistan . As pines are gymnosperms , not angiosperms (flowering plants), pine nuts are not " true nuts "; they are not botanical fruits , the seed not being enclosed in an ovary which develops into the fruit, but simply bare seeds—"gymnosperm" meaning literally "naked seed" (from Ancient Greek : γυμνός , romanized : gymnos , lit. 'naked' and σπέρμα , sperma , 'seed'). The similarity of pine nuts to some angiosperm fruits
4221-419: The size of a small marble, will form from mid-spring through the end of summer; this immature cone will temporarily cease growing and remain dormant until the following spring, then grow again until it reaches maturity near the end of its second summer. The mature piñon pine cone is ready to harvest ten days before the green cone begins to open. A cone is harvested by placing it in a burlap bag and exposing it to
4288-448: The state of New Mexico protects the use of the word piñon for use with pine nuts from certain species of indigenous New Mexican pines. Commonly used species include: Pine nuts will not reach full maturity unless the environmental conditions are favorable for the tree and the cone. The time to maturity varies depending on the species. For some American species, development begins in early spring with pollination. A tiny cone, about
4355-554: The thumb, which develops from a wrist bone entirely separately from other fingers. Convergent evolution in humans includes blue eye colour and light skin colour. When humans migrated out of Africa , they moved to more northern latitudes with less intense sunlight. It was beneficial to them to reduce their skin pigmentation . It appears certain that there was some lightening of skin colour before European and East Asian lineages diverged, as there are some skin-lightening genetic differences that are common to both groups. However, after
4422-424: The time of purchase. Consequently, pine nuts are often frozen to preserve their flavor. European pine nuts may be distinguished from Asian ones by their greater length than girth; Asian pine nuts are stubbier, shaped somewhat like long kernels of corn. The American piñon nuts are known for their large size and ease of shelling. In the United States, Pinus edulis , the hard shell of New Mexico and Colorado, became
4489-490: The two. When the ancestral forms are unspecified or unknown, or the range of traits considered is not clearly specified, the distinction between parallel and convergent evolution becomes more subjective. For instance, the striking example of similar placental and marsupial forms is described by Richard Dawkins in The Blind Watchmaker as a case of convergent evolution, because mammals on each continent had
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