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125-614: The aquatic ape hypothesis ( AAH ), also referred to as aquatic ape theory ( AAT ) or the waterside hypothesis of human evolution , postulates that the ancestors of modern humans took a divergent evolutionary pathway from the other great apes by becoming adapted to a more aquatic habitat. While the hypothesis has some popularity with the lay public, it is generally ignored or classified as pseudoscience by anthropologists . The theory developed before major discoveries of ancient hominin fossils in East Africa . The hypothesis
250-627: A Book of the Month selection in the United States and was translated into ten languages. The book was praised for its feminism but paleoanthropologists were disappointed with its promotions of the AAH. Morgan removed the feminist critique and left her AAH ideas intact, publishing the book as The Aquatic Ape 10 years later, but it did not garner any more positive reaction from scientists. AAH proponent Algis Kuliukas, performed experiments to measure
375-425: A "remarkable book", though he said that he did not agree with all of it. Tobias and his student further criticised the orthodox hypothesis by arguing that the coming out of the forest of man's precursors had been an unexamined assumption of evolution since the days of Lamarck , and followed by Darwin , Wallace and Haeckel , well before Raymond Dart used it. Alister Hardy was astonished and mortified in 1960 when
500-555: A PhD an academic scientist may continue through being on an academic position, receiving a post-doctoral fellowships and onto professorships . Other scientists make contributions to the scientific community in alternate ways such as in industry , education , think tanks , or the government . Members of the same community do not need to work together. Communication between the members is established by disseminating research work and hypotheses through articles in peer reviewed journals , or by attending conferences where new research
625-435: A blog post originally published in 2005 and continually updated since, anthropologist John D. Hawks said that anthropologists don't accept the AAH for several reasons. Hardy and Morgan situated the alleged aquatic period of human nature in a period of the fossil record that is now known not to contain any aquatic ancestors. The traits the AAH tries to explain actually evolved at wildly different time periods. The AAH claims that
750-497: A common ancestor about 660,000 years ago. However, a sequencing of the Neanderthal genome in 2010 indicated that Neanderthals did indeed interbreed with anatomically modern humans c. 45,000-80,000 years ago, around the time modern humans migrated out from Africa, but before they dispersed throughout Europe, Asia and elsewhere. The genetic sequencing of a 40,000-year-old human skeleton from Romania showed that 11% of its genome
875-618: A correlation between aquatic diet and human brain evolution in their "shore-based diet scenario", acknowledging the Hardy/Morgan's thesis as a foundation work of their model. As evidence, they describe health problems in landlocked communities, such as cretinism in the Alps and goitre in parts of Africa due to salt-derived iodine deficiency , and state that inland habitats cannot naturally meet human iodide requirements. Biologists Caroline Pond and Dick Colby were highly critical, saying that
1000-548: A distraction "from the emerging story of human evolution that is more interesting and complex". She argued that AAH had become "a theory of everything" that is simultaneously "too extravagant and too simple". Philosopher Daniel Dennett , in his discussion of evolutionary philosophy, commented "During the last few years, when I have found myself in the company of distinguished biologists, evolutionary theorists, paleoanthropologists and other experts, I have often asked them to tell me, please, exactly why Elaine Morgan must be wrong about
1125-493: A few older societies of men who studied nature such as the Royal Society of London , the concept of scientific communities emerged in the second half of the 19th century, not before, because it was in this century that the language of modern science emerged, the professionalization of science occurred, specialized institutions were created, and the specialization of scientific disciplines and fields occurred. For instance,
1250-433: A given community since membership is often exclusive, their commissions are explicitly focused on serving their governments, and they have never "shown systematic interest in what rank-and-file scientists think about scientific matters". Exclusivity of membership in these types of organizations can be seen in their election processes in which only existing members can officially nominate others for candidacy of membership. It
1375-468: A heavily water-dependent species." But they allege that "under pressure from the mainstream, AAH supporters tended to flee from the core arguments of Hardy and Morgan towards a more generalized emphasis on fishy things." In "The Waterside Ape", a pair of 2016 BBC Radio documentaries, David Attenborough discussed what he thought was a "move towards mainstream acceptance" for the AAH in the light of new research findings. He interviewed scientists supportive of
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#17327836844591500-608: A higher rate of depression. The flow of genes from Neanderthal populations to modern humans was not all one way. Sergi Castellano of the Max Planck Institute for Evolutionary Anthropology reported in 2016 that while Denisovan and Neanderthal genomes are more related to each other than they are to us, Siberian Neanderthal genomes show more similarity to modern human genes than do European Neanderthal populations. This suggests Neanderthal populations interbred with modern humans around 100,000 years ago, probably somewhere in
1625-459: A human developmental plasticity . Human evolution Human evolution is the evolutionary process within the history of primates that led to the emergence of Homo sapiens as a distinct species of the hominid family that includes all the great apes . This process involved the gradual development of traits such as human bipedalism , dexterity , and complex language , as well as interbreeding with other hominins (a tribe of
1750-507: A lesser response in other animals, including human babies up to 6 months old (see infant swimming ). However adult humans generally exhibit a mild response. Hardy additionally posited that bipedalism evolved first as an aid to wading before becoming the usual means of human locomotion, and tool use evolved out of the use of rocks to crack open shellfish . These last arguments were cited by later proponents of AAH as an inspiration for their research programs . Morgan summed up her take on
1875-538: A mere 200,000 years ago . Evidence supports aquatic food consumption in Homo as early as the Pliocene , but its linkage to brain evolution remains controversial. Further, there is no evidence that humans ate fish in significant amounts earlier than tens to hundreds of thousands of years ago. Supporters argue that the avoidance of taphonomic bias is the problem, as most hominin fossils occur in lake-side environments, and
2000-485: A number of clear anatomical differences between anatomically modern humans (AMH) and Neanderthal specimens, many relating to the superior Neanderthal adaptation to cold environments. Neanderthal surface to volume ratio was even lower than that among modern Inuit populations, indicating superior retention of body heat. Neanderthals also had significantly larger brains, as shown from brain endocasts, casting doubt on their intellectual inferiority to modern humans. However,
2125-436: A particular topic. Philosophers of science argue over the epistemological limits of such a consensus and some, including Thomas Kuhn , have pointed to the existence of scientific revolutions in the history of science as being an important indication that scientific consensus can, at times, be wrong. Nevertheless, the sheer explanatory power of science in its ability to make accurate and precise predictions and aid in
2250-500: A proper scientific hypothesis . Langdon also objected to Morgan's blanket opposition to the " savannah hypothesis " which he took to be the "collective discipline of paleoanthropology". He observed that some anthropologists had regarded the idea as not worth the trouble of a rebuttal. In addition, the evidence cited by AAH proponents mostly concerned developments in soft tissue anatomy and physiology, whilst paleoanthropologists rarely speculated on evolutionary development of anatomy beyond
2375-480: A related lineage. In September 2019, scientists reported the computerized determination, based on 260 CT scans , of a virtual skull shape of the last common human ancestor to modern humans ( H. sapiens ), representative of the earliest modern humans, and suggested that modern humans arose between 260,000 and 350,000 years ago through a merging of populations in East and South Africa. Between 400,000 years ago and
2500-472: A seafood diet can aid in the development of the human brain. He nevertheless criticized the AAH because "it's always a problem identifying features [such as body fat and hairlessness] that humans have now and inferring that they must have had some adaptive value in the past." Also "it's notoriously hard to infer habits [such as swimming] from anatomical structures". Popular support for the AAH has become an embarrassment to some anthropologists, who want to explore
2625-469: A study of the life history of Ar. ramidus that the species provides evidence for a suite of anatomical and behavioral adaptations in very early hominins unlike any species of extant great ape. This study demonstrated affinities between the skull morphology of Ar. ramidus and that of infant and juvenile chimpanzees, suggesting the species evolved a juvenalised or paedomorphic craniofacial morphology via heterochronic dissociation of growth trajectories. It
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#17327836844592750-433: A supernatural creation to challenge some naturalistic assumptions that have been proposed in some of the branches of scientific fields such as evolutionary biology , geology , and astronomy . Although the dichotomy seems to be of a different outlook from a Continental European perspective, it does exist. The Vienna Circle , for instance, had a paramount (i.e. symbolic) influence on the semiotic regime represented by
2875-600: Is Kamoyapithecus from the uppermost Oligocene at Eragaleit in the northern Great Rift Valley in Kenya, dated to 24 million years ago. Its ancestry is thought to be species related to Aegyptopithecus , Propliopithecus , and Parapithecus from the Faiyum, at around 35 mya. In 2010, Saadanius was described as a close relative of the last common ancestor of the crown catarrhines, and tentatively dated to 29–28 mya, helping to fill an 11-million-year gap in
3000-435: Is an unjustifiable leap. Professor of animal physiology and experienced scuba and freediver Erika Schagatay researches human diving abilities and oxygen stress. She suggests that such abilities are consistent with selective pressure for underwater foraging during human evolution, and discussed other anatomical traits speculated as diving adaptations by Hardy/Morgan. John Langdon suggested that such traits could be enabled by
3125-445: Is claimed to have been discovered living at the same time period of A. afarensis . There is debate whether A. deyiremeda is a new species or is A. afarensis . Australopithecus prometheus , otherwise known as Little Foot has recently been dated at 3.67 million years old through a new dating technique, making the genus Australopithecus as old as afarensis . Given the opposable big toe found on Little Foot, it seems that
3250-420: Is considered to be a classic example of pseudoscience among the scholarly community, and has been met with significant skepticism. The Nature editor and paleontologist Henry Gee has argued that the hypothesis has equivalent merit to creationism , and should be similarly dismissed. In a 1997 critique, anthropologist John Langdon considered the AAH under the heading of an "umbrella hypothesis" and argued that
3375-461: Is consistent with recent studies indicating that the divergence of some human alleles dates to one Ma, although this interpretation has been questioned. Neanderthals and AMH Homo sapiens could have co-existed in Europe for as long as 10,000 years, during which AMH populations exploded, vastly outnumbering Neanderthals, possibly outcompeting them by sheer numbers. In 2008, archaeologists working at
3500-706: Is evidence of a wide diversity of forms across Africa and the Mediterranean basin during the relatively warm and equable climatic regimes of the Early and Middle Miocene. The youngest of the Miocene hominoids, Oreopithecus , is from coal beds in Italy that have been dated to 9 million years ago. Molecular evidence indicates that the lineage of gibbons diverged from the line of great apes some 18–12 mya, and that of orangutans (subfamily Ponginae ) diverged from
3625-611: Is expected to be achieved by the scientific method . Peer review , through discussion and debate within journals and conferences, assists in this objectivity by maintaining the quality of research methodology and interpretation of results. The eighteenth century had some societies made up of men who studied nature, also known as natural philosophers and natural historians , which included even amateurs. As such these societies were more like local clubs and groups with diverse interests than actual scientific communities, which usually had interests on specialized disciplines. Though there were
3750-486: Is intriguing both for its size and its age, being an example of a recent species of the genus Homo that exhibits derived traits not shared with modern humans. In other words, H. floresiensis shares a common ancestor with modern humans, but split from the modern human lineage and followed a distinct evolutionary path. The main find was a skeleton believed to be a woman of about 30 years of age. Found in 2003, it has been dated to approximately 18,000 years old. The living woman
3875-405: Is limited; both poor preservation – rain forest soils tend to be acidic and dissolve bone – and sampling bias probably contribute to this problem. Other hominins probably adapted to the drier environments outside the equatorial belt; and there they encountered antelope, hyenas, dogs, pigs, elephants, horses, and others. The equatorial belt contracted after about 8 million years ago, and there
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4000-597: Is partly due to the specialized training most scientists receive in very few fields. As a result, many would lack expertise in all the other fields of the sciences. For instance, due to the increasing complexity of information and specialization of scientists, most of the cutting-edge research today is done by well funded groups of scientists, rather than individuals. However, there are still multiple societies and academies in many countries which help consolidate some opinions and research to help guide public discussions on matters of policy and government-funded research. For example,
4125-524: Is presented and ideas exchanged and discussed. There are also many informal methods of communication of scientific work and results as well. And many in a coherent community may actually not communicate all of their work with one another, for various professional reasons. Unlike in previous centuries when the community of scholars were all members of few learned societies and similar institutions, there are no singular bodies or individuals which can be said today to speak for all science or all scientists. This
4250-715: Is seen most completely in the Upper Eocene and lowermost Oligocene fossil beds of the Faiyum depression southwest of Cairo —gave rise to all extant primate species, including the lemurs of Madagascar , lorises of Southeast Asia, galagos or "bush babies" of Africa, and to the anthropoids , which are the Platyrrhines or New World monkeys, the Catarrhines or Old World monkeys, and the great apes, including humans and other hominids. The earliest known catarrhine
4375-523: Is still some debate among academics whether certain African hominid species of this time, such as A. robustus and A. boisei , constitute members of the same genus; if so, they would be considered to be "robust australopiths" while the others would be considered "gracile australopiths". However, if these species do indeed constitute their own genus, then they may be given their own name, Paranthropus . A new proposed species Australopithecus deyiremeda
4500-693: Is supported in part, because some modern humans who live on Flores , the Indonesian island where the skeleton was found, are pygmies . This, coupled with pathological dwarfism, could have resulted in a significantly diminutive human. The other major attack on H. floresiensis as a separate species is that it was found with tools only associated with H. sapiens . The hypothesis of pathological dwarfism, however, fails to explain additional anatomical features that are unlike those of modern humans (diseased or not) but much like those of ancient members of our genus. Aside from cranial features, these features include
4625-404: Is that a branch of this primitive ape-stock was forced by competition from life in the trees to feed on the sea-shores and to hunt for food, shellfish , sea-urchins etc., in the shallow waters off the coast." The idea was generally ignored by the scientific community after the article was published. Some interest was received, notably from the geographer Carl Sauer whose views on the role of
4750-516: Is very important to science pedagogy, the evaluation of new ideas, and research funding. Sometimes it is argued that there is a closed shop bias within the scientific community toward new ideas. Protoscience , fringe science , and pseudoscience have been topics that discuss demarcation problems. In response to this some non-consensus claims skeptical organizations , not research institutions, have devoted considerable amounts of time and money contesting ideas which run counter to general agreement on
4875-408: Is very little fossil evidence for the split—thought to have occurred around that time—of the hominin lineage from the lineages of gorillas and chimpanzees. The earliest fossils argued by some to belong to the human lineage are Sahelanthropus tchadensis (7 Ma) and Orrorin tugenensis (6 Ma), followed by Ardipithecus (5.5–4.4 Ma), with species Ar. kadabba and Ar. ramidus . It has been argued in
5000-537: Is very unusual for organizations like the National Academy of Science to engage in external research projects since they normally focus on preparing scientific reports for government agencies. An example of how rarely the NAS engages in external and active research can be seen in its struggle to prepare and overcome hurdles, due to its lack of experience in coordinating research grants and major research programs on
5125-463: The African hominid subfamily), indicating that human evolution was not linear but weblike. The study of the origins of humans involves several scientific disciplines, including physical and evolutionary anthropology , paleontology , and genetics ; the field is also known by the terms anthropogeny , anthropogenesis , and anthropogony . (The latter two terms are sometimes used to refer to
Aquatic ape hypothesis - Misplaced Pages Continue
5250-756: The Australopithecine and Panina subtribes) parted from the Gorillini tribe between 8 and 9 mya; Australopithecine (including the extinct biped ancestors of humans) separated from the Pan genus (containing chimpanzees and bonobos ) 4–7 mya. The Homo genus is evidenced by the appearance of H. habilis over 2 mya, while anatomically modern humans emerged in Africa approximately 300,000 years ago. The evolutionary history of primates can be traced back 65 million years. One of
5375-561: The British Medical Journal in 1991, calling it "exceptionally well written" and "a good piece of science". In 1995, paleoanthropologist Phillip Tobias declared that the savannah hypothesis was dead, because the open conditions did not exist when humanity's precursors stood upright and that therefore the conclusions of the Valkenburg conference were no longer valid. Tobias praised Morgan's book Scars of Evolution as
5500-634: The Cretaceous , contrary to what is possible given the geologic and evolutionary biology evidence available at the time. He stated: "The postulation of an aquatic mode of life during an early stage of human evolution is a tenable hypothesis, for which further inquiry may produce additional supporting evidence." He later abandoned the concept. Independently of Westenhöfer's writings, the marine biologist Alister Hardy had since 1930 also hypothesized that humans may have had ancestors more aquatic than previously imagined, although his work, unlike Westenhöfer's,
5625-493: The Late Pliocene or Early Pleistocene , 2.5–2 Ma, when it diverged from the australopithecines with the development of smaller molars and larger brains. One of the first known hominins, it made tools from stone and perhaps animal bones, leading to its name homo habilis (Latin 'handy man') bestowed by discoverer Louis Leakey . Some scientists have proposed moving this species from Homo into Australopithecus due to
5750-468: The Pleistocene played a significant role in human evolution observed via human transitions between subsistence systems. The most significant of these adaptations are bipedalism, increased brain size, lengthened ontogeny (gestation and infancy), and decreased sexual dimorphism . The relationship between these changes is the subject of ongoing debate. Other significant morphological changes included
5875-477: The United States ' National Academy of Sciences (NAS) and United Kingdom 's Royal Society sometimes act as surrogates when the opinions of the scientific community need to be ascertained by policy makers or the national government , but the statements of the National Academy of Science or the Royal Society are not binding on scientists nor do they necessarily reflect the opinions of every scientist in
6000-425: The difficulty of ever disproving such a thing meant that although the idea has the appearance of being a parsimonious explanation , it actually was no more powerful an explanation than the null hypothesis that human evolution is not particularly guided by interaction with bodies of water. Langdon argued that however popular the idea was with the public, the "umbrella" nature of the idea means that it cannot serve as
6125-466: The fossil record , cranial capacity had doubled to 850 cm . (Such an increase in human brain size is equivalent to each generation having 125,000 more neurons than their parents.) It is believed that H. erectus and H. ergaster were the first to use fire and complex tools, and were the first of the hominin line to leave Africa, spreading throughout Africa, Asia, and Europe between 1.3 to 1.8 million years ago . According to
6250-569: The gorillas and chimpanzees, diverged from the hominin line over a period covering the same time, so either Sahelanthropus or Orrorin may be our last shared ancestor. Ardipithecus , a full biped, arose approximately 5.6 million years ago. Scientific community The scientific community is a diverse network of interacting scientists . It includes many " sub-communities " working on particular scientific fields, and within particular institutions; interdisciplinary and cross-institutional activities are also significant. Objectivity
6375-553: The 19th century between religion and science has been cited by some as representative of a struggle between tradition and substantial change and faith and reason . . A popular example used to support this thesis is when Galileo was tried before the Inquisition concerning the heliocentric model. The persecution began after Pope Urban VIII permitted Galileo to write about the Copernican model. Galileo had used arguments from
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#17327836844596500-525: The Australopithecine and Panina subtribes) parted from the Gorillini tribe (gorillas) between 8 and 9 mya; Australopithecine (including the extinct biped ancestors of humans) separated from the Pan genus (containing chimpanzees and bonobos) 4–7 mya. The Homo genus is evidenced by the appearance of H. habilis over 2 mya, while anatomically modern humans emerged in Africa approximately 300,000 years ago. Species close to
6625-834: The Early Pleistocene, 1.5–1 Ma, some populations of Homo habilis are thought to have evolved larger brains and to have made more elaborate stone tools; these differences and others are sufficient for anthropologists to classify them as a new species, Homo erectus —in Africa. The evolution of locking knees and the movement of the foramen magnum are thought to be likely drivers of the larger population changes. This species also may have used fire to cook meat. Richard Wrangham notes that Homo seems to have been ground dwelling, with reduced intestinal length, smaller dentition, and "brains [swollen] to their current, horrendously fuel-inefficient size", and hypothesizes that control of fire and cooking, which released increased nutritional value,
6750-477: The German pathologist Max Westenhöfer (1871–1957) discussed various human characteristics ( hairlessness , subcutaneous fat , the regression of the olfactory organ , webbed fingers , direction of the body hair etc.) that could have derived from an aquatic past, quoting several other authors who had made similar speculations. As he did not believe human beings were apes , he believed this might have been during
6875-465: The Indonesian island of Java. He originally named the material Anthropopithecus erectus (1892–1893, considered at this point as a chimpanzee-like fossil primate) and Pithecanthropus erectus (1893–1894, changing his mind as of based on its morphology, which he considered to be intermediate between that of humans and apes). Years later, in the 20th century, the German physician and paleoanthropologist Franz Weidenreich (1873–1948) compared in detail
7000-455: The Near East. Studies of a Neanderthal child at Gibraltar show from brain development and tooth eruption that Neanderthal children may have matured more rapidly than Homo sapiens . H. floresiensis , which lived from approximately 190,000 to 50,000 years before present (BP), has been nicknamed the hobbit for its small size, possibly a result of insular dwarfism . H. floresiensis
7125-529: The Pope and put them in the voice of the simpleton in the work "Dialogue Concerning the Two Chief World Systems" which caused great offense to him. Even though many historians of science have discredited the conflict thesis it still remains a popular belief among many including some scientists. In more recent times, the creation–evolution controversy has resulted in many religious believers in
7250-516: The Scientific Community in Europe. In the decades following World War II , some were convinced that nuclear power would solve the pending energy crisis by providing energy at low cost. This advocacy led to the construction of many nuclear power plants , but was also accompanied by a global political movement opposed to nuclear power due to safety concerns and associations of the technology with nuclear weapons . Mass protests in
7375-659: The Toba catastrophe; however, nearby H. floresiensis survived it. The early phase of H. erectus , from 1.8 to 1.25 Ma, is considered by some to be a separate species, H. ergaster , or as H. erectus ergaster , a subspecies of H. erectus . Many paleoanthropologists now use the term Homo ergaster for the non-Asian forms of this group, and reserve H. erectus only for those fossils that are found in Asia and meet certain skeletal and dental requirements which differ slightly from H. ergaster . In Africa in
7500-471: The absence of aggressive canine morphology in Ar. ramidus and the implications this has for the evolution of hominin social psychology, they wrote: Of course Ar. ramidus differs significantly from bonobos, bonobos having retained a functional canine honing complex. However, the fact that Ar. ramidus shares with bonobos reduced sexual dimorphism, and a more paedomorphic form relative to chimpanzees, suggests that
7625-402: The alleged aquatic nature of humanity is responsible for human patterns of hair, fat, and sweat, but actually all of these things are similar in humans to other primates. To the extent they are exceptional in any primate relative to other primates, or in primates relative to other mammals, they are exceptional for well-understood thermodynamic reasons. Palaeontologist Riley Black concurred with
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#17327836844597750-439: The ancestral hominin line. There is yet no consensus as to which of these groups should be considered a separate species and which should be subspecies; this may be due to the dearth of fossils or to the slight differences used to classify species in the genus Homo . The Sahara pump theory (describing an occasionally passable "wet" Sahara desert) provides one possible explanation of the intermittent migration and speciation in
7875-405: The ancient forest and woodland ecosystems of late Miocene and early Pliocene Africa. Consequently, they argue that humans may not represent evolution from a chimpanzee-like ancestor as has traditionally been supposed. This suggests many modern human adaptations represent phylogenetically deep traits and that the behavior and morphology of chimpanzees may have evolved subsequent to the split with
8000-553: The aquatic theory lacks solid support". While traditional descriptions of 'savage' existence identified three common sources of sustenance: gathering of fruit and nuts, fishing, and hunting, in the 1950s, the anthropologist Raymond Dart focused on hunting and gathering as the likely organizing concept of human society in prehistory, and hunting was the focus of the screenwriter Robert Ardrey 's 1961 best-seller African Genesis . Another screenwriter, Elaine Morgan, responded to this focus in her 1972 Descent of Woman , which parodied
8125-666: The aquatic theory. I haven't yet had a reply worth mentioning, aside from those who admit, with a twinkle in their eyes, that they have also wondered the same thing." He challenged both Elaine Morgan and the scientific establishment in that "Both sides are indulging in adapt[at]ionist Just So stories ". Along the same lines, historian Erika Lorraine Milam noted that independent of Morgan's work, certain standard explanations of human development in paleoanthropology have been roundly criticized for lacking evidence, while being based on sexist assumptions. Anatomy lecturer Bruce Charlton gave Morgan's book Scars of Evolution an enthusiastic review in
8250-466: The biologist Alister Hardy in 1960. When it aroused no reaction in the academic community, she dropped the feminist criticism and wrote a series of books– The Aquatic Ape (1982), The Scars of Evolution (1990), The Descent of the Child (1994), The Aquatic Ape Hypothesis (1997) and The Naked Darwinist (2008)–which explored the issues in more detail. Books published on the topic since then have avoided
8375-520: The brain: A branch of the line of primitive ancestral apes was forced by competition to leave the trees and feed on the seashore. Searching for oysters, mussels, crabs, crayfish and so on they would have spent much of their time in the water and an upright position would have come naturally. Crawford and Marsh opined that the brain size in aquatic mammals is similar to humans, and that other primates and carnivores lost relative brain capacity. Cunnane, Stewart, Crawford, and colleagues published works arguing
8500-571: The characters of Dubois' Java Man , then named Pithecanthropus erectus , with the characters of the Peking Man , then named Sinanthropus pekinensis . Weidenreich concluded in 1940 that because of their anatomical similarity with modern humans it was necessary to gather all these specimens of Java and China in a single species of the genus Homo , the species H. erectus . Homo erectus lived from about 1.8 Ma to about 70,000 years ago – which would indicate that they were probably wiped out by
8625-401: The common ancestor they share with humans. The genus Australopithecus evolved in eastern Africa around 4 million years ago before spreading throughout the continent and eventually becoming extinct 2 million years ago. During this time period various forms of australopiths existed, including Australopithecus anamensis , A. afarensis , A. sediba , and A. africanus . There
8750-497: The community is highly correlated with publication record , and also depends on the status within the institution and the status of the institution. Researchers can hold roles of different degrees of influence inside the scientific community. Researchers of a stronger influence can act as mentors for early career researchers and steer the direction of research in the community like agenda setters. Scientists are usually trained in academia through universities . As such, degrees in
8875-479: The comparative energy used when lacking orthograde posture with using fully upright posture. Although it is harder to walk upright with bent knees on land, this difference gradually diminishes as the depth of water increases and is still practical in thigh-high water. In a critique of the AAH, Henry Gee questioned any link between bipedalism and diet. Gee writes that early humans have been bipedal for 5 million years, but our ancestors' "fondness for seafood" emerged
9000-563: The contentious term aquatic and used waterside instead. Hardy's hypothesis as outlined in New Scientist was: My thesis is that a branch of this primitive ape -stock was forced by competition from life in the trees to feed on the sea-shores and to hunt for food, shell fish , sea-urchins etc., in the shallow waters off the coast. I suppose that they were forced into the water just as we have seen happen in so many other groups of terrestrial animals. I am imagining this happening in
9125-517: The conventional picture of "the Tarzanlike figure of the prehominid who came down from the trees, saw a grassland teeming with game, picked up a weapon and became a Mighty Hunter," and pictured a more peaceful scene of humans by the seashore. She took her lead from a section in Morris's 1967 book which referred to the possibility of an Aquatic Ape period in evolution, his name for the speculation by
9250-474: The design and engineering of new technology has ensconced "science" and, by proxy, the opinions of the scientific community as a highly respected form of knowledge both in the academy and in popular culture . The high regard with which scientific results are held in Western society has caused a number of political controversies over scientific subjects to arise. An alleged conflict thesis proposed in
9375-408: The developmental and social adaptations evident in bonobos may be of assistance in future reconstructions of early hominin social and sexual psychology. In fact the trend towards increased maternal care, female mate selection and self-domestication may have been stronger and more refined in Ar. ramidus than what we see in bonobos. The authors argue that many of the basic human adaptations evolved in
9500-402: The distribution of stone tools), and faster spread of social and technological innovations. All these may have all contributed to modern Homo sapiens replacing Neanderthal populations by 28,000 BP. Earlier evidence from sequencing mitochondrial DNA suggested that no significant gene flow occurred between H. neanderthalensis and H. sapiens , and that the two were separate species that shared
9625-478: The divergence point of the mtDNA was unexpectedly deep in time, the full genomic sequence suggested the Denisovans belonged to the same lineage as Neanderthals, with the two diverging shortly after their line split from the lineage that gave rise to modern humans. Modern humans are known to have overlapped with Neanderthals in Europe and the Near East for possibly more than 40,000 years, and the discovery raises
9750-472: The earlier dispersed H. erectus . This migration and origin theory is usually referred to as the "recent single-origin hypothesis" or "out of Africa" theory. H. sapiens interbred with archaic humans both in Africa and in Eurasia, in Eurasia notably with Neanderthals and Denisovans. The Toba catastrophe theory , which postulates a population bottleneck for H. sapiens about 70,000 years ago,
9875-460: The effects of water on human evolution without engaging with the AAH, which they consider "emphasizes adaptations to deep water (or at least underwater) conditions". Foley and Lahr suggest that "to flirt with anything watery in paleoanthropology can be misinterpreted", but argue "there is little doubt that throughout our evolution we have made extensive use of terrestrial habitats adjacent to fresh water, since we are, like many other terrestrial mammals,
10000-400: The end was: Overall, it will be clear that I do not think it would be correct to designate our early hominid ancestors as 'aquatic'. But at the same time there does seem to be evidence that not only did they take to water from time to time but that the water (and by this I mean inland lakes and rivers) was a habitat that provided enough extra food to count as an agency for selection. The AAH
10125-596: The environment and health. Nevertheless, general scientific consensus is a concept which is often referred to when dealing with questions that can be subject to scientific methodology . While the consensus opinion of the community is not always easy to ascertain or fix due to paradigm shifting, generally the standards and utility of the scientific method have tended to ensure, to some degree, that scientists agree on some general corpus of facts explicated by scientific theory while rejecting some ideas which run counter to this realization. The concept of scientific consensus
10250-484: The evolution of a power and precision grip , a change first occurring in H. erectus . Bipedalism , (walking on two legs), is the basic adaptation of the hominid and is considered the main cause behind a suite of skeletal changes shared by all bipedal hominids. The earliest hominin, of presumably primitive bipedalism, is considered to be either Sahelanthropus or Orrorin , both of which arose some 6 to 7 million years ago. The non-bipedal knuckle-walkers,
10375-550: The forerunner of anatomically modern humans , evolved in the Middle Paleolithic between 400,000 and 250,000 years ago. Recent DNA evidence suggests that several haplotypes of Neanderthal origin are present among all non-African populations, and Neanderthals and other hominins, such as Denisovans, may have contributed up to 6% of their genome to present-day humans, suggestive of a limited interbreeding between these species . According to some anthropologists,
10500-594: The form of bones in the wrist, forearm, shoulder, knees, and feet. Additionally, this hypothesis fails to explain the find of multiple examples of individuals with these same characteristics, indicating they were common to a large population, and not limited to one individual. In 2016, fossil teeth and a partial jaw from hominins assumed to be ancestral to H. floresiensis were discovered at Mata Menge , about 74 km (46 mi) from Liang Bua. They date to about 700,000 years ago and are noted by Australian archaeologist Gerrit van den Bergh for being even smaller than
10625-1002: The fossil record. In the Early Miocene , about 22 million years ago, the many kinds of arboreally -adapted (tree-dwelling) primitive catarrhines from East Africa suggest a long history of prior diversification. Fossils at 20 million years ago include fragments attributed to Victoriapithecus , the earliest Old World monkey. Among the genera thought to be in the ape lineage leading up to 13 million years ago are Proconsul , Rangwapithecus , Dendropithecus , Limnopithecus , Nacholapithecus , Equatorius , Nyanzapithecus , Afropithecus , Heliopithecus , and Kenyapithecus , all from East Africa. The presence of other generalized non-cercopithecids of Middle Miocene from sites far distant, such as Otavipithecus from cave deposits in Namibia, and Pierolapithecus and Dryopithecus from France, Spain and Austria,
10750-538: The genomes of modern humans outside Africa. HLA haplotypes from Denisovans and Neanderthal represent more than half the HLA alleles of modern Eurasians, indicating strong positive selection for these introgressed alleles. Corinne Simoneti at Vanderbilt University, in Nashville and her team have found from medical records of 28,000 people of European descent that the presence of Neanderthal DNA segments may be associated with
10875-641: The genus Homo . Based on archaeological and paleontological evidence, it has been possible to infer, to some extent, the ancient dietary practices of various Homo species and to study the role of diet in physical and behavioral evolution within Homo . Some anthropologists and archaeologists subscribe to the Toba catastrophe theory , which posits that the supereruption of Lake Toba on Sumatra in Indonesia some 70,000 years ago caused global starvation, killing
11000-820: The higher body mass of Neanderthals may have required larger brain mass for body control. Also, recent research by Pearce, Stringer , and Dunbar has shown important differences in brain architecture. The larger size of the Neanderthal orbital chamber and occipital lobe suggests that they had a better visual acuity than modern humans, useful in the dimmer light of glacial Europe. Neanderthals may have had less brain capacity available for social functions . Inferring social group size from endocranial volume (minus occipital lobe size) suggests that Neanderthal groups may have been limited to 120 individuals, compared to 144 possible relationships for modern humans. Larger social groups could imply that modern humans had less risk of inbreeding within their clan, trade over larger areas (confirmed in
11125-405: The hypothesis in 2011: Waterside hypotheses of human evolution assert that selection from wading, swimming and diving and procurement of food from aquatic habitats have significantly affected the evolution of the lineage leading to Homo sapiens as distinct from that leading to Pan . The AAH is generally ignored by anthropologists, although it has a following outside academia and conferences on
11250-573: The idea, including Kathlyn Stewart and Michael Crawford who had published papers in a special issue of the Journal of Human Evolution on "The Role of Freshwater and Marine Resources in the Evolution of the Human Diet, Brain and Behavior". Responding to the documentaries in a newspaper article, paleoanthropologist Alice Roberts criticized Attenborough's promotion of AAH and dismissed the idea as
11375-602: The last common ancestor of gorillas, chimpanzees and humans may be represented by Nakalipithecus fossils found in Kenya and Ouranopithecus found in Greece. Molecular evidence suggests that between 8 and 4 million years ago, first the gorillas, and then the chimpanzees (genus Pan ) split off from the line leading to the humans. Human DNA is approximately 98.4% identical to that of chimpanzees when comparing single nucleotide polymorphisms (see human evolutionary genetics ). The fossil record, however, of gorillas and chimpanzees
11500-413: The later fossils. A small number of specimens from the island of Luzon , dated 50,000 to 67,000 years ago, have recently been assigned by their discoverers, based on dental characteristics, to a novel human species, H. luzonensis . H. sapiens (the adjective sapiens is Latin for "wise" or "intelligent") emerged in Africa around 300,000 years ago, likely derived from H. heidelbergensis or
11625-459: The location of the trachea in the throat rather than the nasal cavity, the human propensity for front-facing copulation , tears and eccrine sweating , though these claimed pieces of evidence have alternative evolutionary adaptationist explanations that do not invoke an aquatic context. The diving reflex is sometimes cited as evidence. This is exhibited strongly in aquatic mammals , such as seals , otters and dolphins . It also exists as
11750-598: The majority of humans and creating a population bottleneck that affected the genetic inheritance of all humans today. The genetic and archaeological evidence for this remains in question however. A 2023 genetic study suggests that a similar human population bottleneck of between 1,000 and 100,000 survivors occurred "around 930,000 and 813,000 years ago ... lasted for about 117,000 years and brought human ancestors close to extinction." Homo habilis lived from about 2.8 to 1.4 Ma. The species evolved in South and East Africa in
11875-494: The morphology of its skeleton being more adapted to living in trees rather than walking on two legs like later hominins. In May 2010, a new species, Homo gautengensis , was discovered in South Africa. These are proposed species names for fossils from about 1.9–1.6 Ma, whose relation to Homo habilis is not yet clear. The first fossils of Homo erectus were discovered by Dutch physician Eugene Dubois in 1891 on
12000-407: The musculoskeletal system and brain size as revealed in fossils. After a brief description of the issues under 26 different headings, he produced a summary critique of these with mainly negative judgments. His main conclusion was that the AAH was unlikely ever to be disproved on the basis of comparative anatomy, and that the one body of data that could potentially disprove it was the fossil record. In
12125-453: The national Sunday papers carried banner headlines "Oxford professor says man a sea ape", causing problems with his Oxford colleagues. As he later said to his ex-pupil Desmond Morris , "Of course I then had to write an article to refute this saying no this is just a guess, a rough hypothesis, this isn't a proven fact. And of course we're not related to dolphins ." Elaine Morgan's 1972 book Descent of Woman became an international best-seller,
12250-654: The oldest known primate-like mammal species, the Plesiadapis , came from North America; another, Archicebus , came from China . Other similar basal primates were widespread in Eurasia and Africa during the tropical conditions of the Paleocene and Eocene . David R. Begun concluded that early primates flourished in Eurasia and that a lineage leading to the African apes and humans, including to Dryopithecus , migrated south from Europe or Western Asia into Africa. The surviving tropical population of primates—which
12375-486: The other great apes at about 12 million years; there are no fossils that clearly document the ancestry of gibbons, which may have originated in a so-far-unknown Southeast Asian hominoid population, but fossil proto-orangutans may be represented by Sivapithecus from India and Griphopithecus from Turkey, dated to around 10 mya. Hominidae subfamily Homininae (African hominids) diverged from Ponginae (orangutans) about 14 mya. Hominins (including humans and
12500-764: The possibility that Neanderthals, Denisovans, and modern humans may have co-existed and interbred. The existence of this distant branch creates a much more complex picture of humankind during the Late Pleistocene than previously thought. Evidence has also been found that as much as 6% of the DNA of some modern Melanesians derive from Denisovans, indicating limited interbreeding in Southeast Asia. Alleles thought to have originated in Neanderthals and Denisovans have been identified at several genetic loci in
12625-401: The presence of fish remains is therefore not proof of fish consumption. They also claim that the archaeological record of human fishing and coastal settlement is fundamentally deficient due to postglacial sea level rise . In their 1989 book The Driving Force: Food, Evolution and The Future , Michael Crawford and David Marsh claimed that omega-3 fatty acids were vital for the development of
12750-476: The pseudoscience label, and described the AAH as a "classic case of picking evidence that fits a preconceived conclusion and ignoring everything else". Physical anthropologist Eugenie Scott has described the aquatic ape hypothesis as an instance of "crank anthropology" akin to other pseudoscientific ideas in anthropology such as alien-human interbreeding and Bigfoot . In The Accidental Species: Misunderstandings of Human Evolution (2013), Henry Gee remarked on how
12875-477: The recent African origin theory, modern humans evolved in Africa possibly from H. heidelbergensis , H. rhodesiensis or H. antecessor and migrated out of the continent some 50,000 to 100,000 years ago, gradually replacing local populations of H. erectus , Denisova hominins , H. floresiensis , H. luzonensis and H. neanderthalensis , whose ancestors had left Africa in earlier migrations. Archaic Homo sapiens ,
13000-495: The rejection of Hardy and Morgan is partially unfair given that other explanations which suffer from similar problems are not so strongly opposed. A conference devoted to the subject was held at Valkenburg , Netherlands , in 1987. Its 22 participants included academic proponents and opponents of the hypothesis and several neutral observers headed by the anthropologist Vernon Reynolds of the University of Oxford . His summary at
13125-627: The related subject of hominization .) Primates diverged from other mammals about 85 million years ago ( mya ), in the Late Cretaceous period, with their earliest fossils appearing over 55 mya, during the Paleocene . Primates produced successive clades leading to the ape superfamily, which gave rise to the hominid and the gibbon families; these diverged some 15–20 mya. African and Asian hominids (including orangutans ) diverged about 14 mya. Hominins (including
13250-452: The relevant scientific sub-disciplines are often considered prerequisites in the relevant community. In particular, the PhD with its research requirements functions as a marker of being an important integrator into the community, though continued membership is dependent on maintaining connections to other researchers through publication, technical contributions, and conferences . After obtaining
13375-463: The seashore in human evolution "stimulated tremendous progress in the study of coastal and aquatic adaptations" inside marine archaeology . In 1967, the hypothesis was mentioned in The Naked Ape , a popular book by the zoologist Desmond Morris , who reduced Hardy's phrase "more aquatic ape-like ancestors" to the bare "aquatic ape", commenting that "despite its most appealing indirect evidence,
13500-583: The second interglacial period in the Middle Pleistocene , around 250,000 years ago, the trend in intra-cranial volume expansion and the elaboration of stone tool technologies developed, providing evidence for a transition from H. erectus to H. sapiens . The direct evidence suggests there was a migration of H. erectus out of Africa , then a further speciation of H. sapiens from H. erectus in Africa. A subsequent migration (both within and out of Africa) eventually replaced
13625-566: The site of Denisova Cave in the Altai Mountains of Siberia uncovered a small bone fragment from the fifth finger of a juvenile member of another human species, the Denisovans. Artifacts, including a bracelet, excavated in the cave at the same level were carbon dated to around 40,000 BP. As DNA had survived in the fossil fragment due to the cool climate of the Denisova Cave, both mtDNA and nuclear DNA were sequenced. While
13750-404: The specimen was a good climber. It is thought given the night predators of the region that he built a nesting platform at night in the trees in a similar fashion to chimpanzees and gorillas. The earliest documented representative of the genus Homo is Homo habilis , which evolved around 2.8 million years ago , and is arguably the earliest species for which there is positive evidence of
13875-480: The term scientist was first coined by the naturalist-theologian William Whewell in 1834 and the wider acceptance of the term along with the growth of specialized societies allowed for researchers to see themselves as a part of a wider imagined community, similar to the concept of nationhood. Membership in the community is generally, but not exclusively, a function of education , employment status , research activity and institutional affiliation . Status within
14000-431: The theory with zoologist and ethnologist Desmond Morris 's theories of sexuality, which she believed to be rooted in sexism. Anthropologists do not take the hypothesis seriously: John Langdon characterized it as an "umbrella hypothesis" (a hypothesis that tries to explain many separate traits of humans as a result of a single adaptive pressure) that was not consistent with the fossil record, and said that its claim that it
14125-422: The topic have received celebrity endorsement, for example from David Attenborough . Despite being debunked, it returns periodically, being promoted as recently as 2019. Academics who have commented on the aquatic ape hypothesis include categorical opponents (generally members of the community of academic anthropology ) who reject almost all of the claims related to the hypothesis. Other academics have argued that
14250-668: The transition to behavioral modernity with the development of symbolic culture, language, and specialized lithic technology happened around 50,000 years ago (beginning of the Upper Paleolithic ), although others point to evidence of a gradual change over a longer time span during the Middle Paleolithic. Homo sapiens is the only extant species of its genus, Homo . While some (extinct) Homo species might have been ancestors of Homo sapiens , many, perhaps most, were likely "cousins", having speciated away from
14375-402: The use of stone tools. The brains of these early hominins were about the same size as that of a chimpanzee, although it has been suggested that this was the time in which the human SRGAP2 gene doubled, producing a more rapid wiring of the frontal cortex. During the next million years a process of rapid encephalization occurred, and with the arrival of Homo erectus and Homo ergaster in
14500-626: The warmer parts of the world, in the tropical seas where Man could stand being in the water for relatively long periods, that is, several hours at a stretch. Hardy argued a number of features of modern humans are characteristic of aquatic adaptations. He pointed to humans' lack of body hair as being analogous to the same lack seen in whales and hippopotamuses , and noted the layer of subcutaneous fat humans have that Hardy believed other apes lacked, although it has been shown that captive apes with ample access to food have levels of subcutaneous fat similar to humans. Additional features cited by Hardy include
14625-415: The work provided "no significant new information that would be of interest to biologists" and that its style was "speculative, theoretical and in many places so imprecise as to be misleading." British palaeontologist Henry Gee , who remarked on how a seafood diet can aid in the development of the human brain, nevertheless criticized AAH because inferring aquatic behavior from body fat and hairlessness patterns
14750-403: Was simpler and therefore more likely to be true than traditional explanations of human evolution was not true. According to anthropologist John Hawkes, the AAH is not consistent with the fossil record. Traits that the hypothesis tries to explain evolved at vastly different times, and distributions of soft tissue the hypothesis alleges are unique to humans are common among other primates. In 1942
14875-535: Was Neanderthal, implying the individual had a Neanderthal ancestor 4–6 generations previously, in addition to a contribution from earlier interbreeding in the Middle East. Though this interbred Romanian population seems not to have been ancestral to modern humans, the finding indicates that interbreeding happened repeatedly. All modern non-African humans have about 1% to 4% (or 1.5% to 2.6% by more recent data) of their DNA derived from Neanderthals. This finding
15000-479: Was also argued that the species provides support for the notion that very early hominins, akin to bonobos ( Pan paniscus ) the less aggressive species of the genus Pan , may have evolved via the process of self-domestication . Consequently, arguing against the so-called "chimpanzee referential model" the authors suggest it is no longer tenable to use chimpanzee ( Pan troglodytes ) social and mating behaviors in models of early hominin social evolution. When commenting on
15125-549: Was controversial from its first proposal in the 1990s and by the 2010s had very little support. Distinctive human genetic variability has arisen as the result of the founder effect , by archaic admixture and by recent evolutionary pressures . Since Homo sapiens separated from its last common ancestor shared with chimpanzees , human evolution is characterized by a number of morphological , developmental , physiological , behavioral , and environmental changes. Environmental (cultural) evolution discovered much later during
15250-411: Was estimated to be one meter in height, with a brain volume of just 380 cm (considered small for a chimpanzee and less than a third of the H. sapiens average of 1400 cm ). However, there is an ongoing debate over whether H. floresiensis is indeed a separate species. Some scientists hold that H. floresiensis was a modern H. sapiens with pathological dwarfism. This hypothesis
15375-554: Was initially proposed by the English marine biologist Alister Hardy in 1960, who argued that a branch of apes was forced by competition over terrestrial habitats to hunt for food such as shellfish on the coast and seabed , leading to adaptations that explained distinctive characteristics of modern humans such as functional hairlessness and bipedalism . The popular science writer Elaine Morgan supported this hypothesis in her 1972 book The Descent of Woman . In it, she contrasted
15500-721: Was rooted in the Darwinian consensus. On the advice of his colleagues, Hardy delayed presenting the hypothesis for approximately thirty years. After he had become a respected academic and knighted for contributions to marine biology, Hardy finally voiced his thoughts in a speech to the British Sub-Aqua Club in Brighton on 5 March 1960. Several national newspapers reported sensational presentations of Hardy's ideas, which he countered by explaining them more fully in an article in New Scientist on 17 March 1960: "My thesis
15625-531: Was the key adaptation that separated Homo from tree-sleeping Australopithecines. These are proposed as species intermediate between H. erectus and H. heidelbergensis . H. heidelbergensis ("Heidelberg Man") lived from about 800,000 to about 300,000 years ago. Also proposed as Homo sapiens heidelbergensis or Homo sapiens paleohungaricus . Homo neanderthalensis , alternatively designated as Homo sapiens neanderthalensis , lived in Europe and Asia from 400,000 to about 28,000 years ago. There are
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