The Aquatic Ape Hypothesis

by Elaine Morgan

Why do humans differ from other primates? What do those differences tell us about human evolution? Elaine Morgan gives a revolutionary hypothesis that explains our anatomic anomalies--why we walk on two legs, why we are covered in fat, why we can control our rate of breathing? The answers point to one millions of years ago our ancestors were trapped in a semi-aquatic environment. In presenting her case Elaine Morgan forces scientists to question accepted theories of human evolution.

Genres: Science, Nonfiction, Anthropology, Evolution, Biology, History, Prehistory

208 pages, Paperback

First published November 1, 1982

About the author

Welsh feminist and proponent of the aquatic ape evolution theory, which claims that mankind evolved from sea-based apes.

Morgan was appointed Officer of the Order of the British Empire (OBE) in the 2009 Birthday Honours for services to literature and to education.

Reviews

[Jan-Maat]

A clever and interesting book. Elaine Morgan worked in television professionally, at some point she became interested in a hypothesis called 'the Aquatic Ape Theory' and became involved in promoting it to a wider public. And indeed you get the sense of a gifted amateur throughout the book as she attacks on all fronts with any weapon, the big guns and handfuls of dried peas, there is no sense of discrimination or a hierarchy of evidence; that people like to sit on a beach and look out to sea seems to carry equal weight with evidence of ear exostoses bone growths in the ear common among habitual swimmers.

Morgan had a big idea, or a big conception that many of the weird features of the human being, relative hairlessness, walking upright on two legs, speech, sweating and tears, human reproductive habits, the ability to speak, brain size, and our blubber could all be explained by a prolonged period of several million years in which our distant ancestors became separate from the ancestors of the other great apes because our ancestors adapted to living in watery environments, like the seashore (ocean shore in this case). The hypothesis was not regarded, I believe, very seriously among students of human evolution. The problem I feel is that it is too all embracing and maybe too exciting. In the end all we have to know about our distant ancestors are such skeletal remains that have been found, to that one can add with some caution what we understand about the environment in which those ancestors lived, I say with caution because of the challenges in dating. You can also compare and contrast modern humans and modern apes. The basic point that Morgan makes is that we look and are in not so obvious ways fairly different to the other great apes, the problem is we don't and possibly may never know when those differences occurred.

All of which reminds me of Tyrannosaurus Rex. People get very excited about Tyrannosaurus Rex, experts can get very heated on the subject of whether it was a slow moving scavenger or a fast moving, agile hunter, but I heard once that there are only seven complete fossil Tyrannosaurs, which isn't much of a sample. But the idea of them is charismatic, so people study them. Likewise how we came to be the way we currently are and how we diverged from our evolutionary close relatives is interesting, Morgan caters to that interest, she has a big picture story, everything significant, or at least lots of significant things happened, she said during a few million years as adaptations that allowed our ancestors to thrive in flooded or marshy environments, beachcombing and feasting on seafood. If that is so is easier to claim than to prove as neither soft tissues nor behaviours get preserved in fossils, the evidence which did impress me was a map showing that five find spots in the Turkana basin (Kenya/Ethiopia) four million years ago would all have been within the area of a lake, if those individuals died in those spots when the lake was there, or were deposited there postmortum or if they died at a time when the lake wasn't there is the question I suppose, still an entertaining and provocative read.

[Christina · Rating 3 out of 5]

This is a tough book to review. I first heard about the aquatic ape hypothesis from Sharon Moalem's Survival of the Sickest, and for years I intended to read more about it but never got around to it. A few months ago I read an NPR article in which the writer made a brief dismissive comment about the theory, which I recalled feeling positive about from its portrayal in Moalem's book. That dismissive comment finally motivated me to request the book through my university's interlibrary loan.

I read it in nearly one sitting... It was a Friday evening and I was exhausted from work, but I cracked open the book and then was COMPLETELY absorbed. I had woken up at 6am and was ready to sleep by 10pm, but it wasn't until 1am when I realized I had to put the damn book down before I passed out.

This book caused an intellectual crisis in me. And I mean CRISIS. Whenever I took a break I would find my husband and just unload all my thoughts and emotions on him ("It all makes so much sense! This changes everything! But if it makes sense, why is it dismissed by modern physical anthropologists? What am I missing? Is there something completely obvious that I'm missing?"). As a result of reading this book I even developed my own theory about the evolution of the human brain in light of the aquatic ape hypothesis... a theory which I've completely forgotten everything about now (all I remember is that I excitingly rattled it off to my husband and thought maybe it was publishable in Science... it's hilarious that I can't even remember it now).

On its own, everything presented in this book is incredibly persuasive. Elaine Morgan was a strong writer. She was simple and straightforward. The writing did not convey a sense of exaggeration or a desperate desire to convince the reader of her viewpoint. Instead, evidence was presented matter-of-factly. And wow was that evidence compelling! The complete dismissal of every theory of the evolution of bipedalism affected me the most. What I see as the biggest weakness of those theories (which Morgan pointed out) is that they can't explain the "in between" stage. A little bit of bipedalism wouldn't have increased fitness enough for the reasons those other theories outlined; only complete bipedalism would perhaps make a real difference for fitness. But wading through occasionally flooded terrain? A little bit of bipedalism would result in a meaningful increase in fitness in that environment, which would be enough to result in gradual change until full bipedalism was achieved (which could then be useful for all the other reasons that have been proposed to explain the benefit of bipedalism).

Morgan's proposals started to get a little "out there" toward the end of the book. I could totally buy that human ancestors lived in an "occasionally flooded" environment where wading would have been important. But in the last few chapters she started to write about diving and breathing under water, which is a whole different ballpark than wading as a result of occasional flooding.

In complete crisis mode, the next day--I finished the book shortly after waking up--I searched the internet for criticisms of the aquatic ape hypothesis to find what I was missing. All the evidence she presented was just SO COMPELLING, yet the hypothesis is completely rejected by the field, so what was I missing?!?! Well, my internet search revealed that the thing I was missing was the quality of the "evidence." It appears the evidence presented in this book is selective, incomplete, and occasionally even misrepresented. If you only know what she presents, then of course it makes sense. But she wasn't presenting everything, according to the criticisms that I read.

After reading that, I was completely discouraged and depressed, and I basically just gave up. I will trust the anthropological community: If they say the evidence doesn't support this theory, then that must be true. (But at the same time, as a researcher I know how often the people in my own field--myself included--get it wrong. This includes sticking with a false idea for years. It's hard to abandon my own ideas even when data I've collected suggest they're wrong. It's called "belief perseverance." Psychologists may have the same biases as other scientists, but at least we know about the biases.) I could have delved further into the debate, but I didn't... To be honest, I was emotionally exhausted. This book had caused such a crisis in me. It took me from one end of the emotional pendulum ("This all makes so much sense! I look at everything differently now!! How could we be missing this?! This is incredible!!") to the other ("This was all a lie? Or was it not?! I don't know what to believe! I've been betrayed!"), and I am not joking when I say the crisis was a disruption in my daily activities. Eventually, I just had to give up, put it aside, and move on with my life. Yes, I am a strange person, for this to have caused such drama in my life. Those were a crazy two and half days.

P.S. This book was 5-stars in terms of reading enjoyment. It was completely and utterly engaging, as well as easy to read. But because it seems Morgan misrepresented (so other people say... I don't know who to believe! Argh! Wait, no, I fear the crisis is going to begin again! I need to end this review), I am lowering my rating to 3 stars.

P.P.S. This book rekindled my desire to be a physical anthropologist, specifically, a paleoanthropologist. In another life, maybe I could have pursued that... But I am so done with schooling. I'll stick with my current career. Besides, I have way too much back pain to be bent over fossil sites, and I bet grad students have to do all the digging.

[Matal “The Mischling Princess” Baker · Rating 3 out of 5]

I **vaguely** remember reading “The Aquatic Ape Hypothesis” by Elaine Morgan as a graduate student. Morgan argued that the ancestors of human primates evolved in water, but the vast majority of anthropologists today (and even back when this book was published) proscribe to the Savannah Hyopthesis that our ancestors instead evolved on the savannahs .

[Mari Biella · Rating 4 out of 5]

For a long time, the version of evolutionary theory I was exposed to was, (very) roughly, as follows: at some point, an ape came down from the trees and ventured out onto open grassland, where it learned to walk bipedally and gradually lost its fur and learned to speak. All well and good, but this left certain nagging questions: wouldn't such an ape need to keep its fur on the sun-scorched African savannah? Wouldn't the loss of speed caused by bipedalism far outweigh its possible advantages? Why, if our ancestors lived in a hot, dry climate, are we so thirsty and so sweaty? Isn't sweating about the most wasteful and inefficient means of thermoregulation possible, for a land animal?

Elaine Morgan's aquatic ape hypothesis offers at least some potential answers to these questions. If our ancestors had, at some point in their development, spent at least some time as semi-aquatic creatures, a lot of these developments would begin to make a certain amount of sense. Our thirstiness, combined with the profligacy with which we get through fluids, would be more logical if our ancestors had lived in an area where water was abundant. Our bipedalism would be very useful if we had to occasionally stand upright to wade through water. The loss of fur would make sense in an aquatic environment, as would our levels of body fat, which are much higher than in any other primate.

Morgan presents her theory as a series of questions rather than answers, and there are of course many possible (and contradictory) future developments in evolutionary theory (just as there are scientists who steadfastly reject the aquatic ape hypothesis). But it presents a plausible alternative explanation for those of us who always found ourselves wondering how on earth our ancestors could in any way be suited to life on the open savannah. The book is also written in clear, jargon-free language, so you don't have to be a palaeontologist or evolutionary biologist to appreciate it.

As to whether it's true or not ... well, not having any specific scientific knowledge, I wouldn't like to make a guess. It sounds plausible, from my non-scientific point of view, but I'm happy to defer to the experts in this case...

[Nicholas Griffith · Rating 3 out of 5]

An exploration of the raison d'etre for hairlessness among apes (that is, among human beings), this book delivers a swift kick to the collective nuts of evolutionary anthropologists. Sadly, after years of fighting scientific pedagogy her arguments come off as defensive in the extreme. We shouldn't hold this against her though. She is a rebellious thinker possessing the acerbic wit that leaves a scar. We likewise shouldn't be surprised if her theories are whole heartedly, even if posthumously, assimilated into the rigmarole of "facts" in another fifty years. Say what you want about Morgan, she has bigger ovaries than most men's balls. All of us argument prone penis-toting hominids owe her a salute.

[Joel Nichols · Rating 5 out of 5]

Morgan is my new hero and should be yours. Radical, simple, insightful and brilliant. One day they will find this proof and we will know her name like we know the Leakeys or Darwin.

[Glen · Rating 3 out of 5]

A popular science book explaining the Aquatic Ape theory of the evolution of the human species.

Fascinating, but on the other hand, every time the book took up a question, such why humans lack body hair, or walk upright, I couldn't help but picture the guy with weird hair saying "Aliens!"

[aloveiz · Rating 4 out of 5]

AAT is right up there with holographic mind theory when it comes to speculative conjectures that are detested by the scientific community and adored by me. There is a lot to write about this topic and Elaine Morgan’s postulates. Let’s try just a quick summary.

In consideration of the driving forces that transformed simian to sapiens it is generally supposed that apes were driven out of their arboreal habitat to a savannah environment and the new conditions of savannah life drove the evolution of man. In 1960, marine biologist Alister Hardy, published a thesis containing tenets that stood to challenge that supposition with an elementally different model. In Hardy’s conjecture he presented the potential that human-precursor apes lived for a time in a semi-aquatic habitat and it was this environment that prompted the bulk of human evolution. His concept, now known as “The Aquatic Ape Theory”, (alternately, and more rightly by popperian standards, “aquatic ape hypothesis”) has persisted over the last 50 years through the efforts of several figures in the scientific community who have expanded upon it and fought to champion its relevance and rationale. Let’s agree that hypotheses like the aquatic ape theory should not attempt to prove one thing or another based solely on their plausibility or perceived logic. To do so would go against the concept of critical rationalism that forms the basis of modern scientific method. However, controversial concepts like the AAT are of great use to the scientific community because they have the power to alter and broaden the bias held by researchers and theorists working in the field of anthropology.

In support of the AAT, a myriad of postulates have been devised to explain the anomalies of the human form. The most significant of those correspond to what the average person would likely consider the greatest disparities between chimp and human. A scant introduction to AAT would probably include reasoning relating to spoken language, bipedalism and hairlessness.

☻Humans are unique among primates in their ability to consciously control their breathing rate (a trait shared with aquatic mammals) and their descended larynx, which is responsible for the increased range of sounds humans are capable of creating. Together these characteristics are instrumental to the system of human vocalization and are theorized to have been adapted to serve a diving simian that needed to be able to gulp large quantities of air when rising to the surface.

☻Man’s upright posture distinguishes him among most mammals and its weaknesses are explored by anyone who suffers chronic lower back or knee stress. It is possible that advantages gained through the ability to comfortably reach and gather things high above his quadrapedal height encouraged this drastic change in morphology. A proponent of AAT would note the observation that primates who reside in areas prone to flooding (including the proboscis monkey and the bonobo ) walk on two legs when wading through water, an adaptation that serves the important purpose of allowing then to keep their chattel, babes and breathing apparatuses well out of water while traversing waters over three feet high.

☻In regards to hairlessness we observe that a degree of hirsuteness persists in h. sapiens yet any ape is far hairier. Aquatic theory asks us to consider that all other known hairless mammals, (including elephants, whales, and hippopotamuses) with the exception of naked mole rats who live entirely underground, have been found to have had an aquatic developmental phase, during which the hair that covered their ancestors would have likely been cumbersome and hindering. These ideas form a very incomplete summary of the lexicon of ideas that have been imagined to support AAT but I would hope that their novelty might start to encourage the curiosity of the lettered community.

Morgan has been compiling work about AAT for decades. Critical reception has led her to more conservative guesses and a more laymen vernacular. If conservatism and brevity are of little consequence I recommend looking to her 1972 work, “The Descent of Woman.” This book is a sophomoric version of it.

[Linda R. Thompson · Rating 5 out of 5]

A brilliant hypothesis of human evolution

I read Elaine Morgan's book 'The Descent of Woman' in the late 1970s, shortly after it's publication in 1976. I was drawn to her very different theory of human origins at the time and have thought about it from time to time since then. Recently I have again been drawn to the issues of our human origins and have returned to her writings for additional understanding of the more recent discoveries and hypotheses. This book contains even more information about the probability that we developed into very different primates through an aquatic phase and adaptation to spending a lot of time in the water. We were also isolated for a critical period of time from our primate cousins who continued their development in a mosaic environment of forest and grassland and who lack the adaptations to an aquatic ecosystem. Very thought provoking and highly recommended.

[Bev · Rating 5 out of 5]

I read this back in 2009 and was struck by the beautiful logic of it. While I was not 100% convinced, being well educated in The Savannah Theory of human evolution like most of my generation, I found it compelling enough to follow the developments which have been made in the years since Morgan's death.
Today I listened to Sir David Attenborough talking about the influence of a marine/fresh water habitat in the descent of our species and how it has now become accepted as a fact, although there is argument about when, and I was again reminded of this wonderful work of scholarship.
This is a marvellous read, not easy at times, but it pays dividends for the effort.

[Ginna · Rating 4 out of 5]

If you've ever wondered why humans have little hair, subcutaneous fat layer, and generally have sex facing front, this book is for you...

[Erik · Rating 5 out of 5]

Original review: As beautiful a theory of evolution as I've ever read. Makes for great dreams.

Addendum 2025: Just finished my fourth re-read of this classic.

I realize that some feel this theory has been debunked; a particularly odious supposed debunking example is a very disingenuous article appearing in Scientific American. The article briefly glosses over the evidence and the authors indulge in the very worst of scientific paternalism. It's a stretch to believe the authors even read the material before pronouncing it drivel, even patting Sir David Attenborough condescendingly on the head and telling the esteemed naturalist that he's being daft.

And I've heard complaint that Morgan is not a scientist. By the standards cited then neither was Leonardo da Vinci. A scientist is someone who keenly observes and follows the evidence, weighing it and comparing it to a control grouping. Morgan is indeed a scientist, in the best of all respects, and any lack of a college degree does not tarnish that credential. People can bootstrap themselves into the knowledgesphere, most innovators and great scientists have done precisely that, often with an onslaught of ridicule hurled at them by the established priesthood of science boffins who claim anyone disrupting the status quo as peddling pseudoscience.

Also, there is this complaint: "Where is the fossil record?" We're dealing with humanoids 6-9 million years ago. There's barely a speck of any fossil record from that period. There's a lot of groping around in the dark for everyone searching. For one side to throw stones at another's ideas about this time period is pure hubris. That said, the 'fossil record' is so succinctly expressed in the title of Morgan's follow-up book, "The Scars of Evolution," pointing out that the trail blazes bright with alignment in all of our divergent physical features. It is a fossil record in our current physical features, and when looked at with an open mind and keen observation reveals the elusive obvious that's right there, ready to be recognized if science would pull its microscope out of its own ass:

Physical Adaptations that we do not share with any other ape:

• Streamlined body shape compared to other apes
• Reduced body hair with remaining hair following water flow patterns
• Subcutaneous fat layer (like marine mammals, unlike terrestrial primates)
• Descended larynx enabling breath control for diving
• Webbing between fingers and toes (vestigial)
• Tears with high salt content for clearing saltwater from eyes
• Prominent nose for preventing water entry during diving
• Kidney structure adapted for processing higher salt intake
• Ability to hold breath much longer than other primates
• Swimming ability present from infancy

Behavioral/Physiological Features:

• Preference for face-to-face mating (like aquatic mammals)
• Bipedalism as adaptation for wading in shallow water
• Loss of estrus swelling (would create drag underwater)
• Large brain development (supported by omega-3 rich marine diet)
• Sweating mechanism different from other primates

Even if you argue with some of these points this theory should not be dismissed. The Savannah and Neoteny hypotheses are still part of the grand equation, but they needn't fight, it would be so much more productive to please consider a synthesis so that understanding becomes a win-win instead of this current pissing match.

I encourage you to read this wonderfully written book by a very spunky mind. Her second to last book, "The Descent of the Child" is particularly enlightening, especially if the reader is a parent. She also gives a TED talk where her Spirit is on full display and I totally recommend viewing that, too. If nothing else, as stated in my original review, it makes for very satisfying alignment in the psyche, as if some mysterious piece of memory has been restored, and makes for very enjoyable dreams.

[Steven H · Rating 5 out of 5]

HER DEFINITIVE STATEMENT OF THE ‘AQUATIC APE THEORY’

Elaine Morgan (1920-2013) was a Welsh writer for television, as well as the author of numerous books such as 'The Scars of Evolution,' 'The Descent of Woman,’ ‘The Descent of the Child,’ etc.

She wrote in the Preface to this 1997 book, “This book, like the others I have written, is addressed primarily to the general reader… This time, however, I have included numbered references. After disputing for 25 years with professional scientists, I have learnt to respect the high standards they set themselves, and expect from others, in identifying their sources. The references are unorthodox in one respect: a small percentage does not relate to the written word. The study of natural history owes a considerable and growing debt to the camera crews who travel the world recording the behavior of rare species in inaccessible places. It is time that this material was accorded, as source material, equal status with the observations of a scientist with a notebook.

“The idea on which this book is based does not qualify in the strict Popperian sense adopted by scientific philosophers---it is more accurately a ‘hypothesis.’ But the acronym AAT (Aquatic Ape Theory) has been in use now for so long that it would be confusing to change it now.”

She begins Chapter 1, “It is generally agreed that around eight or nine million years ago there lived in the forests of Africa… the ‘last common ancestor’ (l.c.a.). The descendants of the l.c.a. split into different lineages … Of these, humans differ more markedly from the African apes than the apes differ from one another… It would seem reasonable to conclude that something must have happened to our ancestors which did not happen to the ancestors of the other apes. The question at issue is simply: WHAT HAPPENED? Twenty years ago, that was regarded by anthropologists as a pertinent question, and most of them were convinced that they knew the answer to it. Today that confidence has so far evaporated that some of them query whether an answer to it is possible or even desirable.” (Pg. 13)

She explains, “The explanation current in the 1960s was … the divergence between apes and humans was said to be due to… the rapid expansion of a grassland ecosystem---the African savannah… humans were descended from populations which were driven out of the shrinking forests and forced to make a living on the savannah… It has been repeatedly asserted (for example, on the Internet) that there was never such a thing as the ‘savannah theory,’ that it was a straw man constructed by Elaine Morgan … and that no reputable scientist can be shown ever to have used the phrase ‘savannah theory.’ The last part of the statement is perfectly true…” (Pg. 14)

She adds, “[With] Donald Johanson’s discovery of … ‘Lucy’ at Hadar in 1974, the savannah hypothesis began to fall apart. Until then bipedalism had been generally believed to have followed after the move to the savannah… But Lucy did not fit easily into that picture… [She was] at least partially bipedal. She did not die in a savannah habitat, but in a wooded and well watered area of Ethiopia.” (Pg. 16)

She continues, “by imperceptible stages references to the habitat of our earliest ancestors began to be modified. They changed from ‘savannah’ to ‘savannah mosaic’… to denote a patchwork environment where tropical forests and woodlands were interspersed with tracts of open country… Now we have… a greatly watered down version of the savannah theory… To date, the only genuinely alternative hypothesis is the aquatic one. This is the idea that … the ancestors of the hominids passed through a stage of semi-aquatic existence before returning to a predominantly terrestrial lifestyle… The Aquatic Ape hypothesis suggest that the events which diverted our own ancestors along an unusual evolutionary path had something to do with water.” (Pg. 17-21)

She later continues, “the fossil record is perfectly compatible with the supposition that … one section of the l.c.a. population found itself living in a watery environment and… began to adapt to a semi-aquatic existence…. Their days as big game hunters… would have to wait… until the savannah eco-system became established.” (Pg. 29-30)

She acknowledges, “it has been claimed that if they were or had been passing through an aquatic phase their fossil remains would show unmistakable signs of it, as do the skeletons of seals and dolphins; their legs would have become shorter instead of growing longer and their arms would have begun to turn into flippers. This argument shows a total misconception of the course of events that AAT proposes…” (Pg. 31)

She summarizes, “The idea that bipedalism may have arisen as a consequence of wading behavior is a hypothesis, just like all the others. None of them is proved… in favor of the aquatic hypothesis… it provides a scenario which at the same time offers a possible solution to a wide variety of other unsolved problems. The next of these is: Why naked?” (Pg. 70)

She states, “There was no way of making the fat layer sound like a neat answer to the hominid’s putative difficulties with thermoregulation… the AAT approach is to enquire: ‘Where else is fatness at a premium?’ The answer is clear. There are two classes of mammals which are liable to accumulate large quantities of adipose tissue---hibernating mammals and aquatic mammals.” (Pg. 90)

She says, “‘We are the only species that copulates face-to-face,’ wrote Jacob Bronkowski in 1974. Later he admitted having forgotten the aquatic mammals… In my first book (‘The Descent of Woman’) I posed the usual AAT question: ‘Where else is this behavior at a premium?’ and came up with an increasingly familiar answer: ‘In the water.’ Whales and dolphins and beavers and many other aquatics use then ventro-ventral approach as humans do… I argued that both bipedalism and swimming realigned the spine and hind limbs into a straight line, instead of the right-angled arrangement common and convenient in quadrupeds.” (Pg. 150)

She notes, “It is a new area of research and there is a long way to go. But since there is strong evidence that the hominids’ habitat was mainly, if not exclusively, by the waterside… it is slightly surprising that in all the speculations of what they live on, aquatic resources are so rarely mentioned.” (Pg. 169)

She concludes, “The questions posed by the Aquatic Ape Theory are important and valid. The answers it offers are speculative, but no more so than those of any other available model. It is now generally agreed that the last common ancestor of apes and men lived in Africa in a landscape which was… a mixture of trees and grassland. One subgroup of these animals---for some reason---began to change. First, they stood up on their hind legs and began to walk bipedally… the hair on their bodies changed direction… and they became functionally naked…

“The mosaic theory implies that these changes were … because the hominid’s ancestors [lived in]… the open spaces between the forested areas. Open spaces have never caused any of these changes in any other mammal. That explanation is not good enough… In July 1996 the … magazine ‘Discover’ predicted: ‘For all the effort it has taken to bring down the savannah hypothesis, it will take much more to build up something else in its place.’ This book is offered as a contribution to the building process.” (Pg. 176-177)

This book will be of keen interest to those studying the Aquatic Ape hypothesis.

[Bob · Rating 5 out of 5]

If this is the first of Morgan's books that you read, you may find the defensive tone a bit off-putting. It's something that she's been forced to by the rabid attacks on her ideas mounted by people who claim to be serious scientists.
Morgan's previous books were much more readable, though less 'scientific', which she got slated for.
Essentially, she has expanded on the hypothesis that humans went through a semi-aquatic phase, which very neatly explains a host of features: hairlessness, upright stance, proportion of fat and the fact that it adheres to the skin, which make us different to other primates, but similar to other water-adapted mammals.
You may not be convinced that it is right, but you will at least have a lot of fun trying to think of ways that it might be wrong. More likely, you will then turn to other accounts and wonder why they bother, since their explanations are so much less convincing.

[ActionScientist · Rating 5 out of 5]

What hypothesis? The conventional wisdom handed by the Fathers of science that we first started walking on the savannah is missing something fundamental, imo, and this book helps fill in the gap. Written by a WOMAN scientist, it brings a different perspective to thinking about our genetic roots. To me it's so basically obvious that we've been at home in lakes, rivers and coasts for probably millions of years.

I'm an aqautic ape, and feel proud to say that. My Mom swam for the national team in butterfly when she was a kid and I've competed in long distance coast swim triathlons up to 4km in length and survived a solo 10-mile coastal swim ... so like what hypothesis? In the event of nuclear catastrophy, this monkey heads straight down to the coast, armed with wetsuit and snorkeling kit. Who knows, there may be a living to be found in selling fish, no matter what happens on-shore.

[Samantha Cira · Rating 4 out of 5]

Even though Elaine's facts/data may be widely criticized by the scientific community, I enjoyed it and it brings up some interesting ideas about the evolution of man.

This book is an UPDATE to her 1960's book the Aquatic Ape Theory which is now sorely out-of-date, so if you're going to read it, read the 1990's version called Aquatic Ape Hypothesis.

In a nutshell, it's a book written for the non-academic masses, so don't expect it to be written in a scholarly manner. It's short, you could get through this in a couple of days.

[Ariana · Rating 3 out of 5]

While I thoroughly enjoyed reading "The Descent of Woman" by Morgan, "The Aquatic Ape Hypothesis" was more of an overview of the progress of the hypothesis since the seminal book written so many years ago. It was concise, but not meant to be entertaining. It was certainly interesting, suffice it to say, but it was also a bit too rambling, as if the author was trying to make an academic treatise more readable for the general public. Nonetheless, I certainly found it fascinating and worth the read.

[Helena Eflerova · Rating 3 out of 5]

A good book to read for someone who is interested in a revolutionary ideas around aquatic stage and minority of anthropologists thoughts on human evolution subjects of bipedalism, nakedness, body fat in aquatic mammals, menstruation lunar cycle, babies are born as swimmers. Sport and professional Apnea divers would benefit from reading about diving reflex, breath hold, heartbeat, buoyancy and body heat, inventions around water lifestyle at the end of this book. You have to be comfortable reading scientific facts.

[Kirstin · Rating 4 out of 5]

Perhaps not as scientifically written as, well, a scientist, Elaine Morgan manages to concisely argue alternatives to other evolutionary theories that still intrigue me years later. This is the foundation hypothesis, but her other books on the subject are equally worthwhile.

[rose kala · Rating 4 out of 5]

A very popular suggestion as to explain the key differences from fellow apes like Gorilla and Chimpanzees by asserting that homosapien had become an aquatic dweller..
She writes it in such simple and easy terms that its enjoyable to read, wether you want to belief or not

[E.j. Kay · Rating 5 out of 5]

An absolutely life-changing read for me! Whilst I'm not completely convinced that we had a totally aquatic past at any stage, the questions this hypothesis raises and the intelligence and bravery of Elaine Morgan's work make this a seminal read. Wonderful!

[Zrinka · Rating 3 out of 5]

Of all her books that I've read, this one has the best and most updated arguments. You should read it even if you think AAH is bollocks, there's some funny stuff too. She always makes me chuckle :)

[Whiskeyb · Rating 4 out of 5]

I don't care if it is true or not, its a great story.

[Samyy · Rating 5 out of 5]

As with all of Morgan’s work, I am impressed.

This book builds on and corrects on many of the theories outlined in the 1982 Aquatic Ape. This one is much better.

Although Morgan has no formal science education, she should not be written off. In her writing it is evidence that she has done her research: she is reasonable, intelligent, and has a curiosity that shines.

Too many lingering questions not answered by the savannah theory are answered neatly by the AAT. Maybe not all, maybe not thoroughly, but the answers are sufficient to merit further investigation. At this point I think too many people have not given serious enough consideration to this alternative hypothesis. Even Daniel Dennett and David Attenborough have opened the floor to the idea of AAT.

I learned many new things about Homo sapient in this book - some of them eye-opening (the carbon dioxide override).

At the end of the day is AAT the ultimate answer to these lingering questions? Maybe not, and I don’t think Morgan thinks that is the case either. It’s just another possible building block for the foundation that is our evolutionary history.

Overall, Morgan is brilliant and eloquent - some could say even conservative in her ideas. She keeps an open-minded approach, and I could read her all day.

[Simon Dobson · Rating 1 out of 5]

Discussions of human origins invariably rest on rather shaky foundations. The fossil record – such as it is – has huge gaps, isn't a random sample of the fauna, and only preserves the gross features of anatomy evident in bones. So it's hardly surprising that a range of theories have been proposed to explain the division between apes and humans.

The aquatic ape hypothesis is one such. It has some supporting evidence – or, rather, it isn't definitively contradicted by the evidence that there is. In this it falls into the common evidential trap of turning a lack of evidence against into prima facie evidence for: the classic pseudoscience bait-and-switch.

It's possible to pose the theory at several strengths. The strongest, that hominids went through an aquatic phase long enough to give rise to evolutionary adaptations that haven't been wholly lost, seems unsupported; the weakest, that hominids spent time near water and waded in order to access rich food supplies, seems unobjectionable.I'm unconvinced there's much else to it, or indeed that there ever could be given the limitations of the evidence available.

[esztereszterdora · Rating 4 out of 5]

disclaimer: I am not a biologist and I don't want to act like I am an expert

but I found the reasoning in this book quite persuasive. I also found the historical and theoretical battle behind the whole aquatic ape hypothesis fascinating (and quite typical in fields of natural scienses). For me, (a psychologist, who had a short adventure in evolutionary psychology and seen some highs and lows) it was ridiculous to see the resistance to even think about and consider the validity of AAT.

As an interesting fact from the Hungarian edition: the introduction was written by Hungary's main and most respected etologist and evolutionist, Vilmos Csányi.

A well worth read if you're interested in evolution, human phylogeny and some sweet scientific drama.

[Quentin Feduchin · Rating 5 out of 5]

I have read several authors on the subject of pre-history and human development.
I very much like Elaine Morgan books. She writes in a conversational way that is easy to read and understand, and I think her theories are very believable, indeed one might regard some of them as common sense.
You can easily find truly complicated texts by various authors, which in themselves demonstrate fine research.
You will not find an author who is so readable, however, and more 'quotable' during your philosophical discussions..

[Iain Crawford · Rating 4 out of 5]

We're hairless. Except on our heads - so that our babies can cling on when we're in deep water. Babies which are sometimes born with webbed digits. Apparently women's hair follicles grow stronger during pregnancy. And of course, women don't go bald.
Just one piece of evidence to support the hypothesis that humans evolved on an island with insufficient food supply, so went into the surrounding waters in search of food.
Possibly also explains the enduring popularity of sea-monster stories,🦈 especially Jaws.

[Francesca Roffe · Rating 4 out of 5]

The aquatic ape hypothesis is the idea that our ancestors went through an aquatic mammal evolutionary stage.

Morgan’s study considers characteristics of the human development and form that lend themselves to the water; the placement and size of body fat in Homo sapiens compared to that of primates, the lay of our body hair following the flow of water, the breasts of women being for buoyancy and rather than to attract a mate/ the pleasure of men.

Hooray for buoyant breasts!

[Manuel Gómez-Ortigoza · Rating 5 out of 5]

Fascinating down to earth explanation of our origins

Elaine Morgan gives a thorough explanation of many of our physical characteristics as it relates to evolution.
Her ideas make a lot of sense and are worth understanding and discussing. She provides evidence and common sense