The Scars of Evolution – transcript
Two part BBC Radio 4 programme, originally broadcasted Tuesdays 12 and 19 April
2005, 11.00-11.30am. Presented by David Attenborough, produced by Richard Collins
and Monty Funk Productions for BBC Radio 4. Audio podcast available on:
http://www.bbc.co.uk/radio4/science/scarsofevolution.shtml
Transcript history:
April 22-24 2005: 1st version compiled by Christine Bjørnstad and uploaded to
http://tech.groups.yahoo.com/group/AAT/.
June 8-9 2012: 2nd version edited by C.H. Engelbrecht.
Part 1
BBC announcer: Now on BBC Radio 4 the first of a two part series “Scars of
Evolution”. David Attenborough explores the rise of a dramatic theory of human
evolution, which for forty years has been challenging the status quo, and which in the
words of one of its critics “Just refuses to lie down and die”.
Elaine Morgan (EM): I did a presentation in Oxford years ago, and Richard Dawkins
turned up with his friend Douglas Adams. Douglas Adams was a mad farm.
Michael Crawford (MC): I consistently denied it over the years. I mean, if anything is
really true, it’s going to go through fire and hot water to get there.
Dan Dennett (DD): It would be lovely to confirm the Aquatic Ape Hypothesis, because
it’s such an interesting and fascinating idea.
Marc Verhaegen (MV): I think we have most of the evidence, everything is there. There
is only what we need is a switch in the minds of the people. There is no real alternative
anymore to the waterside theory.
Lynn Cox: A lot of what you’re doing when you’re sprinting in cold water is you’re
watching what is going on with your body. So a lot of the time, I’m watching my hands
trying to figure out if I’m holding my fingers together, because if they are splaying apart,
that means that I’m not pulling water. But it also means that my brain is cooling down,
and if that happens, that means that I’m in a midst of hypothermia, which is really
dangerous.
David Attenborough (DA): Lynn Cox, a legend in the world of long distance
swimming, recalling her historic swim from Alaska to Russia in 1987, across the Bering
Straits. The water was barely 6 degrees above freezing. Lynn completed the extraordinary
swim in 2 hours and 6 minutes. What is perhaps more extraordinary, is that she did it
without a wet suit, and without the lanolin grease that channel swimmers typically cover
themselves in to keep out the cold. But Lynn, although exceptionally gifted at endurance
swimming, is not unique. Long distance swimming is a sport in which women are
unusually well represented. Over the last hundred years women such as Florence
Chadwick, Penny Dean and Alison Streeter amongst others, have regularly held the world
records outright, both for men and women. It’s been suggested that it may be because
women have a slightly thicker layer of body fat than men, making them more buoyant in
the water, as well as better insulated against the cold. Humans are truly remarkable
animals, able to achieve an incredible range of feats from swimming to Antarctica to
climbing Everest. But there are also things that we can’t do. It may sound obvious, but
we can’t fly, for example, like birds and bats. And we can’t hibernate, like bears and
hedgehogs and many other mammals. And though we can run fantastically long
distances, our top speed is somewhat less than a rabbit. Most four footed animals will
leave us for dust. But we can swim, and dive under water to considerable depths, holding
our breath for upwards through 6, 7, 8 minutes. For a largely land-based animal, this
might seem a curious set of skills. Why and how did we acquire them? In these 2
programmes, we’ll be looking at a theory of human evolution that has confounded
scientists and provoked continuing controversy for more than 40 years. It’s been called
“The Aquatic Ape Hypothesis”.
Phillip Tobias (PT): Regrettably, the name is its own worst enemy, I believe. That’s
what makes people laugh. Let’s just talk about water and human evolution.
DA: Professor Phillip Tobias of Witwatersrand University has been a leading light of
South African anthropology and fossil hunting for the last 50 years. In 1924, his professor
and mentor Raymond Dart unearthed a small humanoid skull which became known as the
“Taung Child”. Although it took time to become accepted by the mainstream, that
discovery was to turn the story of human origins on its head. The earliest human ancestor
was no longer from Java or Peking, or even Europe as previously suggested, but
demonstrably from Africa.
PT: Dart’s discovery was of immense importance in switching the spotlight from Asia to
Africa. The discoveries were found not along the coast, particularly, but in the hinterland
of Africa.
DA: Professor Leslie Aiello of University College London, and former editor of the
Journal of Human Evolution, was raised like generations of anthropologists on the
scenario established by Raymond Dart. By the 1960s, it was accepted as orthodoxy that
the earliest human ancestor had descended from the trees and moved out to exploit the
wide rolling grasslands.
Leslie Aiello (LA): What Dart could be said to have done is establish the “Savannah
Hypothesis” for human evolution. So you had a rather simple idea that early humans
lived in open country, apes lived in forested environments. And that’s gone through a
number of changes. What many people forget is that there is a huge spectrum of
environmental type in Africa. It’s not just, you know, totally open savannah like the
Serengeti, and totally closed rainforest. There seem to be a mosaic or mixed environment.
DA: Books by Robert Ardrey and others fleshed out the story of how we became human.
Perhaps the best selling of all was “The Naked Ape” by Desmond Morris, in which he
gave a vivid potted version of the ape into human transformation:
Quoting Desmond Morris: “The ancestors of the naked ape struck out, left the forest,
and threw themselves into competition with the already efficiently adapted ground
dwellers. With strong pressure on them to increase their prey-killing prowess, vital
changes began to take place. They became more upright, faster, better runners, their
hands became freed from locomotion duties, strong efficient weapon holders. Their
brains became more complex, brighter, quicker decision makers. A hunting ape, a killer
ape was in the making.”
DA: The story of the killer ape, of how we stood up and became mighty hunters, spearing
game across the plains of Africa, found a ready and eager audience. Perhaps it was the
endless procession of war in the 20th century, from the first to the second world wars, and
then Korea and Vietnam, that made the idea of a highly aggressive male going out to kill
for the survival of his troop just all too believable. Certainly Raymond Dart, very much
the alpha male anthropologist by the dawn of the 1960s, was keen to complete this
picture of “Man the Ruthless Carnivore”. As he demonstrated in a television
documentary of the period:
Quoting Raymond Dart: “The australopithecines particularly liked the lower jaws of
animals that had long canine teeth, because these could be used as formidable weapons.
And you can see how, with a weapon like this, they could gouge out the eyes of any
animal, and even this primitive hyena jaw could rip up a belly.”
DA: A nice and simple, if rather bloodthirsty story. Although even 40 years later, it’s still
the basic account of early humans most commonly told in schools, it gradually became
apparent, through the 80s and 90s, that the story was a bit over-simplified. We didn’t
head out from the forests and make a completely new life on the open plains. And we
didn’t make a simple switch from grazing on fruit to chasing down big game and eating
their meat. Most significantly, the evidence that something was wrong with the story
came from the very fossil beds in South Africa where Raymond Dart had found the
Taung Child’s skull and set the savannah hare running. Phillip Tobias had been a student
of Dart’s, and he had spent decades helping to fill out the standard account of our early
ancestors as hunters on the plain, as had many other academics working in the developing
field of paleoanthropology. But by 1995, the doubts were overwhelming.
PT: Just 10 years ago, to a large London audience, with a histrionic gesture, I said, “The
Savannah Hypothesis is no more! Open that window and throw it out!” At Sterkfontein
and other South African sites and East African ones, these early hominids were all
accompanied by woodland and forest species of plants and animals. Of course, if
savannah is eliminated as a primary cause for selective advantage of going on two legs,
then we are back to square one.
DA: Or not quite square one. There was an alternative account of how humans had come
to be so different from their ape cousins, and it had been around for more than 30 years. It
offered a single dramatic explanation for a large array of the physical characteristics that
distinguish us from all the other apes. Our bipedal locomotion on two legs; our strange
hairlessness; our layer of fat just beneath the skin; our big brain and unique language
skills; as well as a host of other features, including the curious paradox that our noses are
very large, but our sense of smell is comparatively poor. But in establishment circles the
alternative explanation was regarded as too bizarre and too radically different from the
accepted savannah story to be taken seriously. But why was it regarded as bizarre
pseudoscience, and why did mainstream hostility continue for nearly 40 years? It was
back in the late ‘60s, that a young woman from the Welsh valleys named Elaine Morgan,
an award winning playwright and journalist, came to read Desmond Morris’s “Naked
Ape” soon after it came out in 1967. Her initial reaction to it was one of simple irritation.
She was a young wife and mother, and experiencing the trials of combining a writing
career with raising her family. But the Naked Ape’s description of the place of the female
in the transition from ape to human struck her as all wrong.
EM: I started out of pure sort of irritation, with people like Robert Ardrey and Desmond
Morris. Not because of what they said, because they were only saying the same as all the
scientists were saying, but they were popularizing it. And I wasn’t a scientist, so it was
the popular version I was reading. And I thought that they were being very male centred,
and I thought it didn’t work, and I disliked the way the female, everything about the
female, was accounted for because of her need to suck up to the men, so that they’d give
her a bit of meat, you know? And I thought you wouldn’t have a whole species evolving
along such extraordinary lines for the benefit of the male, unless it was also at least not
disadvantageous to the females. And I thought a lot of those things would have been
disadvantageous for the females. I mean, they imagine these mighty hunters racing across
after game and getting very hot and sweaty. So they shed their fur, so she’s got to shed
hers. But I mean, she’s not doing racing. She’s sitting there, it gets very cold in the
nights, doesn’t it? I mean, the babies had something to cling to, she got all rid of the... I
thought, you know, this was very maladaptive for her, and evolution doesn’t work like
that. There must be another explanation.
DA: So Elaine Morgan read The Naked Ape again. And this time she was struck by three
short paragraphs on page 29. Desmond Morris had briefly described another more
ingenious theory, that before he became a hunting ape, the original ground ape, that had
left the forests, went through a long phase as an “aquatic” ape. When she contacted
Morris to ask more about this ingenious theory, she learned that it had originally been put
forward by an Oxford marine biologist Sir Alister Hardy in an article in the New Scientist
in 1960. The article was simply titled “Was Man More Aquatic in the Past.” Hardy in
turn had been influenced by the anatomical observations of Professor Wood Jones 30
years earlier, regarding the peculiar layer of fat tightly bonded to the skin, that humans
have and other primates lack.
Quoting Alister Hardy (AH): “I read this in 1929 when I had recently returned from an
Antarctic expedition where the layers of blubber of whales, seals and penguins were such
a feature of these examples of aquatic life; such layers of fat are found in other water
animals as well; and at once I thought perhaps Man had been aquatic too.”
DA: Later in the article, Hardy ventured that a shore-based environment might also help
to explain man’s upright posture and bipedal locomotion.
AH: “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. [...] Wading about, at first paddling and toddling
along the shores in the shallows, hunting for shellfish, Man gradually went farther and
farther into deeper water; […] resting with his feet on the bottom and his head out of the
surface: in fact, standing erect with the water supporting his weight. […] It seems to me
likely that Man learnt to stand erect first in the water and then, as his balance improved,
he found he became better equipped for standing up on the shore when he came out, and
indeed also for running. He would naturally have to return to the beach to sleep and to get
water to drink; actually I imagine him to have spent at least half his time on the land. […]
My thesis is, of course, only a speculation - an hypothesis to be discussed and tested
against further lines of evidence.”
DA: Hardy wrote the New Scientist article because of a furore that he had inadvertently
caused a month earlier. For 30 years, Hardy had sat on his aquatic ape idea, because he
knew it would impede his academic career, and he wanted to make it to the top. But by
1960, he had made it to the top. So where was the harm? As Elaine Morgan explains:
EM: He never went public until the time came, when he was a professor and he was a
fellow of the Royal Society, and he was getting old, and so… But even then he thought,
“Well, I’ll try it on and on”. He was invited to go and talk to a subaqua club, and he
thought, “Well, you know, I’ll give them a little citic slant on it. And nobody will ever
hear about it, only these people here in this little room.” But there was a reporter sitting in
that little room, who knewd this odd stuff, took it straight to Fleet Street, and all the
Sunday papers: “Oxford professor says man is a sea ape!” And the balloon went up, and
he got back to Oxford, and Wilfrid le Gros Clark rang him up, “Alister, never do that
again! Because you are exposing the whole profession to ridicule.” And I wrote to him
and asked whether it would be all right if I wrote this book quoting his theory. His first
reaction was, “Well, you know, I’m thinking that I might write it up myself sometime.”
Then I got another letter saying, “I’ve talked to my publisher about it, and he thinks it
would be good idea if a more popular version came out in advance, you know, to clear
the way for it. So go ahead with my blessing.” So I did, I went ahead with his blessing.
But his never came out. He was an outsider to the extent that his field was marine biology
and not anthropology, so they had that against him as well.
DA: One might think it odd, that an eminent marine biologist and fellow of the Royal
Society would be barred as an outsider from venturing some observations about human
evolution. But academic boundaries can be fiercely patrolled. And if Hardy was regarded
as beyond the pale, what of Elaine Morgan? She wasn’t an anthropologist either, she
wasn’t even a scientist. But she was a brilliant writer, with an Oxford degree in English,
and most of all an indefatigably inquiring mind. So she wrote her book in the form of an
account, from the female point of view, of what might have happened to make us human.
And it was an instant success. So much so, that in 1972 she was invited on a publicity
tour of the United States, appearing on television and radio chat shows across the
continent to talk about the proposal of an aquatic phase in human evolution. And what
did Sir Alister Hardy make of it?
EM: I rang him up to say that my book had been accepted, and he said, “What’s it
called?” And I said, “It’s called ‘The Descent of Woman.’” Long silence. “The Descent
of What?!” Because, I mean, for him the water had no connection with any at all.
Anyway, it did come out and he was sent a complimentary copy. He sent me a telegram
in New York, saying “Brilliant!” And of course he wrote a foreword to the next book I
wrote.
DA: But a best-selling book is one thing, academic acceptance is quite another. It was
still 20 years before Phillip Tobias would stand up to declare the Savannah Theory dead.
And professional anthropologists liked the idea of the aquatic ape theory even less
coming from Elaine Morgan, than they had when it came from Sir Alister Hardy. It didn’t
matter that she had researched the subject in great depth, and had added a number of
other human characteristics to Hardy’s original three or so, that would seem to point to an
aquatic shore-based past. If anything, the accumulation of further detail that she had
painstakingly carried out made the anthropologists dig their heels in all the more firmly.
EM: The scientific reaction was bitter anger and contempt. I mean, it was very hard on
them. I wasn’t qualified. “She doesn’t even know that when you write Homo sapiens, it’s
got to have a capital letter and a small letter and be in italics.” “And she talks once about
canines, and she means dogs being canines, not teeth! How stupid can she get?” But I’ve
had some very nice experiences since then. Dan Dennett invited me over to go to Tufts
University in Boston. And people from Harvard came to it, and I got a very, very good
reception there.
DD: I brought her over to give a talk at Tufts, the only time I’ve met her. And in a packed
hall, she entranced everybody, and absolutely pushed one anthropologist over the brink,
and he responded with emotional declarations, that were really in the end hilarious. And
she handled them very deftly, it was as if she had planted him in the audience! It was a
stunning demonstration of the sort of irrational hostility that she engenders, and she
parried it brilliantly. The audience was in her pocket.
DA: Dan Dennett is professor of philosophy at Tufts University in Boston. He’s also the
author of a number of highly acclaimed books on aspects of evolution, including
“Darwin’s Dangerous Idea”, in which he touched on the curious reluctance of scientists
to engage seriously with the aquatic ape hypothesis, either to embrace it or to refute it.
DD: If I were one of the chief architects and defenders of an establishment theory, in any
field, and a grandmotherly journalist were to propose the idea that this theory was wrong,
I would be a little unsettled, and it would be hard to maintain my cool. I’ve seen level
headed, calm, serious scientists get quite flabbergasted and unable to express themselves
in their discomfort with the aquatic ape theory. I’m really surprised in a way that there
hasn’t been the right sort of measured and sober response. At least if there has been, I
haven’t been able to find it.
DA: Professor Graham Richards of the British Psychological Society was similarly
intrigued by the failure of the scientific establishment to address the aquatic ape with due
seriousness. The fact that Alister Hardy and especially Elaine Morgan were both
outsiders to the field of paleoanthropology had clearly provoked not just a prudent
scientific caution, but something more visceral, even jealousy.
Graham Richards (GR): One of the reasons, I think, for an early hostility to it, was
purely a feeling that, “Well, why didn’t one of us come up with that? If it was true, one of
us would have come up with it first.” It was a kind of incredulity almost, that this outsider
could produce this theory which seemed to pull so many threads together. But there was
also a feeling that they were all glancing around the room, feeling, “Well, I can’t
personally think of the knock down argument, but surely one of you can.” And there was
the thing that, “Which one of us it that has got the knock down argument?” And it
gradually became apparent that none of them had the knock down argument! And so they
resorted to this kind of rhetoric about, “Oh, she’s cobbled together a kind of collage of
different facts and figures...” Which is exactly what scientific theory’s supposed to do.
Why was Newton’s theory of gravity so important? Because it integrated everything from
why the moon went round the earth to why apples fall. That is the key thing of a good
scientific theory, that it does this linking job on a lot of phenomena, that were hitherto
thought to be totally unrelated. And whatever the long term merits of the theory are
judged to be, it certainly did that.
DA: Conscious of the accusations that she wasn’t a scientist, Elaine Morgan went on to
write four more books on the subject of humanity’s aquatic past; each, as she says, “More
po-faced than the last.” Providing notes, referencing every citation, dotting i’s and
crossing t’s. And increasingly laudatory reviews came in from ever more august journals.
From the British Medical Journal:
Quoting British Medical Journal: “Elaine Morgan seems to have succeeded where the
professionals have failed. She’s made a genuine contribution to evolutionary theory,
which synthesizes research from a wide range of scientific disciplines.”
DA: From the Annals of Human Biology:
Quoting Annals of Human Biology: “My views about her latest book, and what she was
trying to achieve by writing it, changed completely while I was reading it. It deserves to
be read seriously.”
DA: And an enthusiastic review from the Journal of the Royal Anthropological Institute
in 1990 ended with the tolling of a warning bell:
Quoting Royal Anthropological Institute: “The cost of conceding to Morgan would be
a paleological crisis as profound as that of the Earth scientists, when adjusting to the
equally impossible idea of floating continents.”
DA: The reviewer was referring to the theory of Alfred Wegener; that the continents of
the earth are drifting apart. As a meteorologist, Wegener was also a classic outsider, and
his theory was roundly ridiculed and rejected by geologists for over 30 years. But when
the submarine research in the 1960s finally proved that the Atlantic sea floor really was
spreading apart, hostility faded and Wegener’s “Plate Tectonics” became the accepted
paradigm. So, what of the aquatic ape theory? Will it too finally be endorsed as the
paradigm account of how we became human? For 30 years, the anthropologists have
maintained closed ranks and either ignored it, denounced it as bizarre, or said simply,
“There’s no testable evidence”; no equivalent to the spreading sea floor. But now it
would appear that the missing evidence is finally appearing. And in next week’s
programme, we will look at some of the evidence and see where it leads. Meanwhile, the
mainstream anthropologists’ view of where humans really grew up appears to be moving
hesitantly down to the seashores. If not in a headlong rush, at least with the gingerly
placing of a toe in the water. Indeed, in much the same way, one might say, that those
earliest ancestral apes probably did too, on first arriving at the coast. Leslie Aiello:
LA: If we’re talking about humans using aquatic resources, shellfish, fishing, living near
lakeshore, seashore environments. There’s every reason to believe they did that, at
specific phases, you know, throughout our evolutionary history. But, you know, if we’re
talking about myself believing in the aquatic hypothesis, I would say I’d only believe in
the aquatic hypothesis, if I can define exactly when in the evolutionary period, I can see
when we were using aquatic resources, and how our anatomy or behaviour may have
been moulded or reflected by that. But, you know, there is no one aquatic hypothesis. It
depends what you mean by semi-aquatic. Do you mean having one toe in the water, or...?
EM: When Raymond Dart said, “I found this skull and I think it’s not quite a chimp’s,” it
took 30 years before they believed him. And Wegener said, “I think the continents have
moved.” Rubbish! Shouted down in Harvard. Thirty years later, “Yes, you were right.”
So I thought, “I’ll give it thirty years”. Well, now it’s had 32.
BBC announcer: “Scars of Evolution” is presented by David Attenborough. It’s
produced by Richard Collins, and is a Monty Funk production for BBC Radio 4.
Part 2
BBC announcer: First on BBC Radio 4, we’ve the concluding part of “Scars of
Evolution”. David Attenborough looks at the accumulating evidence of the Aquatic Ape
Hypothesis.
LA: There is no one aquatic hypothesis. It depends what you mean by semi-aquatic. Do
you mean having one toe in the water...?
DA: In the first programme, we traced the history of reactions to the Aquatic Ape
Hypothesis, as first suggested by Sir Alister Hardy in 1960, and then fully developed by
the writer Elaine Morgan. The hypothesis claims that the features that distinguish humans
from other apes, standing upright, naked and sweaty, swimming and diving, with our
very fat babies, big brain and language skills, are best explained as water adaptations. In
other words, that we diverged from the other apes by moving to a lake and seashore
environmental niche for a considerable length of time in prehistory. For how long
exactly, where and when it occurred, whether indeed it has ever stopped, are all open
questions. But what is increasingly agreed is that the exploitation of aquatic resources
was an essential component of early human evolution. For forty or more years, the
accepted crucible of humanity was the open savannah grassland of Africa, and the aquatic
alternative was ridiculed. Then really since the early 90’s, the consensus began to fall
apart. Why? What new evidence has come to the fore the last 10 or so years to cause such
a paradigm shift? To drive the anthropological mainstream off the savannah and, with a
certain amount of pushing and shoving and cautious hesitation, down to the water’s edge.
We’ll start with the brain.
Michael Crawford (MC): It was manifestly clear that this idea of Homo sapiens
evolving a big brain through fierce competition, off the savannahs of Africa with the big
cats and all the rest of it, was just rubbish. I mean, there was absolutely no parallel
example of evolution of a brain on the savannahs. Every single species without exception
lost its relative brain size, as it evolved bigger.
DA: Professor Michael Crawford of the Institute of Brain Chemistry and Human
Nutrition in London.
MC: When we came to do the studies on the reasons why there were different sizes of
brains in different animals, and realized that, really, the brain required fat; 60 percent of
the structural material is fat. So, where do these fats come from? When we did these
studies, it all sort of fits together.
DA: Michael Crawford and his team had established two crucial facts. First, that the
brains of all other savannah animals had shrunk in relative size, as they evolved larger
bodies. By contrast, the human brain had grown, three-fold. But secondly, and more
importantly, they demonstrated that to evolve a larger brain, you need an abundant supply
of Omega-3 fatty acids, especially DHA, but also crucially Iodine. And the only place to
find that accessible and abundant supply of brain selective nutrients was at the shoreline,
in the marine food chain.
MC: When one compares the land base with this universal collapse of brain size with
what goes on in the marine system, I mean, you’ve got the dolphin, which is about the
same body weight as a zebra. The zebra’s got about 360-70 grams of brain in its head, the
dolphin’s got 1.8 kilograms. You know, it’s just phenomenal. The only way Homo
sapiens could end up today with 2% of his body mass as brain, would be to find an
ecological resource that would provide him with the nutrients that were required for the
brain to grow. And the only place you can do that is at the coastlines.
DA: Some researchers were still sceptical. They suggested that the brains and the bone
marrow of big game on the savannah might supply the essential DHA. But if that were
the case, then surely the dominant predators, the big cats, far better equipped than a small
fruit-eating hominid ape to crunch through bones and skulls, would have got into the
brain and marrow first and thereby grown their own big brains. Well, they haven’t.
MC: Believe you me, if you want to try and get the brain out of a buffalo’s skull, you
really need a hacksaw to do it. It’s no joke. And it would certainly have not gone ‘round
to try it for argument’s sake. And by the time you got it home to where the women were,
it would probably have festered and be foul. Whereas by contrast, it would be totally
natural for a woman at that time, even heavily pregnant, which is the most important
physiological time for brain development, to be able to walk around the coastline and
pick up food, because at that time, it would have been incredibly rich, the richest food
resource on the planet on your doorstep.
DA: Dr. Steven Kinay worked with Professor Crawford in the 1980s and 90s, unravelling
the story of how the large human brain came about. He was increasingly struck by
another curious feature of humans: That our babies are quite extraordinarily fat. Newborn
chimps and gorillas, by contrast, have no fat at all.
Steven Kinay (SK): Our babies have a ten-fold increase in fat in the last 12 weeks before
birth. A ten-fold increase in their total body fat. So, you’re talking about 30% of that
baby’s weight is brain and body fat. Now a chimpanzee’s brain is almost as big as an
infant’s brain at birth, but it has no body fat to speak of whatsoever. So it abandons brain
expansion at birth, because it can’t run it.
DA: By contrast, the human brain trebles in size from birth to around age 10. And there’s
another persuasive aspect to the theory. It’s predictive. It predicts that because Iodine and
other nutrients in the marine food chain are essential to the evolution of the human brain,
then, if we switched to a new land-based diet, that is poor in those nutrients, brain
function will suffer. And that’s exactly what has happened. According to the World
Health Organization Report in 2004, Iodine deficiency amongst inland populations,
affects around 740 million people worldwide.
MC: In Corella the school children, 60 percent of them, are Iodine deficient. I saw
exactly the same in Indonesia when I was there for the World Health Organization. 60
percent of the school children, the same number, had palpable goiter. When we got to the
fishing villages, not one. So this movement inland, which has happened as a consequence
of population expansion, has brought about some serious degenerative disorders.
DA: Even for pillars of the anthropological mainstream, including former editor of the
Journal of Human Evolution, Professor Leslie Aiello, the marine food chain account of
brain evolution is becoming compelling. And it’s tied up with another compelling story.
Of migrations.
LA: Personally, I feel that the dietary and nutrition side of things would be a very
interesting area to research further. Because there’re many convincing arguments that
migration would be easier along the seashore-type of environment. But, you know, we
need to be able to address the features. We need to be able to test them in a scientific
manner.
DA: Marc Verhaegen, a Belgian medical physician, who has researched and published
widely in support of the Aquatic Ape Hypothesis, describes the “boom years” of the
Homo erectus dispersal across the globe. This early hominid relative of ours arguably
experienced greater brain growth than any other branch of the hominid family tree.
MV: About 1.8 million years ago, we suddenly find fossils of Homo all along the warm
coasts of the old world. We find them from Algeria, Ain Hanech, over DManisi in
Georgia, to Iran they have found tools near paleo lake, a large paleo lake, on till Java,
Modjokerto. So suddenly, 1.8 million years ago they find them everywhere.
DA: But why did it happen then? Was there an environmental catastrophe, or perhaps a
population boom, that drove these early bipedal hominids first to the beach, and then
around the coastlines. What pushed them?
MV: Well, I don’t think it was a push. It was... Perhaps you can better call it a pull. It
was an opportunity. I see it like this, at the beginning of the ice ages there was enormous
amounts of water that were kept as ice at the poles. And so there was a drop of 100
meters and more of the sea level, and on the continental shelf there came an enormous
space free, probably abundant in aquatic, in shellfish and crabs, and so that was simply an
opportunity for our ancestors.
DA: And the story took a dramatic step further in October last year, when newspapers
across the world put a startling image on their front pages. It was a picture of Homo
floresiensis, a curiously small hominid fossil discovered on the Indonesian Island of
Flores. The adult was only 3 feet tall. Mike Morwood and his colleagues who made the
extraordinary discovery nick-named it “The Hobbit”. But from one perspective this
Hobbit skeleton, dated to 12,000 years ago, was just a follow up, albeit an odd one, to
another remarkable find by the same team a few years earlier. Peter Brown is professor of
archaeology and a lead member of the team:
Peter Brown: On Flores we have a site called Mata Menge, where there are stone tools
dated to 840,000 years ago. So it looks like some tool making biped got to Flores at least
by 840 and perhaps earlier in time than that. The concern was never so much the date, but
how they got to Flores, this small island, and on the evidence we have, Flores was always
an island. Maybe they were Stegodon jockeys; maybe they rode on the backs of elephants
between the islands. Unlikely, I would have thought. They could have built water craft,
and come from island to island. If you can see the next island, I suppose it’s possible. Or
it could have been accidental process, and... In the 1930’s a man called Wood Jones said
Australia was populated by a pregnant woman on a log with a dog. And it obviously
takes more than one pregnant woman on a log to populate an island, but it could have just
been an accidental process rather than intentional, building of boats. We will never really
know, but what we appear to be certain of is that water had to be crossed to get there.
DA: As the decades pass, and the evidence accumulates, from sometimes unexpected
directions, Elaine Morgan is still going strong. At 84 and with a new book out, she
doesn’t see any difficulty with getting to Flores.
EM: They’ve said, “Maybe we were riding on the backs of elephants, or else we drifted
across on some kind of craft.” But if you’re an anthropoid ape, or some variation of an
anthropoid ape, you don’t get to construct crafts unless you are very confident in the
water already, and quite happy with crafts. I also think that at that stage we would have
been perfectly capable of swimming across.
DA: Swimming. When did humans learn this considerable skill? Professor Erika
Schagatay, an authority in apnoeic breath control, would argue that we learn it at about
the same time as we learned to dive in water. And if you consider what you have to do to
skin dive; well, most importantly, you have to hold your breath; then you find something
very interesting. In land mammals, including our primate cousins, the chimps and
gorillas, breathing is entirely involuntary. You can’t get a chimp to hold his breath.
Breathing is as unconscious as the beat of its heart. And it is for us humans too, a lot of
the time.
Erika Schagatay (ES): Most of the time our breathing is completely automatic. It’s not
something we have to think about. For instance, when we’re asleep our breathing pattern
is completely run by autonomous systems of the brain. We don’t stop breathing when we
sleep.
DA: But there are other times for example right ... now as I’m talking to you, and perhaps
I might want to ... emphasize a particular word, I then switch to voluntary, conscious
control of my breathing. It’s second nature and we do it all the time. But it gets even
more intriguing, when we look at the fully committed aquatic mammals, like dolphins.
Dolphins and some whales have actually lost the ability to switch back again from
conscious breathing to unconscious breathing. One might ask then, “So how do they
sleep?” Well, it’s fascinating. Brains scans of dolphins show that when they sleep, and
they sleep for the very typical mammalian eight hours a day, they can only let one half of
their brain go to sleep at any one time. They have to keep the other half awake to ensure
that they surface regularly for a breath of air. So there’s a fantastic symmetry to how the
whole range of mammals handle breathing. Fully aquatic, exclusively conscious; fully
land based, exclusively unconscious. But semi aquatic, we can switch between the two,
as and when it suits us. And if you want support for this idea, that expert breath control is
necessary for speech, just listen to this:
Hoover (H): “Hey! Ge’ over here... Hey! Over here... Hey, hey, hey, hey, hey, hey, hey,
wah!”
DA: It’s the voice of Hoover, a popular character in Boston, who had a two column
obituary in The Globe And Mail, when sadly he passed away in 1985.
H: “Hey, yey, yey, yey! Hoy, hello ... Hello, there …. Ha, ha, ha. Hey, hey, hey. Hey!
Get over here! Hey, ge’ over here...”
DA: Hoover died at the grand old age of 14. You see, Hoover was a harbour seal. It’s
said he was the only non-human mammal ever to make the sounds of human speech. By
all accounts, he learned the phrases from the couple who rescued him as an orphan in
1971, George and Alice Swallow, and who raised him for the first few months in their
bath.
H: “Uwah. Uwah. Hey! Uwah.”
DA: Not everyone, however, is convinced about which came first, speech or swimming.
Professor Leslie Aiello:
LA: Language is obviously one of the primary human adaptations. And breath control is
essential to language. But breath control can be used for other things as well as language.
One of them is swimming. So our ability to swim, controlling our breath and all, might be
just the by-product of our ability to speak. It’s as reasonable of a hypothesis as turning it
around and saying we can speak because we went swimming.
DA: Well, it’s an interesting possibility. What we do know is that both the diving
response and natural swimming abilities are displayed extremely early in the growth of
the human infant. Indeed they are strongest at birth.
ES: In the Indonesian Suku Laut water people, the traditional way of giving birth was to
go in the sea. But missionaries now try to make this population stop. They were still
trying to practice it, because they knew it was so much easier for the women to give birth
in water. And also the children of course, they are baby swimming from very early age,
and they swim and dive very well before they can walk.
Susan Vervel (SV): Lots of people get very worried that if a baby is born under water,
it’s going to drown, because the first human response is to want to take a deep breath. But
human beings are amazing, when they’re born, they still have intact the diving reflex, or
we call the duck reflex. Which means if there’s water on the face, there’re receptors on
the face that will close the throat off, so actually the baby will not inhale water. Once air
hits the baby’s face, the receptors will trigger off the breathing response, and the baby
will take the deepest breath it will ever take for its whole life. So the baby’s quite safe to
be born under water. The longest I’ve seen a baby under water was probably about a
minute, and that’s quite a long time, a minute.
DA: Susan Vervel is consultant midwife at Addenbrooke's Hospital in Cambridge. With
many years experience of training midwives in water birthing, she’s still impressed at
how very comfortable humans are, both mother and baby, with giving birth in water.
SV: After water birth, babies seem to be very relaxed at a birth that’s been under water.
They come to the surface, they take their first initial deep breaths, and then they settle
quite quickly, and the mother holds the baby skin to skin. The cord, which is still attached
to the placenta, in most cases is just long enough for the mother to bring the baby to the
breast, so again evolution has worked really well in our favour. So if the mother was on
her own in a river, for example, she doesn’t need anyone to help her, she can bring the
baby to the breast.
DA: It seems extraordinary that humans, reputedly a land mammal, should find giving
birth in water a perfectly natural thing to do. Professor Peter Wheeler, Dean of Science at
Liverpool John Moores University, is a leading opponent of the Aquatic Ape Hypothesis,
and has argued for many years that it’s misguided and wrong. He believes that giving
birth in water could not be an evolutionary adaptation, because it would be simply too
cold for the baby.
Peter Wheeler: Human babies lose heat very easily, because they are so small, they have
a high surface air to volume ratio. And even in air they’ll start to lose body heat, or
additional body heat, at temperatures as low as 33-34 degrees centigrade, just a few
degrees below body temperature. So even in air they’ve got problems, in water they’d
probably be even greater. The baby will have to start producing heat maybe just one or
two degrees below body temperature, and if water temperature falls a couple of degrees
below that, they can’t maintain their body heat production to maintain their temperature
at a stable level, and very soon they’ll die. So when you see pictures of babies swimming
around in water, this is warm water. In the sort of temperatures you get in natural water
bodies of the sea, they would die very quickly.
DA: Susan Vervel, as a consultant midwife, is more worried about the opposite problem.
SV: What we do know, when there has been some problems with babies needing to go to
special care, is often the water has been too hot. But when I was talking to some of the
home birth midwives in Moscow recently, a couple of them were taking women to the
Black Sea, where the women would go up to waist height and maybe crouch down with
support, and give birth to their babies under water in the summer in the Black Sea. Where
often the temperature is down to 19-20 degrees, which for me would be quite chilly.
DA: There is one other odd feature of human birth. It’s so odd, indeed it’s thought to be
unique to humans, that it’s not much studied or written about in the medical literature.
It’s called vernix caseosa, Latin for “cheesy varnish”. And it’s the name of the fatty,
greasy coating on the skin of the human infant when it’s born.
SV: From a midwifery perspective, if I saw a baby come out *** water with a lot of
vernix over its whole body, I may be a little bit concerned if we’ve got the gestation and
length of the pregnancy right.
DA: In other words, if the baby has an excessive vernix all over at birth, it’s probably a
sign that it’s slightly premature. It’s been suggested that it waterproofs the skin while it’s
submerged in the amniotic fluid in utero. But if so, then surely all unborn mammals
would get this protection. But they don't. Apparently, it's only human babies who arrive
covered in a layer of grease, looking, as Elaine Morgan described it, rather like a cross
channel swimmer. Dr. Peter Jackson, veterinary obstetrician at Cambridge University for
30 years, has written:
Quoting Peter Jackson: “As far as I know, vernix caseosa is a purely human condition,
and I do not believe that it occurs in neonatal animals. It’s interesting that it does not
occur in any of the other primates except human beings. Looking for vernix in animals
produces no references.”
DA: Now, over the years one of the arguments put against the Aquatic Ape Hypothesis,
is that it makes no testable predictions. But this case of the apparent uniqueness of vernix
seemed more and more intriguing. Could it really be unique? And why would it be so?
And moreover, a possible test suggested itself. If entering water during labour really is a
semi-aquatic evolutionary adaptation of some antiquity, and not a recent fad of civilized
societies, then one could make a prediction. Other semi-aquatic mammals should have it
too. Mammals that either give birth in water, or swim soon after being born, would also
have a coating of vernix. So in the course of making these programmes, we’ve scoured
the scientific literature. Nothing. We contacted professors of mammalian physiology in
Europe, Japan and the United States. Nothing. Vernix really was unique to humans. We
wrote to marine biologists in Norway, Russia and Alaska. They reported back that they
had never seen it. It was a dead end, a human curiosity. Then just a month ago, a week
before we finished recording, we got a call. Professor Don Bowen in Nova Scotia,
Northern Canada:
Don Bowen (DB): For a period of about 10 years, we had an opportunity to handle
newborn harbour seals on a regular basis. And certainly if you do handle one within
minutes or so of birth, they are covered with this waxy substance. It’s very noticeable, in
fact if you handle a pup with bare hands, then your hands are coated with it. And it’s all
over the entire body of the animal. Harbour seals enter the water usually within about a
half an hour to an hour of birth, and are able to swim with their mothers almost
immediately. I mean, we always assumed that it was analogous to the vernix that humans
are born with. We actually never pursued it in a systematic way.
DA: Now this is pretty interesting. For as far as we’re aware, it’s the first time that vernix
has ever been reported in an animal other than humans. So do other species of seal have
vernix as well?
DB: Grey seals do, but the concentration is noticeably less. That is, if you handle a
newborn grey seal, you can feel a slight waxiness to the fur. But certainly the
concentration of vernix is much less than it is on harbour seals. And in hunter seals it
seems to be even less so. The concentration is noticeably reduced, compared to even grey
seals. They probably on average don’t enter into the water until they’re, you know, a
week or ten days old.
DA: These are only observations and have not been systematically studied and written
up. But from what Professor Bowen reports, there appears to be some basic correlation
between the amount of vernix on an infant at birth, and how soon it takes to the water. It
would almost seem to be a case of “the thicker, the quicker.”
DB: Certainly spotted seals and some of the other small phocid social seals in the North
Pacific I would assume have it, but nobody’s really reported it. It is something that I think
is fascinating. And, well... I’d very much like to follow it up.
DA: Over these two programmes, we’ve tried to trace the history of the Aquatic Ape
Hypothesis to see how reactions to it have changed over the last 45 years. Although it
still provokes fierce debate, the evidence, bit by bit and year by year, really does seem to
be accumulating in its favour. Perhaps like Wegener and his continental drift, the tide
really is turning toward Alister Hardy and Elaine Morgan and their proposal that our
earliest human ancestors were born not on the grasslands or the forest, but in the shallows
and lagoons at the margin between sea and land. Last year a book was published by two
very eminent and mainstream paleoanthropologists, David Cameron and Collin Groves,
in which they state:
Quoting David Cameron & Collin Groves: “At first the Aquatic Ape Hypothesis was
simply ignored as grotesque, and perhaps unworthy of discussion because proposed by an
amateur. But Morgan’s latest arguments have reached a sophistication that simply
demands to be taken seriously.”
LA: I’m not totally against it, but I’m not for it either. I think the take home message on
this is, you know, as with anything there’re probably kernels of truth.
EM: I think in 10 years we’ll be over the cusp. The tide is beginning to drift in that
direction. And I think it’ll pick up speed, and I think that a lot of people will bring up
their own reasons why they think that the difference between man and the apes had
something to do with water. I go no further than that, but they all seem to be trickling in
that direction. And I don’t know whether I’ll be alive to see it, but I’m confident this is
going to come.
BBC announcer: “Scars of Evolution” was presented by David Attenborough. It was
produced by Richard Collins, and is a Monty Funk production for BBC Radio 4.