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Blutwölfin
Wednesday, October 5th, 2005, 02:02 AM
Consensus amongst scientists (known as the Savannah Theory) has it that the following sequence occurred:

* When human predecessors in the African jungles became overpopulated, some of them were forced to live on the open plain or savannah.
* Having to hunt game for food, they learnt to stand on their hind legs to see their prey more easily
* Because it was so hot out there, they shed their hair to enable sweat to flow freely
* Speech and intelligence grew from the need to communicate and hunt in packs

Hence humans evolved. On the surface it makes a lot of sense, and we can be forgiven for not questioning any aspects of this theory. We know from images in encyclopedias and popular culture that primitive men hunted animals for food and skin, and that they lived in caves. They were hairy brutish thugs and a perfect intermediary between the chimpanzees and humans of today.

However, the Savannah Theory is riddled with conundrums, such as:

* Primates such as baboons and vervet monkeys live on the savannah - they have not become bipedal, nor have they lost hair
* The many thousands of years it took to evolve from being able to move quickly on four legs, to beings able to run on two legs, would have left the prototype humans extremely vulnerable to predators.

Mammals are not designed to walk vertically, because it is grossly inefficient. If the first apes attempted it, they would have been like year old babies: falling over all the time. Furthermore, the “missing link” would have lacked the locking mechanism of the knees that we have today. Imagine trying to stand with your knees bent for a few hours. Without a high priority reason to do so, the human predecessors would have simply given up. Evolution does not have an agenda. Animals cannot see into the future and aspire to being human, they can only respond to need. To gain a better view over the tall grass, a more obvious change, seeing as our ape relatives are good at jumping, would have been to jump higher.

The mammalian spine is designed like a clothes rack - things hang from it. It consists of a long, slightly arched rod supported by two sets of legs. The animal’s body weight is evenly distributed and the centre of gravity is low, making for a well-balanced individual. Using four legs has been shown, by the evolution of all the other species, to be best way of getting about. In rare cases like kangaroos and ostriches, you can see how evenly their weight is distributed. No other animal walks perpendicular like humans - it isn’t an efficient way of doing things. If you need more convincing, simply consider the terrible back problems the majority of us will suffer during our life time due to our ridiculous posture.

There is, however, one primate species that regularly walks on its hind legs, the proboscis monkeys of Borneo. They live in mangrove swamps and regularly drop down into the water below them. They are excellent swimmers, but if they are able to touch the bottom they elect to walk, just like humans. With the support of water around them, the instability and discomfort of terrestrial bipedalism disappears. With their heads held up high they are able to breathe easier than when swimming.

The plot thickens when we delve into he geological and climatic history of North East Africa, where the fossils of “Lucy” and other famous human ancestors have been dug up. Lucy’s scientific title is Australopithecus afarensis, because she was found in the region of Ethiopia known as Afar. From seven million to 70,000 years ago this area was an inland sea, sea water that flooded in and then got trapped, separated from the ocean proper. This is typical of the environment we would expect an Aquatic Ape to evolve in. Today it has all dried up, leaving a virtually impassable desert, with salt deposits thousands of feet deep.

A key problem cited by orthodox scientists, the lack of fossil evidence for the Aquatic Ape Theory, is ridiculous. None of the aquatic characteristics listed here can be deduced from fossils. So theoretically any ancient hominids may have had these features, we just can’t tell. For the same reason, scientists might guess at the skin or hair colour of fossils, but they cannot know.

Turns out that most African hominid fossils have been found in or near bodies of water. This is explained as “they were passing by, and stopped for a drink” or “heavy rains made the river overflow and they drowned”. The obvious explanation, that they lived in and beside the water (as most humans still do), is rarely considered.

There is considerable evidence to show that regions of Africa once had the same characteristics as the mangrove swamps of Borneo.

A press release from the University of Toronto, August 1999, states:

“The first humans may have been beach-dwellers foraging for shellfish, not grassland hunter-gatherers… ….evidence that the large brains of the earliest humans could only have evolved on the nutrient-rich diet provided by shellfish and other animal life found near shorelines. "You don't need a big brain to collect mussels and clams. But living on them gives you the excess energy and nutrients that can then be directed towards brain growth."

The popular image of the earliest humans living on the African savanna must be wrong, [Stephen] Cunnane says. His team has found that a specific fatty acid, DHA, necessary for human brain and eye development, is easily available in food near shore environments but not in the diet of savanna mammals. This suggests humans evolved near water before spreading inland, he says.

"We'd like to see early humans as hunters who took advantage of nature and grew a big brain in the process," he says. "But how could that hunting ability miraculously appear overnight? Well, it didn't. Instead, they evolved in a place where they didn't have to hunt."

Cunnane believes recent hominid finds in South Africa that show proto-human fossils in close association with the remains of aquatic creatures are more evidence for the theory, which he hopes to further test next year by isotopic analysis of early human fossils.”

Fat, Sweaty and Hairless

Charles Darwin once wrote:

“The loss of hair is an inconvenience and probably an injury to man , for he is thus exposed to the scorching of the sun and to sudden chills, especially due to wet weather. No one supposes that the nakedness of the skin is any direct advantage to man; his body therefore cannot have divested of hair through natural selection."[2]

The Savannah Theory fails in this regard. These areas of Africa can cool to 11ºC at night, and it would not be an advantage for humans to sleep there even on a dry night. It is normal for terrestrial animals to have fur or thick hair. Humans still have the capillary muscles which enable our hair to stand on end. If our hair were longer it would then trap a layer of air close to the body, creating a thermal blanket of sorts. Feathers work the same way. Most animals have the ability to adjust their exterior in accordance with changing air temperature, whereas us poor humans have to resort to clothing. Hair or fur is also very useful for protection against injury, something very important in the wild. Obviously we lost our hair, not because hairlessness was an advantage, but because at one time our habitat was such that having hair was a distinct disadvantage.

The easiest way to determine why humans are hairless is to study other mammals that have evolved into a similar situation. Charles Darwin commented thus:

“Whales and porpoises, dugongs and the hippopotamus are naked, and this may be advantageous to them for gliding through the water; nor would it be injurious to them from the loss of warmth, as the species which inhabit the colder regions are protected by a thick layer of blubber.”[3]

Elephants are virtually hairless and are capable of swimming many miles, their trunks perfectly suited to use as a snorkel. The tapir of Asia, Central and South America is like a mini elephant, with a small proboscis nose. It’s hair is very sparse and it loves to swim and dive. Pigs such as the babirusa are yet another mammalian species which have evolved to suit living in the water - losing hair and gaining blubber. (Mammals living in subterranean circumstances have also lost hair, and usually sight as well - this angle is best put aside for whoever invents The Mole Ape Theory,)

Pigs and hippopotami readily come to the minds of children when searching for animal personifications to bait their obese acquaintances with.

Compared to all the other primates, humans definitely deserve the “fatty” tag. A gorilla or chimpanzee kept in a cage might put on a fraction of extra weight, as might an old horse that can’t run about as much as it use to. But the only land mammals capable of doubling or trebling their natural weight, to have rolls of fat hanging from arms, legs, hips and bellies, to be unable to walk without breaking into a sweat, are humans.

This fattiness is normal. If a woman’s body is underweight it chooses not to conceive. A typical 16-year-old girl should have 27% of her body weight in fatty tissue. If it were to drop below 22%, her menstruation cycle will cease. The reason that we need to stitch up serious flesh wounds is because the layer of fat just below our skin tries to ooze out. The edges of the cut become separated and are unable to rejoin and heal - other mammals don’t have this problem, their skin sits on top of muscle, not fat.

The concept of sweating as a cooling device is ridiculous. This system, which is unique to humans (other mammals that sweat do it less profusely than us, and use a different type of gland) is flawed. It is prone to activating at the wrong time (in humid weather), is too slow to start and stop, provides far more than the thin layer of moisture required for cooling, and wastes salt. We are the only mammal that expels salt when we sweat. Even when a human is nearing total dehydration it will continue sweating in hot weather and even die. Our sweating system is yet another disadvantage of being human.

So why do we sweat? One possible reason is to expel salt. If and when they first took to the sea, our ancestors would have been eating seafood (which by definition is salty) and accidentally swallowing salt water. The overload on our kidneys would have created a need for a secondary system to evolve. Seabirds have special glands for removing salt from their body.

Humans cry, the function of which that has long baffled evolutionary scientists. It is also for the purpose of expelling salt. You may have noticed that if you cry too long, the saltiness will sting your eyes. Why this action is nowadays connected to our emotions is unknown. Have you heard of crocodile tears? Well it is true, crocodiles also cry as a means of expelling salt from their system (of course this is not case with freshwater crocs). Walruses cry. Elephants cry. Non-human primates do not cry. Although we obviously look like monkeys, in some ways we have close connections to water-loving mammals. Pigs love to “wallow”, and we use pigs as organ donors. Elephants are, when you think about it, smooth-skinned, swimming, crying, intelligent, overweight social animals - just like us. It appears that they evolved in the ocean as well, but chose to come back on land rather than becoming whales. Humans made a similar decision, whereas dolphins chose the sea.

Swimming & Diving

Swimmers and Divers require a large opening to enable the rapid inhalation and exhalation of air - and our mouths are large compared to the small opening of our nose and the noses of most other mammals. They also need to be able to close their air passages, making it harder for them to accidentally swallow water.

"Several unrelated aquatic species have evolved some kind of movable flap either instead of, or in addition to, valvular nostrils. The penguin has one, and the crocodile has one. Alone among the primates, humans have such a flap - that is, the back of the soft palate, known as the velum, which in our species can be raised and lowered to isolate the nasal passages from the mouth cavity. It could not opeate in this fashion if the larynx had not retreated out of its way to its present position below the back of the tongue.

"The only other mammals which are known to feature a descended larynx are diving mammmals - the sea lion and the dugong. These two species are about as unrelated to one another as they are to humans. The descended larynx must have evolved independently in each of them, after their respective land-dwelling ancestors entered an aquatic environment."[4]

While we were aquatic mammals, our descended larynx helped us with communication - as we began to speak we were capable of a wider range of sounds. The primary reason why apes such as the chimpanzee can not "speak" is not because of the limited range of sounds available to them - they can say "ah", "ee", "oo", and pronounce the letters k, p, h and m. These few sounds are ample to create a large number of words. They have proven to be capable of excellent communication using sign language, and they also understand verbal instructions, but they lack the capacity speak as we do. The reason is not intelligence, it is to do with breathing. Like most mammals, the breathing function in chimpanzees is not voluntary, it is as automatic as the heart. To some extent it is also involuntary in humans, like when we sneeze, hiccup or get a sudden fright. But the rest of the time we get to choose how we breathe - this is directly attributed to our aquatic past, when we had to hold our breath to dive below the surface.

Conscious control of breath is a characteristic that we share with all other diving mammals, and something that no other non-aquatic mammals have.

The Penis

The large comparative size of the penis in adult male humans (man 13cm vs gorilla 3cm) is not related to the frequency of deployment. It is a necessary consequence of the retraction and relative inaccessability of the vagina.

“An aquatic environment seems to have had a broadly similar effect on some other species - that is, relative retraction of the femal sex organ leading to a corresponding extension of that of the males. For example, most birds and reptiles do not possess a penis; the pressing together of the cloacal apertures seems to suffice for the transference of the sperm. But many species of aquatic reptiles (crocodiles and turtles) and aquatic birds (swans, ducks, geese) have found it necessary to evolve a penis as part of their adaption to a watery habitat.”[5]

Scent Signalling

“In mammals, oestrous status is communicated by scent signalling - a pheromonal message emitted by the female. Being airborne, it may be carried quite a long way - as evidenced by the distance a dog will travel to locate a bitch on heat. But in a wading or swimming ape the pheromones would be washed away almost as soon as they were scented.

“...But in humans the ability to receive and interpret scent signals is very low. The olfactory lobe in our brains is proportionately smaller than in the brains of apes. (This is a common feature in aquatic mammals. In whales and seals the olfactory lobe has diminished almost to vanishing point.) So one reason for the ending of the oestrus could be that it ceased to work properly. As a result of the pheronomal secretions being washed away, plus diminished scent perception, the signal was simply not getting across.”[6]

The Missionary Position

As humans we have a common sexual position that is quite different to that of other land-based mammals – front to front. The usual explanation is that we wish to kiss...

“Ventro-ventral copulation, very rare in land mammals, is the commonest mode in aquatic mammals except for those that go ashore to breed. Whales and dolphins, dugongs and manatees, beavers, and sea otters are among the numerous aquatic species which mate face to face. Swimming promotes this method of copulation in the same way that bipedalism does, because in both cases the spine and the hind limbs are realigned, forming a continuous straight line instead of the 90-degree angle found in most quadrapreds.”[7]



NOTES:
[1] Few authors have contributed to this idea, therefore most of this information has been gleaned from the excellent books of Elaine Morgan, and she got her ideas from Sir Alistair Hardy

[2] Probably Origin of Species.

[3] Probably Origin of Species

[4] The Scars of Evolution: What our bodies tell us about human origins, Elaine Morgan, Penguin 1990, p135-140

[5] The Scars of Evolution: What our bodies tell us about human origins, Elaine Morgan, Penguin 1990, p146-147

[6] The Scars of Evolution: What our bodies tell us about human origins, Elaine Morgan, Penguin 1990, p148-151

[7] The Scars of Evolution: What our bodies tell us about human origins, Elaine Morgan, Penguin 1990, p148-151





Source (http://www.survive2012.com/aquatic_ape_theory.php#_edn5)

Dr. Solar Wolff
Wednesday, October 5th, 2005, 05:40 AM
This theory was proposed by a woman non-anthropologist in the 1970s. She was a writer or something and got some attention among feminist groups but was laughted at by anthropologists. She faded away.

At first blush, this is a crazy theory but the more you think about it the better it sounds. To me this is not about the transition of apes from the trees to the savannah but the final act of human evolution, sapiens.

Why do we envison H. erectus, H. heidelbergensis, H. neanderthal without hair? Certainly, even if Heidelberg-Neanderthal entered Europe hairless, they would quickly re-evolved a pelt after a few glacial advances. As the article pointed out, no savannah animal is hairless. Even a hunting lion has fur and they hunt in the heat if they have to do so.

Isn't it reasonable to conclude, for all the reasons mentioned in the article, that sapiens arose from creatures living along rivers, lakes and the seashore where they were exposed, daily, to water, enough that fur was counterproductive? These creature simply had to walk along or gently swim to make a good living and one provided with the fats necessary for a big brain. Why is it that fish oil is so important for health today? Can you imagine a Neanderthal being fussy about fish? There isn't a scrap of evidence that in the almost 300,000 years of their existence that they ever ate fish. Yet it is essential for sapien's health.

We now know sapiens spread via seacoasts around the world. The one exception is about 40-50,000 years ago when sapiens entered the area just east of the Caspian and spread both east and west--the Gravetian People. These were the Predmost-Bruenn people who looked more like sapiens-Neanderthal hybrids than anything else. They hunted mammoth and live in houses just like the Neanderthals before them. This is the one exception to the ---almost Law---that sapiens spread via coastlines.

Given all the evidence, doesn't this Aquatic Theory deserve a second look?

Dr. Solar Wolff
Wednesday, October 12th, 2005, 06:56 AM
I sure would like to get some feedback on Blutwoelfin's post. Any opinions?

Siegfried
Wednesday, October 12th, 2005, 03:14 PM
I sure would like to get some feedback on Blutwoelfin's post. Any opinions?

I am not too familiar with the arguments against the Aquatic Ape Theory, but thus far it seems quite plausible to me. Most likely both the Savannah and the Aquatic theory contain bits of the truth though. Fascinating topic.

Oswiu
Sunday, October 22nd, 2006, 03:58 AM
Very interesting idea, with some persuasive points.
Here's my half-arsed attempt at a critique;

However, the Savannah Theory is riddled with conundrums, such as:
* Primates such as baboons and vervet monkeys live on the savannah - they have not become bipedal, nor have they lost hair
But evolution is about the possible, working with the material you already have, not the ideal. Baboons started from a different base.

* The many thousands of years it took to evolve from being able to move quickly on four legs, to beings able to run on two legs, would have left the prototype humans extremely vulnerable to predators.

Mammals are not designed to walk vertically, because it is grossly inefficient. If the first apes attempted it, they would have been like year old babies: falling over all the time. Furthermore, the “missing link” would have lacked the locking mechanism of the knees that we have today. Imagine trying to stand with your knees bent for a few hours. Without a high priority reason to do so, the human predecessors would have simply given up.
But what if we're dealing with a situation where the ancestors had little choice but to keep walking - if there was a sudden reduction in wooded habitat, forcing them to walk between remaining islands. In this hypothesis, they would be safe if they reached these havens, and the period of risk would not be all the time. That might be enough to exert a strong evolutionary pressure to true bipedalism but without wiping them all out, no?

Using four legs has been shown, by the evolution of all the other species, to be best way of getting about. In rare cases like kangaroos and ostriches, you can see how evenly their weight is distributed. No other animal walks perpendicular like humans - it isn’t an efficient way of doing things. If you need more convincing, simply consider the terrible back problems the majority of us will suffer during our life time due to our ridiculous posture.
We live with this bad design, but the author was previously assertin gour ancestors couldn't possibly have done so. Why?

And shouldn't we be considering bipedalism ONLY FROM the base of an arboreal ape, with long arms, and accustomed to erect posture in a tree, and NOT from that of an ordinary quadruped?

The plot thickens when we delve into he geological and climatic history of North East Africa, where the fossils of “Lucy” and other famous human ancestors have been dug up. Lucy’s scientific title is Australopithecus afarensis, because she was found in the region of Ethiopia known as Afar. From seven million to 70,000 years ago this area was an inland sea, sea water that flooded in and then got trapped, separated from the ocean proper. This is typical of the environment we would expect an Aquatic Ape to evolve in. Today it has all dried up, leaving a virtually impassable desert, with salt deposits thousands of feet deep.
Might another way of looking at the results of such a habitat be the likelihood that there may have been an isolated area where unusual creatures might have escaped the usual predation pressures, at least for a few 100,000 years?

Turns out that most African hominid fossils have been found in or near bodies of water.
Aren't almost all fossils, from the simple mechanics of fossilisation occuring most easily in such conditions?

Cunnane believes recent hominid finds in South Africa that show proto-human fossils in close association with the remains of aquatic creatures are more evidence for the theory, which he hopes to further test next year by isotopic analysis of early human fossils.”
This is promising. Has it been finished and published yet?

“The loss of hair is an inconvenience and probably an injury to man , for he is thus exposed to the scorching of the sun and to sudden chills, especially due to wet weather. No one supposes that the nakedness of the skin is any direct advantage to man; his body therefore cannot have divested of hair through natural selection."[2]

The Savannah Theory fails in this regard.
Is there any suggestion that Darwin himself might have toyed with an aquatic theory? Odd that he would not have noticed the parallels. Or did he have reason not to follow such a line of reasoning?

Obviously we lost our hair, not because hairlessness was an advantage, but because at one time our habitat was such that having hair was a distinct disadvantage.
But aren't bonobos a relatively naked species too?
I read that we have the same number of hairs as a chimp, but they're just thinner. Bonobos seem to be as thinly haired to me [making them rather grotesque!].
QUOTE] Compared to all the other primates, humans definitely deserve the “fatty” tag. A gorilla or chimpanzee kept in a cage might put on a fraction of extra weight, as might an old horse that can’t run about as much as it use to. But the only land mammals capable of doubling or trebling their natural weight, to have rolls of fat hanging from arms, legs, hips and bellies, to be unable to walk without breaking into a sweat, are humans.[/QUOTE]
A hasty compensation for our poor fur?

We are the only mammal that expels salt when we sweat.
Why is this not seen in the other semi-aquatic mammals?

Humans cry, the function of which that has long baffled evolutionary scientists. It is also for the purpose of expelling salt. You may have noticed that if you cry too long, the saltiness will sting your eyes. Why this action is nowadays connected to our emotions is unknown.
And until it is solved, we can't talk with any certainty on its aquatic nature.

While we were aquatic mammals, our descended larynx helped us with communication - as we began to speak we were capable of a wider range of sounds. .... But the rest of the time we get to choose how we breathe - this is directly attributed to our aquatic past, when we had to hold our breath to dive below the surface.
Might communication be a better candidate for the prompting of these developments?

The large comparative size of the penis in adult male humans (man 13cm vs gorilla 3cm) is not related to the frequency of deployment. It is a necessary consequence of the retraction and relative inaccessability of the vagina.
Because of our new bipedal posture.

“...But in humans the ability to receive and interpret scent signals is very low. The olfactory lobe in our brains is proportionately smaller than in the brains of apes. (This is a common feature in aquatic mammals. In whales and seals the olfactory lobe has diminished almost to vanishing point.) So one reason for the ending of the oestrus could be that it ceased to work properly. As a result of the pheronomal secretions being washed away, plus diminished scent perception, the signal was simply not getting across.”[6]
An outcome of a tendency ALREADY observed in [primarily visual] apes?

As humans we have a common sexual position that is quite different to that of other land-based mammals – front to front. The usual explanation is that we wish to kiss...

Again, the author does not take into account the bonobo's love of this way of doing things.

Or might we view the Bonobo as another post aquatic ape?