Earthlings (documentary) - Page 9

Being self-skeptical is what scientific rigour is all about. I just think some scientists take it too far. Then it just becomes the pretence of rigour.

Don't be too harsh on Desmond Morris. I agree with you that some of his speculations in "The Naked Ape" were rather comical (e.g. "breasts for buttocks" "noses for penises" and Elaine Morgan gave those ideas what they deserved. But let's be fair. Speculation is a big part of scientific progress and Morris was only speculating.

If he hadn't written that book, Elaine Morgan might never have been driven to get interested and this idea might have been all but forgotten by now.

Also, Desmond Morris was the first person to spark my curiosity in human evolution. I loved his book "Soccer Tribes" and it was his documentary (The Human Animal?) that mentioned the "aquatic ape" idea and really got me interested in the whole controversy about it.

..dont think you necessarily find lots of sharp tools just lying around the savannah. The point is that humans somehow learned to make these sharp tools for themselves by cracking stones and then chipping away at them. Where better to begin to learn how to do that, than on pebbly beaches where there are millions of them? They may be rounded by erosion to start with, but once they've been cracked against a shellfish, or another pebble they may break open and create sharp edges.

In East Africa, there is an abundance of flint. These stones fracture easily (naturally - they explode, I think because they contain methane gas ) leaving a very sharp and strong edge. Also in areas around volcanoes, there is obsidian, which is a natural glass and it also breaks into sharp edged shards.

Also there are mollusc shells which when broken can have very sharp edges; in fact Australian aborigines still use them as cutting instruments. Flint Hand axes are so numerous all over East Africa (I remember coming across them frequently in the playing fields surrounding my boarding school in southern Tanzania). These are distinct artifacts and more recent but the earliest tools like broken flint rock, obsidian shards or even molluscs shells would now be indistinguishable from naturally broken ones. Crude digging sticks and early throwing sticks will no doubt have degraded over the last six million years and so we may never find proof of these either.

...I agree that it is incredible how anyone can support the multiregional hypothesis but the interbreeding argument is not a strong one as far as I know. Lions and tigers can interbreed and they are separated by much more time than even the multi-regionalists need.

I think it is likely that tigers are basically lions which have adapted to a forest environment. Their cryptic coloration is for the Indian type jungle ecosystem.

Lions have evolved from other cats into a savannah environment. These savannahs are also in parts of India (where there are lions - the same as the African ones) and probably existed in Iran and the Middle East as far west as the Afar triangle in the Horn of Africa - during major glacial periods.

This leads me on to answering David's comment

Andrew MacKay wrote:Knowing the geography of East Africa - I don't recall any areas of seasonally flooded galleries.

... It isn't what it's like now that matters, Andrew, it's what it was like millions of years ago. It is known for sure, that NE Africa has a very different geological history from the rest of Africa/Europe. As a result, it also acted as the last redoubt of C3 vegetation in East Africa, although you wouldn't thionk so to look at it now! The rotating Arabian plate ensured that. For example, the Afar depression was not and could not always have been an arid, hostile salt basin. The effect of the volcanism was to create periods of flooding and of drying, and of new terrain not just in the last 80KY, but the last 7MY. I have linked some references in previous threads on human evolution.

I read somewhere that major glaciations have occurred on this planet every 100,000 years. It is assumed that Jupiter is in such a position, every so often, to pull the Earth away from the Sun, thus making it cooler for a while. I have also read that our Solar System completes a tour round the Milky Way every 110 thousand years or so. So the difference of the Earth from the Sun may also have something to do with this.

It follows that a cooler climate in Northern Kenya, Sudan, Ethiopia, Yemen, Iran would have had a great impact on the vegetation. The Afar Triangle - like all parts of the northern Rift Valley will not have been in the arid state they are today. I believe man came out of Africa during one of these major glaciations - probably about 200,000 years ago.

This is a big topic. I figure that an entirely hairless condition (vestigial pelage) came first for both males and females. The condition was advantageous for the heat of the open savannah, and provided an effective surface for evaporative cooling (perspiration). However, with total hairlessness, the braincase was exposed to harmful rays from the Sun. Selection for a thick hair covering came about subsequently.

Male body hair, particularly beards and moustache areas - and even chest areas may have been selected for at a much later stage. This type of hair distribution would be advantageous in concealment requirements for predation or being preyed upon. Beards, like those twigs and nets adorned by soldiers, break up the characteristic outline - predators or prey are watching out for. This works most effectively in dense forests. So early man on the savannahs may have been quite hairless. Beards and chest hair may have emerged when early man moved into the dark rainforests of Central Africa and also when they reached the forests of India.

Looking at it this way, hairlessness (as in our females) is the default condition and this is confirmed really by the fact that our children are hairless. The masculine characteristics of musculature, extra body hair and aggressiveness are sex linked and must come into play when extra genes governing these characteristics ( on the Y chromosome) are switched on at puberty.

I still believe sexual selection by males has fashioned the looks of human females. The group leaders or alpha males will have had the choice of the most aesthetic or 'fit' females and resultantly their survival had more chance over less aesthetic ones - because they would be more priveledged and would produce more offspring.

Some of these apes must have had a good eye for proportions - look what they produced!

My term savannah ape is an umbrella term to cover all the intermediates between rainforest apes and the type of modern man which moved out of Africa, some 200,000 years ago - as I hypothesised. The term savannah too is a vague generality of which many pedantics will criticise me for. Nevertheless I mean (in the context of Africa) anything which is not tropical rainforest or harsh desert. This can be sparse scrubland savannah, acacia thornbush with the occasional baobab, or open grassland. All these ecosystems would require the apes to move considerable distances on the ground between trees - where I assume they nested safely at night. I think that the open grasslands, though, are more recent and probably a result of tree destruction carried out by hungry elephants. This clearing effect has been observed in Kenya Tsavo National park when elephant populations are excessive.

I estimate the rainforest apes started to evolve into savannah apes sometime within time frame of 6 to 5 million years ago. All we can go on so far are the bones of robust and gracile Australopithecines which date to 3 million years ago but this does not mean that they were not in existence long before then.

As long as conditions are favourable for an animal in its niche environment - there is no need to try other niches.
This is what I call stasis in evolution. The chimpanzee has had its niche in the rainforest for more than 8 million years and as long as that environment continues like that, the chimpanzee will stay like that. It is only when overpopulation occurs that some are pushed out into less favourable - or even harsh environments. It is interesting to consider what we would have looked like if the African rainforest had been surrounded entirely by ocean. We may have ended up as merguys and mermaids! It was just happenstance that the attached area to the rainforest was a more open eco-system. The pioneer apes had to run the gauntlet of a very different lifestyle. That difficult lifestyle favoured intelligence and ingenuity. It fashioned all our distinct attributes.

When I talk about hairlessness in humans - I really mean vestigiality. Yes some women are quite hirsute - even very feminine ones. Hair, like skin darkness, must be controlled by multiple gene sets and there are many different levels of hair growth. Some of these gene sets are on the X chromosomes (of which males have too) but there will be extra helpings of gene sets on the male Y chromosome - making them sex-linked traits. In a similar way there are genes for testosterone production on X chromosomes (in females) but an extra portion on the Y chromosomes. XYY men have a double extra share of testosterone manufacturing genes. Some women have high testosterone levels which can be apparent in their aggressive behaviour or masculine features and so testosterone controlling genes on the X chromosomes can vary considerably between different females.

I think female savannah apes will have found athletic looking males attractive because this would suggest that they are good strong hunters. Strong torsos and leg muscles would be likely attributes selected by these females.
Early savannah ape females, though, were probably quite masculine in build, and quite aggressive in nature - because they may have needed to be strong to defend the nest and young.

That is simply not the case. Even if that is the purpose, why then do we still have rather naked bodies that are easily noticeable? Why don't we have other traits for breaking up the outline of our main body?



Early man will have applied his own camouflage for hunting. Aborigines in Australia still disrupt their outlines with spot marks made with ochre and lime. Many African tribes used to cover themselves in red dust mixed with urine as well as apply ochre in camouflage patterns.

So you are saying we had body hair, then lost body hair, then regained specific body hair?


Yes I am saying we had fairly thick black hair like chimpanzees (dense forest animals are often black) initially. This was reduced to a vestigial pelage (like we have now) and this stuck because it provided a better surface for evaporative cooling. Then those with thicker head hair survived over those with thin head hair. There will have been a change of hair (and skin colouring) to one which blended more effectively with the savannah back-drop - perhaps a reddish colour or a grey colour like elephants and warthogs.

It could be that pubic hair came about on more intelligent stages of savannah apes. Males may have selected females with a 'natural' covering over their genitals. As pubic hair is not sex linked it appeared also in mature males.This probably coincided with the stage where our minds were getting a little too sensitive and too intelligent for our own good. We probably also started worrying about superstitious 'controlling forces' at this time.

I don't think there has been very much done, in the way of hypotheses testing for either (waterside or savannah) idea. I suppose that most anthropologists assume the later hypothesis, without the need for any testing, in the same way that most religious people assume the God Theory. Perhaps I am biased, but I do think that mot waterside proponents are, at least, a little more evidence based. We tend to say - but hold on a minute. If we evolved on the savannah like so many other mammals did, how come we're so different to them? If we came down from the trees and began scavenging/hunting - how come our olfaction is even worse than chimps, let alone any typical terrestrial scavenger? How come we're fat and naked? How come we're bipedal? Big have brains/small teeth etc etc.

In the video, I very briefly describe a set of experiments I did to test just one part of one hypothesis. The wading hypothesis of bipedal origins. I conducted a series of experiments measuring the energy consumption of bipedal locomotion in various depths of water, at various speeds and with various knee flexions. We confirmed earlier studies that showed that on land, a bent-hip bent-knee (i.e. inefficient ape-like) gait was 55-60% more costly than a fully upright (extneded hip, human-like) gait, but most importantly, we showed that this differential was reduced in water. At some sppeds, depths and knee flexions it is easier to move in water than on land. This provides a very clear and elegant solution to the problem of the energy efficiecny model of human bipedalism - how did it begin? How could bipedalism have been practiced even before the anatomical changes evolved to make it efficiient? Shallow water is the perfect answer.

I had five attempts to get the research findings published rejected by the authorities of anthropology. Only twice did it even go to peer review and even then the comments indicated a severe ignorance and bias about this idea.

This research address just one of about a thousand really interesting research projects that are still to be done to test various waterside hypotheses of human evolution but, I suspect, not a single post-graduate student anywhere in the world has ever been encouraged to do any proper science in this area for fear of ridicule by the peers of the potential supervisor.

It's a scandal of Piltdown proportions because the idea has been so badly misunderstood, rejected more on the basis of gossip than of any science and a whole culture of authority-led self-righteousness has prevented any objective study being done in the area for 50 years.

Well, a model of human evolution that took into account females, other than passive sex objects or exclusive child rearers, was one of Elaine's main points in her early books "The Descent of Woman" and "The Descent of the Child".

Her version of the so-called "aquatic ape hypothesis" is purely Darwinian though, you can be sure of that. I think waterside hypotheses are generally more Darwinian than orthodox ones. If they can be criticised, it is for being rather too adaptationist. Opponents to these ideas tend to invoke random drift more than we do.

In my opinion, a key aspect of human evolution is our increased altriciality. We need a model where the mother-infant pair have more time together, more time for play, more time for bonding and more time for the early stages of language to evolve through some vehicle which might enhance breath control. There is no doubt that the relatively food-rich (and especially when it comes to nutirents needed for encephalisation) and predator-poor habitat of the coast is a far more plausible habitat for this to have happenned than the wild, brutal savannah.

There is no doubt that the relatively food-rich (and especially when it comes to nutirents needed for encephalisation) and predator-poor habitat of the coast is a far more plausible habitat for this to have happenned than the wild, brutal savannah.

This is an issue I have a question about. There is clearly a distinction between brain development and brain evolution. The first refers to individuals and their growth and development throughout life, while the second applies to the entire species over many, many generations.

I understand that certain dietary fatty acids found in relatively high concentrations in fish and mollusks(?) are helpful in the development of brain tissue, particularly during fetal development and early childhood. I don't believe anyone disputes this.

However, I have never seen an adequate explanation of how a diet high in fatty acids would lead to the evolution of larger brains. It would seem that if the evolutionary pressures to have greater intellect, hand-eye coordination, and advanced communication were absent, no amount of dietary fatty acids would induce the evolution of larger brains. Conversely, if there were a selective pressure in favor of larger brains in a population that didn't have a diet high in fatty acids, there would be a concurrent pressure in favor of endogenous synthesis of fatty acids (or some other comparable physiological change, such as the evolution of a slightly different type of brain tissue not as dependent on fatty acids).

I'm not attempting to start an argument with you on the subject. I'd just like to understand what mechanism you believe is responsible for translating the availability of fatty acids into the evolution of larger brains.

I did not know of the newspaper rags you mentioned, and I would regard daily newspapers especially the ones mentioned in explaining anything of value as a joke!

In order to clarify my original post, and not sure where my dissertation was I went to Wikipedia in desperation and behold:
The similarity of the subcutaneous fat in aquatic birds and larger aquatic mammals to the fat in humans had already been noticed by marine biologist, Sir Alister Hardy in 1930, while reading Frederic Wood Jones' Man's Place among the Mammals, which included the question of why humans, unlike all other land mammals, had fat attached to their skin. Hardy realized that this trait sounded like the blubber of marine mammals, and apparently began to suspect that humans had ancestors more aquatic than previously imagined. Fearing the backlash of such a radically different idea, he kept this hypothesis secret until 1960, when he spoke, and later wrote, on the subject, which became known as the Aquatic Ape Hypothesis, in academic circles.

Hardy delayed reporting his theory. After he had become a respected academic, Hardy finally voiced his thoughts in a speech to the British Sub-Aqua Club in Brighton on 5 March 1960.

News of Hardy's speech generated immediate controversy in the field of paleoanthropology, and Hardy followed up by publishing two articles in the scientific magazine New Scientist[4]. In the article of 17 March 1960[17] Hardy defined his idea: "My thesis is that a branch of this primitive ape-stock was forced by competition from life in the trees to feed on the sea-shores and to hunt for food, shell fish, sea-urchins etc., in the shallow waters off the coast. I suppose that they were forced into the water just as we have seen happen in so many other groups of terrestrial animals. I am imagining this happening in the warmer parts of the world, in the tropical seas where Man could stand being in the water for relatively long periods, that is, several hours at a stretch." (Hardy 1960:642) Despite receiving some positive feedback in the Letters pages of New Scientist in the weeks that followed, and strong backing from a professor of geography,[18] the idea was largely ignored by the scientific community.

In 1991 a symposium was held in Valkenburg, Holland, titled "Aquatic Ape: Fact or fiction?", which published its proceedings.[31] The chief editor, Vernon Reynolds, rejected the strong version of the hypothesis, but accepted a weaker form, summarizing that "overall, it will be clear that I do not think it would be correct to designate our early hominid ancestors as ‘aquatic’. But at the same time there does seem to be evidence that not only did they take to the water from time to time but that the water (and by this I mean inland lakes and rivers) was a habitat that provided enough extra food to count as an agency for selection. As a result, we humans today have the ability to learn to swim without too much difficulty, to dive, and to enjoy occasional recourse to the water."32]
Despite the conciliatory wording of the summary, and the fact that half of the submitted papers were in favour of the hypothesis, it was reported in the anthropological press that the hypothesis had been rejected.[27]
However there has since been some acceptance. In 2004 Colin Groves, Professor of Biological Anthropology at the Australian National University in Canberra, Australia with co-author David W. Cameron stated that
"..nor can we exclude the Aquatic Ape Hypothesis (AAH). Elaine Morgan has long argued that many aspects of human anatomy are best explained as a legacy of a semiaquatic phase in the proto-human trajectory, and this includes upright posture to cope with increased water depth as our ancestors foraged farther and further from the lake or seashore. At first, this idea was simply ignored as grotesque, and perhaps as unworthy of discussion because proposed by an amateur. But Morgan's latest arguments have reached a sophistication that simply demands to be taken seriously (Morgan 1990, 1997). And although the authors shy away from more speculative reconstructions in favour of phylogenetic scenarios, we insist that the AAH take its place in the battery of possible functional scenarios for hominin divergence.

So now instead of pretending that divine inspiration was involved maybe this conversation should start from where the giants left their footprints, and a more adventurous approach to the existing framework provided may possibly start.

you guys are good

Since I haven’t heard back from AlgisKuliukas, I’m going to assume that he hasn’t had time to return to this topic since I last posted, and I’m going to go ahead and post my response.

AlgisKuliukas, please understand that I respect you and your hypothesis. I have a fair idea of how much study you have put into it, and I’d like for us to be able to discuss this like gentlemen. Please read my most recent post where I politely request that we engage in a critical examination of some of the key elements.

http://www.richarddawkins.net/forum/v...f=4&t=68111&start=50#p1666499

So, here goes.

AlgisKuliukas wrote:Firstly, I think it is likely that increased intelligence would always provide a selective advantage, no matter what the evolutionary scenario. We certainly don't need to postulate any harsh 'Dartian' savannah environment where humans are on the edge of survival for it to have evolved.



It is not true that increased intelligence always provides a selective advantage. There are metabolic and other costs to maintaining a large brain that are not always compensated by a particular animal's lifestyle. If what you say is true, we have to explain why all species on earth aren't going through a process of continual increase in intelligence. We have no reason to believe that crocodiles, sharks, or insects of today are any more intelligent than crocodiles, sharks, and insects of 300 mya. With regard to mammals living during the time of humans, we have no reason to believe that felines, canids, or equids of today are any more intelligent than their ancestors of 5 mya. Of a fishy diet is the limiting factor, and increased intelligence is always a selective advantage, we'd at least expect to see significantly greater intelligence among walruses, seals, nutrias and the like.

No, intelligence has highly variable selective advantage that applies in very specific and individualized circumstances. Mother Nature tends to be stingy. Every feature of every animal is precisely as developed as that animal needs for it to be, no more, and intelligence is no different. (Dawkins relates the story of the Detroit automaker who went through a junk yard looking for parts that never wore out so he could make them out of cheaper materials.)

I wholeheartedly agree with you that we don't have to posit a harsh savannah environment for the evolution of human intelligence. However, a neo-Darwinian adaptationist is going to expect that something in the environment consistently selected for greater intelligence over a fairly long time period. Since the mechanism of selection is differential survival1, for the environment to impose a selection pressure it must impose a situation in which some individuals die while others live. So, whether it was the savannah or the waterside, something about it was harsh.

(AlgisKuliukas, I realize that you haven't made the following argument, so please don't take offense.) Mr. Dosed has suggested that it was sexual selection, but I find that explanation profoundly unsatisfying for advancements that made humans the dominant species on the planet. It's like when you're in a pathology conference and someone points out a strange cell type on the slide. After several people fail to identify it, you all just agree that it must be "connective tissue" and you move on. It's a cop out! Similarly, sexual selection seems to be the default assumption whenever we get stumped. I have no problem agreeing that sexual selection plays a role in sexually dimorphic traits and various other interesting features, but not the bread-and-butter traits that permit a species to out-compete all others and become the dominant species on the planet. It's like saying that sexual selection is what makes cheetahs fast and enabled bats to develop sonar. It just doesn't make sense.

AlgisKuliukas wrote:Secondly, it seems likely to me that Crawford's idea that evolution is often driven by changes in nutrition is very plausible.



I completely agree with you that evolution is often driven by changes in nutrition. This proposition is more than plausible, it is certainly beyond any reasonable doubt. However, "evolution is driven by changes in nutrition" is still a generalization that requires certain assumptions before it translates into the specific hypothesis of encephalization/diet proposed here.

One way in which evolution is driven by diet is the general trend that scarcity leads to increased efficiency while abundance leads to inefficiency and even dependency. Consider the following examples:

Scarcity of water and water consumption needs:

Common rats must drink water. Eating ordinary food with moderate amounts of moisture is insufficient. This is the result of complex physiological factors such as urinary output, moisture lost through skin, etc., and it is due to the fact that common rats are able to obtain drinking water in their environment.

Desert-dwelling kangaroo rats, however, never have to drink. The water they produce metabolically within their cells during oxidation of organic molecules obtained from food is sufficient for them. Kangaroo rats' kidneys and skin (among other things) are modified so that they simply don't lose moisture the way most mammals do. Obviously, this is an adaptation to living in a desert, where drinking water is difficult or impossible to find.

This general trend is seen in every animal in every environment throughout all of nature. When some essential nutrient is scarce in a particular environment, animals within that environment adapt to utilize that nutrient very efficiently.

Abundance of vitamin C and dependency:

The common ancestor of all mammals produced its own vitamin C. We know this because all modern mammals inherited this gene. However, somewhere along the line mutations occurred in several lineages rendering the gene dysfunctional. Keep in mind vitamin C is absolutely essential for collagen synthesis in mammals. If a coyote or tiger is born with a dysfunctional vitamin C gene, it will certainly die in short order. So, how is it that some mammalian lineages survive just fine without the ability to synthesize vitamin C? It's because vitamin C is abundant in their diets.

Somewhere in the distant past there was a dietary change for certain lineages to a food source with plenty of vitamin C. At some point an individual was born with a dysfunctional vitamin C gene, but for this individual there was no survival penalty because of the abundance of vitamin C in the local diet, and he ended up producing just as many offspring as everyone else. Over time, this mutation spread to the whole population (or similar new mutations arose de novo), and the entire population became dependent on dietary vitamin C.

Humans and chimpanzees are two such species. Our common ancestor had a dysfunctional vitamin C gene, and both species inherited it. Today we are completely dependent on dietary vitamin C.

Because of the molecular basis of the neo-Darwinian explanation of evolution (namely that accumulated random mutations lead to diminishing function tremendously more frequently than improved function), this trend is essentially universal throughout nature. When an essential nutrient is abundant in the environment, species utilize it less and less efficiently over time and may even become completely dependent on it.

Challenge to the encephalization/diet component of WHHE: The way I understand it, the scarcity/abundance pattern provides a challenge to the encephalization/diet component of the WHHE. Please correct me if I'm wrong, but this is how I understand the encephalization/diet argument:

1) There were selection pressures for increasing encephalization in early hominids.
2) At some point these pressures failed to generate continued encephalization because the diet of early hominids lacked sufficient amounts of certain critical nutrients.
3) Once these hominids began consuming fish/shellfish they obtained the necessary nutrients and the barrier to increased encephalization was lifted.
4) The result was that the trend in increased encephalization was able to continue.

Am I close?

Ok, so here are the problems I see with that explanation:

1) There is no reason to believe that early hominids lacked sufficient omega-3 fatty acids in their diets. Omega-3 fatty acids are found in high concentrations in the flesh of grass-feeding ungulates of all kinds, as well as in many plants, plant seeds, and nuts. Just as one example, flax seed is 6 times richer in omega-3 than fish oils. Modern populations that eat no fish at all have no trouble developing and maintaining ordinary human brain size with other sources of omega-3.

2) There is no reason to believe that early hominids were any less efficient in utilizing dietary omega-3 fatty acids, metabolizing them, or secreting them in breast milk than modern humans are. Why is this significant? Because modern humans do not require a diet of fish or shellfish to maintain our current brain size ("modern" = any time in the past 50,000 years). There have been myriad cultures around the world in the past tens of thousands of years with diets containing zero shellfish and minimal if any fish of any other kind. If a diet of fish/shellfish was a barrier to encephalization, how would any of these people have maintained ordinary human brain size and intelligence? We would expect to see a return to early hominid brain size for humans who didn't maintain a fishy diet. Otherwise, we have to propose that there was a physiological mechanism by which recent human populations liberated themselves from a high fish diet and somehow maintained large brain size, and we have to explain why that physiology wasn't adequate for early hominids to develop large brains with a non-fish diet in the first place.

3) According to the general principle that scarcity leads to increased efficiency of utilization, it does not follow that there would have ever been a dietary barrier to encephalization. Humans obtain varying amounts of omega-3 fatty acids from all manner of animal flesh, plants, and plant seeds. This essential nutrient is concentrated and secreted in breast milk2. Whatever selection pressures led to increasing brain size in early hominids would have led to a simultaneous increase in the efficiency of utilization of these nutrients.

Here's the basic mechanism: Within the population of early hominids, there would have been varying brain size (and corresponding varying intelligence) as well as varying concentration of omega-3 fatty acids in breast milk from individual to individual. The following combinations of results would have been produced (among others). Let "small" mean tendency toward small brain size, "large" represent tendency toward increasing encephalization, "adequate" represent efficient utilization of dietary fatty acids such that adequate amounts for large brain development are found in breast milk, and "inadequate" just the opposite of adequate:

a. small + adequate >> no increasing encephalization
b. small + inadequate >> no increasing encephalization
c. large + inadequate >> no increasing encephalization
d. large + adequate >> INCREASING ENCEPHALIZATION

As long as there was a selective pressure toward increasing brain size, there would have been an accompanying pressure for efficient utilization and secretion of nutrients in breast milk. The combination of step d. would have prevailed in the population, and whatever dietary barrier there may have been to encephalization would have been addressed at the same time as brain size increased. Now, it is not debatable that step d. (or some physiological equivalent) took take place at some point, because it is an observable fact that humans all around the world, eating extremely varied diets many of which contain little or no fish, have been able to obtain adequate amounts of omega-3 fatty acids for current levels of brain development. The question is when did this happen.

The WHHE explicitly or implicitly proposes that this liberation from a fishy diet is a recent development ("recent" = within the past couple hundred thousand years, after the evolution of our large brain). If this is true, we have to explain how modern humans came to utilize fatty acids efficiently while early hominids were unable to.

4) According to the general principle that abundance leads to decreased efficiency of utilization and dependency, it follows from the WHHE argument that humans would have become dependent on fish/shellfish for current levels of brain development. As concentrations of essential nutrients increased in the diet, the population would have ceased utilizing them efficiently. The mechanism for this would be similar to that of vitamin C dependency:

Let's imagine a population where females concentrate a particular amount of fatty acids in their milk. It is sufficient for slightly larger than chimpanzee-sized brains size (for example), but insufficient for increasing encephalization. Then they start eating fish/shellfish. The result is that the increased dietary nutrients appear in breast milk or directly in the diet of the young. Now, what would happen to an individual who didn't concentrate fatty acids efficiently in her milk? Well, elevated levels in her diet would result in her milk having the nutrient anyway, and her offspring could obtain it directly from the fish they ate.

Her mutation (which would be harmful in some other environment) would be able to spread throughout the population. Similar mutations in other females would also be free to spread. Over the same time period as brain size was increasing due to abundance of essential nutrients in the diet, the ability of the species to efficiently utilize those nutrients would diminish. The result would be similar to our current vitamin C dependency. Modern humans (meaning any time in the past 50,000 years) would have been restricted to environments where fish/shellfish are abundant.

AlgisKuliukas wrote:It is certain that certain limiting factors involved in brain growth are plentiful in the oceans.



This statement is a bit imprecise. The imprecision is in the words "limiting", "growth" and "oceans". It gives the impression that it is an established fact that brain growth is definitely limited by terrestrial diets. While this is necessary for your hypothesis, it is obviously not true, since most of the human race over the past 50,000 years has had a terrestrial diet and had no problem maintaining a large brain. It also fails to distinguish between brain development in individuals and brain evolution over time. It also fails to specify where in the ocean these factors are found.

It would be more accurate to say that nutrients that contribute to human brain growth are plentiful in the flesh of fish and shellfish.

AlgisKuliukas wrote:These factors were clearly not a limiting factor in the early evolution of nervous systems and brains, since that early evolution occurred in the sea.



Again this statement is extremely imprecise to the point of being misleading. It gives the impression that a marine environment in general promotes nervous system development. The simple fact that there were no limiting factors to early nervous system evolution in the sea does not lead to the conclusion that there are limiting factors on land. If this were the case, we should expect for sea life to be the most intelligent -- fish, sharks, and sea turtles, as opposed to lions, wolves, apes, etc.

I believe that generalizations like this hurt your argument because they are extremely vague and lack any reference to a mechanism.

AlgisKuliukas wrote:Therefore it makes sense that a return to a partial reliance on the marine food chain would 'liberate' any limiting factors that terrestrial life might have imposed.



If this were true then turning away from the marine food chain would be expected to replace the barriers to enchephalization, and we'd see progressively diminishing brain size in all animals as their distance from the coasts increases. In humans we'd expect decreasing intelligence in grain farmers, reindeer herders, and many, many of the world's other populations. In fact, we'd expect to see the largest brains, greatest intelligence, most sophisticated language, and most advanced tools among coastal populations. Is there any evidence to support that?

AlgisKuliukas wrote:If there were certain nutrients that under normal (savannah-based) circumstances limited certain aspects of brain development - for example Iodine and omega 3 fatty acid deficiency - which suddenly became plentiful, it is only to be expected that any mutations that occurred in that area of metabolis could have made that population still more vulnerable to those deficiencies and more able to take advantage of plenty.



As I have already pointed out, if there were deficiencies in dietary nutrients, any selective pressure for greater encephalization would have resulted in a simultaneous pressure for more efficient utilization. Similarly, an abundance of those nutrients in the diet would have led to inefficient utilization and dependency. Since all human populations everywhere, including those that have returned to the savannah, have typical modern human encephalization, there doesn't appear to be a good reason to suppose that there was ever a barrier or that we overcame it by changing our diets.

AlgisKuliukas wrote:I suppose the other thing is to put the argument the other way around: Let's imagine that a group of early hominids, that lived on the coasts, were able to become more intelligent simply by eating certain foods and there was sufficient energy in that food to fuel this brain growth then it is hard to conceive of a scenario why they wouldn't have done so?



If there were a savannah-diet barrier, and if that barrier were removed by returning to a marine food source, and if the waterside environment presented selection pressure for increasing intelligence, then I agree that we would expect to see increasing brain size over time. But that conclusion is based on a series of ifs all of which have to be true and some of which seem pretty speculative.

Let's apply this to animals other than humans. Is there any reason why any coastal mammal wouldn't benefit from increased intelligence? If simply eating certain foods fueled their brain growth, why haven't they experienced something similar to the explosion humans underwent?

The answer is that according to the basic mechanisms of neo-Darwinian evolution, abundance of something in the diet does not lead to increased efficiency of utilization of that nutrient over time. Instead it leads to less-efficient utilization and ultimately dependence (like with vitamin C).

The mechanism that leads to evolutionary development of something is selective pressure in the form of differential survival1. In an environment in which there was selective pressure for increased brain size we would expect to see increased brain size. If there were a limiting factor in the diet, we'd expect to see a simultaneous evolution of increased utilization or endogenous synthesis of that nutrient. In an environment where there was selective pressure for increased brain size AND there were abundant critical food sources, we'd expect to see an increase in brain size and a dependency on those specific food sources.

My thanks to OHSU for giving me a notice about this very interesting discussion on the waterside hypothesis.

However, the bulk of the past pages of discussion in this string of Evolution and Natural Selection have dealt with the subject of brain development
The waterside hypothesis should fail entirely to deal with this subject. The only thing involved here is that a waterside lifestyle would not preclude nor promote larger brains.

The waterside hypothesis proposes that mans split with chimps involved adapting to a shore environment rather than an arboreal environment, and that this promoted bipedalism and an assortment of other adaptations. A large brain was not amongst the adaptations we see at this time.

Now let us look at the time frame and the evolutionary changes that resulted.

at 10 mya we split from the gorillas.
at 6 mya we split from the chimps
at 5.8 mya we split from the bonobo (some suggest this was a chimp-bonobo split)
at 3 mya we had well developed bipedalism
at 2 mya we began to develop larger brains
at 1 mya we have a modern man
at 72,000 we have an eruption on Toba, and the bottleneck in population.
at 60,000 we have a shore fisher gather movement out of Africa along the coast of the Indian Ocean.

(feel free to update or correct my timeline if you have more up to date information)
The Chad fossil at 7 mya seems to be just at or before the chimp human split, but may be in the gorilla lineage rather than the human one. The evidence to support this as a bipedal animal is quite thin.

What should be immediately obvious is that whatever caused bipedalism (5 to 3 mya) was quite different than what caused larger brains (2 to 1 mya).

Our discussion of larger brains should be a very different subject than our discussion of bipedalism. Pretending the two are related is much like setting up a strawman. (I find the throwing hypothesis of brain development to be more convincing than other proposed ideas)

By 60,000 ya we had the clear ability to live as shore fisher gatherers. We must at some point have developed adaptations that made this lifestyle possible, so some period of a waterside lifestyle would seem to be well indicated. The skills did not develop overnight. When did we develop waterside skills, and just what changes would we expect to see from a waterside environment?

1 ) bipedalism ... wading clearly promotes this.
2 ) a subcutaneous fat layer. We have this although it is the wrong kind of fat, so we should presume a non-exclusive semi-aquatic life, not a fully aquatic life.
3 ) hair modification. Most aquatic animals develop oily hair, loosing the hair altogether is also a reasonable modification.
4 ) beginning tool use. Wading sticks, rocks to crack shellfish shells, and perhaps even fishing spears would be the first obvious tools. floating logs and perhaps rafts are an outside possibility. Seals use rocks to crack open clams, so it is entirely reasonable to think a shore living ape would also. We know chimpanzees (at least one tribe) are using rocks to open nuts. The skill transfer, shells to nuts is an easy one to expect.

I feel the Waterside Hypotheses of Human Evolution has merit, but proponents should not let it get derailed with strawman arguments such as large brains not being an aquatic feature. In the time period from chimps to Lucy, we see a full change in bipedalism, but a minimal change in brain size.

On February 24 2009 09:57 SakiSaki wrote: As much as I in general always have felt some despise towards idealists(for no real reason I might add) the faked pragmatism and nihilism of our generation seriously fucking pisses me off. Everyone is hiding behind bogus pragmatic excuses for doing nothing when 90% of the time the motives are simply egotistical and the driving factor is lazyness. Its funny how nobody ever provides a better argument for eating meat than simply "i enjoy it" which in my opinion is an unacceptable excuse for making animals suffer. You cant just disregard the message of PETA because they are on a high horse, have dreadlocks or smell funny, and you definitely cant look down on them. They are doing the world a greater service than most of you guys ever will. As for eating meat, I dont necessarily think its anything wrong with killing an animal to eat it in terms of just the act of killing, the world wide implications excluded. However, making animals suffer in the process is unacceptable. I wouldnt be suprised if in 200 years people will look upon how we treat animals today in a similar way that all of us look at slavery. Im not saying animals and humans are equal, but that doesnt give us a free pass to do whatever the fuck we want with a cow. Personally I have been thinking of going vegetarian on and off for years, I still havent managed to take that step and that doesnt make me feel good. However, I almost exclusively eat meat from swedish organic farms which are pretty well regulated and where I like to think the suffering of the animals is minimal. That is probably not a good enough justification in terms of moral responsibility though, but atleast I have the balls to admit it. To Loco: Mad props sir, you have a stronger character than me and for that I applaude you. To CrownRoyal: It seems you have similar delusions of grandeur regarding intellect as you have in poker. Guess what? If this thread was a poker game, you would be the micro stakes grinder.

I eat meat because its extremely enjoyable and tasty is not a good reason? dude you have your priorities fucked up here, last time i checked i have extreme priorities in enjoying my life every second as possible in everything i do.

If you think its not relevant to give up what you consider a total pleasure every single day for the rest of your life then your retarded, because it is for people who like meat, most vegans werent big fans of meat anyway (despise what some say lol) i know many people who rarely eats meat not because of dumb moral views, just because they dont like it much and/or its hard to digest.


For Loco, ok you listed a lot of pretty things, and you failed again, donating $1,000 a year will give what like a thousand times more to the enviroment and food problem? and i think in getting short, oh but wait "you dont know where the money is going", then make sure you choose the proper association before you donate to them and problem fixed.

So if you are aware donating money is more effective than not swallowing cows why dont you eat meat and donate instead?, oh but i already know this, because giving this money wouldnt give you this inflated maskeraded sense of awareness superiority.

i see your point... but i beg too differ because:



and if we take



this obviously implies that

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