The Aquatic Ape Hypothesis

 

Many schools in the USA still don’t teach evolution in school curricula, some others teach them but mention “controversial” as a label to the theory. Controversies are always there on human origin. It is a concept of debate between religion and science. Was adam and eve was the origin of humans and their sin gives us the life that we are living today or the origin was a total accident? through any sudden changes in evolution human being came into existence through homo Erectus, homo Habilis and finally homo sapience. There are many controversial theories of human evolution as all are the examples that we got from the shreds of evidence from the past. One of the theories is the Aquatic ape theory.

What is an Aquatic ape?

 Aquatic Ape is the conspiracy theory about the origin of humans or apes from aquatic brothers of ours. This theory talks about the aquatic evolution of our ancestors and how apes evolved in aquatic situations.

The theory proposes that as the early ancestors ate fruits and nuts they also consumed various kinds of aquatic foods mainly weeds and tubers later various kinds of shellfish. It is been told that apes took a divergent from the evolutionary line of land and went to adopt the more aquatic lifestyles, which lead to various evolutionary changes in them, some of which are still present in us. Later with the Pleistocene cooling, they left the aquatic lifestyle and came back to the ground and started hunting and gathering and scavenging food.

The Hardy/ Morgan Hypothesis

Hardy's hypothesis as outlined in the New Scientist was:

My thesis is that a branch of this primitive ape-stock was forced by competition from life in the trees to feed on the sea-shores and to hunt for food, shellfish, 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.

 Morgan summed up her take on the hypothesis in 2011:

Waterside hypotheses of human evolution assert that selection from wading, swimming and diving and procurement of food from aquatic habitats have significantly affected the evolution of the lineage leading to Homo sapiens as distinct from that leading to Pan.

 Features in Humans that gave rise to the theory

1. Lack of Body Hair- Lack of body hair in primates is a very rare thing in terrestrial animals. all the mammals that some little to no fur at all are mostly aquatic and some are even marine.
2.  Subcutaneous Fat Layer- Humans have a huge amount of subcutaneous fat layer in the body which is quite rare in terrestrial animals and is very common in aquatic animals. This kind of fat is basically a water blubber fat that keeps the body warm for the animal to store energy from aquatic habitat and icy cold climates.
3. Bipedality- The bipedalism of humans are habitual and complete, although bipedalism is seen in many primates and other animals while in hurry or in need. The complete erectness of the spine is quite unique in humans and penguins. The Lateoli man’s remains match with the penguins as they had giant feet and short limbs.
4.  Hair Follicles on Human Head- In humans men have shorter hair than women. The human neck, face and upper torso are very large sebaceous glands and are not connected with terminal hair follicles like other mammals or other parts of the body. These secrete sebum out of the body. This is also very common in aquatic birds. these unique sebaceous follicles are also a common field of humans with aquatic animals.
5. Intranasal Adaptations- All aquatic animals have the ability to close the nostrils and they use this technique very much underwater. Humans also have very good control of nostrils closing. Our nostrils can close underwater and even a slight change in humidity while lying down. This makes the erectile tissue of the conchae swell and shrink ad stop the canal. This can stay up to 90 secs which is quite seen in some Korean women swimmers.
6. Diluted Urine- Human urine has 1430 m0 sm/l, which is between mammals to free access to fresh water and marine mammals, but is far below that of savanna dwellers. According to the salt concentration of human tears and urine, human ancestors probably lived once near salt or brackish waters, in a mixed lend/water habitat or at simultaneously or successively different aquatic habitats.

These are some examples of the aquatic resembling features that are present in humans. There are many more features that are claimed to come from the aquatic lifestyle, but I just mentioned some of them.

Possible Explanation

Verhagen told that there can be some possible scenarios from where the aquatic adaptation came into being. Having so many aquatic features means that once our ancestors spent a considerable amount of time swimming and diving. There can be four suggested possible stages in our evolution : (i) from a water-loving forest-dweller (ii) to a freshwater-plant-eater (iii) to a coastal omnivore, and finally (iv) to a terrestrial hunter-gatherer.

Conclusion

The Aquatic Ape theory is generally ignored by anthropologists, but it has a following outside of academia and has received various celebrity endorsements like David Attenborough.

Some Academics have commented on the aquatic ape hypothesis and rejected almost all of the claims related to the hypothesis. Other academics have argued that the rejection of Hardy and Morgan is partially unfair because other explanations which suffer similar problems are not very opposed. A conference devoted to the subject was held at Valkenburg, Netherlands, in 1987. The conference had 22 participants including academic proponents and opponents of the hypothesis and several observers headed by the anthropologist Vernon Reynolds of the University of Oxford. His summary at the end was:

Overall, it will be clear that I do not think it would be correct to designate our early hominid ancestors as 'aquatic'. But at the same time, there does seem to be evidence that not only did they take to water from time to time but that the water (and by this I mean inland lakes and rivers) was a habitat that provided enough extra food to count as an agency for selection.

 Criticism

1. Anthropologist John Langdon considered the Aquatic Ape Hypothesis under the heading of an "umbrella hypothesis" and argued that the difficulty of disproving this kind of thing meant that although the idea has the appearance of being a Parsimonious explanation, it actually was no more powerful an explanation than the null hypothesis that human evolution is not particularly guided by interaction with bodies of water. Langdon argued that however popular the idea maybe with the public, the "umbrella" nature of the idea means that it cannot serve as a proper scientific Hypothesis.
2. Anthropologist John D. Hawks wrote that it is fair to categorize the AAH as pseudoscience because of the social factors that inform it, particularly the personality-led nature of the hypothesis and the unscientific approach of its adherents.
3. Eugenie Scott has described the aquatic ape hypothesis as an instance of "crank anthropology" like other pseudoscientific ideas in anthropology such as alien-human interbreeding and Bigfoot.