Aquatic Ape Human Ancestor Theory

Aquatic Ape Theory - What is it?

A Brief Summary of AAT - key arguments

A Brief History and Key Proponents of AAT

When / Where / How?

Ape to Human Evolution Timeline

Alternative theories of human evolution

Wikipedia and the scientific community

... Anatomical Evidence
... Bipedalism
... Birth and babies
... Brain
... Breath control
... Descended larynx
... Diet
... Diseases
... Fat
... Fingers, toes and feet
... Furlessness
... Hair and baldness
... Human ailments
... Kidneys
... Language & Song
... Menopause
... Nose
... Olfactory sense
... Pachyostosis
... Paranasal Sinuses
... Platycephaly
... Reverse osmosis
... Sexual features
... Sleep (USWS)
... Surfer's ear
... Sweating
... Tears
... Underwater vision
... Viruses
... Waterside environments

. Homo Ancestors
... Trachillos bipedal hominids
... Homo erectus
... Homo neanderthalensis
... Sea Gypsies/ the Moken
... Homo sapiens - water afinity
... Coastal Migration
... Pan and Gorilla ancestry
... Semi-Aquatic Animals

. Testable Hypotheses
. Fossil evidence
. Genetic evidence
. Paleoecological evidence
. Retroviral marker in apes
. Acheulean handaxes

A call to scientists...

Recent News and Updates

Books and publications


Videos links



Infiltrating Transdermal Reverse Osmosis

If our semi-aquatic ancestors did indeed survive the Miocene droughts on the seashore, and spread around the coastlines of Africa, Asia and even Europe during the Pleistocene, what did they do for fresh water? Of course in many instances they may have been close to fresh water sources such as rivers, lakes or natural springs, but - besides the dangers posed by carnivorous predators and water born parasites and gastro-intestinal infections - many thousands of miles of coastline would not have been close to fresh water, creating a very basic problem for a species that probably spent the majority of its daily life swimming and diving for marine foods.

Gareth F. Morgan decided to take a look at this question when he read about a man who suffered from eczema and could find relief only by spending many hours soaking in the bath. The man was puzzled as to why he frequently had to get out of the bath to pee, especially as he never drank anything while in the bath. Where was all the water coming from?

Being immersed in water produces a powerful diuretic response caused by a hormone called atrial natriuretic peptide, which is why we feel the need to pee when we get in the water, but if we stay in the water for many hours, without intaking fresh water, surely we would soon become dehydrated?

The general consensus regarding human skin is that it is 100% waterproof, and this is true in that the 'stratum corneum' itself is completely waterproof. However, as Morgan states: "there is a global hundred billion dollar skin moisturiser industry based on the premise that skin can indeed absorb moisture. There is also an eight billion dollar market for medicated skin patches that can deliver hormones, pain killers, nicotine and a whole range of other water-soluble substances into the bloodstream."

Homo sapiens is unique among apes in having eccrine glands distributed over the entire body surface. Reverse osmosis is a well documented function of the eccrine glands, where the epithelial sodium channels in the apical membranes of the ducts reabsorb salt before perspiration excretes mostly water. Human sweat is less salty than the interstitial fluid that sweat comes from due to this salt being reabsorbed. Sodium channels are not present in apocrine glands (armit/groin), which is why sweat from these areas is much saltier than from the rest of the skin. Sodium channels do exist in sebaceous glands, but these excrete sebum rather than water, which is thought to be for waterproofing the hair in associated follicles. The layers of skin under the stratum corneum are also well provided with sodium channels to enable the distribution and balanacing of sodium and potassium ions throughout the tissues. A clearly marine adaptation like eccrine reverse osmosis in modern humans would significantly reduce the likelihood that naked apes acquired this adaptation on the savannah.

reverse osmosis experiment apparatusMorgan devised a series of experiments with the aim of discovering whether water (fresh and/or salt water) could be absorbed through the eccrine glands transdermally, and whether the amount was sufficient for normal hydration. If so, he wanted to know if surplus salt from the sea would be excreted via the kidneys or filtered out by sodium channels before absorption.

He conducted 4 experiments. In the first, the subject's hand was immersed in a sealed container of water for 3.5 hours. The weight of the water was measured before and after the experiment. In the second, the subject spent 4.5 hours in warm, fresh water, without eating or drinking. In the third, the subject spent 4 hours in the sea (Mediterranean) and undertook moderate exercise, without eating or drinking. In the fourth, 5 subjects spent 4 hours immersed in the sea and were compared to four control subjects in an interior environment. Measurements were taken of body weight, urine quantity, urine density, air & water temperatures, before, during and after the experiments.

What he found was that, in the first experiment, the hand absorbed 10g of water. In the second a total of 250g of water was absorbed. During the second salt water experiment, it was found that participants produced an average of 1050g of urine vs 113g on land (control). They lost an average of 1261g of bodyweight vs 454g on land (control). Therefore, when immersed, the participants produced an extra 234g of urine per hour but lost 193.25g of bodyweight per hour compared with the control. The amount of extra urine produced was significantly more than the extra weight lost and therefore must have included water absorbed from the sea.

Regarding the density of the urine produced, the average density of the urine produced by the immersion subjects was 1018.3g per litre, compared to 1030g per litre for the controls, indicating that the immersed participants were better hydrated. After the experiment, none of the subjects reported feeling thirsty.

Morgan plans to complete the study with two complementary experiments. The first will use heavy water (DO2) to moisten the skin of a volunteer, followed by a saliva test to show that deuterium has been absorbed and dispersed throughout the body fluids. This is intended to put beyond doubt the fact that water is absorbed through the skin. The second experiment will involve a six to eight hour continuous immersion in sea water to confirm that the observed effects are sustained over time.

If the results of the experiment are as conclusive as the preliminary findings have suggested then it would have implications for several fields of research. For instance, in a 32 year long study Professor Steven Blair, University of South Carolina, discovered that swimming confers previously unsuspected health benefits far in excess of those provided by other forms of exercise. In a study of more than 40,000 men ages 20 to 90, he found that swimmers were 50 percent less likely to die during the study period than were walkers or runners. No reason for this disparity has yet been suggested.

One possibility is that, if water is absorbed through the skin, then it must help to flush out every inch of the interstitium as well as all the dead cells, lymphocytes, proteins and fats that can accumulate in the lymphatic system and which may go on to form arterial plaque, whereas water absorbed from the gut will take a more direct route to the kidneys. This could have major implications for a number of cardiovascular conditions. [1]

Participants in the reverse osmosis experiment

For further details of the third experiment, see below:


Reverse osmosis is a well documented function of the eccrine glands. The epithelial sodium channels in the apical membranes of the eccrine gland ducts reabsorb salt before perspiration is excreted to maintain water and salt homeostasis.

A series ofexperiments was devised to determine the following matters: whether water can be absorbed through the skin; if so whether the amount of water absorbed is sufficient for normal hydration and thirdly whether reverse osmosis can operate in both directions, that is, whether a person immersed in sea water could absorb water through the sweat glands and, if so, whether surplus salt would be excreted via the kidneys or filtered out by the sodium channels before absorption. An adult male subject underwent a series of immersions and measurements were taken of changes in weight and the quantity and density of urine produced. It was found that fresh water was absorbed at a rate sufficient to maintain normal hydration in both fresh and salt water. In evolutionary terms this mechanism would have provided a means of surviving a drought of any duration simply by adapting to a seafood diet, whereas land based hominins would perish after just a few days without water. [Read the paper 2]


Website: F. Mansfield, 2015

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