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...

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Anatomical evidence: the human body

Take a look at the human body and you will notice that we differ from our closest living relatives (bonobos and chimpanzees) in many obvious anatomical ways. This is strange considering that our genome is 94-96% identical. Most of these differences, therefore, are likely to be the result of environmental factors shaping our evolution, and it is worth noting that most, if not all, of these features are shared by many aquatic, semi-aquatic or historically acquatic species.

Anatomical differences between Pan and Homo possibly relevant to our semi-aquatic past have been argued to include:

• a relatively hairless body*
• orthograde / vertical but flexible spine, with head and legs in one line*
• longer, thinner legs* (as a result of wading in archaic Homo)
• much larger brain*
• fat / thick subcutaneous fat tissues*
• superior breath control abilities*
  
• protruding nose with downward pointing nostrils and midfacial prognathism
• poor olfactory sense (smell)*
• larger penis in males*
• angled vagina in females*
• larger fatty breasts in females*
• menopause*
• floating babies*
• lanugo hair*
• squalene-rich sebum & vernix*
• copius thermo-active sweating*
• multi-pyramidal (renculated) kidneys*
• spleen enlargement (for diving)*
• (salty) tears*
• eyebrows
• long hair and male baldness
• autonomic wrinkling of fingers when submerged (research pending on whether this exists in other apes)
• flat feet with relatively long first and last digital rays, and short close toes*
• webbing between finger and toes*
• platymeric (dorso-ventrally flattened) femora*
• underwater vision / colour vision*
• wide and deep thoraxes (as in most shallow-diving endotherms)
• water loss inefficiency: tears / dilute urine / moist faeces / the inability to drink much at a time*
• thicker tooth enamel (for possible consumption of shellfish)

Differences in archaic Homo - Homo erectus, Homo neanderthalis, etc., (since lost or decreased) include:

• platycephaly (flat skulls)*
• pachyostosis (heavy, dense skeleton)*
• paranasal sinuses (also in Gorilla and Pan, He, Hn, Hs) and freshwater species (not marine)
• ear exostosis (surfer's ear)
• larger brains (decreased)

Features or behaviours that may possibly be associated with an ancestral semi-aquatic or littoral lifestyle

• a natural attraction to coasts, shores and rivers, and a need to immerse ourselves in water on a daily basis (if possible)
• the ability to swim before we can walk*
• the ability to speak / grammatical language / song*
• habitual bipedalism
• ease of water birth*
• assisted childbirth*
• maternal tolerance for allomaternal assistance*
• moro reflex
• infant swimming reflex*
• gasp reflex / SIDS
• accurate overhand throwing (assists fast swimming)
• requirement for DHA* (found in seafood) for brain growth, mental health, etc.
• high need for water, sodium, DHA and iodine*
• small mouth with smooth palate (suggests soft & slippery foods, such as shellfish)
• MYH16 inactivation (weak masticatory muscles, as above)
• descended hyoids (function debated. Possibly for suction of seafoods)
• aversion to foul odours
• poor climbing abilities*
• care of the infirm or elderly*
• grandparenting (see also menopause, above)*
• cleanliness (bathing & washing)
• personal adornment
• parasites – at least 3 species that require water to complete their cycle
• a variety of unique ailments (obesity, asthma, acne, cretinism, seborrhea, male pattern alopecia, vasomotor rhinitis, sinusitis, sleep apnea, Cheyne-Stokes, varicosis, orthopedic problems, etc.)

Further research is needed to clarify the function and/or prevalence of:

• descended larynx (ascended larynx in cetacea)
• degenerated epiglottis
• muscle myoglobin (for deep diving mammals)
• handedness

*Comparative anatomical features shared with some aquatic or semi-aquatic species

List of Uniquely Human Features

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