Other non aquatic species have the mammalian diving reflex.okay, how about the ability to be born and know how to swim?
i don't know what mammals you are talking about but whales and dolphins have the same fat layer we have (no other primate has by the way) to keep them and us warm and buoyant and it also prevents hair growth. speaking of things we have that no other primate has is the membrain in our nose that allows us to hold our breath, why? we also have webbing between our fingers and toes that no other primate has, why?i dunno, how do you explain that every other aquatic and semi aquatic mammal that doesn't dive for long periods of time have very dense fur?
you are correct the current idea is the cooling of the body which i say is an added benefit and not the reason for once we lost the hair we evolved sweat glands in the skin or something to that effect. although i admit i am no expert.Other non aquatic species have the mammalian diving reflex.
I'm partial to the idea that our lack of hair is an adaptation for hunting in the heat of the day. Persistence hunting - Wikipedia, the free encyclopedia
this refutes it pretty well.* Hairlessness – Most aquatic mammals that are comparably sized to humans are not hairless, but have dense, insulating fur and swim very well, with fatty layers beneath the skin. Aquatic mammals do not vary greatly in their body hair, while humans do. Hairless skin is also only an advantage for fully-aquatic mammals that dive, swim quickly or migrate long distances such as whales and dolphins, and only appears and is an advantage for extremely large aquatic mammals who would overheat with large amounts of body hair, who are fully-aquatic and have evolved as an aquatic species for millions of years. The loss of body hair is also explainable through a lower parasite load, and maintenance through sexual selection. Furthermore, while shaving human swimmers to eliminate the little body hair that remains results in a minor decrease in drag, this cannot be extrapolated to a beneficial effect of loss of a full coat of fur, which has been shown to have superior drag reduction ability. While relative hairlessness and hair direction is cited as an adaptation to swimming and diving, there is no evidence of similar skeletal or soft tissue adaptations that are expected to accompany such adaptations.
* Breath control – The position, evolutionary timing of changes, and size of the nerve openings in the vertebrae suggest that breath control in humans improved because of the increased complexity and use of speech rather than an aquatic phase of evolution. In addition, breath control is thought to be preceded by bipedalism, which frees the muscles around the upper torso from locomotion and allows breathing rates to occur independent of locomotion. Voluntary speech is thought to be a sufficient evolutionary pressure to explain breath control, independent of other explanations. The vocalizations of dolphins and other aquatic species are not thought to be comparable to humans. In addition, certain birds have speech and breath control comparable to humans, without a phase of aquatic adaptation.
* Diet – a broad terrestrial diet would ensure sufficient access to required essential fatty acids without a high consumption of seafood and the "best" fats found in fish are from cold water fish that did not occupy the same coastal environments as humans. In addition, the requirements of these fats are very minimal, with no evidence that extra fats would result in an evolutionary pressure towards a larger brain. Humans without access to shoreline foods also develop normal brains.
* Diving reflex – the mammalian diving reflex is exhibited by terrestrial mammals as well as aquatic ones and humans have not been compared to other living hominoids; there is not enough information on for this reflex for it to be used to support the AAH.
* Body fat – the subcutaneous fat distribution in humans is more similar to a domesticated animal than an aquatic one, and is nearly identical to that of other primates. The subcutaneous fat of aquatic mammals and humans also seems to serve different uses – it forms the streamlined shape of seals, while in humans it is used for sexual selection. In addition, the distribution of fat and blood vessels allows for improved thermoregulation, as hot blood from the body can bypass the fat to radiate heat through the skin.
* Bipedalism – the disadvantages cited for bipedalism within the AAH are often the result of comparing humans to medium, terrestrial quadrupeds, but human evolution never included a period of quadrupedal locomotion. Instead, human evolution features mainly brachiation, suspension and climbing as the primary method of transportation, with a gradual increase in bipedal locomotion over time. In addition, the elongated lower limbs of humans, which is explained as improving swimming speeds, appears only after the evolution of the Homo genus.
* Descended larynx – the human larynx is not shaped like the larynxes of aquatic animals; it forms and descends as an infant begins to speak, making it easier to aspirate water and drown. Additionally, a descended larynx is not unique to aquatic animals, and permanently or temporarily descended larynxes are seen in dogs, pigs, goats, monkeys, big cats, deer, and young chimps. Mainstream anthropology explain the descended larynx as an adaptation to improve vocalizations by increasing the number of pronounceable vowels and improving the ability of humans to control their speech.
* Nose shape – the shape of the human nose is extremely variable within the species, and believed to be related to climatic adaptations and the warming and moistening of air before it enters the respiratory tract, not to prevent water entry while swimming. In addition, the muscles surrounding the nose show no evidence of having been previously more developed, but are part of a complex of muscles that are specially developed in humans to show emotion and aid in communication.
* Interdigital webbing – Morgan's claims for syndactylism, the presence of webbing between the fingers, were based on the purported "rareness" of birth defects "adding" features normally thought absent from an evolutionary order. Interdigital webbing is not the "addition" of new tissue, it results from the failure to eliminate skin cells connecting the fingers, a process common to all tetrapods.
* Sebaceous gland – many aquatic animals have rudimentary or no sebaceous glands. In humans, sebaceous glands become active during puberty with men having far more than women while women have much better scent receptors. This suggests the glands are sexually dimorphic for sexual selection rather than waterproofing. In seals that use sebaceous glands for waterproofing, the glands are active from birth and are secreted by hard, keratinized skin that is very different from human skin.
* Swimming – humans are inefficient swimmers, with shapes that are not well suited to rapid travel through water. Swimming is also a learned trait, and though newborns are able to propel themselves inefficiently through water, they are unable to lift their faces to breathe.
Generally the evidence provided for the AAH is equally well accounted for by land-based adaptations without needing to posit an aquatic phase of human development. In addition, the AAH is contradictory in several places; the AAH theorizes humans developed some unique skin features due to adaptation to water, but other features emerged after leaving the habitat, and the specialization that is hypothesized for an aquatic life are uneven, with humans lacking many truly specialized features of aquatic species (such as head shape, repositioned nostrils and streamlining of the body). Parallels made by proponents of the AAH between humans and the proboscis monkey, which shows mainly behavioral adaptations to a water-based habitat, contradicts any claims of anatomical evidence for the theory. Many species of modern primates demonstrate some sort of aquatic behaviors (such as swimming, wading or diving) and use of aquatic environments (for thermoregulation, display behavior, range, diet and predation) but many do not display the traits posited by AAH, suggesting the traits listed above facilitate aquatic behavior rather than evolving as a result of it.
yeah i read that too and yes those could be explinations as well but it just sound like the creation arguement vs evolution arguement to me. the preamble to the examples you gave also says that the aquatic ape theory has no evidence and only trys to dispute the theory without any REAL evidence ot their own (kind of like michael breahe's book darwin's black box). the problem with evidence is that it is all in the water and can easly be washed away. we have plenty of evidence we lived right next to the water why not take that step our ancestors didn't take? did you read elaine morgan's book? in it she gives her reasoning for these adaptations you linked to which is very similar to charles darwin's explinations in his book the origin of species in that the layman can understand and is logical.this refutes it pretty well.
Yet with the fatty layer (which varies from individual to individual), we still lose body heat extremely rapidly in the water. (32x faster than on land) Shivering occurs with just a 2 degree drop in body temp. Four degree drop and thinking gets fuzzy. In 50 - 60 degree water (which is much of the world's avg ocean temps), most people would be unconcious in an hour without some kind of exposure protection. For us, movement in the water only increases the rate of heat loss. So, we can stay in the water longer as long as we don't move. What would be the purpose of that?me too without that fatty layer i'm guessing it would be MUCH colder.
We don't NEED to bathe in it every day, we only do so now because society dictates cleanliness.spud, also i noticed you didn't mention why like almost no other primate do we "love the water"? why do we need to bathe in it every day unlike other primates? why is the sound of it soothing to us unlike (apparently) other primates?
you are correct things do cool down much faster in water that is what tempering metal is all about. i'm just saying without that fatty layer we would be like other primates and have nothing to do with water much less drench ourselves on almost everyday. as for not NEEDING to bathe every day you are correct socially. but i would argue we not only bathe for social reasons but we also bathe for health reasons as well and that IS nessessary.Yet with the fatty layer (which varies from individual to individual), we still lose body heat extremely rapidly in the water. (32x faster than on land) Shivering occurs with just a 2 degree drop in body temp. Four degree drop and thinking gets fuzzy. In 50 - 60 degree water (which is much of the world's avg ocean temps), most people would be unconcious in an hour without some kind of exposure protection. For us, movement in the water only increases the rate of heat loss. So, we can stay in the water longer as long as we don't move. What would be the purpose of that?
I'm not saying there weren't aquatic apes, but if there were... they had a different body temp regulation than we do.
We don't NEED to bathe in it every day, we only do so now because society dictates cleanliness.