quote:Amongst primates, kidneys normally exhibiting lobulated, multipyramidal, medullas is a unique attribute of the human species. Although, kidneys naturally multipyramidal in their medullary morphology are rare in terrestrial mammals, kidneys with lobulated medullas do occur in: elephants, bears, rhinoceroses, bison, cattle, pigs, and the okapi. However, kidneys characterized with multipyramidal medullas are common in aquatic mammals and are nearly universal in marine mammals. To avoid the deleterious effects of saline water dehydration, marine mammals have adaptively thickened the medullas of their kidneys - which enhances their ability to concentrate excretory salts in the urine. However, the lobulation of the kidney's medullary region in marine mammals appears to be an adaptation to expand the surface area between the medulla and the enveloping outer cortex in order to increase the volume of marine dietary induced hypertonic plasma that can be immediately processed for the excretion of excess salts and nitrogenous waste. A phylogenetic review of freshwater aquatic mammals suggest that most, if not all, nonmarine aquatic mammals inherited the medullary pyramids of their kidneys from ancestors who originally inhabited, or frequented, marine environments. So this suggest that most, if not all, aquatic mammals exhibiting kidneys with lobulated medullas are either marine adapted - or are descended from marine antecedents. Additionally, a phylogenetic review of nonhuman terrestrial mammals possessing kidneys with multipyramidal medullas suggest that bears, elephants and possibly rhinoceroses, also, inherited their lobulated medullas from semiaquatic marine ancestors. The fact that several terrestrial mammalian species of semiaquatic marine ancestry exhibit kidneys with multipyramidal medullas, may suggest that humans could have, also, inherited the lobulated medullas of their kidneys from coastal marine ancestors. And a specialized marine diet in ancient human ancestry could, also, explain the reactivation and enumeration of corporeal eccrine sweat glands and the copious secretion of salt tears. The substantial loss of genetic variation in humans relative to other hominoid primates, combined with the apparent isolation of early Pliocene human ancestors from particular retroviruses that infected all other African primate species, may suggest that such a semiaquatic marine phase, during the emergence of Homo, may have occurred on an island off the coast of Africa during the early Pliocene.
The other item is Homo Florensis is looking a lot like Homo Habilis. Florensis has large, splayed flat feet, not great for walking, but very handy for swimming. Florensis did not walk to Indonesia. It had to arrive by water.
I see these as smoking guns. The Savanah model for bipedal evolution has been trashed, given the wet world flora of the hominid seeding era, leaving a need for another model. I vote for the water adept Homo Habilis.
Homo Erectus took our evolution another step by adapting a foot model like ours. Now we are a sleek naked ape that can run and throw stuff. Cool.
Edited by Adminnemooseus, : Put quote box around quote and removed extra line breaks inherited from source. Still could use some paragraph breaks.
It really helps moderators figure out if a topic is disintegrating because of general misbehavior versus someone in particular if the originally non-misbehaving members kept it that way. When everyone is prickly and argumentative and off-topic and personal then it's just too difficult to tell. We have neither infinite time to untie the Gordian knot, nor the wisdom of Solomon.
There used to be a comedian who presented his ideas for a better world, and one of them was to arm everyone on the highway with little rubber dart guns. Every time you see a driver doing something stupid, you fire a little dart at his car. When a state trooper sees someone driving down the highway with a bunch of darts all over his car he pulls him over for being an idiot.
Please make it easy to tell you apart from the idiots. Source