When it comes to the standard model of how modern humans evolved from our primate ancestors, especially apparently the chimpanzee, you should be prepared to ask the tough questions and see if they get answered to your satisfaction. Questions like can you really go from chimpanzee stock to what makes you, the reader, you, via natural selection in 6 to 7 million years? That’s not just a little change, but a massive change and on several broad physiological, anatomical and behavioural fronts. Contrast your society, lifestyle and body-plan with that of the chimpanzee. So, if you think the standard model is unlikely, and you reject any supernatural explanation, that leaves but two alternatives, an artificial selection by ancient aliens, or we’re akin to characters in a video game – we are simulated beings.
Modern humans have evolved over the past six to seven million years a number of traits that make us, Homo sapiens, a very unique species indeed. We alone of all the mammals (as well as all invertebrates, amphibians and reptiles) have a bipedal gait. We alone of all of our primate cousins are for all practical purposes hairless. Of all the animals that are, or have ever been, we’re top of the pops with respect to brain size as a function of body size, and in terms of intelligence, king of the hill full stop. And while animals can communicate via vocalizations and body language, none can communicate the extremely wide range of practical and especially abstract concepts that we can. Last, but not least, humans are nearly unique in making and using external tools, tools unique in terms of their sophistication.
All five major traits noted above, and a lot more that’s related besides, don’t seem to be a requirement for basic survival, since other species survive and thrive without them, and in fact all these major five defining traits (and more) seem to have some actual evolutionary drawbacks, not the least of which require very serious modifications to basic primate anatomy for apparently no increase in that Darwinian phrase “survival of the fittest”. The proof of that pudding is that our ultimate primate ancestor still survives – the chimpanzee; their ultimate descendent survives – the modern human; yet all those in-betweens hominids who were presumably adapting via natural selection resulting in all those evolutionary changing improvements, went kaput – over twenty species of them. If these “survival of the fittest” evolutionary adaptations were all that crash hot and necessary, then why was their demise? Any ancestral hominoids that went extinct prior to 200,000 years ago can’t have Homo sapiens as the villain. Those 20 plus extinct hominid species aside, why aren’t many of those natural selection improvements really so crash hot for us modern humans either? Here’s the trouble with human evolution. But first consider this.
THE ROOT CAUSE & DRIVING FORCE
The current standard model of human evolution explains the ‘why’ question due to rapid and extreme shifts in climate in continental Africa over that six to seven million year period. The central problem there IMHO is why these shifts failed to drastically produce evolutionary changes in the rest of the animal populations like elephants, lions, hyenas, giraffes, zebras, wildebeests and other African landlubbers as the Dark Continent went from jungle to forest to savannah to arid deserts and back again.
Now of course environmental change is a major driving force behind biological evolution, at least when it comes to natural selection. But one has to look at the Big Picture, the entirety of the bio-realm and not just isolate one changing species and link the two and ignore all else. The environment changes and hominoids change but all the other species seemingly don’t change. That makes for an anomaly.
One of the key phrases in evolution is that “there is a price to pay” for change – no free lunch or get out of jail card is authorized. That “no pain, no gain” price applies whether you’re dealing with natural or artificial selection. But I sometimes wonder whether one is getting a fifty-cent gain return on a dollar investment worth of pain. Consider the following.
OUR BIPEDAL GAIT
* Is an anomaly in that human beings, alone of all the mammals, walk routinely on just two legs.
* It called for a complete redesign of our musculoskeletal system vis-à-vis our chimpanzee ancestors.
* That results in an increase in all our various painful bad back trials and tribulations.
* And it also requires a rearrangement of our internal organ attachments.
* A bipedal gait needs a harder working heart to pump blood up to our now higher upper reaches, like the head and neck, instead of mainly sideways. A bipedal gait means having to fight the better fight against gravity.
* A bipedal gait results in an increase in difficulties in maintaining an upright balance (especially as one grows older) because the centre of gravity has shifted dramatically. It’s much easier to push over a standing human than say a standing dog.
* A bipedal gait further results in a decrease in survival value due to the ever possible loss of or injury to a leg, foot, ankle, etc. Lose the use of a leg and in the wilderness, you’re nearly helpless.
* A bipedal gait has to the best of my knowledge only arisen once before, and that was in the theropod dinosaur branch, like T-Rex, etc. That was the branch that gave rise to the birds, therefore they are also bipedal, but it originated with an early, early ancestor of T-Rex. Some may argue that kangaroos and their relatives like the wallabies are bipedal, but they don’t put one leg in front of the other in a left-right-left-right-left-right fashion. They hop, which doesn’t quite put them in the same category as humans or even birds. Further, the theropod dinosaurs, the birds, and even the kangaroos all have tails to help keep their centre of balance, well, balanced. That’s cheating!!! Humans lack that support structure (a rather sad tale I’m sure), so I’ll argue that the human bipedal gait is still unique among all animals, past and present. Humans remain the one and only really bona-fide bipedal entity. Okay, a few tailless primates can ‘walk’ for brief intervals, but their normal locomotion is via their four limbs on the ground when not swinging in the trees.
C - A bipedal gait isn’t a lifestyle walk-the-walk gait that is commonly noted in cats – in fact it isn’t noted at all. Why cats? Why not cats? C is for Cat; C is for Comparison. So as a comparison, let’s take cats, who have a multitude of feline relatives (tigers, lions, etc.) and who have survived and thrived for quite some considerable time. Why cats? Firstly because I’m familiar with cats and secondly because they are an advanced multicellular relatively sophisticated mammalian species, much liken to us. Cats share a great deal with us humans apart from being warm-blooded mammals. Cats, like humans are curious, playful, tend to look after number one, are territorial, like to sleep, dream, have a good memory, show emotions, and like humans have colonized the globe – except Antarctica – either as domestics or as ferals or as wild animals, etc. But, they don’t walk-the-walk on just their two hind legs!
A LARGE HUMAN BRAIN
* Is an anomaly, along with that associated brain thingy high IQ or intelligence we have, relative to the rest of the animal kingdom, which collectively aren’t quite, by any stretch of the imagination, in Einstein’s league. Humans have the largest brain size as a function of body size in the entire animal kingdom, again, apparently both past and present. .
* A large human brain makes for an increasingly hazardous childbirth. The relatively large head of the foetus at childbirth, having to pass through the space available via the hip opening, has resulted in not just a rather painful experience for the mother (and presumably the infant too) but has often led to the premature death of a lot of said newborns and/or their mothers. Now another anomaly here is that if the human body has accommodated all the massive anatomical changes required for a bipedal lifestyle, you’d think an increase in the birth canal hip opening size would have been relatively evolutionary child’s play.
* The human brain takes years to develop fully, nearly two decades worth in fact, leaving infants totally dependent on others for survival. Infants need care not just for a few weeks or months or seasons, but for many, many years, extending right through their teens, thus cramping the lifestyle of the parents. This length of time for brain development and associated acquiring of survival skills to fully develop is unprecedented in all other primates.
* A large human brain is a very energy-intensive organ. In fact 25% of our energy requirements are required to fuel our upstairs grey-matter wetware. That in turn puts additional pressures on hunting and/or gathering for that extra in food resources required to supply that energy need. Apparently the increase in those energy demands is what drove us to begin to hunt down and eat meat and invent cooking (to make the meat easier to digest). Well, maybe.
C - Cats, however endearing, are not a little feline version of Einstein.
A LACK OF FUR
* Is an anomaly since humans alone of nearly 200 species of our primate cousins are considered a “naked ape”.
* Our relative lack of fur makes us dependent on sweating for temperature regulation, also making us highly dependent on sources of freshwater and salt.
* Our relative lack of fur has the apparent advantage of enabling humans to become long distance endurance runners since we can continually keep cool, even while running, by sweating, yet what we are running after (prey), or from (predators), don’t sweat and therefore are quickly overcome by heat exhaustion. We get a meal, or escape from being one. Well that’s the standard scenario. I think it would have made more sense to have used our social group numbers, increasing IQ and tool making abilities to hunt and ambush game rather than running them down. As for escaping predators, perhaps we should have retained our tree climbing abilities, and if no trees were available, there are always rocks to throw and sticks to club predators with. I’m not convinced loss of fur in order to sweat in order to run marathons in order to eat or avoid being eaten are related in a cause-and-effect way. In any event running is also very energy consuming and it isn’t normally sound practice to expend more energy than you have to, especially when you don’t know where and when your next meal is coming from. And if it is advantageous for evolving hominoids to lose fur, take up sweating, take up jogging, and run to exhaustion large prey animals, then it should also be advantageous for other predators, like the lion, to do the same. But that hasn’t happened. Why not?
* Our relative lack of fur requires the need, as a substitution, for clothing in cooler environments. Why a human, originating in and adapted to a tropical climate without need of fur, therefore without need of clothing, would migrate into cooler, even cold habitats where fur, or now a clothing substitute instead, is a near requirement, is itself an anomaly. You swap fur for clothing, but clothing in itself requires a whole lot of special skills to produce – fur doesn’t.
C – Cats, as well as their wildlife big cat cousins, do not lack a natural covering of fur.
To be continued…
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