Debunking Shits About Evolution - Episode 13 [Rate of evolution; moving further from natural selection]

Some people have believed that the human species were formed by some supernatural forces, and this has created serious opposition to the science of evolution. This is not to talk about some other legends and myths relating to the existence of man; like that of the Fulanis (in the Northern part of Nigeria and the Chadian region) that believe that humans were created from a big drop of milk - no wonder their love for Fura d Nunu (fresh cow milk), but also, other tribes are not left out of some weird beliefs too. I once heard of a very funny myth sometimes ago that expresses that humans came from a very mysterious tree called "anunebe"... lol, holy shit!!. But asides that; coming to the religious aspect of it, some have also believed that everything we see today (including humans) were created by a supreme supernatural being - as cited in the holy books. And like you would guess right; your belief in one is inversely proportional to your belief in another, and that is why I earlier stated that the concept of evolution is mostly theorized.

Get the fuller details here.

INTRODUCTION

The human specie has been recognized as the most evolved species of the hominids, and also as the only surviving single independent specie of the hominins; asides the fact that the genome of other extinct species (like the Neanderthals and the Denisovans) have been traceable to some of the modern humans. But in relation to other species (both hominins and non-hominins), what can you say about the rate at which human evolution has been occurring? No doubt, evolution has almost conquered Mother Nature, but yet again, there have been some areas of evolution that have been left in the dark zone for long, and we're about bringing them out to light. Among some of the questions we would consider in this episode is; in relation to the age of the earth, and some other proofs of dynamism of the earth, how have humans evolved? Welcome again to another myth-buster episode of evolution. Length Alert: Be sure to grab a bowl of popcorn, and join me as we evolve together.

RATE OF HUMAN EVOLUTION

The age of the earth has been calculated to be about 4.5billion years _[ref] - at least, the Last Universal Common Ancestry should also be dated back to almost the same number of years. But what of the hominid species, when was their evolution initiated? Based on fossil analysis, the Sahelanthropus was dated to around 7million years ago. I chose to make reference to the Sahelanthropus because it is recognized as the breakthrough specie between the Ancient Ape and the Ape-men. Though some other species pre-dated it with a few years, but they had more Ape features and had more resemblance to the present day Apes than humans. So let's do a little maths here. If the age of the eath is about 4.5billion years, and the age of the earliest hominids was dated to about 7million years ago - that means, the evolution of humans represents about 0.15% of the entire age of the earth - not to even talk about when the modern man first appeared; which is just few thousand years ago. That means; humans are still very much in their infancy.

Pictoral representation of the difference between hominid and hominin. By EoD Licence:CC BY-SA 3.0

But in the very few years the hominids and hominins have spent here, there have been massive alterations that have happened here and there. Okay before I continue, I need to clarify a point: I used both "hominid" and "hominin", but not interchangeably, because they do not mean the same thing. Hominids are the ancestors of both the present day Apes (Chimpanzees, Gorillas, Orangutan, etc) and the humans alike. But hominins are narrower to just the ancestors of the modern day humans (that's the Homo - Homo habilis, Homo erectus, Homo naledi et al). That means; hominins are subclass of the hominids. By summation, all the hominins can be grouped as hominids, but all hominids are not necessarily hominins. Maybe the image at the right side would provide a useful tool to y'all. Okay let's continue; in the very few years of our existence; and by reason of our evolution; we have acquired some new abilities, while at the same time losing some. Yes, evolution is not always a forward-only reaction - it could go either ways. Can I tell you something? Some parts of the body that were dominant in our earlier ancestral species have gone into disappearance.

Okay let's take this example: If you look closely at the present day monkey, you would agree with me that some of them have wiggling tail (I'm sure you have seen one), these are also from the same shared ancestry as the present day humans, so why are we not with tails? Or do we actually have them? Actually, way before the emergence of the Sahelanthropus, the earlier hominids had tails. Of course, it was useful for them to maintain their balance in their arboreal habitat while hoping from trees to trees, and also for mobility. But evolution kicked in, and we started losing them; maybe because natural selection perceived that we are not in need of them again. But even at that, we still have tail bone; the Coccyx; which is well reduced and found at the termination of the spine. But considering also our embryos; at the early stage of development; the tails were more pronounced. but with further development in the uterus, they become lesser until they are almost disappeared - that is why you were not born with tail _{Except you were}.

But even at that, a mutation can occur and the suppressed gene for tails might dominate again, and the individual might be born with a weird-looking tail... eww! just like hell-boy from DC comics. Even though it is almost completely classified as a vestigial organ, but this proves that evolution could actually make us to lose some of our traits and features. I'm not saying that the tail bone is completely useless though. After all, your weight when your are sitting down is borne almost completely because of the presence of the coccyx - only that we do not need that long wiggly monkey-like tails.

But like I said earlier, within the short period of human evolution, we have changed drastically. One could be quick to assume that; if the speed of human evolution had been sustained at that same rate which organs were lost/gained, in a couple of years from now, humans would be entirely different from what we have now. But sorry guys, I have to disappoint y'all, evolution has a different way of working. Here's a little shocker: According to the theory of punctuated equilibrium, a specie; during the course of evolution; could move into a period of long dormancy (where no noticeable alterations would occur in the specie), after which the process would resume. But this does not also take away the fact that the process of evolution can move in reverse (we talked about the process of de-evolution in an earlier episode, so I would not bore us again with it).

_{We’re at the zenith of the food chain, so back off. Image From Pixabay}

But how amazing, humans were able to rise to the apex of evolution (and even to the zenith of the food chain) without being a predator, but a prey. Okay I guess the usage of tools was instrumental to this. But with the advent of tools, the pressure that was laid on humans to fully adapte to their immediate environment was lessened, and in turn, this also hampered the natural evolutionary processes. That means, our adaptation and survival transcends just the natural selection processes. Do you remember David Attenborough from our last episode? The same man that postulated that we have an aqua-ancestral descent; also said that humans have put a stop to natural selection. Oops!!

CESSATION OF NATURAL SELECTION

In the recent times; and observing the trend of adaptation of the modern humans in this extant form; one can be quick to infer that many factors have mutilated the evolutionary processes. Because; as it were; our intelligence has been a major actor on the scene. As generations transcend into another, the subsequent ones would build on the strengths and weaknesses of their parents to make for better adaptation. That means; natural selection is slowly getting replaced by intelligence selection. That is why, your chances of adaptation and survival is no longer dependent on your strength nor on your hunting skills, but on your intelligence, creativity, and mental acumen. That also means that the pressure of adaptation has shifted from our bodies to our minds.

To buttress this point: The average Intelligence Quotient of this generation is way larger than that of our fathers. If you get an IQ test used by your grandfather, you would be so surprised how easy it would appear to be - not because the test got simpler, but because our minds have evolved further. But the question that might have crossed your mind is; if natural selection is slowing down, does it also mean that evolution is slowing down? Well, here's the point; the rate of evolution is not dependent on natural selection. That is why; even though natural selection has slowed down (or ultimately stopped); human evolution never ceased, but the goal of evolution has been directed away from our bodies towards our minds.

So if you are still expecting the extant modern humans to evolve with superhuman ability, you might be disappointed, because it seems evolution has charted its own new course. But like I said before, evolution (as well as genetic transmutation) does not happen overnight, but might span up to a million years - so we should not rule out the possibility of humans picking up one or two superhuman abilities. But the bottom line is; we should not expect the process to be purely natural. Remember the example I sighted in an earlier episode about genetic engineering being done at the embryonic level _[ref]; now this could be one of the tools to further alter the course of evolution - and with the cybernetic technologies, it could be a farewell to natural selection.

FINAL WORDS

Humans have been recognized as the most successfully evolved hominin, but looking at the rate at which our ancestors kicked off evolution, one would have expected that by now, we must have gone way beyond this point. But evolution does not only focus on body changes, and as it were, there has been a switch from adaptation of our bodies to the adaptation of our minds. In plain terms; evolution that was initially a purely natural selection process is now tilting towards intelligence selection. And yes; human evolution is very much at a tender and infant stage, which means we are yet to see more changes coming our way. But like we have seen, these changes would be majorly caused by non-natural factors, and finally we would bid natural selection a farewell.

Thanks for reading