A Beginner’s Guide to Evolution, Natural Selection, Survival of the fittest and Genetic Mutation
Many people think they know what evolution is and many others still have little or no real idea of what evolution is, or perhaps have been mistaken or misled in some way in their understanding. I therefore offer here a brief explanation of evolution, natural selection, survival of the fittest and genetic mutation, in what I hope is an easily understandable format. You may find you had it down correctly anyway. If that’s the case, then I’m sure you’ll understand why I felt the need to try and simplify it for those less certain and perhaps iron out a few misconceptions.
All species it seems, work exactly as Darwin and others described; they live and die by natural selection, or the ‘survival of the fittest’ rule. Now this is not the survival of the fittest in an, “I’m tougher than you!” kind of way, but survival of the fittest where, if I have a physiology which is better suited to coping with a given environment than my neighbours, then it follows that I and my offspring that also carry that advantage, should naturally survive longer in that environment than my neighbours.
Now genetic mutations occur with regularity, but every now and again, an individual of a species is subject to, as far as we can tell at this point in time, a ‘fluke’ mutation somewhere within its structure, which is good news and not bad, and enables that individual to cope better with its environment than it did before. Now this individual is not suddenly going to jump up and say, “Ha ha! I’m better than you neighbours and therefore you will die!” no, the change will simply become part of that individual’s gene makeup, and will be replicated in its offspring, making those offspring themselves ever so slightly better built to cope with their environment too.
What species, or more precisely, individuals sometimes also manage to do, is to learn an adaptation of the use of their current form which will help them survive better in their current environment. These adaptations are subsequently learned by their offspring and so on and so forth. We are not sure yet, but these adaptations may themselves be the direct cause of other mutations that allow these adaptations to be genetically transferred to offspring in order to improve species survival prospects. Instinct.
So countless generations later, and throwing in a few more ‘fluke’ genetic mutations along the way, including some that may well be caused directly by intelligent adaptation itself just for good measure, there is generally one branch of a species that becomes more and more suited to their environment.
With me so far? OK.
So now let’s imagine that both the original lines of the species that we are talking about, the ones with the beneficial mutations and adaptations, and those without, both relied entirely on exactly the same prey for survival and were not built to be able to survive on any other prey. Let’s also imagine that the mutations and adaptations were improvements in the way that one line of the species was able to hunt and capture its prey.
It follows then that the mutated line is able to feed itself more readily than the line without the beneficial mutations and adaptations, therefore likely to procreate more readily and become the dominant line in terms of numbers. If this happens, then it also follows that the non-mutated line will find it harder to come by the prey, as the mutated line is taking the lions share so to speak, and will not be able to procreate so readily, thus becoming the less populous of the two lines. Follow this logic to its natural conclusion and you see that one line of the species dies out because it was not the fittest at catching its prey, whereas the mutated line was more suited or fittest at catching its prey and therefore survived.
There, I hope, you now have an understanding of natural selection and survival of the fittest in its most basic form.
Another consideration to take into account is abrupt climate or environmental change, for example, global warming or cooling or even a cataclysmic event such as an asteroid impact or a super-volcanic eruption. These types of events change environments so rapidly that evolution is not quick enough to enable all species to survive, thus mass extinctions often occur as a result.
There is one species however that has sufficient intelligence in its current form and has had for many, many millennia in fact, that has learned to exploit and manipulate its environment to such a degree that it is actually able in some circumstances to protect itself from its environment, or in extreme circumstances has been able to move quickly away from an unfavourable environment to a more favourable one and adapt extremely quickly to be able to survive there. Indeed, this species has even ventured toward living in environments that are naturally hostile to that species, by being able to build self-contained favourable environments within the hostile ones. I am of course talking about the human race.
With that in mind, here is a little something further to consider. The very peculiarity of the human race and their place in the order of evolution could lead to some very interesting evolutionary developments indeed. These may well seem outlandish or extreme scenarios, but consider first if you will just how far evolution has brought our species so far from single celled animals to the walking, talking, thinking and adaptable beings we are today.
Consider for instance whether our race might one day get to a stage where we have no further need of travelling by foot? Will adaptive genetic evolution over many millions of years eventually do away with our legs as a result? And what of our arms? Machines are already doing a good deal of our manual work. Will our technologies advance so far that we need never manufacture anything by hand again or even use anything by hand? Adaptive evolution could then do away with our arms too. Perhaps with virtual reality, thought controlled communications and meal in a tube injections delivered by machine, we might arrive at a stage where we never need talk or eat via our mouths again either. Will evolution get rid of our mouths too? How about reproduction? Will sexual congress become obsolete as artificial insemination, cloning, and maybe even artificial stimulation become the norm? Will evolution get rid of our.....?
On that slightly worrying note, I think I’ll leave it there.....Fascinating though.....wouldn’t you agree?