Wednesday, February 12, 2014

It's Darwin Day Again!

"Nature And Nature's Laws
Lay Hid in Night
God Said Let Newton Darwin Be
And All Was Light"

Two years ago, Darwin's day was celebrated here with a blog commemorating his qualities and personal life, so things are bound to be different this time.

The theory of evolution, and that of natural selection are two very subtle statements of knowledge. No wonder then that creationists who set out to disapprove either, if they can tell the difference in the first place, end up mostly making a farce out of their comprehension and reasoning abilities.

But this applies equally well to some proponents of the two theories, especially when it is journalists, or screenwriters we are talking about; alas, the two major sources of information for most of us nowadays. Thus, perhaps, dispelling common misconceptions of the proponents will make for a proper celebration this year, given that debunking creationist nonsense is becoming too hackneyed a topic to write about.

Three misconceptions in specific will be dismantled today; to wit, that natural selection is intrinsically cruel; the evolution as a ladder metaphor; and, finally, the mis-employment of natural selection as an overarching explanation of life. Here goes:

Nature red in fang and claw: Natural selection is exclusively understood by many as a perpetual arms race between different individuals. We are told, for instance, that the gazelle's magnificent agility would have never come to be if it was not for the cheetah's unusual speed, and vice versa. While this might be true, it definitely can't be extended unconditionally, for cases of cooperation are present in nature as well.

Luckily, we don't have to look far away to demonstrate this. Our human body's existence owes much to mutualistic agreements struck with other species. One of these is the mitochondria, which in exchange for the protection offered to them as inhabitants of our massive Eukaryota cells - long before we even were humans - have happily ever since reciprocated with powering our cellular activities, among providing other services. There is also the relatively less stable agreements our bodies have forged with a host of other microbes - i.e. scientifically referred to as the "Human Microbiome" - which while not always essential, have nonetheless made our existence a lot easier.

It remains to be noted that the above is not an exhaustive argument against the misconception of concern here. I remember once watching a fine documentary that shows how we are better off understanding natural selection, and the whole of nature for that matter, in the context of a complex mesh of connections, as opposed to trying to tease out the overall picture from mere dyadic relationships (you can watch the said documentary here).

Evolution likened to the scaling of a ladder: Or put alternatively, the idea that recently evolved species/phenotypes are superior to their earlier counterparts. Not only has this particular misconstruction fueled many extreme ideologies, but has also formed the basis for one of the most worn-out themes in the sci-fi genre of literature and movies!

Scientifically speaking though, every evolutionary biology professor I have met is of the opinion that evolution exhibits some sort of progression - namely, a tendency towards achieving higher complexity - but that this in no sense translates to what the layman would think on hearing or reading such a thing. One doctor even told me that some taxas - unfortunately he did not mention the name of any - had come to develop a brain at some point in their evolutionary history, only to lose it all together when it seized to confer on them any survival advantage.

Hard to swallow, but think of it like this: many wild felines - a group of animals the names of which alone strike us with awe - are eking out their existence at the moment. Roaches and insects in general, on the other hand, are faring exceptionally well, and will probably continue to, outliving humanity in the process. What I'm trying to get across here is the fact that the poetic value of a species is of no concern to nature. The only thing that matters is whether or not the species can adapt fast enough to perturbations in its ecosystem. This in essence is what separates the extant lines from the extinguished ones.

Stretching natural selection beyond its legitimate domain of application: One eccentric professor I had in the past used to end his lecture with an inexplicable smile while teasingly stating that "a fool with a tool is still a fool". Natural selection is no exception; to be applied properly, it requires scrupulous attention to the particulars of the case, or else, it degenerates to become just another pseudoscientific explanation.

Prof. Coyne aptly explains this with the following concrete example: hemoglobin is red not because this is a color of any survival value at all, but rather because it happens to be an unintended, dependent property - like spandrels in architecture - of an oxygen-carrying molecule that has been selected over other potential carriers solely for its efficiency in delivering oxygen (and probably Carbon dioxide as well). Yet, it is not in any sense removed from reality to imagine that some sociobiologist might try to explain the redness of blood with a tortuous link to some survival advantage - e.g. it produces a blushing effect that helps to attract high quality mates. Actually, if you think about it, natural selection is known to most people nowadays through similar titillating explanations of human behavior.

To get things straight, this is not to deny that some aspects of the psychology and sociology of a given species can be the product of natural selection. But due to the unique epistemic properties of the theory, we have to be extremely cautious before declaring one trait or another as advantageous. The gist is, next time you read an article explaining in natural selective terms why teens act as such, or why women are so and so, then you'd do science a favor taking them with a liberal amount of salt.

At the end, we should stay reminded that no celebration is commensurate with this day other than upholding those traits and values that comprise an essential foundation of scientific inquiry. But if you are looking for an excuse to pop a bottle of beer, then by all means, have a one for the old man!