Unnatural selection

Published December 26, 2016
The writer is a journalist.
The writer is a journalist.

EVOLUTION is a funny thing. Species can plod along for millennia relatively unchanged until some seminal event forces them to adapt or perish. Usually, that event is climatic or due to some other act of nature, but ever since humanity arrived on the scene we’ve taken on the role of serial killer of species with great aplomb.

Along with causing extinctions, we’ve also forced species to evolve and adapt at a rate rarely seen in nature. Take the example of the peppered moth during Britain’s industrial revolution: this nocturnal moth sported a mottled white colour, which provided effective camouflage as it spent its days dozing on various tree trunks. But the massive levels of pollution produced by factories during the early 1800s covered trees and other surfaces in black soot, making the moths an easy target for predators.

Instead of going extinct, , the moths mutated, switching colour from mottled white to solid soot black — ensuring their survival in this new, man-created environment.


We’ve forced species to evolve at a rate rarely seen in nature.


There are modern examples as well, as in the case of the US state of Virginia’s Elizabeth River, where pollution levels are a staggering 8,000 times the normal lethal limit. Instead of dying out, the Atlantic killifish that populate these toxic waters rapidly evolved — in real time — to survive them.

Something similar is happening with African elephants, which have seen their average tusk size decrease by half in the past 150 years. With larger male elephants — who also have the largest tusks — being hunted and poached for their ivory on a massive scale, the field is thrown open for smaller males — with smaller tusks — to successfully breed and have calves who inherit the smaller tusk size.

Thus, changes that would ordinarily have taken millennia are occurring in the span of decades — thanks to humanity’s depredations.

We’re doing it to ourselves too: researchers say that the increase in C-sections, which now account for more than 30pc of all deliveries in the US, is having a profound effect on human evolution. They say, women’s hips are becoming narrower and the heads of newborns are becoming larger.

This is significant when you think about the evolutionary problems posed by childbirth in the first place; while larger brain size is no doubt an evolutionary advantage, it also led to increased maternal mortality among ancient humans, with the result that early childbirth (when the babies’ heads were less developed) meant a greater chance of survival for both the mother and the child.

An evolutionary advantage also accrued to women who had wider hips and were thus more likely to successfully give birth. (Interestingly, this is also a reason why such women have been a preference across cultures; this has its roots in when humanity was simply an upright ape with a degree of existential angst).

In essence, we may be reversing millions of years of evolution thanks to the overuse of a relatively recent medical procedure.

Then there are the effects that our technological tools are having: you may be amused to learn that humans have altered their style of walking in order to accommodate the demands of smartphones. On any given street you’ll find dozens of people walking while staring down at their phones and yet managing to avoid bumping into obstacles and other people by adopting what researchers are calling a ‘text shuffle’ — moving at a slower pace and with more exaggerated gestures and movements.

Those of us born before the advent of mobile phones will recall that we routinely committed dozens of phone numbers to memory and could recall them at will. Try to do the same now without turning to your phone’s contact list and most of us will struggle to recall more than a few.

Consider that, prior to the keeping of written records, many humans had to develop prodigious memories capable of storing entire legal and religious codices and epics, an ability that later fell into disuse. Lamenting this change, Plato wrote: “Their trust in writing … will discourage the use of their own memory. You have invented an elixir not of memory, but of reminding.”

We too are in the process of outsourcing our memories themselves to a variety of devices — what effect this will have on the very function and architecture of our brains is something we will see in the near future, especially if the resource and technological gap between the classes continues to grow.

Scientists now agree that there was a time when the earth was populated by not one but several human species which lost the evolutionary race to Homo sapiens, and with the advent of genetically and technologically enhanced humans now all but inevitable, we may well be in the process of creating new subsets of humanity without even realising it. And all by our own hand.

The writer is a journalist.

Twitter: @zarrarkhuhro

Published in Dawn, December 26th, 2016

Opinion

Editorial

‘Source of terror’
Updated 29 Mar, 2024

‘Source of terror’

It is clear that going after militant groups inside Afghanistan unilaterally presents its own set of difficulties.
Chipping in
29 Mar, 2024

Chipping in

FEDERAL infrastructure development schemes are located in the provinces. Most such projects — for instance,...
Toxic emitters
29 Mar, 2024

Toxic emitters

IT is concerning to note that dozens of industries have been violating environmental laws in and around Islamabad....
Judiciary’s SOS
Updated 28 Mar, 2024

Judiciary’s SOS

The ball is now in CJP Isa’s court, and he will feel pressure to take action.
Data protection
28 Mar, 2024

Data protection

WHAT do we want? Data protection laws. When do we want them? Immediately. Without delay, if we are to prevent ...
Selling humans
28 Mar, 2024

Selling humans

HUMAN traders feed off economic distress; they peddle promises of a better life to the impoverished who, mired in...