Humans really are a piece of work. We evolve to a level that we can postulate the most elegant explanation ever as to why every living thing is as it is, and still it’s not good enough for us. Deniers believe evolution reduces the value of man and God while adherents can’t seem to hide their frustration with the slowness of it all.
Protein heavy ‘Caveman diets’, for example, have become fashionable, based on the premise that we apparently haven’t evolved as fast as the technology we have developed to process food. Therefore, the argument goes, we are developing health problems and obesity because our bodies have not adapted to our culinary creations.
Evolutionary Biologist Marlene Zuk, author of Paleofantasy: What evolution really tells us about sex, diet and how we live, calls it ‘Palaeo-nostalgia’. “We don’t really know what they [prehistoric men] were eating. It’s turning out that they may have eaten more starch and carbohydrates than we had realised.”
But have we been too slow to evolve? Zuk doesn’t think so pointing to our ‘Lactase Persistence’, “Our genes have changed extremely rapidly so that at least some populations of humans can digest milk into adulthood.”
But that’s hardly the swift observable evolution of something like the peppered moth. Before the late 19th century these moths had black and white speckled markings to camouflage themselves against the lichen covered trees they called home. Following industrialisation, and the spread of soot, a black variant emerged which, by 1895, accounted for 95% of the population. The speckled versions were just too easy for birds to spot against the soot black trees and were being devoured before they could pass on their genes. Then, following the 1956 Clean Air Act, the trees returned to their normal colouring and the black form of the moth declined again.
Cliff swallows nesting in road bridges have provided another example of speedy evolution. A recent study shows that though 80 million birds are killed by US traffic each year, there has been a steady decline of swallows as victims of roadkill; even though roadside nesting has increased. An answer has been found comparing roadkill swallows with live ones caught in ‘mist nets’ for study. It seems the survivors have shorter wings. The ability for greater vertical take-off and quicker manoeuvrability means they have a much better chance of avoiding vehicles. ‘Everything fits with the idea that it’s vehicular selection,’ says Ronald Mumme of Allegheny College in Meadville, Pennsylvania.
So if they’re doing it? Why aren’t we?
Theories abound about why our evolutionary development has either slowed or even ground to a halt. Is it because we evolve in response to our environment and since modern man has pretty much harnessed his environment, right down to air conditioning and home wellness suites, we just have no need to improve? Or what about the fact that the weak and the needy in civilised countries have as much chance of survival and propagation as the beautiful and powerful? Or perhaps, as humans are in an almost constant state of war, are we halting diversity by trying to eliminate those less like us and protect those more so? Maybe, some argue, we have gone beyond individual evolution and we are becoming like ants, en masse, an evolving societal super organism sprawling out over every continent in the world?
In the last month findings have been published about the 2 million year old Australopithecus sediba skeletons found in South Africa in 2008, ‘a pivitol species that may bridge the gap between the ape-like australopiths and the first members of our own genus,’ reports the New Scientist. And though A.sediba is much more like modern humans than the 3 million year old ‘Lucy’ found in Ethiopia, ‘Lucy’ had rigid feet showing she walked upright, whereas our more recent ancestor had the flexible chimpanzee style tree-climbing feet.
So it seems we can even evolve backwards as our needs for survival change. Maybe that’s why we hang on to our appendixes and male nipples, we never know when we might need them.
If human evolution has slowed, maybe the increments are smaller as we hone towards perfection, or maybe we’re just changing in ways we have no way of understanding in our subjective state. I just have to look at my children to know they are better than me, but then so is my wife – so maybe that’s just successful selection as my own crappy genes get weeded out.
Yet humans have proved their worth as one of the most adaptable creatures on the planet. Unlike any other creatures, the trick to our survival is not to physically change ourselves but change the things around us that threaten us. It makes our adaptation faster than any other species. That’s why we developed tools. And to make and use tools, many speculate, was why we developed consciousness.
If that’s true, ironically it’s our tools, our creations, our processed foods and our industrialisation which are markers of our evolution and development as a species rather than a threat to it. The pot-noodle is part of our advance as a super species and the bionic man is not a freak from 70s TV, he’s our evolved future.
“What a piece of work is a man,” said Hamlet, “how noble in reason, how infinite in faculties, in form and moving how express and admirable, in action how like an angel, in apprehension how like a god! The beauty of the world, the paragon of animals…”
Other species – watch us and weep.
First published in