As we further develop technologies that enable us to survive changes in our environment, does this mean that we will stop evolving?
This question of whether humans are still evolving has been the subject of much interesting debate of late. Medical advances mean that our physical and reproductive health are no longer the major determinants of our ability to pass on genes. This means that natural environmental factors will have less influence on which people pass on genes than in our distant past. However, the process of evolution will still be at work.
Human beings have stopped evolving after becoming the only species to “put halt to natural selection of its own free will”, Sir David Attenborough has said, as he predicts the “cultural evolution” of the future.
It has been suggested that within many cultures women now have greater freedom and choice in partners, so arguably traits that women in our culture find attractive are more likely to be passed to the next generation. One might think that in' our modern technological world, genes for high intelligence would be favoured. However, success in modern societies seems to cause those successful people to have fewer children, not more. So perversely, genes for intelligence may be being selectively bred out of the population.
Humanity is now able to rear up to 99 per cent of our babies, so as a people we are no longer subject to Darwinian theories natural selection.
Instead, humans would continue to develop in a cultural sense; inheriting knowledge from previous generations and building upon it. Information would be selected for it's evolutionary benefit to the spread of the species rather than genetics.
Could the human species split in two over time due to evolutionary pressures as predicted by science fiction writer H.G. Wells?
Alternatively, the human species could conceivably evolve into two separate genetic pools: an intelligent and affluent pool with low reproductive rates and longer lifespans because they can afford the latest medical treatment; and a larger pool of the lower intelligence, poorer, exploited class that has a high reproductive rate and lower lifespan. However, there is probably too much crossover of members between the two groups for this to happen, and it is also questionable whether such a society would be stable long enough to form two separate species. Long live the revolution!
Evolutionary theorist Oliver Curry of the London School of Economics says it could happen in 100,000 years. Curry believes that the near-term descendants of the genetic upper class will be tall, slim, healthy, attractive, intelligent and creative.
"Underclass" human beings will have devolved into dim-witted, short, goblin-like creatures.
Further down the road, upper class humans will pay a price for reliance on technology. Spoiled by technology that will do everything for them, humans could come to resemble "domesticated animals."
Chins would recede, as a result of chewing on carefully processed foods. Reliance on medicine would result in weakened immune systems, with genetic weaknesses no longer thrown out of the gene pool. The logical outcome, says Curry, would be two sub-species of human beings; one group gracile (slim and attractive) and the other more robust and physically strong.
H G Wells wrote about what is called "allopatric speciation," in which physically isolated populations no longer interbreed [Editor's note: Darwin wrote of this phenomenon's occurrence in the animal kingdom].
Curry is apparently proposing speciation without geographic isolation—what is called "sympatric speciation." Some scientists reject it outright. One species, the Rhagoletis pomonella maggot, which originally fed on hawthorn fruit, may be undergoing sympatric speciation in this country following the introduction of the apple in North America. Rhagoletis pomonella that feed on apples no longer feed on hawthorn fruit and vice-versa.