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Asked by ciaracarroll to Andrew, Aggelos, Eileen, Naomi, Shane on 16 Nov 2012. This question was also asked by kenny13.
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Aggelos Zacharopoulos answered on 16 Nov 2012:
@ciaracarroll,
evolution never stops. It will either be a change in our genes that will make us healthier or maybe a change in the environment that we live that will force us to evolve and adapt!
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Naomi Elster answered on 17 Nov 2012:
Yes – evolution is happening all the time. An example of this is our appendix. Our appendices have no real use anymore and have gradually been getting smaller – I’ve heard some scientists suggest that in a few generations, it will have shrunk away completely. The reason this would happen is that it costs us a certain amount of energy to keep an organ functioning, even a small one, and if that organ doesn’t have a role to play, it would be better for us to save that energy.
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Andrew Jackson answered on 17 Nov 2012:
Hi Ciara. So, im going to disagree a bit with Aggelos and Naomi 🙂
Evolution happens when there is a difference between individuals in who lives and dies, and more importantly who has offspring and who does not. This selection process is what picks out the genes that improve things for organisms and removes those that are harmful or simply not needed.
The situation with modern humans, at least those living in modern societies, is that pretty much everyone lives to produce offspring. We have invented medicine and technology that mean that we can save people that would otherwise die, and most societies value the lives of all the people that make it up.
Because of this, there is no real selection pressure in any direction to remove negative genes, and select for positive genes. Short-sightedness is one example of a negative set of genes. Because we have glasses to correct vision, it means that people like me who cant see well are not killed by predators or starve and instead my children will very likely have bad eyesight too. The same is true for lots of other features.
Its likely then that humans will start to collect more and more bad genes that will either need technology or medicine to overcome. Many scientists are also working on ways to alter the genes of ourselves and our offspring to remove these negative genes from our population permanently. This opens up the possibility for humans to direct our own evolution. Many scientists, philosophers and people find this idea quite scary as it has the potential to be used by bad people to take advantage of weaknesses in others.
But, evolution will keep happening in humans, but it is more likely to be a kind of aimless drifting around with new genes, both good and bad appearing. However, without the natural process that chooses whether these genes stay or go, its likely that we will not evolve in any particular direction.
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Eileen Diskin answered on 19 Nov 2012:
I think my answer is somewhere in between what Aggelos and Naomi said compared to what Andrew said. I do think that nowadays, we can overcome most things because of modern medicine. But I don’t think that we can always count on that, because there might be diseases that we cannot overcome, or there might be certain groups of people who don’t have access to those medicines – or maybe who the medicines don’t work on.
It’s a really interesting question though, and maybe on that you could do a project on yourself to see what you can find out!
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