Thursday, October 9, 2008

Is human evolution over?

I have rarely posted any of my discussions on evolution and God or religion on my blog. I don't know why - it's bound to produce a lot of interest, but I have avoided it because it feels like it would end up being a lot of work. Anyway - here goes nothing.

In a recent bold statement, British geneticists Steve Jones said that human evolution has come to an end. He puts it down to 3 basic facts:

  • Older men are having fewer children (older men have more mutated sperm, so this influences the mutation rate)
  • A vast majority of people are living to reproduce (not dying before they can reproduce like the "good old days of low life expectancy")
  • Small populations that don't mix is pretty much a thing of the past, spreading out genes and "averaging" everyone out
Having read a lot of books about evolution and having a keen interest in the evolution versus creationism/intelligent design "debate", I have to say, I would expect more from a guy like Steven Jones. He is supposed to understand this stuff.

All of his points are correct - all of these things are true. Yet, why would he reach a conclusion like that? I don't exactly know.

Firstly, even according to his own words, mutation rates have lowered, not disappeared, so even according to his own facts, evolution has slowed down, not stopped.

Also, as someone who has played with genetic algorithms, I know that selection, not mutation is the driving force behind evolution. Has selection stopped?

Jones would say yes, since people aren't dying early like they used to. However, dying before reproduction is only one part of selection - there is another part: How do we choose mates?

People are very picky (even after taking alcohol into account) - what kind of things do people like in a mate? Both men and women have strong feelings about who they would pick to have children with.

I have no doubt that human evolution is proceeding in complete ignorance of what Dr. Jones concludes. No doubt, in a few years, the idea that human evolution has stopped will be look at like an earth centered universe.

2 comments:

Paul Heinz said...

Yeah. I think you're right to expect more from Mr Jones.

Even if you accept his argument that physical evolution is less of a factor in the human species (and for the record, I do NOT), he completely ignores the memetic social evolution of culture.

He also reminds me of past arrogant (and ignorant) statements by 'scientists' of the day claiming that all important knowledge was now known. This belief was quite popular in Victoria times.

On a more personal note, I can understand your reluctance to post more about evolution and religion.

They're contentious topics and you can't rationally argue with someone who is launching an emotionally driven 'discussion' at you.

But please don't let that stop you. I for one would love to hear more from you on those two subjects, since they are both dear to my heart and core to my thinking.

Determinist said...

Hey Paul,

Thanks for the comment.

I agree with you - he isn't even right about the rate of evolution in humans. The environment for people has changed SO much in the last few thousand years that it would be very difficult for human evolution to have settled.

There was a recent article in a New Zealand magazine called "The Listener" which is about human evolution. Even scientists like Steven Pinker and Stephen Jay Gould believed that human evolution had stopped (what were they thinking!), but recent developments have changed Pinker's mind (I'm sure Gould would be convinced too, but he died).

I actually LOVE talking about evolution versus intelligent design or creationism AND talking about religion and God.

However, in my usual environment, that is actually more about poking holes in other people's arguments. Writing a blog/essay type thing is much harder to do. So, really, it's just an effort/time thing.

Still, I think I will.