Natural Selection and Mondern Humanity

[Treadstone]

I had a thought a while ago about the state of natural selection as it pertains to modern humans. I'll define modern humans as those living in industrialized nations. My idea is that natural selection no longer applies to modern people. Why? With health care as advanced as is, most people surivive for a very long time, a long enough time so that they have children. This may be based on a flawed perception, as i have not looked at census numbers, but i would guess that a very high percentage of people have children and thus pass their genes onto the next generation. Moreoever, our incredible mobility alows us to find mates where ever we'd like. If no one in our home towns will have children with us, there is someone, some where who will.

 

Centuries ago there were many more premature deaths by natural means, such as animals and dangerous work, and political means such as, wars where a larger percentage of the populace was sent to fight and die. Child birth was also more difficult resulting in a higher infant mortallity rate. Point is, less people were able to pass their genes on in pre-modern humanity.

 

After thinking that and with trhe knowledge that modern evolutionary theory uses natural selection as a mechinism i can up with this questions. What is currently driving humans' evolution? Are we still evolving?

 

Discuss...

 

Nathan

[Sayonara]

Look at the many other threads in this section that deal with exactly that issue.

[Treadstone]

seriously? wow, i looked through and didnt see any others.....will look harder

[Sayonara]

They don't have very obvious titles, but the question "are humans still evolving" comes up all the time on here.

[Skye]

What is currently driving humans' evolution?

This isn't really such a hard question. Since there's less pressure on us from our physical environment, things like sexual selection and fecundity will play a greater role.

[Treadstone]

This isn't really such a hard question. Since there's less pressure on us from our physical environment, things like sexual selection and fecundity will play a greater role.

 

right, thats what i'm saying...but also i'm saying that even sexual selection isn't playing a large role since nearly everyone has children.

 

Nathan

[Chem-Maniac]

Evolution is not a matter of years, not even of decades.

Okay, you're right if you say, selection is not taking place right now. Most countries have good health care, almost everybody can reproduce, we live in paradise .

But on the other hand, think about what drives selection. Events of a dangerous outcome for a species have selectional worth. And now: How many such events took place in the recent 20 years, just in the U.S.? None.

 

My conclusion: Right now there is no real selection,but there is still evolution and always will be. Just wait until the climate changes, a global war gets started, a Virus like Ebola breaks out and turns out to be an air-agent or a Meteor finally hits the earth. I guarantee you: You'll find yourself in a very selective environment.

[Sayonara]

Of course there is selection. You can't have a situation where there isn't selection, unless every member of the species is completely dead.

 

There is no requirement for selective pressures to be dramatic and obvious, nor for them to work on huge swathes of a population simultaneously.

[Skye]

Don't forget that there are very different reproductive rates around the world, we are undergoing incredible growth, but it's not even growth. If one population is growing by 5% a year, and another at 1%, then the species is going to become more like the former population.

[Cap'n Refsmmat]

You want to see humans evolving?

Evolution in action:

http://www.darwinawards.com

[Sayonara]

In the West we're actually in a period of dropping birth rates at the moment, for the record.

 

There's a great deal of concern about it (for some reason).

[john5746]

In the West we're actually in a period of dropping birth rates at the moment' date=' for the record.

 

There's a great deal of concern about it (for some reason).[/quote']

 

Yes, wealth and possibly higher I.Q seems to lower birth rates. Civilization is bringing the opposite of "survival of the fittest". But, as Chem-? said, eventually there are disasters that will bring selective pressures into play - AIDS in Africa, etc.

[Skye]

The places with high growth rates are usually civilised, the main defining societal feature is that many of them are aggrarian.

[AzurePhoenix]

In my expereince, idiots outnumber intelectuals. Yup, we sure are an advanced species. I'm so proud, sniff, sniff, teardrop

[AzurePhoenix]

Okay, I didn't make a point, but here's one. Sure, when push comes to shove we're probably going to get back on track, but is that really the best solution? Instead of trying to cure genetic diseases so more people can have healthy kids, so that more people will be around, shouldn't we take the logical aproach and just emove bad genes from the pool so to speak. Snip snip. No more cystic fibrosis. Sorry if I'm being too blunt, but we've grown sentimental. "Give everyone a chance to have more kids," "oh no! Not enough children are being born!!" Cut the crap.

 

For god's sake, we should just start requiring a license to breed. Of course, we'd need some way to ensure a new age hitler didn't get in charge of who gets a free pass on the parental slip n' slide. Also, two kids per couple (or one set of twins, or triplets, or a single first child then a second dose of twins or triplets)

 

Of course, it would also help if we reverted to a more natural lifestyle. Scratch that last bit, I hate the amish...

 

but if we lived in a limited population, in a society where people spent more of their lives out in the real (environmental) world, it wouldn't matter how advanced we became because we'd be more isolated form the rest of the world.