Are humans still subject to natural selection?

Thanx Muttrox. I’ll put it on my reading list.

Cheers,
Hodge

I meant to reply to a thread, not to post a new one. Note to self: Preview, preview, preview.

Well, since I was replying to Muttrox on an evolution thread, I might as well throw something out on my own. It’s my understanding that humans are no longer subject to natural selection. Is this due to that fact that our populations are no longer isolated and/or we have, for the most part, mastered our environment? Also, I was thinking about the plague in middle ages and how that would apply as selection event of pretty large proportions. Can we see any evidence of resistance in our genes today?

(mods pls feel free to move this to a more appropriate forum and maybe re-title the thread to something like Human Evolution. We wouldn’t want to be giving Muttrox a swelled head around here ;))

Cheers,
Hodge

Damn… and I thought this was a thread about 'The Matrix" for dogs.

Bill

[Moderator Hat ON]

Changed title to reflect actual content of thread.

[Moderator Hat OFF]

We just had a thread on this topic. I’m sure someone less lazy than I am can find it and post a link.

But the short answer is: yes.

Even if every human died of old age at 120, we would still be subject to natural selection.

There would still be variable reproductive rates. Some people have a dozen kids, some have none. And there will be genetic differences between the two categories, even if they are randomly distributed. The next generation will be a biased sample of the gene pool. We will still have mutation, genetic drift, etc. So, human evolution will continue.

Have you ever seen Jackass on MTV? Johnny Knoxville is going to kill himself someday, or someone will do it for him…that’s natural selection at work.

If we define “natural selection” to be “the non random change in genotypcial frequency which is free of human interference”, then humans have never been subject to natural selection. After all, from the very beginning of humanity, humans have affected the “selection” of other humans. If, however, one defines “natural selection” to be “the portion of the change which is outside of human control”, then humans have always been subject to natural selection, and will alomst certainly always be.

We still are subject to natural selection…
For example I’d say that a whole welter of bacterial diseaces are poised to make a big comeback due to antibiotic resistance. (Gangrene, Neumonia, other big bacterial killers). And we still can’t do much about viral diseaces beyond palliative measures. (Aids, Influenza, Rhinoviruses (Colds), etc.)
Also we still are subject to a whole lot of manmade evolutionary pressures such as pollution, UV resistance ( skin cancer). As well as others.

An example of a case in which human populations have been selected for in survival in relation to diseaces…
Sickle Cell Anemia…and Malaria.
And theirs others that I can’t recall of the top iof my head.

Yep, natural selcetion is still at work. Chekc out the Fortean Times (www.forteantimes.com) “Breaking News” index from about January 5th. There’s a story about a man who stole two lobsters by sticking them in his pants, and the dire (men, ya’ll can cringe here) consequences.

Weird! I remember having this same exact conversation in school. Well, anyway, I recall the teacher saying that every miscarriage is a case of natural selection: nature is a aborting a fetus that would not be fit in the environment due to physical or chemical problems/imbalances.

Of course we are. Have you heard of the Darwin Awards?

Humans are most certainly still subject to natural selection.

from http://www.talkorigins.org

A race/country/behavioral trait/health status that has more offspring will be naturally selected for, and those with fewer offspring will be selected against.

Although there is a lot of global travel, the human population of the world is not 100% mixed. Plus, human behevior does not 100% mix (inter-racial/inter-cultural/etc. couples are rarer).

Humans have certainly not mastered the environment. We can make ourselves comfy at times, but we’re all susceptible to natural disasters, droughts, etc. And don’t just look at it with rich, Western eyes. The majority of people in the world can’t even get clean water to drink.

People also have different resistences to disease (genetic, germ). Those that are more resistent to today’s diseases will tend to produce more offspring with the same resistences. Those genes will be succeed through natural selection (of course, the germs are evolving too which changes the genetic playing field…evolution is a journey, not a destination).

Speaking of talkorigins.org, if you view the top feedback in the most recent month:
http://talkorigins.org/origins/feedback/dec00.html

They deal with the idea of humans being subject to natural selection.

I’m somewhat inclined to take a much broader definition of natural selection. If what apes do when they use a “tool” in their day-to-day life is still considered natural, then I would submit, then, that as humans are animals too, everything humans do is also natural. Humans naturally build, explore, learn, teach, fight, and destroy. So, if you use my definition for “natural”, then “natural selection” (as it pertains to humans) would become a process by which humans are selected for survival with the effects of the world around us, as well as result of the things that we, as a species, have done. I think it will be very interesting in 100 or so years to see just exactly what we have selected for. One possibility is a human race that happily breathes pollution, lives on garbage, lives contentedly in vast hives of humanity, and fights off the super-bugs of the future. Or, another possibility is a human being that has a life expectancy of 20 years.

More like a 100 thousand years. :slight_smile:

people that can’t run fast are more likely to be shot by fellow employee going postal.