Have humans stopped evolving? If not, how are we evolving?

[lumpthing]

From a post in a different thread:

Humans no longer evolve, not biologically anyway.

I don't think that's true at all. Surely evolution is inevitably always happening since there are always going to be uneven levels of reproduction? I'm sure genetic factors have an input into those uneven levels.

My pet theory is that humans will evolve into a species that is biologically consciously inclined to have children. Previously a biological inclination to have sex was enough to bring about lots of reproduction. But now we have birth control that's no longer enough to guarantee lots of children. This rests on the assumption that using birth control will eventually be something people learn to do as well the Dutch.

 

[civ_king]

we are still evolving, just very slowly (to the human perception of course), but genetic engineering might become a greater influence

 

[Omni314]

The immune system is always bettering itself roughly at the same rate as virus',
stamina, strength, speed etc are increasing all the time, just look at the world records,
everything else is getting better.
I think we just need to breed in is longevity trouble is its kind of impossible to do that

 

[Yeekim]

Currently we are degenerating rather than evolving.

 

[Narz]

Most humans can handle grains better than most humans 10,000 years ago, IIRC. Ramen Noodles, not so much.

Evolution never stops but due to modern medical advances many fewer are dying before reproductive age so more people are getting a chance to not become genetic cul-de-sacs.

 

[Yared]

People in general have misunderstood the concept of evolution and think that it's like some ladder and that we're eventually gonna learn how to teleport or stuff .

I personally think that natural selection has been pretty much made obsolete by modern medicine and genetic engineering.

Spoiler :

Unless of course I've misunderstood it completely

 

[Gooblah]

As soon as man figured out safe birthing procedures and began medicinal practices, natural selection was basically done in. With the widespread availability of antibiotics and other such materials, people in richer nations have probably degenerated in terms of resistance to various bacteria and viruses; in poorer nations, this will happen as the playing field is leveled over time.

The ability of many to go to old age means that genetic causes of heart disease and other diseases are passed on, since those people aren't killed by puberty (which incidentally has been occurring earlier and earlier).

Edit:

In Discovery Magazine there was a good article about this a few years back. The author discussed how, for example, the placement of our testes makes no sense; in many species, evolution has made sperm more resistant to high temperatures and testes have retreated into the body; in humans, our balls are located between our legs: prime real estate for any animal attack (or spurned lady).

 

[Cutlass]

I've seen articles suggesting we are still evolving. However we don't have enough of a genetic record to confirm that. One theory is that very large populations allow greater evolution because more variations can be tried to see what will work.

 

[lumpthing]

There's no such thing as genetic degeneration. It's a contradiction in terms. I think people are confusing "evolution" with "improvement". Whatever genes cause an individual to reproduce more are not necessarily the ones that lead to an "improved" humanity. If genetic resistance to disease is no longer a significant factor in causing reproduction that doesn't mean that evolution has stopped. Bacteria are the most evolutionarily successful beings on the planet, but I don't think they're the most advanced/worthwhile/improved beings on the planets.

In Discovery Magazine there was a good article about this a few years back. The author discussed how, for example, the placement of our testes makes no sense; in many species, evolution has made sperm more resistant to high temperatures and testes have retreated into the body; in humans, our balls are located between our legs: prime real estate for any animal attack (or spurned lady).

That always puzzled me as I was under the impression that all mammals had their balls in the same place. I had assumed there was some chemical reason why it was more efficient to have sperm thriving at that temperature.

 

[peter grimes]

My pet theory is that humans will evolve into a species that is biologically consciously inclined to have children.

I think your pet theory will run into problems when it encounters childless women [and yes, even men!] in their 30's and 40's.

...stamina, strength, speed etc are increasing all the time, just look at the world records

What makes you think this has anything to do with genetic change? My first impulse is to ascribe it to improved nutrition, health, and training. And then there's always the chemical crutch....

It is very common for people to forget that evolution and natural selection are two completely separate things. In fact, Darwin's contribution wasn't the idea of evolution - naturalists had been writing about that for almost 100 years by the time he published Origin. Natural Selection is one of several constructive mechanisms of evolution. Humans are very much subject to Natural Selection, whether we like to admit it or not.

That's not to say that Western medicine hasn't mitigated some of the more effective selective pressures that nature throws at us, though

It is, as far as anyone knows, biologically impossible for living matter to avoid selection entirely.

 

[Yeekim]

There's no such thing as genetic degeneration.

As our advanced medicine and healthcare has made it possible to live and procreate for people who would have never even reached adulthood without its help (including people with heritable diseases and genetic disorders), we can say that human species is degenerating in certain sense. Just look at the rapidly growing rate of all degenerative diseases that human race is going through.

 

[lumpthing]

I think your pet theory will run into problems when it encounters childless women [and yes, even men!] in their 30's and 40's.

eh? That's my point – having children is now much more of a choice and many people choose not to have children. This choice is linked to their personality which is linked to their genes, therefore the genes which make people more likely to want to actively choose to have children will become more prevalent, because people without those genes will exit the gene pool. Or have I misunderstood you?

It is very common for people to forget that evolution and natural selection are two completely separate things.

I confess I am apparently guilty of this. What is the difference?

evolution = natural selection + random genetic mutations ???

 

[Eran of Arcadia]

Sexual selection is as important as natural selection, so the fact that more people live longer won't be as important as you might think. Also, evolution occurs over vast timescales, so what has happened in the last few generations is just noise.

 

[Narz]

As our advanced medicine and healthcare has made it possible to live and procreate for people who would have never even reached adulthood without its help (including people with heritable diseases and genetic disorders), we can say that human species is degenerating in certain sense. Just look at the rapidly growing rate of all degenerative diseases that human race is going through.

Most degenerative diseases are triggered more by environment (poor lifestyle choices) than because humanity has suddenly become hundreds of times weaker.

 

[peter grimes]

eh? That's my point – having children is now much more of a choice and many people choose not to have children. This choice is linked to their personality which is linked to their genes, therefore the genes which make people more likely to want to actively choose to have children will become more prevalent, because people without those genes will exit the gene pool. Or have I misunderstood you?

Actually, I think it is I that misunderstood you
After re-reading your posts above, and reading the above, I think we're saying the same thing. The only people to pass on their genes are people who choose to raise children. Ipso facto, selection for 'child-wanting' genes.

I confess I am apparently guilty of this. What is the difference?

evolution = natural selection + random genetic mutations ???

Evolution is the term that describes the process of not only speciation, wherein 2 populations become reproductively isolated from eachother in physical space, but also whereby 2 populations become genetically distinct from eachother across time. Humans alive right now are not the same creatures as our ancestors 100,000 generations ago. That's because evolution has occurred.

There are several mechanism that result in evolution. Genetic drift, sexual selection, natural selection, and artificial selection are all different ways that evolution happens.

Random genetic mutations are the 'raw material' that selective forces act upon in differentiating one individual from another...

I'd love to go into this more, but I'm a little pressed for time right now.

Also, I'm sure I've left out other mechanisms - if people know of more, please post!!

 

[Loki130]

I remember reading some reputable article (don't know from where) about this as I recall, it stated that human evolution has in fact increased in speed as of late, a large part of it is of course the fight against various diseases, and one interesting trend is that our brains are growing more efficient, becoming an 8th smaller than our ancestors. (ancestors from when, it didn't say-or I don't remember)

 

[GoodGame]

Currently we are degenerating rather than evolving.

It's all evolution.

I remember reading some reputable article (don't know from where) about this as I recall, it stated that human evolution has in fact increased in speed as of late, a large part of it is of course the fight against various diseases, and one interesting trend is that our brains are growing more efficient, becoming an 8th smaller than our ancestors. (ancestors from when, it didn't say-or I don't remember)

I believe I've read something to that effect also.

 

[lumpthing]

Actually, I think it is I that misunderstood you
After re-reading your posts above, and reading the above, I think we're saying the same thing. The only people to pass on their genes are people who choose to raise children. Ipso facto, selection for 'child-wanting' genes.

Yep we're saying the same thing

And thanks for distinguishing natural selection and evolution, I had mentally grouping all the evolutionary processes as part of 'natural selection'; now I know not to.

 

[Souron]

I suspect that people are still evolving in attractiveness, despite the progress in cosmetics.

 

[Synobun]

I was under the impression our pinkies were getting smaller throughout these past couple thousand years?