Has evolution stopped for the human form?

facepalm

I concur with @johnpowell

Evolution is very much at work in humans today. Find what is killing us and you will find what will change with time.

If anything we are stimulating evolution by altering our environment with man made inventions.

I think we are taking control of human evolution through bio and nano tech.

I often wonder about stuff like this. I mean its interesting because we dont really allow mutations to occur in humans any more if they are prototypical. Ie if someone is born with a bit of a tail, we surgically remove it at birth. We dont really know that this trait wont somehow be advantageous to humans down the road or anything, but its seen as different so its removed.

@uberbatman

“we dont really allow mutations to occur in humans any more if they are prototypical. Ie if someone is born with a bit of a tail, we surgically remove it at birth.”

This doesn’t change the underlying genetic cause at all.

What a great question, @RealEyesRealizeRealLies I have wondered that myself. I saw this article today on the concern that the Internet is making us less able to remember past events. When we try to think of the other film classic that failed to beat out Gone with the Wind__ for Best Picture in 1939, Google or Yahoo! comes into our heads first instead of _The Wizzard of Oz. But then, I understand that Socrates was certain that having a written language was depriving man of memory, as he knew he could simply look past events up in a library. :-)

Baring an ecological catastrophe (which with Republicans still around we can’t really do) we aren’t forced to compete for food and resources as we did in the past. With modern travel, it’s rare to find an isolated population, and we know isolated breeding populations facing unique environmental pressures tend to evolve much more rapidly than large populations where environmental pressures on survival tend to vary from area to area and adaptations in one area are often cancelled out by differing ones in an adjacent locale. Also, and perhaps most importantly, we protect the weak and ill equipped for survival among us. We step between natural selection and human life. We don’t let nature weed out the less successful competitors for food, reproductions, etc.

But there is another huge factor to consider. You may or may not want to call this evolution, but with the mapping of the human genome and gene splicing technology, we will almost certainly step in and start developing x-ray vision and while we’re at it, immunity to kryptonite. :-)

We will probably explore space and at some point begin to colonize. There, we will again have an isolated breeding population facing very different environmental pressures than those we face here on Earth.

So, taking all that into account, I definitely do not know the answer to your question. Will we deny global warming till it ends life for our species, or engineer x-ray vision and the ability to live 100,000 years, and everything it takes to colonize space, and die because ET gets pissed at all the land grabbing we do?

@crisw no, it doesnt but it doesnt allow these traits to be of any advantage or disadvantage. I know the tail thing isnt exactly a realistic example but it works well enough . So say one is born with a tail that could have been advantageous. But at birth it was surgically removed, now sure when this person reproduces it is still in their dna and their offspring can receive the trait but say the tail was left on, and it did turn out to be advantageous, maybe that individual would “survive” better and then go on to mate more thus spreading these genes around more than they would have been if they were just an ordinary person. So yes the gene stays in the background continuing on, but they never get a chance to flourish.

In the scientific sense- the change of allele proportions in a population over time- we are definitely still evolving. Humans are still evolving at about the same rate as other vertebrates. There is still marked variation in human reproductive success, and as long as you have differential reproduction you have evolution. There’s also evidence that women are reproducing earlier and continuing bearing children until later in life. We also have greater incidences of such traits as nearsightedness that would have been a far greater handicap to early humans.

Here are some examples from a recent scientific study on the probable future evolution of humans-

Total cholesterol: going down. Projected to drop 3.6% in ten generations

Weight: going up a tad, projected to increase 1.4% in ten generations

Height: we’re getting shorter projecting a drop of 1.3% (2.1 cm) in ten generations.

Systolic blood pressure: Going down, as predicted. Projected to drop 1.9% in ten generations.

Age at menopause: Going up; projected to rise 1.6% (0.8 years) in ten generations.

Age at first reproduction: Going down. Projected to drop 1.7% (from 26.18 to 25.74 years).

@uberbatman

Actually, what is happening is, in large part, the opposite of what you suggest. Traits that would have been a severe disadvantage to early humans, and definitely would have impacted reproductive success, are less of a concern to modern humans. I mentioned nearsightedness above. 10,000 years ago, you’d have been eaten by that bear you didn’t see coming; today it’s unlikely to affect your chances of reproduction at all, and thus the genes for it are becoming more common.

@crisw I would agree in that sense but what about a mutation that would potentially make us better such as an extra appendage. Things like that never even have a chance to thrive now.

@uberbatman

Mutations rarely cause such large effects, and an extra appendage is very unlikely to simply spring up de novo and be useful. We have evolved, much more recently, very beneficial mutations such as the ability to digest milk after infancy (this has arisen at least twice in human history.)

@crisw oh yes, I know that its not like one generation and bam there it is, i just mean we have been practicing this pheonotypical modification for a while now. If its not normal it must go. I just think itd be interesting to see what would happen over hundreds of years if we just let these things go and flesh themselves out.

What I’m seeing here from the comments and links, is not so out of line with my original position.

Language, has provided us with an ability for Controlled Selection to trump Natural Selection.

It is language which allows us to create eye glasses which allow shortsightedness to be selected as adequate for survival. It is also language which allows geneticists to alter the code which may one day lead to space travelers to produce natural melanin from something other than vitamin D.

Kind of hard to say. In a way we are de-evolving physically. But I think or brains seem to be evolving.
You hear of more geniuses these days. As our phycical needs seem to me met more readily with technology and creature comforts, our bodies are growning weaker because we don’t need to hunt and gather any more. However, our athletes seem to be able to push their bodies harder than before and accomplish things that were thought impossible only a few decades ago.
I think if geniuses started to mate with athletes than we would have some super evolved beings.
Doesn’t always have to be that way. There are simple people who have managed to give birth to a genius, or physically inferior people who have given birth to champions. And vise versa.
My point is that we can never really predict what is going to come out of the gene pool.
You must match your enviroment in order to survive and evolve.
I’m sure if we were able to go back 10000 years, we would be considered God like. And I bet in another 10000 years we would consider them God like and very evolved.

@uberbatman What do you mean, being born with a little tail would confer no survival advantage? It would ba a huge asset in the mating game. Just think how many of us go out night after night trying to get a little tail.

Humans are still evolving. Compare the average size of players in the NFL or NBA 30 years ago and today. Evolution can take place slowly.

For the moment we can say it has stopped but we cannot know what the future will bring.

As for the digital example you added .. I believe that is adaptation because you changed your ways of doing your job to what people were using these days [and still using].
Though our mind will never stop evolving. Look at science. They are constantly growing.

Evolution only “stops” when we look at it over a short duration.
Look in the mirror. Do you really think that is the best nature can do? A single delivery system for reproduction and waste elimination that when damaged can affect both critical systems? I can come up with at last half dozen things that would improve the survival capabilities of the species. When there is pressure for food, oxygen, clean air, clean water there will be quicker changes. The people with the thicker skin, or largest liver, or improved lung capacity and filtering will be the survivors. But we will not see it in our lifetime. We are here for only an instant. Make it count.

I forgot to say the evolution is not only going up and forward. Evolution should take into consideration the past too.

I haven’t read all the other answers, so forgive me if this has been said already.

To an extent, yes, evolution has stopped for humans. This is because evolution is an extremely slow moving process. It can take thousands of years of natural selection to make any kind of real difference. This means that a trait has to be advantageous for thousands of years, so that natural selection continues to favor that trait. But human civilization is moving at such a fast pace that most traits don’t remain advantageous for that long. Consider a few hundred ago, a trait that caused excessive eating would be advantageous, as fat reserves were useful to have in case a famine struck. Now in America, overeating and related heart disease is a leading cause of death – that trait isn’t so useful anymore. Just a hundred years ago, traits that made one a good blue-collar factory worker were most useful; now traits that make one a good white-collar service worker are more useful. Much evolution is unable to take place when civilization is changing so quickly. However, @crisw cited some good examples of traits that continue to remain favorable throughout our changing ways of life and therefore are continuing to evolve.
Also consider modern medicine; it has probably done a number on our evolution too. A very unfavorable trait that gives someone a chronic disease would kill a person off quite easily several hundred years ago; these days, people with chronic illness are surviving and having kids all the time, passing on those unfavorable genes.

@Mariah

In many cases, if a trait is massively beneficial, evolution can move extremely quickly. As I mentioned above, the evolution of the ability to digest milk after infancy is one example. In East Africa, this ability arose only about 3000 years ago. In Europe, it arose only 5–6000 years ago, but some European populations now have 99% milk digesters.

In addition, don’t forget that evolution is just the change in the proportion of alleles in a population over time. Any such change is evolution, even if it’s a deleterious allele becoming more common. Evolution does not go “up and forward, (as @Hibernate put it)” it has no goal and no direction.

@crisw All very good points, thank you for correcting me. I am by no means an expert on this topic.