Is evolution still possible on a large scale?

[Kirker]

So i was thinking about how evolution works, and i realized that at this point there is a huge amount of humans on this planet. And evolution occurs by having one creature with a beneficial mutation that makes it easier for it to survive/find a mate. So if one human with a beneficial mutation is born, is there any possibility that the new type of mutated human could overtake the current population of average humans? and if not doesn't that mean that evolution ceases to happen in today's world?

Any clarification on this would be greatly appreciated.

[Paul the Human]

I'm sure someone with more scientific knowledge and vocabulary than myself will give you a detailed explanation, but in the meantime... I give you my layman's understanding of it.

The word is 'speciation'. Evolution is still at work, but geographical distance and cultural differences have caused it to go in several different directions. That's why there are black people, white people, asian people, hispanic people... etc. The 'races' of humanity.

[Minimalist]

In a strict Darwinian sense I would say no when it comes to humans. Of course, humans are not the only species on the planet - much to the chagrin of the religious fanatics - and evolution continues among isolated populations much as it always has as Dawkins showed in his latest book.

Humans are not really "isolated" and human culture interferes with reproduction and survival anyway.

[IceSage]

So i was thinking about how evolution works, and i realized that at this point there is a huge amount of humans on this planet. And evolution occurs by having one creature with a beneficial mutation that makes it easier for it to survive/find a mate. So if one human with a beneficial mutation is born, is there any possibility that the new type of mutated human could overtake the current population of average humans? and if not doesn't that mean that evolution ceases to happen in today's world?

Any clarification on this would be greatly appreciated.

We still evolve, just differently and I would guess, at an EXTREMELY slow rate. "Natural Selection" doesn't apply too much too humans much. We do, however, carry on traits that help us in many ways and we do pass them on.

Evolution takes place, but not by means of Natural Selection, and at an EXTREMELY slow rate.

[Kirker]

Hmm ok that seems to make more sense, and by the way when i was saying humans i meant any species that has a large population. Also just curious, would anyone happen to know when the last major evolution of any animal occurred? I realize this is very vague, but im very curious as to whether or not anything major has changed recently.

[IceSage]

Hmm ok that seems to make more sense, and by the way when i was saying humans i meant any species that has a large population. Also just curious, would anyone happen to know when the last major evolution of any animal occurred? I realize this is very vague, but im very curious as to whether or not anything major has changed recently.

Yes, actually. I'd have to Google it though, I don't keep track of this stuff. Perhaps another forum member knows. It was some fish or iguana, or something.

You may wish to research this yourself or talk to some professors rather than asking a bunch of people who lack belief in deities, by the way.

(PS. A simple google search provides a ton of species that are considered "new" or "recently evolved." Apparently Polar Bears are a "recent" evolved species.)

[theVOID]

Nothing has changed about evolution except our environment, since the environment is what causes the selection pressures, the pressures have changed and the criteria for surviving to pass on genes has changed. Now is is social prowess more than anything, a person that is socially undesirable and unattractive is less likely to reproduce, though not drastically, but when you consider the few that never reproduce the chances of them fitting that generalisation are rather high. Over several hundred generations one thing that will likely evolved is aesthetics, as it seems to be the only real selection pressure amongst modern western humans. That and an aversion to recklessness.

There are several traits that have evolved in the last few thousand years that we know about, namely our height. We are about a foot and a half taller on average that humans from 10,000 years ago.

[Kirker]

So what you're saying is that we are sort of mentally evolving(and physical evolution has all but stopped?), would it then be safe to assume that humans on average are born smarter/with more desirable character traits? or rather is it that we are better educated/brought up with better values?

[theVOID]

We are still mutating from generation to generation, however because of our relative dominance over the environment and thus the selection pressures, there is much less pressures that would affect our ability to survive and thus much less room for survival of the fittest to work in.

I guess instead of looking at favourable genes as you would in a hospitable environment, because of our level of control over the environment you would need to consider detrimental genes instead. Those leading to impotence would gradually be selected against for instance, because that is a guaranteed way to prevent the passing on of genes, other traits that severely impede our ability to mate, like insanity, recklessness (leading to early death) and ugliness.

There aren't many selection pressures favouring traits any more, and there is no link between intelligence and survivability so there is no selection pressure that favours intelligence. Organisms don't evolve towards some goal, but against the risks of fatality. Those with mutations that aid in survival (and the populations that propagate those genes) are more likely to survive a given selection pressure than those without said genes.

The impending climate change may lead to a selection pressure against heat tolerance, I think the situation in Russia with people dying from heat stroke could be indicative of the potential for this selection pressure to impact us greatly - In that scenario there would be a massive advantage in being heat tolerant, and the genetic factor involved here would be wide open to selection.

Disease resistance is another always looming selection pressure, but our breakthroughs in disease treatment and prevention are even lessening the selection pressure of this phenomenon.

Since intelligence and it's benefits can be shared amongst those without the traits, I don't see higher intelligence as being anything to be selected against any more, as sad as that may seem to those with ideas of looming human perfection, there is simply no advantage of intelligence in terms of our ability to mate better than other humans, where in the past tactics and intelligence could be the difference between populations of hunter gatherers and farmers.

[Anomalocaris]

Evolution is not just mutation, selection, and speciation. A single species' genetic makeup can gradually change without there ever arising a new species, this is also evolution. A species' genetic makeup can change without mutation because sexual reproduction creates new genetic combinations all the time. Probability Mathematics of sexual genetic combination is such certain genes will graduall disappear even if they impose absolutely no disadvantages to its owner, while others will grown to become present in the entire population even if they offer absolutely no survival advantages. This is random genetic drift. In fact there is good evidence to suggest the many differences between races arose from genetic drift, not selection pressure. So our species is evolving even if our social system and medical technology cancels out all overt survival and reproductive advantage of good genes, and compensates for all overt survival and reproductive handicaps of bad genes, and we all travel a lot and mate all over to ensure no population gradually speciate by genetic isolation.

To add on top of this spontaneous genetic drift, there is also the fact that genes can change our response to selection preesures so subtlely that medical technology would not be sensitive to it and social convention would not be attuned to it. But even subtle advantages and disadvantages, when compounded over many generation, can totally alter the genetic make up of our species. An example would be a mutation that alters a woman's chances of suffering an spontaneous natural abortion during early pregnancy. Natural termination during very early pregancies almost always go unnoticed. But it's occurrence has a significant effect on a woman's real fertility,especially if she attempts to get pregnant at a later age. A gene that makes a woman less likely to suffer early natural abortion thus materially increases her chances of passing on her genes as surely as if it could make her run faster before a hungry lion. But because the thing this gene acts on, early stage natural termination, is not easily observed, this selection advantage, or the lack of it, will not pomp any medical or social response. So over many generation, a version of this gene that reduces early termination will gradually dominate, and the alternative gradually disappear. Natural selection would haves acted on us and forced us to evolve without our knowledge, much less consent.

So humans are still evolving, and it's not even within our power to stop it if we consciously set out to do so.