Are We Still Evolving?

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Our evolutionary trajectory over the last three million years took us from small-brained walking apes who lived in East African grasslands to modern humans who have colonized just about every type of environment of every major land mass on the planet. So what's next? Are we still evolving? If so, have our culture and our technology changed our evolutionary trajectory? Using new genetic inventories of world populations, researchers are now tracing our recent evolutionary path in remarkable detail. They are discovering that our culture and our general restlessness as a species have had a big impact on our genetic makeup.

A human living in Africa 50,000 years ago wouldn't look out of place groomed and dressed up in a business suit, sipping coffee at a Starbucks in Manhattan. Yet while fully modern humans evolved in Southern Africa, a glance around a Manhattan Starbucks is enough to show you that human evolution has continued since we migrated out of Africa and settled the rest of the world: our stature, skin color, hair, eye color, and other facial features clearly show where in the world at least some of our ancestors lived. Modern humans began branching out into the Near East, Asia, Europe, and Australia by about 40,000 years ago, finally arriving in South America by 12,000 years ago. As our species colonized new environments around the world, we confronted new foods, new pathogens, and other new challenges posed by differences in sunlight, temperature, and altitude. Different populations around the world evolved in response to their unique environmental challenges; as a result, we differ from each other not only in our outward appearance, but also in the inner workings of our bodies. The effects of different evolved adaptations among humans in different parts of world can be seen today in the strong influence our ancestry can have on our health.

To get a better understanding of the changes in our recent evolutionary past, scientists have been looking under the hood at the genetic workings of those evolutionary changes. They're using large genetic inventories of different world populations, such as the Human Genome Diversity Project, to look for mutations that show signs of being actively promoted by evolution. 

Written By: Michael White
continue to source article at psmag.com

11 COMMENTS

  1. the evolutionary basis for the short stature of “Pygmy” populations that live in the tropical forests of Africa, Asia, and South America;

    I recall some video of hunter-gatherers where significant proportions of the diet were collected from high in trees. The smaller, lighter local populations with supple feet could easily scale up trees using a waist-band loop of vines. The heavier Europeans had little chance of matching them for climbing capability, even with technical equipment.
    Size is a big issue in arboreal primates. Large male chimps cannot reach food on thinner branches which are accessed by youngsters.

    and the different genetic adaptations of Andean, Tibetan, and Ethiopian high-altitude societies to low oxygen levels that would make the rest of us sick.

    Their greater capacity to to breathe because of greater lung capacity, and more red blood corpuscles, together with a tougher digestive system needed to digest food which cannot be properly cooker in low pressure environments, out-competes lowlanders in these environments.

    If these populations continue as isolated groups, they are on their way to evolving into new species or sub-species.

  2. I think we are selectively pruning:

    1. those who like war can always find some spot on earth to get their heads blown off.
    2. extreme sports creates non-breeding paraplegics.
    3. illegal drugs eliminate those who refuse to look ahead at consequences
    4. people who cannot control food intake in abundance are killing themselves off.
    5. people who scrupulously avoid all exercise if they can are killing themselves off.
    6. people who like sex but don’t like children are disappearing.
    • Are We Still Evolving?

      If you ask this question, you don’t understand evolution.

      In reply to #3 by Roedy:

      illegal drugs eliminate those who refuse to look ahead at consequences

      Because the drugs that are illegal er necessarily super harmful and it’s not, like, at all arbitrary.

      • In reply to #10 by Serdan:

        Are We Still Evolving?

        If you ask this question, you don’t understand evolution.

        In reply to #3 by Roedy:

        illegal drugs eliminate those who refuse to look ahead at consequences

        Because the drugs that are illegal er necessarily super harmful and it’s not, like, at all arbitrary.

        nice post

        yes, often apes confuse the concept of “evolving” with “becoming better humans”

        Alcohol is an illegal in some countries, yet its legal status has failed to have any measurable effect on populations. Humans today descended from humans who took substances that are now illegal. Queen Victoria was partial to a little charlie i’m led to believe yet she managed to fire a fair few descendants out.

        There’s no doubt that genetic drift is happening, simply because for it not to happen requires something in nature to stop it happening.

        the question might be better put as “how long before the descendants of todays humans become incapable of interbreeding with any of them?” The single most important factor is seperation. Humans have spread all over the planet making it very hard for nature to set them off in more than one trajectory (which would potentially speed up evolution of one or other groups) but we can be certain that mutations will happen, they will have little or no effect on viability but the cumulative effect probably will, even though there may be no examples of non-mutated humans left to compare to

  3. ” Are We Still Evolving? “

    Evolution is the change in allele frequency over time in a population of organisms.

    In that strict sense we are evolving.

    Are we going to speciate? Under the selective pressures ( many in the article, such as cultural and global warming pressures ) we create as a species it is possible but not predictable.

  4. While-ever we have people starving to death in the third world of course evolution and natural selection are still acting on us. How much those in the west are able due to evolution to evade the grasp of natural selection before breeding may be in debate…

  5. If we continue at the rate we are now we will get there eventually.
    Well done, keep up the good work everyone.
    knowing our luck an asteroid will strike just before we reach the finish line.

  6. How refreshing it is to read an article such as this instead of ones about mind numbing religious drivel.

    I was asked the other day if we are still evolving, and I said that it’s not possible to know where natural selection is going to go in the future because it’s blind and has no goal or target. All that can be done is to discover and analyse what happened in the past.

    The best that can be done is to hazard guesses, albeit fairly good ones.

    I post this with trepidation.

    Was I talking rubbish or do I have a handle on it?

    As always, I stand to be corrected.

  7. Its a silly question….Of course we are and every other living biological life form and we’ve been evolving since Earth cooled a few billion years ago…and all species will continue to evolve or become extinct……like millions of other species who once were around and will never be again…some get 15 minutes of fame and others are more long lasting…like the species (sea sponges) that evolved 760 million years ago…

  8. The human genome seems to be amazingly diverse and adaptable; no doubt evolution continues, with many strains moving in many different directions.

    It would be a supreme irony if creationists interbreeding found themselves swinging from trees (again) in a few million years. :o)

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