Is It Possible to Forecast Evolution?

By Nathaniel Scharping | February 21, 2018 1:37 pm
(Credit: yod67/Shutterstock)

(Credit: yod67/Shutterstock)

Can we predict the course evolution will take?

That’s the question an international team of researchers decided to tackle, using a quarter-century of stick insect observations. Comparing the first half of the data set to the latter half, they set out to see if they could forecast the path of natural selection.

Take A Guess

As it turns out, it’s really hard. The researchers were able to predict some simple evolutionary changes, but the rest were subject to forces they couldn’t account for. Mother nature is still too complex for us to truly foretell the future.

The researchers were using a dataset that stretched back 25 years — an impressively long time period for a study of a single insect. Since the early 90s, one of the study authors and another researcher routinely ventured into the California mountains with nets and captured more than 34,000 stick insects.

They found that the insects could be roughly divided into three categories, based on how they looked: Green with a stripe down their backs, green with no stripe, or brown. The variations relate to the kind of plants the insects chose to hide on. One species is more predominantly white, while the other is more green. The insects camouflage themselves accordingly, and the brown insects are colored to hide out on plant stems.

The dominant coloration among the stick insects changes, though, and the researchers used this fluctuation to try and predict which pattern would be more prevalent in a given year. With the first decade or so of stick insect data as a guide, they attempted to guess what colors would show up in the next few years. They published their work recently in the journal Science.

They were actually successful — to a degree. The researchers were quite good at predicting when the green striped insects or the unstriped green stick insects would dominate over the other. For the next three to five years, they say, they could predict the coloration changes with 90 percent accuracy, and that dropped only to 80 percent by the time a decade had elapsed.

Little Success

When it came to the brown stick insects, though, the researchers had little luck. Their color forecasts weren’t of much use. They think it comes down to the environment. Changes in the color patterns of the green insects are driven by a simple and easily-predictable model called frequency-dependent selection. Basically, it holds that traits can either grow more useful or more dangerous as they become more widespread in a population. For the stick insects, being the same color as most of your friends is bad, because predators learn to recognize what you look like, and can catch you more easily.

The researchers observed a cyclical tradeoff between striped and unstriped insects — as one became more popular, it would also become more dangerous. It’s a kind of balancing mechanism.

But for the brown stick insects, it seems that there are many more variables at play. While frequency-dependent selection doesn’t seem to play a role, there are many other possibilities. The brown insects are more common in warm years, even though they have a lower heat tolerance. They also have fewer fungal infections and greater success at mating. These are all variables that could favor or disfavor the brown stick insects, depending on the environmental conditions.

And predicting exactly how the Earth will change is far beyond our abilities at the moment. The researchers conclude that the intrinsic complexity of the Earth’s interconnecting physical systems makes predicting most evolutionary changes far too difficult.

Their conclusions are backed up by other studies of evolution, such as in Darwin’s finches, or the peppered moth. Scientists had little success guessing how those animals would adapt.

Evolution may not be random, but that doesn’t mean it’s predictable.

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  • OWilson

    No surprise, survival of te fittest,

    Future evolution depends soley on adaptation to future conditions.

    Predict future conditions and you can predict evolution.

    Either way it’s hard! :)

    • jonathanpulliam

      You are mistaken.

      The “fittest” by your definition will buy more artificial life-prolonging medical procedures and prescription drugs, permitting deleterious genes that ordinarily would have been selected out, as the possessor would presumably in many instances not have survived to reproductive age without medical intervention, to instead “load” the gene pool with his or her defective genes.

      • OWilson

        Nonsense!

        That is one very specific factor in many.

        On the macro level, only the strong survive.

        See those Nuclear Tipped ICBMs that are rolled out on May Day?

        Even madmen can survive with that kind of arsenal :)

      • Hibernia86

        Humans have adapted to be more intelligent than other animals. This allows them to survive even with less than perfect genes in other regards. But even humans can only control the world so much. We can’t yet survive for long periods in space without support from Earth, for example.

    • nonlin.org

      “Fit” as in “survival of the fittest” cannot be measured except as “survival” (circular logic).
      Also, Selection and Survival are one and the same – the selected survive and the surviving have been selected.

      The whole story doesn’t make sense. That’s why it’s “hard” to predict.

      • OWilson

        I’d say it rather depends on the size of the next peice of rock that comes hurling at the Earth! :)

        • nonlin.org

          Are you trying to tell a story? If so, it doesn’t seem relevant.

          • OWilson

            The size of the asteroid that hit Yucatan, was a factor in the demise of many species!

            The survivors thrived, went forth, and multiplied! :)

      • Hibernia86

        Evolution is simple enough for even a child to understand. Certain individuals within a species tend to do better and thus pass on offspring. Thus the species changes over time, in other words evolves. All of this was figured out over a century and a half ago. You are lagging behind.

        • nonlin.org

          Yes, this is a children story.
          Too bad it doesn’t make sense to any adult with a modicum of critical thinking as “Natural Selection” fails left and right – see my blog.

  • http://www.mazepath.com/uncleal/EquivPrinFail.pdf Uncle Al

    Can we predict the course evolution will take?” Inner Cities, borders, sanctuary; Pacoima, Chicago. Detroit, Baltimore, Camden; Senate, House; Department of Education? Sure – regression toward the mean, and very mean man at that.

    • TLongmire

      Shed that hundred pounds and wow that leaves a tree free to blow.

    • nonlin.org

      Not even that.
      The whole “evolution” story doesn’t make sense. That’s why it’s impossible to predict.

      • Hibernia86

        It certainly makes a lot more sense than the story about an invisible all-powerful being creating animals by magic 6000 years ago. We aren’t children anymore and should abandon that one.

        • nonlin.org

          Are you admitting “evolution” is a religion?
          Or was that an involuntary confession?

    • Hibernia86

      Did you really come here to rant against minorities?

      • http://www.mazepath.com/uncleal/EquivPrinFail.pdf Uncle Al

        No, to end them.

        • Jim Gentile

          what a douche you are.

      • John Thompson

        Most people are unaware of the real/full title of Darwin’s key book.
        Understand that before Darwin ever set sail and saw the slight variations in the finches in the Galapagos, he was trying to explain the even bigger differences in the races.
        To me it’s the height of hypocrisy to teach part of Darwin’s evolution theory no matter who it offends (if it offends some Christians as an example), but then refuse to teach the equally valid and scientifically accurate part about how the races also evolved to be so different, just because that offends some other people. I thought we were going to teach the truth/theory of evolution no matter who it offended!
        Heck, when you look at the differences in human races, they are enough to be different subspecies if we use the same criteria as in some animals with subspecies designations.
        I’m not claiming across the board superiority for certain races, but there are some things each race is better at than other races.
        Same as the way the different colored stick insects are better at some things and not others.

  • TLongmire

    Every iteration of now will be wrubbed into the tray.

    • TLongmire

      Run and tell the angels all is well

      • DavidSG

        Heh?

        • TLongmire

          What we are experiencing is a pipe dream of some hyper intelligent entity. I was listening to music and once I posted it I heard those words, which seemed to make sense but is gibberish just like evolution itself. Innumerable individuals responding to external factors, to predict that is impossible.

  • TLongmire

    Imagine if you will if your eternal souls only baring was this worlds here and now and thru its will you could pass thru or retry. Purgatory cems away

    • Hibernia86

      The idea of eternal souls is fine in fictional stories, but not in real life science. We shouldn’t waste time on superstition.

  • nonlin.org

    This is not “evolution”.
    Color changes as well as metabolic, antibiotic, antibiotic-resistance, and many other adaptations is what organisms do day in and day out. Yet none of these normal adaptations has ever been observed to cause transmutation into other organisms – the primary claim of Darwinism. And no, classifying closely related organism into arbitrary and poorly defined “species” for the unstated purpose of fabricating evidence does not constitute serious proof on behalf of Darwin’s theory.

    • Hibernia86

      Saying that micro-evolution is true, but macro-evolution isn’t is like saying capitalism within a nation is true, but global capitalism is false. It’s all the same thing, just at different levels.

      • nonlin.org

        “Micro-evolution” is a scam.

        Those that believe the “reproductive isolation” story point to minor adaptations, which they call “speciation” (implying stability) and then ask us to extrapolate these small changes into the dramatic transmutations imagined yet never observed by Darwin or his followers. This is a classic trick – employed extensively by magicians, cinematographers and con artists among others – where one thing is shown and the brain then “sees” another that is not there.

  • Jack Kalpakian

    Broadly, yes. Specifically, no. There are certain trends that keep repeating: For example, marine carnivores tend to evolve into filter feeders, large herbivores evolve in relation to plant availability, spurring the appearance of saber toothed carnivores, etc. This is the idea of guilds … but specifics, I do not it … at least not yet.

  • John Thompson

    “The researchers were using a dataset that stretched back 25 years — an impressively long time period for a study of a single insect.”
    25 years is a speck of time. Evolution can happen over hundreds of years or more, and even then it’s usually minor changes.
    To have rapid evolution on the time scale of 25 years for an organism that reproduces once per year- it would require a much larger change in environment, but not so large that the species can’t tolerate it.
    I’m not complaining about all the work they did over 25 years on the stick insect, just pointing out that real evolution may take 10 times that long at a minimum.

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