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Squirrels Evolving to Suit Global Warming?

Gavinsblog writes "New Scientist is reporting that using a technique called quantitive genetics, researchers have found that due to the effects of global warming, female squirrels now give birth on average 18 days earlier in the year than their great-great-grandmothers. Is global warming also affecting human evolution?
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26 of 96 comments (clear)

  1. causality or correlation? by jo-do-cus · · Score: 5, Insightful

    What i dont get: where did they get the information that these changes are "due to global warming" ?? It's not like you can interrogate a squirrel to ask them why his genes are different.

    Probably the scientists saw the correlation with the changing climate and wrote that this would be 'a possible cause for that'. Journalists normally twist the meaning and content of scientific reports to make a nice headline, eventuakky becoming "Squirrels Evolving to Suit Global Warming".

    Generally, one cannot claim that species evolve for some purpose, and even if it would be so, then how do you prove that any change in genes is due to some cause??? It's all just correlations and some hopeful guesses, if you ask me.

    1. Re:causality or correlation? by e8johan · · Score: 2, Insightful

      "It's not like you can interrogate a squirrel to ask them why his genes are different."

      Can you do that to a human? I think that I know the basic mechanisms generating my genome from my parents, but I don't know why they are different.

      As I understand it gene changes are not fit a certain problem, but completely random. As a random change may be a change to the better, the survival of the fittest will make this change spread to more individuals in the next generation than a less fit gene.

      This does not rule out that the change in birth rate and pregnancy time has been fitter due to a change in the climate. But sience based on correlation is dangerous. It has been used before to "prove" lies.

    2. Re:causality or correlation? by Sgt+York · · Score: 3, Insightful
      I was skeptical about this at first, as well. But there is a bit of logic to it (just a bit). If it is warmer earlier in the year, it is possible for the pups to survive when born earlier. Typically, animals that are born prior to the last freeze don't have a good survival ratio. If the last freeze comes earlier in the year, pups born at earlier times have a better chance. It's logical, but there are holes.

      It is possible that this is a response to warming, but not an evolutionary response. Perhaps the squirrels mate earlier due to increased temperature. Also, this would be an easily saturable effect. Plants don't bloom in response to temperature, they bloom in response to ammount of sunlight. Since the Earth's tilt is still the same, the plants will still bloom at the same time. This means the pups may be alive & toasty warm, but with little/no food in the early stages of life. This would yeild smaller (or no) adults

      Although you are correct that evolution does not have a purpose, it does occur in response to change in the environment. It does not have the "intent" of adapting to he environment, but that is what winds up happening.

      Besisdes, this is probably popular media exaggerating a scientitst's claims again. I haven't read the real paper, but I would wager that the scientist worded things in less absolute terms. He probably said it appears to be due to global warming, or was strongly correlated with increased temperature.

      --

      There is a reason for everything. Sometimes that reason just sucks.

    3. Re:causality or correlation? by perljon · · Score: 2, Insightful

      The general problem with concluding a casual relationship from a correlational study is that it's not objective. the author can create any logic to explain the causal relationship.

      ie, take these facts. There are more computers produced every year.
      When computers are on, they create heat.
      The Earth is warming every year.
      Therefore, The increased existance of computers is causing global warming.

      This may seem insane, but it follows the same logic pattern as this story or any causaality based on a correlational study.
      Causality can only be determined with causal expirements.

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  2. Re:Human adaptation to global warming by dpilot · · Score: 2, Interesting

    You're getting cause and effect backward.

    Perhaps you should be looking at whether more people order air conditioning in their SUVs than their grandparents did. I remember the days of my youth with 475 AC. (4 windows, 75MpH) I'm not sure how to quantify the AC my grand/great-grandparents used on the California trip in their covered wagon.

    --
    The living have better things to do than to continue hating the dead.
  3. Global Warming?--Right... by Henry+V+.009 · · Score: 4, Interesting

    More accurately, New Scientist reports that Red Squirrels in the Yukon are evolving due to local climate change. Which it proceeds to call global warming.

    1. Re:Global Warming?--Right... by MarkGriz · · Score: 3, Insightful

      Agreed.

      I must say I'm a bit surprised that most of the comments here seem to be in the "not global warming" camp. Must be that the doom-n-gloomers are still asleep?

      --
      Beauty is in the eye of the beerholder.
  4. Evolution of human? by Gadzinka · · Score: 5, Insightful

    Is global warming also affecting human evolution?

    There ain't no such thing as human evolution (anymore).

    The evolution is a trials and errors process. During the duplication of DNA sometimes something goes wrong and the result isn't a perfect copy of the original.

    This is called a mutation.

    As a result some function of the organism is different. The change may be beneficial for the organism or it may render it handicaped. For every positive mutation there are houndreds of thousands negative mutations.

    Who's to tell which mutations are positive and which are negative?

    Natural selection.

    If/when a particular mutation has some features that allow it to dominate gene pool it is positive. If the mutation causes premature death, sterility etc the faulty genes do not enter the gene pool. This is negative.

    In order for humans to evolve we would have allow natural selection to work. We don't do this. It is not the survival of the fittest for a long time.

    Robert

    --
    Bastard Operator From 193.219.28.162
    1. Re:Evolution of human? by jazznjava · · Score: 3, Insightful
      There ain't no such thing as human evolution (anymore).

      I agree that natural selection is past its prime in developing countries, but I don't believe evolution has stopped, or that evolution will ever stop. I think people are evolving more by societal selection than natural selection.

      In other words, now it comes down to who has more children, not who has children and who gets killed before they get the chance to (except those lucky Darwin Award laureates).

      So geeks are currently on the road to extinction! It is up to those who can to breed like rabbits to prevent this!

    2. Re:Evolution of human? by bill_mcgonigle · · Score: 3, Insightful

      There ain't no such thing as human evolution (anymore).

      This statement assumes a static environment model, which is uncertain at best.

      Maybe we wipe out the ozone layer, and everybody with light skin dies young from skin cancer.

      Or maybe we blanket the earth with a nuclear winter or there's an mega-killer asterioid hit and everybody with dark skin dies from Vitamin D deficiency. Everybody in temperate climates dies too because it's too cold to grow crops, so only those smart/clever/ruthless enough to migrate south and grow food survive.

      For instance. There may not be any environmental pressures on human evolution at the moment, but that equalibrium is subject to being upset.

      --
      My God, it's Full of Source!
      OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
    3. Re:Evolution of human? by Gadzinka · · Score: 2, Funny

      Do you honestly believe that legless girls with three noses get laid as much as the more conventional folk?

      There is this Polish saying: ``kazda potwora znajdzie swego amatora''. Loosely translated it means ``every monster's gonna find itself a mate''.

      And I've seen several times, that they really do find a mate and often produce lots and lots of offspring.

      Robert

      --
      Bastard Operator From 193.219.28.162
    4. Re:Evolution of human? by JoeGee · · Score: 2, Interesting

      There ain't no such thing as human evolution (anymore).

      I suspect it's the nature of life to adapt. In the past our technology has changed quicker than we could adapt to it, but in one area, diet, species change continues. Look at average weights of individuals in many "developed" countries. This is not an evolved feature, but if it persists through many generations it might very well change part of the human species. Adaptations that allow longer reproductive span of individuals who consume high calorie diets, such as better elimination of extra calories, or better tolerance of high blood cholesterol, might prevail. Adaptations such as a more dense bone structure or altered musculature (to carry the weight), might also occur.

      Unwittingly, or intentionally, in many "developed" countries we now segregate out lower functioning (borderline mentally retarded) individuals who in previous generations might have been able to lead "normal" lives. We put them in special schools/classrooms, we give them medications that change their behavior, and by artificially grouping them into separate social groups we decreased their chances of reproduction. I suspect any evidence to back this up would be anectdotal, but I'd wager if the numbers were there you would see a significant decrease in the number of borderline mentally retarded people who father or give birth to children.

      Similarly, although physical prowess is still a strong attractor, I'd be willing to bet that intelligent guys are sexier now than they have ever been. Although we won't live to see the results, you want to bet this subtle eugenics won't have an effect on the species?

      Just because we don't have lions hunting us on most golf courses doesn't mean the genome of h. sapiens sapiens won't continue to change. :)

      --

      Get off my virtual lawn, you damned virtual kids!
  5. Human Evolution... by jsimon12 · · Score: 3, Insightful

    "Is global warming also affecting human evolution?"

    The envionment really stopped effecting human evolution once we started to manipulate it, so it is unlikely that you will see any similar effects in humans. If it gets to hot for us, we just crank up the AC.

  6. Breaking News? by gi-tux · · Score: 2, Insightful

    I remember seeing this in gray squirrels growing up on the farm 30+ years ago. If food is available early then the squirrels had their litters early. If there were bad rains late in the season and the first litter was drowned, etc. then a second litter was usually delivered.

    I wouldn't call this anything evolutionary. It is interesting that their instinct takes care of this for them, but it isn't any kind of change. We have been lucky over the last few years and have had short winters (at least in the southern US) and that has changed the beginning of spring and most likely the birth dates of some animals.

    I bet that they spent a ton of federal money on that study too. Just another waste of taxpayer money trying to prove that God doesn't exist.

    --
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  7. Bad News! by jfagan · · Score: 2, Funny

    For NASDAQ that is, they have been hit twice by those cute furry things. Once in 1987 and then again in 1994.

    In the UK office we still joke about it, much to the annoyance of the management :)

  8. Re:Human adaptation to global warming by Smidge204 · · Score: 2, Interesting

    Reminds me of a bumper sticker someone suggested for people who drive SUVs:

    "Who cares about Global warming? I've got AC!"

    Humans evolving? Maybe not. Evolution depends on stress from the environment (to severely paraphrase the theory). If the environment isn't changing, there's no "pressure" to force evolution.

    Thanks to human inginuity, we can bottle ourselves up in nice little climate-controlled houses, eat carefully prepared and nutritionally balanced foods, get regimented exercise, and receive all manner of medical treatment that cancel out pretty much everything that evolution has to work with.
    =Smidge=

  9. Affecting evolution? Surely so! by mcgroarty · · Score: 2, Funny
    Is global warming also affecting human evolution?

    Yes. We get hungry for squirrel chili about 18 days sooner 'round here.

  10. weather forecasting by HyperbolicParabaloid · · Score: 2, Funny

    Huh! I thought squirrels were doing well by foecasting if we would have a bad winter; now they are telling us we're going to have a tough millenium!!

    --


    -------------------------
    A person of moderate zeal
  11. Re:Human adaptation to global warming by G.+W.+Bush+Junior · · Score: 2, Funny

    Thanks to human inginuity, we can bottle ourselves up in nice little climate-controlled houses, eat carefully prepared and nutritionally balanced foods, get regimented exercise, and receive all manner of medical treatment that cancel out pretty much everything that evolution has to work with.

    all humans have SUVs and AC?

    That actually sums up pretty nicely why the rest of the world don't like americans:

    if they haven't got a SUV with AC they're not really human.
    =>If they're not really human why don't we shoot them and take their oil for our SUVs?

    --
    "I don't know that Atheists should be considered as citizens, nor should they be considered patriots." -George H.W. Bush
  12. You are all WRONG-GUH! by amarodeeps · · Score: 2, Funny

    Clearly GAWD-DUH is changing these little squirrels to fit his heavenly PLAN-NUH. Oh, he works in mysterious WAYS-UH. All of those SINNERS who believe in EVOLUTION-NUH will be shown the folly of their ways when the find themselves burning in the unholy HELL-FIRES of HELL-UH!!

  13. city squirrels by Parsec · · Score: 2, Funny

    Anyone notice that city squirrels sometimes now pause on the dividing lines on streets? It would be an interesting experiment to transplant some UK city squirrels with US city squirrels to see if the side of the street we drive on is being genetically encoded.

  14. Re:It's called plasticity by Bastian · · Score: 2, Interesting

    Species change in relation to their environment for reasons other than evolution. It's a fairly standard survival adaptation, but it can make for changes in species that people often think are best attributed to evoltion.

    In general, someone whose parents are both Pygmies but who grows up in Spain is going to end up being average height. Turns out a large portion of the reason why pygmies tend to be so short is their diet.

  15. Re:causality or correlation? OT by Scrameustache · · Score: 2, Funny

    Generally, one cannot claim that species evolve for some purpose

    My dad claims the human body evolved so it would fit perfectly on a motorcycle...
    ;- )

    --

    You can't take the sky from me...

  16. soon to publish my research by frovingslosh · · Score: 2, Funny

    I have a small ($3 million) study grant from the E.P.A. and after careful study and review I've determined that global warming is caused by squirrels having their litter earlier and earlier.

    --
    I'm an American. I love this country and the freedoms that we used to have.
  17. You miss the point (but I am not surprised) by jsimon12 · · Score: 2, Insightful

    The point is the fact that humans change their environment rather then adapt to it, whether it be with AC, buffalo skin tents, white clothing or even a simple structure made from fallen branches. The last major physical thing we "adapted" to would probably be UV radiation and the production of vitamin D (hence the reason people have different skin colors).

  18. Not the only development... by ColoradoZippy · · Score: 2, Funny

    ...I hear that they're less likely to be married at the time. ;)