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Science

Roadkill Forcing Cliff Swallows To Evolve 387

Posted by Unknown Lamer
from the also-evolved-laser-eyes dept.
sciencehabit writes "Cliff swallows that build nests that dangle precariously from highway overpasses have a lower chance of becoming roadkill than in years past thanks to a shorter wingspan that lets them dodge oncoming traffic. That's the conclusion of a new study based on 3 decades of data collected on one population of the birds. The results suggest that shorter wingspan has been selected for over this time period because of the evolutionary pressure put on the population by cars."
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Roadkill Forcing Cliff Swallows To Evolve

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  • Re:first (Score:5, Insightful)

    by pecosdave (536896) on Monday March 18, 2013 @09:09PM (#43210121) Homepage Journal

    That will be the downfall of your species. Those who march in front are merely the meat-shields for the warriors that follow, the first torn down by the musket balls and horse mounted cavalry while those behind remain to actually fight.

  • Re:lies, all lies (Score:5, Insightful)

    by Anubis IV (1279820) on Monday March 18, 2013 @09:30PM (#43210237)

    The funny thing, at least to me as a Christian, is that none of the other Christians I know would take issue with anything said in the summary, other than the use of "evolution" to describe natural selection and adaptation: principles with which they have no problems.

  • Re:lies, all lies (Score:4, Insightful)

    by X0563511 (793323) on Monday March 18, 2013 @09:48PM (#43210335) Homepage Journal

    ... even though that's exactly what evolution is?

    I think they have a hard time understanding what the Theory of Evolution really is. If they did, they'd suddenly find it's compatible with faith as-is.

  • Re:not evolution (Score:4, Insightful)

    by Nadaka (224565) on Monday March 18, 2013 @09:52PM (#43210353)

    The definition of evolution existed for over century before genetic material was discovered.

    Keep changing the goalpost because the facts don't match your dogma, kinda like "climate change"

  • by camperdave (969942) on Monday March 18, 2013 @10:06PM (#43210413) Journal
    Yes, this may be due to evolution, not of the birds, but the automobile.

    To generate increased fuel economy, today's automobile is a lot more streamlined than ones of the past. So there is less air disturbance. It may be that the birds with smaller wings are not affected by the turbulence as much as the larger winged birds are now, and can thus survive an encounter, whereas in the past, there was enough turbulence to affect the birds regardless of wingspan. Also, changes in traffic patterns and vehicle types changes the exhaust, which changes the local plant life, which changes the insect life, which ultimately changes the birds.

    While it is simple to observe that long winged birds are being disproportionately killed and that the population's wingspan is growing shorter, and conclude that some sort of selection (Is it natural selection when birds are hit by cars?) is taking place, the reality may be quite different.
  • by Vreejack (68778) on Monday March 18, 2013 @11:45PM (#43210853)

    Um, what? Are you trying to suggest that bird wings are shrinking because automobiles produce less turbulence than they used to?

    I have seen some really stupid write-ups in Science, but this one was concise and accurate. Roadkill birds have longer wings and the average wingspan has decreased over the decades of the study. It is known that birds with shorter wingspans are more agile in the air. The conclusion is that roadkills are placing a selection pressure on the birds for shorter wingspans. Turbulence is not actually believed to play much of a part, as death is caused when the birds are struck by cars, not when they get caught in their wake.

  • by Anonymous Coward on Tuesday March 19, 2013 @12:08AM (#43210929)

    Is it natural selection when birds are hit by cars?

    Why would it not be natural selection?
    The environment in which the birds exist was rapidly changed due to the actions of another migratory species.
    This new environment is more dangerous to birds with a larger wing span. The birds with dominant short wing span alleles were able to survive longer and produce more offspring. Ergo, the nature of the environment selectively breed for short wing span alleles in this species in bird. The fact that the environmental change that catalyzed this selective process was instigated by humans doesn't nullify the premise that this is natural selection at work.

    To believe that humans are so far removed from nature to no longer be considered natural is hubris. Homo Sapiens is a transformer of the environment not unlike the earliest cyanobacteria that polluted the atmosphere with an over abundance of oxygen billions of years ago through their development of photosynthesis.

  • Re:Tricky EIRs (Score:3, Insightful)

    by NFN_NLN (633283) on Tuesday March 19, 2013 @12:25AM (#43210989)

    This could be tricky, if this gets classified as a new species, how do we factor in the need for persistant traffic in environmental impact reports? If we cut traffic this species would lose its competitive edge and thus habitat and could become extinct!

    Unlike religion, taxonomy is based on science. You can't just name something a new species because of a slight variation.

    Species:
    A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding.

    If the short wing swallows can breed with the long wing swallows to create fertile offspring... they probably aren't a new species.

  • Re:lies, all lies (Score:5, Insightful)

    by Anubis IV (1279820) on Tuesday March 19, 2013 @01:41AM (#43211243)

    Hmm...yes and no. When people talk about "evolution", they're generally talking about the creation of new species via the combined mechanics of random mutation and natural selection. Natural selection is something that everyone I know is fine with. Random mutation is something that everyone I know is fine with. But the creation of new species? Not so much. And in this case, we're merely seeing natural selection at play, which is not evolution, in and of itself, any more than a motor by itself should be considered a car.

  • Re:Tricky EIRs (Score:1, Insightful)

    by Anonymous Coward on Tuesday March 19, 2013 @02:15AM (#43211339)

    This could be tricky, if this gets classified as a new species, how do we factor in the need for persistant traffic in environmental impact reports? If we cut traffic this species would lose its competitive edge and thus habitat and could become extinct!

    Unlike religion, taxonomy is based on science. You can't just name something a new species because of a slight variation.

    Species:
    A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding.

    If the short wing swallows can breed with the long wing swallows to create fertile offspring... they probably aren't a new species.

    That's not "based on science". Nobody experimentally determined that to be the definition as if the English word "species" and its definition were a immutable naturally occurring property of the universe. That's merely "based on semantics".

  • Re:lies, all lies (Score:2, Insightful)

    by spongman (182339) on Tuesday March 19, 2013 @02:56AM (#43211465)

    Fortunately, zero percent of all the grains of sand in the world believe that god created man. There are fewer incorrect grains of sand than there are ignorant Americans.

  • by gsslay (807818) on Tuesday March 19, 2013 @10:46AM (#43213765)

    A "day" might be 1 billion years.

    And "seed" might be asteroids, "fowl" might be spaceships, "creeping thing" might be nanotech bots and "blessed" may be "provided a 1 billion year support contract". If you like to provide your own translation of every word and concept in the Bible, you can make it anything you want it to be, prove anything you like and be infinitely update-able.

    If we were to accept this, it must be very comforting that Genesis can seem to be more than simplistic myth. But it doesn't stop it being fiction.

  • by yurtinus (1590157) on Tuesday March 19, 2013 @10:54AM (#43213853)
    I'm pretty sure any non-idiotic *anybody* simply says the Bible is a collection of stories and parables with valuable life lessons for the place and time in which it was written. As with all old stories, they're usually rooted in some factual event that occurred at the time. Christians take it a step further claiming its writing was guided by God. Idiotic Christians take it even one step further claiming every word as a literal truth, but luckily there are very few of those.

    I know it's fashionable to assume everybody who believes in Christianity takes every kernel of the Bible as an absolute truth, but most take the book as a whole. You talk about ignoring the details - with all of our modern science, we *still* can't grasp the details of how the universe was created.

    Hell, I'm not even a Christian. Why do you jump to inflammatory conclusions and make me take their side?

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