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Roadkill Forcing Cliff Swallows To Evolve
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."
cuz of evolution I made it here first
Any animal or fungis that has four-dimensional capablililtities would be totally awesoerme! It could evade owls and cars both at the same time with blood!!! But Darwin did not predict this, so, NO!
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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!
Now if only humans would evolve that fast...
Disagreeing with you does not make me a troll.
If I keep on smacking my kids, their arms will get shorter?
...And this is yet another proof that God exists. My prayer circle has spent the last 10 years asking for Divine intervention to halt the senseless deaths of road-adjacent animals. Thanks to our unceasing intervention, He knew to trim a wee bit off the tip of every bird's wings (gradually, of course, so that mommy birds would still recognize their babies - and left longer wings on the sinner birds so that they would die and serve as a warning to others). Praise Jesus!
these evolutionists are just trying to force these lies down your throats.
how can the birds be changed by the overpasses? the bible tells us that the overpasses have existed since the creation of the universe, 3 decades ago.
What is the new air speed velocity of an unladen cliff swallow?
...are you sure we can't tie their shortening wingspan to global warming somehow?
Natural selection. Not evolution.
No new genetic material is being added.
Two completely different things.
There is going to be less meat on the little swallow wings. Less meat == less reason for swallows. Perhaps I should hit a few short winged swallows with my car to select for swallows with more tasty swallow wing meat.
The article says it's because they are more maneuverable, but what if they just sit on their asses a lot unlike their easier flying longer winged relatives? Fly less, get hit less.
I have yet to see a Cliff chew let alone swallow.
I would have at least expected some controlled laboratory tests and a data plot pertaining to air-speed velocity...
The article says it's because they are more maneuverable, but what if they just sit on their asses a lot unlike their easier flying longer winged relatives? Fly less, get hit less.
Fly less, grow obese
Fly less, get less food, starve to death?
I was driving up in the mountains a year or so ago and saw a chipmunk run out into the road between me and the car coming the other way. Now normally this is pretty much certain doom for the chipmunk, but this one stopped calmly on the yellow line, stood up and waited for us to pass before continuing. I've always wondered if the evolutionary pressure of traffic combined with their short generation cycles would lead to critters less likely to become roadkill. Guess I have my answer.
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
What the hapless biologists could not discern from their data is that the birds wings have not changes over an insignificant period of three decades; they submitted their report and their buddies reviewed it with glowing remarks.
The birds are just smart. That is all.
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.
When our name is on the back of your car, we're behind you all the way!
It's actually related to the amount of CO2 in the air - atmosphere volume has increased via burning liquid fuels, which increased the air density at the surface, which allowed shorter wings to provide the same lift as the larger historical wings. Or the car thing.
Fly with a purpose when needed, live. Play dodge the highway traffic because you can, splat. If it takes more effort to fly then maybe you cut down on your recreational flying. Sort of like higher gas prices.
Cliff Swallows?
Not if you're a short-winged pimp swallow, having all the other long-winged swallows doing all the wing-work, while taking a cut out of every insect returned.
would take about 2 of OpenBSD versus Don't be a sling polite to bring
more idiots. From antilock brakes to airbags to life-saving medicine and surgery, the more people likely to benefit from these technological advances ensures that more idiots, imbeciles and morons remain alive and viable to pass on their stupid-genes.
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You moonbats will believe anything. Yet you call those who believe in God crazy.
Look in the mirror, idiots.
More birds with large wings dieing, and more birds with smaller wings taking over breeding is not evolution, its natural selection.
To prove evolution you should have to show that in their DNA it has mutated to make smaller wings. Big difference. Evolution would be expected only after heaps of gene mixing of small wing birds over hundreds of generations.
Wow...am I the only one who thought thid was a new game devo? Or maybe, a new distro of Linux that I hadn't heard of this week.
Finally, someone with the guts to tell it like it is! Why can't you moonbats see the truth? Why can't you see that everything FOX News says is true? Why can't you see that Mitt Romney really did win the election, that he's sitting in the Oval Office right now, and that the sky is purple?
Glory, glory hallelujah! And you call us crazy??? Look in the mirror, idiots.
*Shakes head*
I had to go through a set of lights by a couple truck stops back in the day more than once a week. I noticed grackles (crowish kinda birds) that would wait on the posts or nearby for the lights to turn red. Then they would jump down and pick the grasshoppers and bugs out of the 18 wheeler grills. When the light turned green, they all flew back up and waited. They were quite well fed.
ill take the dark side of the observation and say its just the pollution from the vehicles that pass by as well as chemical's seeping into the roadkill before they eat it causing the birds to have stunted growth issues, in this case, when it comes to the bird's wing's...
Yeah, the maneuverability part was supposition (it's not like they tested the birds with shorter wingspans to see how much more maneuverable they were).
Here's an alternative possible explanation. Older birds are bigger. Older birds have slower reactions. As overpasses became more common, it was predominantly older birds which were killed disproportionately by passing cars. Consequently the birds may have increased in number, but their population distribution is now skewed towards the younger, smaller end.
Slight pedantry: The swallows aren't being forced to evolve. The selection pressure is causing evolution among the swallows.
What effect does this have on their air speed and coconut carrying ability?
re: I see hawks or eagles circling some highways nowadays
:>)
My understanding of why birds of prey are often seen circling highways is that they are taking advantage of thermals, rising columns of air heated by the asphalt/cement roadway surfaces, to power and maintain their gliding and flying. The fact that there's also an abundance of roadkill may have something to do with it also. See also http://en.wikipedia.org/wiki/Wedge-tailed_Eagle#Behaviour_and_diet for how the eagles can observe thermals with their infrared vision.
Just read the article. The wing span only decreased one centimeter. That is less than one millimeter a year. A one centimeter difference in wingspan won't help a bird at all, let alone one millimeter. You are not going to be "selected" because of one centimeter. Most of the birds I have hit with my car are usually in the middle of the windshield. To avoid the impact, the bird would have had to suddenly move more than two+ feet out of the way. One centimeter ain't going to help you there either...
I remember the 1980's. Lots of rain, lush green fields. Now here in the south in 2012, Everything is dead and brown, with fires everywhere from drought. Yet these two dimwitted "scientist" blame "evolution" for these smaller birds.
Probably just used the word evolution to get more grant money. Crooks...
Is that seriously enough time for such an evolution to take place? I was not aware evolution happened so quickly, even accounting for their quicker viability for reproduction. Seems like there might be a million other reasons why this is happening, not because of something so recent.
I'm a short-winged pimp swallow. And short-winged pimp swallows don't commit suicide.
... to simply avoid building nests that dangle precariously from highway overpasses? Why not chose safer nesting places? What if a huge truck passes on top of the bridge, shaking it so much that the nest comes off and falls down on the highway below? Then the brood is dead, shorter wingspans or not...
We often get stories like this where some scientists make some observation and declare that that was due to evolution. If evolution is such a great theory, how about someone come up with a prediction for once, as in something like, "Due to these conditions, this so-and-so life form will eventually evolve to have such-and-such appurtenances with such-and-such characteristics". Anybody up for the challenge?
Dropbox drops it like it's hot.
What's their air speed velocity now?
What happened then was hilarious. The hare saw the left head light, became scared and jumped to the right. Being now closer to the right head light, it became scared again and jumped to the left. Then again to the right, and so the hare became trapped between her head lights. This continued until the next village where there was light all over the place, and the hare got away (... while the village people shook their head how anybody could let a perfectly good hare run away after having had such an easy opportunity for miles...)
Fast forward 35 years later. I was also driving on a nightly country road, and you guessed it a hare. Not knowing how to dress one either (and not being that fond of venison anyways), I just followed it for 2-3 jumps, then briefly switched off my lights to let it go...
So, apparently hares didn't evolve in those 35 years...
You are aware that the size difference in fish is NOT to seperate fit from unfit fish but that is a seperation on AGE of the fish?
Basically you are suggesting that the answer to a healthy fish stock for the future is to kill all the young and life the adults to swim free...
I know this is Slashdot and that with your intelligence we should all be grateful you got so little practical experience with reproduction but I think that even you might need to read up a bit on how a species survives.
Hint: It involves adults dying and being replaced by something that came out of them before they died.
You know people are to far removed from nature when people seriously suggest that killing the babies is the way to preserve a species.
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
Now, they either wait patiently or bolt across the road when everything looked all in the clear.
Here the squirrels like to run 3/4 across a road, where they do a quick 180 and then head back to the original curb. And the little rat bastards always make it, even if you floor it. I guess only running 3/4 across the road is an evolutionary advantage to running curb-to-curb. 8^B (squirrel smiley face)
Because evolution of the form in fossile record and outside is what we observe. Natural selection is the theory trying to explaining it. Those folk thinks it is the theory of evolution when in reality it is the theory of natural selection based on observed evolution....
Reminds me of the English "white" moths that "evolved" into black moths, when pollution turned the tree bark darker. When pollution was decreased, and the tree bark lightened, the moths "devolved" back to white. It's adaptation, not evolution, folks. Words mean things.
Are the short-winged swallows unable to mate with other swallow in their parent population?
There is no dispute that traits are inherited and that of the traits in the gene pool of an organism, certain traits can be selected, either through breeding or through environmental selection pressure such as road kill of swallows, soot on trees with moths, or superbugs emerging with antibiotic resistance.
Has anyone, however, observed this selection effect going on for a long enough time for the emergence of new species?
Has anyone seen mutations arise that weren't in the gene pool of an organism and seen the mutated form "take over" a population because the mutation conferred a survival advantage, in other words, a Hopeful Monster in the lingo of evolutionary biology?
So in the Arthur C Clarke sense of any tech beyond current knowledge takes on the appearance of magic, evolution is and remains magic. There are a variety of hypothesized ways to generate entirely new species, but they have not been observed directly.
I have no respect for a bird that gets killed 4 - 6 feet off the ground.
I haven't thought of anything clever to put here, but then again most of you haven't either.
Nothing is forcing anything. The swallows with longer wingspans are dead. It's a filter, not a change. It's not like there was a swallow conference where they adopted new, shorter wing standards.
Up until "abrought" I almost believed you!
+1 Disagree
There is an exhibit at the New England Aquarium about exactly this. It claims that fishing has drastically reduced the size of Atlantic cod since the 17th century.
[Sir Garlon] is the marvellest knight that is now living, for he destroyeth many good knights, for he goeth invisible.
This is the same as Darwin's finches. Their beaks lengthen again after some amount of years when their environment changed back.
These birds already had the genes for shorter wings...they were just selected out. Once we are all using flying vehicles don't be surprised when their wings lengthen back to equilibrium. It's natures way of saving a species.
They didn't need to. Other experiments have established that shorter wingspan correlates with faster takeoff times and greater maneuverability.
They could be suffering from depression, they know they are doomed in twenty years when the world runs out of oil.
smaller body, smaller food requirement.
The guy who said the election was rigged won the presidency with the second-most votes.
No, my understanding of evolution is limited to attending a public lecture of the late Stephen Jay Gould and reading most of his popular-literature-for-the-layman books on the subject. There are things observed directly, such as the moths in smoggy London or the swallows in the highway overpass, and there are many things observed indirectly, such as the cladistic relationships in the fossil record or the Woese genetic distances. Gould discusses many of the gaps in scientific understanding of evolution, and maybe I haven't kept up on the latest science on the filling in of those gaps. But I was suggesting, that parts of evolution are "magic" in these sense of Arthur C Clarke, not magic in the sense of violating any natural laws, but magic in the sense that there are many hypothesized mechanisms for which scientific research is still filling in the details. At your suggestion, I Googled "nylonase", and as the name suggests, this is an enzyme that is inferred to have entered the gene pool of bacteria through a mutation that allows these bacteria to process a man-made substance. As another response to my post suggested, there is a big gap between what happens in bacteria with speciation in sexual-reproducing multi-celluar eucaryotic species. And something for which there is compelling evidence can be discussed in reasoned, even-tempered prose, without ad-hominen attacks on the knowledge of someone one barely knows, and without the words "zero" and "absurd" in shouting caps.
Shorter wings, yes. Same organs, same brain, same pretty much every thing except wingspan. Less efficient flight, requires more energy.
touche
The guy who said the election was rigged won the presidency with the second-most votes.
BTW, **NINE** digits of years? 100 million or more? Only three million years ago we were Australopithecenes, do you actually think Homo Sapiens haven't made 'long term' changes in the interim? 70 million years ago we were rat-sized egg-laying insectivores, are you really sure that we haven't changed significantly since then?
Meet my ex-wife