Author Topic: fast natural selection  (Read 1260 times)

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Offline wright

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fast natural selection
« on: March 21, 2013, 04:52:12 PM »
Interesting article on an example of natural selection acting over just a few decades:http://www.sciencenews.org/view/generic/id/349028/description/Shorter-winged_swallows_evolve_around_highways

From the article:
Quote
Starting in 1983, the researchers collected fewer birds killed by cars each year, until they found only four in 2012. And when Charles Brown measured preserved specimens’ wing lengths, he saw that, compared with the rest of the population, swallows that died on the road had wings that were a few millimeters longer.

A few millimeters — about the width of a Tic Tac — might seem like a small change, but for birds’ wings, “a little bit can make a big difference,” says evolutionary biologist Ronald Mumme of Allegheny College in Meadville, Pa.

Petite wings let birds take off quickly and maneuver deftly through the air. Like quail, which have short, rounded wings and can explode off the ground almost vertically, Brown says, swallows might be better served by short wings that help them whiz up and out of harm’s way.

He thinks the population’s shorter average wing lengths could help explain why roadkill numbers are going down. “It’s amazing what natural selection can do,” he says. 
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Offline mrbiscoop

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Re: fast natural selection
« Reply #1 on: March 21, 2013, 05:18:39 PM »
Bbbbbbut it's still a swallow. &)
When I was a kid I used to pray every night for a new bicycle. Then I realised that the Lord doesn't work that way so I stole one and asked Him to forgive me.
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Offline wright

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Re: fast natural selection
« Reply #2 on: March 21, 2013, 05:41:19 PM »
Bbbbbbut it's still a swallow. &)

Dammit, checkmated again!  &)

Ooh, ooh, and:

"That's just microevolution, not macroevolution!"

and:

"That's not evolution, just adaptation!"
Live a good life... If there are no gods, then you will be gone, but will have lived a noble life that will live on in the memories of your loved ones. I am not afraid.
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Offline The Gawd

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Re: fast natural selection
« Reply #3 on: March 22, 2013, 07:32:44 PM »
"his eye is on the sparrow, not the swallow"

Offline Tonus

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Re: fast natural selection
« Reply #4 on: March 22, 2013, 07:47:54 PM »
Same thing has been happening with elephants, also over a relatively short period of time.

Elephants evolve smaller tusks due to poaching.
Quote
It appears that in at least one case, however, evolution is occurring at what seems like jet speed. In the last 150 years, the world’s elephant population has evolved much smaller tusks.

The average size of an African elephant’s tusks has gone down by half in the last century and a half. Indian elephants have undergone a similar tusk size reduction.

Experts believe the rapid evolution of the massive land mammals is due to poaching. Zoologists from Oxford University suggest that ivory poachers, who go for the largest males with the largest tusks, have caused the breeding behaviors of the animals to change rapidly in a short time.

Africa's elephants 'ditch tusks' to survive
Quote
Research at the Queen Elizabeth National Park, Uganda, showed that 15% of female elephants and 9% of males in the park were born without tusks.

In 1930 the figure for both male and female elephants was only 1%.

Genetic accident

Experts say the reason why some elephants are tuskless is a result of a chance genetic mutation.

They say elephants are losing their tusks as a rapid and effective evolutionary response to escape slaughter by ruthless and resourceful poachers who kill elephants for their ivory trophies.

Offline jaimehlers

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Re: fast natural selection
« Reply #5 on: March 22, 2013, 08:38:37 PM »
Evolutionary natural selection is pretty amazing, isn't it?

Online JeffPT

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Re: fast natural selection
« Reply #6 on: March 23, 2013, 06:57:31 AM »
Bbbbbbut it's still a swallow. &)

African or European?
Whenever events that are purported to occur in our best interest are as numerous as the events that will just as soon kill us, then intent is hard, if not impossible to assert. NDT

Offline Anfauglir

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Re: fast natural selection
« Reply #7 on: March 25, 2013, 06:49:17 AM »
What I would like to see started is a seriously long-term experiment on mice (or something that is equally "visible" - fruit flies no good!).

Set up your control group of mice, and your experiment group.  And in the experimental group, do some seriously active selection for particular physical traits (much as dog breeders have been doing for generations).  Mice being mice, with fast reproduction, you should be able to push traits a lot further, a lot faster, than with dogs.  Make the experimental group's lair conditions dramatically different to what a "normal" mouse would experience.

I'm talking a seriously long-term experiment here - 30+ years at a minimum - with the intention of proving that given enough generations, you will produce a creature significantly different to the mice in the control group.
Just because you've always done it that way doesn't mean it's not incredibly stupid.
Why is it so hard for believers to answer a direct question?

Offline Nick

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Re: fast natural selection
« Reply #8 on: March 25, 2013, 08:17:18 AM »
So this is the drive thru version of evolution?
Yo, put that in your pipe and smoke it.  Quit ragging on my Lord.

Tide goes in, tide goes out !!!

Offline mrbiscoop

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Re: fast natural selection
« Reply #9 on: March 25, 2013, 05:35:23 PM »
Bbbbbbut it's still a swallow. &)

African or European?
^^^From the funniest movie of all time.
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Offline Add Homonym

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Re: fast natural selection
« Reply #10 on: April 03, 2013, 10:31:19 PM »
What I would like to see started is a seriously long-term experiment on mice (or something that is equally "visible" - fruit flies no good!).

Set up your control group of mice, and your experiment group.  And in the experimental group, do some seriously active selection for particular physical traits (much as dog breeders have been doing for generations).  Mice being mice, with fast reproduction, you should be able to push traits a lot further, a lot faster, than with dogs.  Make the experimental group's lair conditions dramatically different to what a "normal" mouse would experience.

I'm talking a seriously long-term experiment here - 30+ years at a minimum - with the intention of proving that given enough generations, you will produce a creature significantly different to the mice in the control group.

Won't work. Evolution needs mutation, and a long time frame. You can't really fake that. Just using a god-like selection of traits is also not going to work. Dog breeding has shown that breeds just get more in-bred and ridiculous, because they select a trait irrespective of the whole health of the breed. You have to allow evolution to solve a problem in diverse ways, because the way you select to solve a pseudo problem, will not use available mutations. Say you put food up higher, in order to breed longer necks, or legs, but the animals first have a mutation which allows them to jump higher, or stand on top of each other. The way you want it to happen will take longer, because it's not diverse.


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Offline Graybeard

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Re: fast natural selection
« Reply #11 on: April 08, 2013, 06:27:23 AM »
Interesting article on an example of natural selection acting over just a few decades:http://www.sciencenews.org/view/generic/id/349028/description/Shorter-winged_swallows_evolve_around_highways

You have to be careful with these stats - one major cause of fewer roadkills of any wild animal is a lower population. Also, if slightly smaller wings give rise to better manoeuvrability  then this would also help catching insects, so perhaps the swallows's wings have evolved for different reasons.

There are stories in the UK of hedgehogs  running when a car comes, rather than curling up in a ball http://news.bbc.co.uk/1/hi/programmes/more_or_less/4665482.stm
Nobody says “There are many things that we thought were natural processes, but now know that a god did them.”

Offline wright

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Re: fast natural selection
« Reply #12 on: April 08, 2013, 11:31:58 AM »

You have to be careful with these stats - one major cause of fewer roadkills of any wild animal is a lower population. Also, if slightly smaller wings give rise to better manoeuvrability  then this would also help catching insects, so perhaps the swallows's wings have evolved for different reasons.

There are stories in the UK of hedgehogs  running when a car comes, rather than curling up in a ball http://news.bbc.co.uk/1/hi/programmes/more_or_less/4665482.stm

Quite true. I believe the article and the researchers make those claims provisionally, giving the car-evasion theory only as the most likely explanation, not a definitive one. Either way, it's observable evolutionary change in the human time scale, though of course any dedicated creationists aren't going to see it as such.
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Offline Graybeard

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Re: fast natural selection
« Reply #13 on: April 09, 2013, 09:33:45 AM »
More fast evolution:

Environmental change 'triggers rapid evolution' http://www.bbc.co.uk/news/science-environment-22039872

Quote
Changes to their surroundings can trigger "rapid evolution" in species as they adopt traits to help them survive in the new conditions, a study shows.


Studying soil mites in a laboratory, researchers found that the invertebrates' age of maturity almost doubled in just 20-or-so generations. It had been assumed that evolutionary change only occurred over a much longer timescale. The findings have been published in the journal Ecology Letters.

"What this study shows for the first time is that evolution and ecology go hand-in-hand," explained co-author Tim Benton, professor of population ecology at the University of Leeds, UK. "The implicit assumption has always been, from Darwin onwards, that evolution works on long timescale and ecology works on short timescales. The thinking was that if you squash a population or you change the environment then nothing will happen from an evolutionary point-of-view for generations and generations, for centuries."
Nobody says “There are many things that we thought were natural processes, but now know that a god did them.”