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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."
No. The change is likely morphological rather then genealogical. As a result they will stay the same species, just like dogs do.
http://www.gallup.com/poll/155003/hold-creationist-view-human-origins.aspx
"Forty-six percent of Americans believe in the creationist view that God created humans in their present form at one time within the last 10,000 years. The prevalence of this creationist view of the origin of humans is essentially unchanged from 30 years ago, when Gallup first asked the question. About a third of Americans believe that humans evolved, but with God's guidance; 15% say humans evolved, but that God had no part in the process."
Squirrels. They used to zig-zag back and forth (can't make up their mind) and get crushed. Now, they either wait patiently or bolt across the road when everything looked all in the clear.
But yes, it would seem the indecisive critters got weeded out.
Life is not for the lazy.
Depends on which definition of 'species' you use. Grizzly bears and polar bears can physically interbreed, but they don't. Are they the same species? Some biologists will say yes, others will say no. Species is one of the messier words in science.
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?
"Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
That's what I thought too, but then I actually looked it up and found the GP is actually right. Two groups of animals can be morphologically the same, but still considered different species due to natural inhibitions against interbreeding.