Sure, you've got those great opposable thumbs, complex culture, and the ability to walk on two legs. But don't let those facts lull you into thinking that evolution is on your side. It's not. It's not really on anybody's side. Which is why the same process that produces super-smart, super-creative apes (like us) is also responsible for helping cockroaches evade our attempts to murder them
. — Maggie
In Tulsa, Oklahoma, over the last 30 years, the number of cliff swallows killed by moving vehicles has drastically decreased. That change can't be accounted for by alterations in traffic patterns or swallow populations, say scientists. Instead, they think it's tied to the fact that the birds' wingspan is also decreasing
. This adaptation — whether selected for by vehicular birdicide and/or other factors — helps swallows be more nimble in the air at high speeds, making it easier for them to avoid oncoming traffic. (EDIT: Sorry guys, I made an error here. Some of the researchers were from Tulsa, but study actually happened in Nebraska. Evolution takes place throughout the plains states.) — Maggie
Up north — in Canada and other places where snowy winters are reliable (and reliably heavy) — you find more animals whose fur comes in various shades of white. This is true even for species that are brown or black further south. The difference is obvious. But how does it happen? Carl Zimmer presents two possible paths to paleness — random mutation, and fortuitous cross-species mating
. In related news: Golden retrievers are probably getting it on with Canadian coyotes. — Maggie
According to a new book, the human overbite developed at different times, in different places — and was always coincident with the widespread use of eating utensils. In Europe, for instance, evidence suggests that humans have only had an overbite for about 250 years. — Maggie
Plants and animals have to adapt to live in high latitudes and chilly mountain environments. With animals, we kind of instinctively know what makes a creature cold-weather ready — thick, shaggy fur; big, wide snowshoe paws. But what are the features of cold-weather plants? It's one of those really interesting questions that's easy to forget to ask.
At The Olive Tree blog, Tracey Switek has at least one answer. In cold places, you see more plants that grow in little mounded clumps. Of course, plants can't really rely on huddling together to create warmth. So you still have to ask, "Why is it better to grow in a mound when it's cold out?"
The dome-like shape which the cushions tend to take (made possible by an adaptation that makes all the plants in the clump grow upward at the same rate, so no one plant is high above all the others), and the closeness with which those plants grow, makes these clumps perfect heat traps. The temperature on or inside a cushion can be up to 15 °C more than the air temperature above it. The cushions are able to retain heat radiating up from the soil, as well as absorbing heat from the sun (a very dense, large, clump of green can get surprisingly warm on a sunny day at high altitude). Add to that the fact that the wind speed in and around a cushion can be cut by up to 98% from open areas, you have a perfect recipe to prevent heat loss. Many alpine cushion plants also have very hairy leaves, which trap even more heat within. This allows the plants to maintain a relatively stable, warmer than average microclimate that is resistant to sudden changes in weather and temperature outside (such as freezing temperatures at night or sudden storms). Interestingly enough, this stabilizing effect can also be a benefit when it gets too hot out, maintaining lower temperatures against baking sunshine.
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Via Sci Curious
Image: Michael Haferkamp, via CC
I was on Bloggingheads.tv Science Saturday this week, talking with Jessa Gamble, a science journalist and the author of Siesta and the Midnight Sun, a book about how culture and biology effect the way we experience time.
Jessa was in Japan in 1999, when an accident at a nuclear fuel processing facility in the prefecture just south of Fukushima killed two workers. We started off our conversation talking about the industry lapses that led to that accident, and how government and the media responded to it.