Bell curves are everywhere. Pick 100 random people and measure them: measure their height, their weight, their blood pressure, their time to run a mile, or to sprint 50 yards, and their IQ, and you find that most of us fall in the middle of the spectrum, while there are always some people on either extreme. Why?

The puzzle grows deeper when you think about genetics. If a trait like height is controlled largely by genes, how is it that height falls into a bell-curve pattern? Bell-curves seem completely at odds with what we learn about the discrete genetics of Mendel's round and wrinkled peas in high school biology.

It turns out that the solution to this puzzle is fairly simple (although the details get messy). In fact, Darwin's cousin hit on the right answer (long before he or anyone else knew about Mendel's genetics), with what he called the "Supreme Law of Unreason": a bell curve is exactly what you expect when you toss together "a large sample of chaotic elements." In other words, genetics is like one big game of The Price Is Right.

Show Me The Science Month Day 25 Installment 25



In nature, there is a sucker born every day. We humans may think that we're clever, but evolution has produced con games that would put Bernie Madoff to shame. One common natural swindle is mimicry, when one species tries to pass itself off as another. Orchids and cuckoos are classic examples of nature's swindlers, but mimicry isn't limited to plants and animals. A recent study has looked at how a fungus outsmarts a termite by dressing up as a termite egg.

Show Me The Science Month Day 24 Installment 24



How do new genes arise? One common way is through gene duplication - the creation of a second copy of a gene when the DNA replication or repair machinery goes awry, followed by the the evolution of a new function for one copy. How genes are accidentally duplicated is reasonably well understood, but once a gene is duplicated, but how does the new copy acquire a new function?

A pair of researchers in New York have looked at the role of a class of reproductive proteins in the mating behavior of different species of flies. One thing you can learn from this paper is that biologists will go to any length to learn about evolution - nobody watches fly sex for fun. Except for fly number three: (which was apparently put in by Photoshop):


But there are more lessons here. Mating behavior is in fact an excellent place to look for lessons about evolution, since reproduction is subject to strong evolutionary pressures.

While you're sipping that morning cup and looking for excuses to put off work, here's what's interesting in science around the web today (well, ok, not just today - I haven't done one of these in about a month):

Your tax money pays for the research, so shouldn't you be able to read that research without paying an arm and a leg? Biologist Michael Eisen defends the National Institute Health policy that scientists put copies of their manuscripts in a freely accessible, public repository, as Congress plans to revisit that policy at the behest of for-profit publishers. Eisen argues the policy doesn't hurt publishers, and thus there's no reason to scrap it: