Posts tagged with BENEFICIAL MUTATIONS

1 Results

Evolving the Wow! Factor

(Being the third part of an occasional series about mutations.)

Here are two pieces of bizarre natural history:

One. The crab spider Thomisus onustus. Some individuals are a most unspiderly color: they are hot pink. This allows them to hide in hot pink flowers — and ambush unwary bees. Other individuals are yellow, and hide in yellow flowers. Even more surprising, their colors are not fixed: move a pink spider to a yellow flower, and she can change her color to match.

Two. In the center of the Atacama desert in northern Chile, it rains less than five millimeters (less than quarter of an inch) a year, yet there are bacteria living inside quartz pebbles. Like plants, these bacteria make energy from sunlight. (The quartz is translucent, so it lets in some light, but at the same time, shields the organisms from the worst of the ultraviolet radiation.)

I mention these oddities because this week, I want to resume my obsession with mutations, and look explicitly at a type that I’ve so far mentioned only in passing: beneficial mutations.

All mutations are accidental changes to DNA. Beneficial mutations are those accidental changes that in some way improve an organism’s chances of surviving and reproducing. Obvious examples from recent decades would be a mutation that confers antibiotic resistance on bacteria that cause disease in humans, or one that confers poison resistance on a rat. Less obvious are mutations that produce hot pink spiders and quartz-dwelling bacteria. But the point is that such mutations allow organisms to evolve to fit their environments better — a process known as adaptation.

Adaptation is the “wow!” factor of nature: when we see something spectacular or exquisite, we are typically looking at an adaptation. And what underpins adaptation is the appearance and spread of beneficial mutations: the process is not possible without them. Yet despite their central role in adaptive evolution, beneficial mutations have — until recently — received surprisingly little attention. Read more…