I'm marking exams. They're not … good. But they're taking up most of my time, along with endless bloody meetings where we go around and around and around — but not, unfortunately, in ever-decreasing circles. If we did, at least we'd get somewhere.
In the moments between marking and swearing and meetings and swearing, I'm writing for money, which is A Good Thing. And in my spare nanoseconds, I'm reading Sean Carroll's Endless forms most beautiful, which explains evo-devo to those of us who studied embryology before Hox genes were big.
Evo-devo is the branch of evolutionary biology that looks at embryonic development and the way in which it leads to differing morphologies. Development is shaped by a handful of Hox genes, which are pretty much the same whether they're in crabs, crinoids or kookaburras. PZ Myers gives a good intro to their role in this post at Pharyngula. And he's written plenty more about them.