Carroll’s essential tool kit genes…Hox Genes they’re called (for reasons he explains a lot better than I can…)
Anyway, it turns out these clever little monkeys have been around for what is effectively forever…so all the variations of all the bodies we see around us from wasps to whales…were sort of…(and here I’m getting foggier and need help) …potentially already there too.
In embryology (which is suddenly REALLY interesting again, having not been sexy for ages, according to Carroll) what these clever folk are finding out at the moment is that building bodies is largely a matter of time and space…of the same Hox Genes, the same toolkit… being switched on and off in the earliest stages of development in ALL animal embryos…so that your leg ends up THERE (if you’re a fruitfly) as opposed to THERE (if you’re Simon Cowell)…
And that switching OFF is possibly more important more of the time than switching ON.
(No…don’t put a leg there…or there…or there…or there…wait for it!…NOW)
This may be just bonkers, but doesn’t that view of life (as lots of no-es punctuated by well placed yes-es) rather tend to argue, or lie on similar lines, for and to Stephen Jay Gould’s proposed “inversion” of the cone of diversity as alluded to in my last post?
That evolution…natural selection…progressively favours simplicity? Maybe maybe.
That evolution is an arrow with no built-in direction? Bet your shirt on that one!
And doesn’t (as Carroll also thrillingly describes) the evolution of the same parts (from the same genes being expressed) into wings in one animal and gills in another…tend to point the same way?
That complexity has always BEEN there…
Just a thought.
Leading (me anyway) to lots of other thoughts…which I may berate you with when they’ve stopped swirling around my cranial cavity…
Meanwhile I hope that someone who’s cleverer than I am in these matters is reading this rubbish so they can electronically belt me over the head and tell me to stop being silly.
Or give me the Nobel Prize for my insight…either will do.
Next time...a bit of a poem...and almost immediately...a call to conversation!