With larger size, there are further development of the primate brain, arboreal agility and versatility in the use of limbs, hands and feet; but all these developments are subordinate to that great crossing of the day-night borderline. When our ancestors abandoned a furtive existence in the forests of the night, a way of life that had lasted for many tens of millions of years, the curtain rose on a new chapter in primate evolution. By invading the day, they thrust a new mammal presence into the teeming theatre of bird, lizards, insects, and millions of lowering, fruiting, sun-fed plants.
Even today there are countless night-to-day successions that mirror, or at least symbolise, that extraordinarily prolific and significant evolutionary event. I remember a dawn in Uganda. A blush of pink had begun to suffuse the eastern sky, a delayed fruit bat winged urgently back to its communal roost, but the red-tailed monkey troop that I had risen so early to be with was already on the move. Animals followed one another out of their sleeping tree in the valley bottom and, in an untidy procession, moved up the slope, through a broken canopy. Before the sun was up they were into the red milkwood trees, stuffing their cheek pouches with sweet orange cherries. By the time parrots swept in with fast, braking swoops and the hornbills arrived, braying, low over the treetops, the red-tails were half ready to go, having creamed off the ripest fruit from the richest clusters. By mid morning the trees were alive with pigeons and barbets, turacos, still more hornbills, gentle monkeys and mangabeys; but the red-tails were gone. In hastening to make the most of another dawn in their ever-changing forest, I envisioned those monkeys as triumphant successors to a procession of long-extinct primates, among them my own direct ancestors. As I lumbered through the undergrowth, I could find some solace in the thought that I, too, once traversed branches high in a dawn-lit canopy, close on the heels of my fellow troop members, all of us drawn by the anticipation of savoury cockchafers of sweet cherry pulp. It is only now, with an imagination that is informed and inspired by Darwinian (or Mendelian) insights, that we can treasure and value such moments, snatched from the rich texture of primate life in equatorial Africa. We can connect, today, with some of the most vital and vivacious expressions of life that have ever flourished on this planet: primates here for some 100 million years, diverse, constantly changing, and source of our own existence.
Thursday, February 14, 2008
There was an embarrass not all of it de richesse around the anniversary of Charles Darwin's birth a couple of days ago. Among the more efficient pieces was Kevin Padian in Nature on Darwin's enduring legacy, which included a quote from Thomas Hardy of all people ("Let me enjoy the earth no less / Because the all-enacting Might / That fashioned forth its loveliness / Had other aims than my delight"). Olivia Judson (A tyrannical romance) was reliably fluid, knowledgeable and naughty (although there was a touch of Phil Space about it). But I'd like to mark the date with a passage from Lowly Origins (2003) by Jonathan Kingdon from the end of his chapter on early primates From Gondwana to the forests of Egypt: