Evolution takes place all the time. As I am writing this, some animal somewhere has changed the way it lives, and the body part that allows it to be most effective at the new way of living has also changed. Normally, these changes are so minute that one can’t see it until millions of years later when these changes add up and become so huge that one sees it as a shortened wing or lengthened arm, more colour or less fur. In places like the wonderful island chain of Hawaii, which I visited recently, these evolutionary processes have become faster because of the volcanic activity of the earth. If Darwin, they say in the islands, had come to Hawaii before he went to Galapagos, he would have cracked the mystery of evolution so much faster!
Adaptation at its best
I watched the amazing honey-eaters on the Big Island of Hawaii with amazement, my gape as wide open as theirs! And their gapes were what you should be looking at if you wanted to see the evolution at work. Many thousands of years ago, so it is believed, a flock of Asian rosefinches lost their way at sea and landed on the volcanic islands of Hawaii. There, they changed their bills. From the small seed eating bills of the finches (which are related to sparrows) they changed to fit every habitat niche. The wonderful palila, which is endangered to the extent that it is only found in 30 square miles of the island, has a thick bulging beak to deal with the tough bark and the poisonous seeds of the Mamane tree. When they eat the seeds, they look a little like a small parrot and that possibly was the niche they were trying to fit into, because there are no parrots in Hawaii. The iiwi is scarlet pink in colour and its bill is curved like a sickle as it dips into flowers to suck honey. The apapane which also feeds on nectar has a slightly shorter but thinner bill adapted to a different tree than the iiwi . And the akiapalau has done the most interesting evolutionary trick. Noting that there are no woodpeckers in the island, the mysterious force of evolution has shortened the lower bill making it short and hard like a woodpecker’s while the longer bill is long and curved like that of a honeyeater! Two birds in one, can evolution can be more wonderful than that?
Watching the golden palila and the scarlet apapanes, I was transported momentarily into Darwin’s world and I saw like he no doubt did centuries ago, how evolution was transforming our natural world into a million forms, all fitting the best way for us to survive and proliferate.
