Wednesday, September 10, 2008

Santa Cruz

I hope there were cool pictures posted by the company. I also want you all to know that I am, daily, the last passenger awake on this ship. Because of my dedication to you.

Today marks our return to civilization, and our time among the tortoises. Santa Cruz is home to the largest population of humans in the Galapagos, centered around the city Puerto Ayora. This is also home to the Charles Darwin Research Center, a small collection of painted cinderblock buildings with corrugated steel roofs next to artificial tortoise habitats and incubators. The center is our first stop.

Here they have gathered tortoises-in-exile, stolen cruelly from their home islands so long ago that they don't remember where they belong. They have been rescued and brought back to the Galapagos from their house-pet or circus-freak existence, but are no longer fit for the wild. Really, the life at the center doesn't seem so bad: sleep, eat, and breed -- in order of the apparent preference of the tortoises. The largest part of the facility, however, is taken up with baby tortoise cages, incubators, and protective habitats for the still-prey-for-hawks young. What seem like hundreds of tiny black-green already ancient (although less than five years old) critters crawling in a slow tumble across the ground like, well, like nothing so much as hundreds of tiny tortoises. None of my metaphors work, I need new ones.

The star of the center, however, is lonely George -- the last of his subspecies -- who at the tender age of 100 or so has finally figured out how to successfully procreate (there was some confusion about which end to use. I dare you to think about that without giggling) and who can, therefore, no longer be truly deemed 'lonely' at all. We caught him chasing after a female, as fast as his stubby tortoise legs could carry him. The whole place has the air of a zoo, planned breeding programs and controlled incubation to optimize the male:female ratio and, above all, corrals. (I decide that they are all named Plautus, except the ones who are named Lightning, even though I know that not all Tortoises are governed by a cruel fate in the form of a tutor-turned-hermit or a slightly off mathematician: "This is called Self-determination").

We see Tortoises in the wild as well, trek through the mud to peer into their ancient wise old eyes. They are unruffled by everything, eating and breathing and passing gas with a vengeance, until at a point, staring one in the face, all I can hear are his aging tortoise breaths. I snap a picture. He blinks. They seem like stones; boulders, mountains, exactly how I imagined turtles to be only so very much bigger. The guides order us not to sit on any, because we have a firm hands-off policy when it comes to the wildlife. It's not until I see the animals that I want to break the rule, but I hold myself back. (Today has been full of self-control: first when I refrained from buying Megan an "I like boobies" shirt, and now when I refrain from climbing on top of the wild tortoise.)

Later on, walking through the forest of daisy trees (yes, daisy trees: fifty foot tall trees with bright green leaves and tiny daisy flowers), Collette says something that clicks in my head: they have to protect the park from invasive species because, she says, invasive species will out-compete the endemic species for sunlight, water, and life. Invasive species are invasive simply because they are "better suited" for the particular job that they do.

It goes back to something that bothered me about some of the guided tours. In short, it is this: more evolution does not take place at Galapagos versus anywhere else on the world. If it is to be powerful, a law, a valuable concept, Evolution must take place everywhere and anywhere and at equal rates. It must be wholesale. (And in fact, it does, is, will be: Nothing in biology makes sense except in light of evolution, quoth Dobzhansky). But something about the Galapagos must be special in order for it to have had the profound impact on the human consciousness. The question is, what, and the answer I think lies with the Daisies being outcompeted by other trees.

The essential characteristic of the Galapagos seems to be their isolation. These islands are 500 miles or so from any other land, in the middle of the Pacific ocean. To get here is hard. Really, really hard. To get here and be healthy enough to start a species is even harder. So not many animals, and not many plants, get here in the first place. Which means that maybe for a while daisies were the tallest plant, and the taller daisies got more light, creating a positive feedback loop that created fifty foot tall daisies. That wouldn't happen in a forest where trees already grew: any other tree would make a two-foot daisy no stronger than a one-foot daisy. But since there was an open niche, and only a daisy to fill it, the daisy grew into its monstrous shape.

Similarly, with the finches, which have evolved divergently to eat everything from seeds to leaves to cacti. Every finch has a different beak, and all of these niches can be, and are, filled by finches because there weren't sparrows or whatever desert birds often eat cactus (roadrunners?) or... you get the point. You can "see evolution in action" because there are so few kinds visibly diverging in a limited number of ways into a large variety of species, not because the islands are special and unique in that they foster evolution to move particularly faster than anywhere else.

Of course, the relative youth of the islands helps to isolate them. But in my opinion that is secondary to the geography of the situation.

1 comment:

ayn said...

Fifty-foot daisies sound like awesome story fodder.