Evolution – The Tales of Two Travelling Turtles

Evolution

Coming face to face with Evolution in the Galapagos

Time and time again during our stay we have been confronted with the evidence that led Darwin to his theory of evolution. It’s simply amazing to witness – the evidence is all around you every day.

Take for example the giant tortoises. With them, it’s about the shape of their shells. On some islands, the tortoises have to reach high up into the vegetation in order to reach their food, and over the centuries these populations developed more streamlined “saddleback” shells – in order to better reach the food. When Darwin visited in 1835, the vice governor told him that he was able to tell which island a tortoise had come from by the shape of its shell. Isn’t that amazing?

Tortoise No 22 in hurry

These are simply extraordinary creatures. In the conservation centres on the three islands we visited they have eggs and babies all the way up to over 100 year old grandees. It’s not just at the edge of a black hole that time goes slowly – it unfolds slowly in their world too. Mating takes them several hours (…lots of huffing and puffing from the male!), and they don’t exactly skip along. For them, 150 years no doubt pass by in a flash.

It’s a miracle that they still survive. The tortoise population was decimated by rats imported by ships feeding on their eggs and sailors taking the poor animals off with them for fresh food, as they live for weeks without water. Sadly, Lonesome George, the last member of the Pinta Island species, died in 2012 at over 100 years old. But there are conservation centres, and the breeding programmes have been a success, such that only 3 out of 14 species are extinct and the others seem to be out of immediate danger.

There are the famous Darwin Finches, whose beaks are of very different shapes – again determined by the predominant food available on the island on which they live. Like most of the animals on the Galapagos they aren’t particularly timid, and you come across them often on walks through the countryside.

And then, there are the extraordinary marine iguanas ….that swim! They’re black, unlike their brown/green land-living cousins, in order to meld into the black volcanic rocks that they bask on. And, just to ram the evolution point home, on Isabela Island they are very noticeably bigger than their counterparts on San Cristobal and Santa Cruz.

The authorities are well aware of the uniqueness of the Galapagos, and a lot of effort goes into preserving it. It’s a daunting job. For example, they inspect every piece of imported fruit and veg (which is most of it) for unwanted pests, but even this doesn’t always work. An acquaintance of one of our guides working in customs on Isabela island failed to notice a tiny spot on a piece of fruit a few years back. Now there are fruit fly on Isabela island. A flotilla of sailing boats that were in port on their way to French Polynesia had to have their hulls checked for barnacles by divers before they were allowed to dock. And so on. The list of work necessary to preserve the uniqueness of the place is long.

It’s all of this that makes visiting the Galapagos very special and unique.

by Chris