23 September 2008

Hello Galápagos!

I occasionally check our map of visitors (very kindly provided gratis by Clustrmap) to see if any new places have tuned in to the Beagle Project. I always keep an eye on the Galápagos Islands, hoping for a click, and today, there it was, red as red! So helloooo there, whoever you are, and welcome to The Beagle Project Blog!

In other Galápagos news, researchers at Yale report that an extinct species of giant tortoise from the island of Floreana (which you might remember from my earlier post, Saving Darwin's muse), might be brought back from the dead.

I'm guessing some of you are probably having visions of Jurassic Park in the Galápagos, but it's not as sexy/scary as that. The methods by which these tortoises can be brought back are tried and true breeding and artificial selection (from which Darwin derived his then new idea of natural selection), though in this case instead of just selecting offspring that look like the extinct tortoise the researchers can use DNA to monitor their progress. This is called marker-assisted selection, and...

Hmm, I think this calls for a new post specifically about the paper. In the meantime, I can recommend the BBC news item.


Bob O'Hara said...

I can't imagine anyone volunteering to do a PhD on MAS in tortoises.

Ha! How about writing an advert for a studentship, to produce near isogenic lines. See who applies. :-)

Karen James said...

I don't know, Bob, in the US, PhDs are just about long enough to get through at least one generation of tortoises

Karen James said...

p.s. I feel an April Fools joke coming on.

Anonymous said...

I'd not heard of marker-assisted selection, but I don't see how this counts as bringing a species back from the dead. Surely what they'll end up with is something very like the extinct Geochelone elephantopus, but not actually Geochelone elephantopus - it would not have the right lineage.

But then I'm old-fashioned, and like stuff to be black and white. Why do you geneticist types have to complicate and greyify matters so?

Karen James said...


Scientists live to greyify things.

There are problems with the proposal, but perhaps not the one you identified.

Depending on the sizes of the intact stretches of Geochelone elephantopus genome contained in the relatives, it may indeed be possible to reconstruct the 'real' Geochelone elephantopus, in the sense that it would have an identical genome to its extinct ideal, using marker assisted selection.

The main problems I see complicating this claim are

1) one bona fide Geochelone elephantopus individual does not a healthy, genetically diverse population make and

2) there are other factors besides the genome itself, epigenomic factors, that could be inherited from the surrogate relatives and affect the development etc. of the organism, even if the genome is 100% correct and

3) is this the best use of our conservation dollar? I'd sure like to see some money poured into saving the still-extant but critically endangered Floreana mockingbird for example, or tightening controls on the introduction of invasive species to the whole archipelago, for example...