Biodiversity, Islands and Anolis Lizards – Adam Algar

26th November 2012

Today we’re joined by Adam Algar who is talking about biodiversity, islands and Adams favourite anolis lizards!

Adam with Carl and George in the studio!


Our first topic is islands, you may think you know about these since most of us live on one, but islands have proved to be pretty important when it comes to determining things such as biodiversity and evolution.Darwins Finches

Adam actually researches islands, and more specifically lizards, leading him to work in the Caribbean and the canary islands. Lizards to tend to live in warm areas so he’s got pretty lucky! Islands by definition are a singular block of land with no easy in/out for a lizard, this means the research is easier out there.

Adam used a process adaptive radiation, this is the evolution of ecological and phenotypic diversity within a rapidly multiplying lineage – thanks Wikipedia! A good example of this is Darwins Finches shown on the right.

Anolis Lizards

Anolis lizards are something that Adam particularly researches, they are a great example of adaptive radiation and Adam “fishes” for the lizards takes particular note of their temperature for his research.

They are very small lizards, some smaller than your little finger and at the largest the length of your forearm and live mostly in the trees. They’re famous to having evolved to use different parts of the tree, varying from the trunk to the twigs. In the lab people have discovered that the difference in leg length is why they live in certain areas of the tress, shorter legs and they live in the twigs, longer legged varieties live lower down.

There is a toss up between a lizard warming up and operating at below its perfect temperature, the more they sit out warming up the more they are at risk, and the less food they can catch. Sometimes they’ll trade off between the two.

An interesting feature of the Anolis lizard is the fact it has a ‘double chin’. The dewlap is not unique to the Anolis lizard, but it is particularly known for it.

These are used for a few different reasons. The first and possibly most obvious is to show off to females in part of a mating ritual. The other is to show to another male lizard to ward them off a territory.