Sunday, September 30, 2012

Lizard Team uses labs and field work

 When asked about where a scientist works, most people would probably think of the laboratory.  And while it is true many scientists spend a lot of time working in labs, that is certainly not the only place they work.  Here I will highlight a lab experiment performed by the Lizard Team, as well as the field work.

Lab work: What are the advantages?

Members of the Lizard Team have studied anoles in “the lab” setting. While many wild animals are difficult to study in the lab, the brown anole is not.  Anoles do great in captivity. as they readily eat, mate and reproduce.  Advantages of the lab are that conditions can be carefully controlled, which allows the scientist to expose the many lizards to the same conditions to see how they behave.

Lizards in the lab, with nesting containers at the bottom of the cage.

Aaron Reedy and Dan Warner recently published a paper on some lab research.  However, the lab was not at a traditional research institution, but was Aaron Reedy’s high school classroom!  For this experiment, the students helped Aaron and Dan answer an original research question:  Where do mother anoles like to lay their eggs?  And why has this nesting behavior evolved?    To do this, they set up 20 cages with 3 female lizards and one male lizard each.  In each cage they also placed 5 different containers with soil that lizards could lay eggs in.  Each container had a different amount of soil moisture- ranging from 0% to 75% moisture.  Each week students checked the containers for eggs.  It turned out that mom’s really preferred to nest in the moistest nests.  A subsequent incubation experiment showed that eggs from these incubation conditions were more likely to hatch, and the hatchlings were larger, and survived better. Dan, David (a high schooler) and Aaron concluded that evolution has favored moms that are more likely to lay eggs in these optimal nest conditions, which is why they showed this behavior.   This is an excellent example of how a lab experiment helped them answer a research question. Don’t you wish your classroom had done an experiment this cool!

Field Work: What are the advantages?

While lab work is very useful, the natural world is far more complex.  So studying animals in their natural environment might give us a better idea of what is really happening in nature.  However, it can be difficult to manipulate variables in the natural world.  Dan Warner, the Lizard Team leader (also known as the Lizard King), has utilized islands to get the best of both worlds.
 Lizards can't get on or off the island, so its perfect for experiments
For these lizards an island has all the complexity of the natural world except for one thing: being able to come and go as a lizard pleases. The water separating the islands from each other and from the mainland are impenetrable to these lizards. The only way a population increase or decrease is births and deaths, not immigration and emigration.

For the Lizard Project, this feature is excellent.  By using islands, we have been able to manipulate the sex ratios of the lizards. On some islands there are more boys than girls, other islands more girls than boys.  Other than that, these lizards are living their natural lives. We will be able to learn a lot about how a biased sex ratio influences various aspects of lizard biology.  More of that to come in future posts.

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