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Lizard Evolution Virtual Lab
What conclusion can you draw about the evolution of the Anolis lizards based on these figures?
4. What is convergent evolution? Use evidence from the trees to explain how the Anolis lizards are
an example of this concept.
e 3: Experimental Data
1. In Dr. Losos’s experiment, why was it important that the experimental islands lacked lizards?
2. Dr. Losos’s data suggest that after only a few generations, the lizards on the experimental
islands have shorter legs on average than the lizards on the larger island. Explain how the data
you collected either supports or does not support this claim.
3. Based on what you know about the experimental islands and the lizards that were placed on
these islands, explain how and why the average leg length of the population might change over
time. Include the concept of natural selection in your discussion.
4. If the population from one of the experimental islands were reintroduced on the original island,
do you predict that lizards from the two populations would still mate and reproduce? Justify
your answer with scientific arguments.
The conclusion I can draw about the evolution of the Anolis lizards is based on
ecological niches on an island rather than the entire island itself. Two anoles on
different islands can have similar traits as long as their ecological niches are similar.
Convergent evolution is where organisms that aren't closely related independently
evolve and have similar traits due to similar environments or ecological niches. The
phylogenetic trees show this type of evolution because similar traits are based on
environments, and not location/species type. For example, anolis cybotes and anolis
sagrei both are trunk ground anoles, but live on different islands.
It was important because it allowed each ecomorph to be isolated and easier to study
The data I collected supported Dr. Losos's claim because it shows that because the
environment on the island was more suited for shorter legs, the lizards evolved to have
shorter legs. Ecomorphs are based on ancestral causes, not geological
location/isolation, so the anoles evolved with shorter legs because shorter legs
increased their chances of survival.
I believe that the average leg length of the population will shrink because of the
environment/ecological niches of the experimental island. Because the advantage of
longer legs has been lost, some of the anoles will evolve with shorter legs, and some
will not. The ones with shorter legs will survive better and the ones with longer legs will
survive worse/die off. Therefore, in the end anoles with shorter legs will dominate the
population. This process is called natural selection.
I believe that the lizards from the two populations, both short legged and long legged
will still mate and reproduce. First of all, the lizards are still of the same species.
Secondly, the lizards would mate and reproduce because it will increase their species
chances of survival. In general, any chance of increasing survival rates will be taken in
any natural circumstance.