Gerbil species living in more open habitats have longer hind feet (for leaping)

What is it about?

Many desert animals move around by leaping (jumping). Leaping, in turn, is associated with elongated hind feet and tails. Several adaptive hypotheses exist for the connection between open (aird) environments with leaping, such as it being an effective strategy to escape predators in open environments (with few natural shelters). Here I examine this link in gerbils, a wide-spread, predominantly desert-adapted group of rodents (that also includes nondesert species). I use a recently published molecular phylogeny of the group to correct for the evolutionary relationships among the species before statistically testing the association between indices jumping ability with those of habitat openness -- I find a singicant (positive) correlation, that is robust to phylogenetic correction. I also find support for Allen's rule, where gerbils from warmer habitats were found to have proportionately longer tails.

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Why is it important?

This study is an example of how general patterns in nature can be rigorously examined (statically). More specifically, it is a demonstration of how adaptive hypotheses can now clearly be tested at the interspecific level with the aid of phylogenies to correct for evolutionary relationships.

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