Macroecological Patterns
of Body Size in Mammals Across Time and Space
Paper by S. Kathleen
Lyons and Felissa A. Smith
Blog by Tanner Hawkins
Kate Lyons is a
researcher at the University of Nebraska. Her research is in responses to
climate change, extinction risks, and macroecology and macroevolution.
Felissa Smith is a
researcher at the University of New Mexico. Her research is in ecological and
evolutionary consequences of body size, in particular for mammals.
Body size distribution changes are a particularly important
area of study. Evolutionary biologists and ecologists have focused a lot of
attention in that area because of its relationship with physiological
processes. It’s of some interest whether range size and body size have any
relationship, but it’s not entirely clear how that works on a continental
scale. Also of interest is whether that changes with different spatial or time
scales.
Continent by continent range and body size patterns are largely
the same, all being approximately log-normal. However, these patterns are not
consistent over time, shifting from unimodal, to bimodal, back to unimodal
across the Cenozoic. The final shift from bimodal to unimodal resulted from an
extinction event (late-Pleistocene). It’s interesting to consider, although
while a unimodal distribution makes sense, I’m a bit puzzled as to how this
distribution could shift to bimodal.
I found the variation of body-size distribution in North America across the different time scales to be interesting, with modern day distributions being much narrower. As noted in the paper this could be the result of sampling issues or climate change. With current extinction rates I wonder if there is a bias towards certain body sized mammals.
ReplyDeleteI thought this paper was very well written, concise, and unambiguous. I find it surprising that the community body size was not previously evaluated on the largest continent, Eurasia, or Australia until very recently. Another point of interest was that, the patterns found on individual continents, "the shapes of body size distribution", along with "the moments of the distribution", are quite similar regardless of differences in evolutionary and geological histories.
ReplyDelete