[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Temperature and Offspring Size
Not sure of the implications for dinocritters since all the eggs/newborn
that I ever read about are small, even for large parents...
In a new study from The American Naturalist, Michael Angilletta (Indiana
State University), Chris Oufiero (University of California, Riverside),
and Adam Leach (University of California, Berkeley) used a new statistical
approach that can test multiple theories at the same time, an approach
they hope will shed light on many evolutionary problems.
They used data from many populations of Eastern Fence Lizards (Sceloporus
undulatus), which revealed that the lizards in colder environments produce
larger offspring than lizards in warmer environments.
So why do animals in colder climates produce larger offspring? One theory
suggests the larger size of offspring counteracts their slow growth in the
cold. Yet another theory suggests large offspring are not directly linked
to temperature at all. Instead, large offspring just happen to be produced
by large mothers, who grow large because they require more energy to
reproduce in the cold.
When they tested the theories simultaneously with their new approach, the
team concluded that temperature's effect on reproduction is a byproduct of
its effect on adult size. "This result could have widespread
significance," says Angilletta. "Temperature determines the adult size of
virtually all organisms. For many of these organisms, we expect
temperature to also leave an imprint on reproduction."