RICE, STANLEY A. Department of Biological Sciences, Southeastern Oklahoma State University, Durant OK 74701-0609, srice@sosu.edu. - South with the spring: teaching evolution through budburst times of deciduous trees.
Organisms adjust to stress by tolerance or avoidance. Buds of
deciduous trees that open early in the spring may be damaged by frost,
but if they can tolerate frost, they have a longer growing season than
deciduous trees that avoid frost by opening their buds later. Native
tree species in a location have adapted to recent climatic conditions;
however, tree species within families with a northern (Laurasian)
origin have adapted more often by tolerance, and tree species within
families with a southern (Gondwanan) origin have adapted more often by
avoidance. A class project in which students monitor bud opening
dates, then test the hypothesis that trees from northern families open
their buds earlier, enhances student cooperative learning, awareness
of biodiversity, and understanding of evolution. The project works
best in temperate regions with high deciduous tree species diversity.
Key words: budburst, deciduous trees, evolution, phenology