In this study, we investigated the relationship between
introductory biology students’ tree-thinking skills and
their acceptance of evolution to determine whether using
tree thinking as an organizing framework throughout an
introductory-level course can improve students’ acceptance
of evolution as a valid, scientific theory that unifies
a diverse array of empirical evidence and provides a
foundation for all areas of biology. Thus, the tree thinking
framework we are investigating can be summarized as
embodying the classic statement by Dobzhansky (1973)
that, “Nothing in biology makes sense except in the light
of evolution,” and its two more recent logical extensions
that “Nothing in evolution makes sense except in the light
of phylogeny” (Society of Systematic Biologists 2001) and
“Nothing in evolution makes sense except in the light of
DNA” (Kalinowski et al. 2010).