Antennaria
spp.
are a group of plants in the family Asteraceae, commonly known as pussytoes.
They are especially common in the alpine zones of North America and
Europe. They are unusual in that they are dioecious, i.e. there are
separate male and female individuals. But they are even more unusual
in that some species of Antennaria have no males at all. These
species reproduce by parthenogenesis, i.e. seeds are produced by mitosis
rather than by meiosis, making them exact genetic copies of their mother.
This is reproduction, but without sex (which to a biologist means the
mixing of genes from two parents).
Thus Antennaria are ideal organisms for investigating a long-standing
puzzle in evolutionary biology: why do most organisms reproduce sexually
rather than asexually?
I conducted experiments to answer this question over the space of 10
summers at the Rocky Mountain Biological Laboratory in western Colorado;
many undergraduate students assisted with the work, and one of these
students, Vince Eckhart, coauthored one of my papers on the subject.
Vince is now a professor at Grinnell College.