Zoologisches Kolloquium
Vortrag im Rahmen der Reihe „Evolutionsbiologie“
Donnerstag, 09. Juni 18.15 Uhr, Kleiner Hörsaal Zoologie
Patrik Nosil
University of Boulder, Colorado, USA
“The ecology and genomic basis of species formation”
Adaptation to different ecological environments, via divergent natural selection has
been shown to promote the formation of new species in many taxa. However, this
process of ‘ecological speciation’ proceeds to highly variable degrees. For example,
sometimes speciation is initiated, but only weak or partial reproductive isolation
evolves. I will focus on two ecologically based hypotheses for this variability in how
speciation proceeds, with speciation being greatly promoted by: (1) stronger natural
selection and (2) selection on a greater number of independent characteristics. I will
describe results testing these possibilities from taxon-pairs of Timema stick-insects
that vary in how far speciation has proceeded. The first lines of evidence will stem
from measurements of selection at the phenotypic level. I will then turn to tests of
these hypotheses at the genomic level. Evidence for each selective hypothesis
exists, but is still scarce, and thus further work is required to determine their relative
importance.
Stefan Scheu & Ernst Wimmer