Abstract The five major groups of deuterostomes offer stark contrasts in rates of evolution. While echinoderms, hemichordates and vertebrates are evolving relatively
The five major groups of deuterostomes offer stark contrasts in rates of evolution. While echinoderms, hemichordates and vertebrates are evolving relatively slowly, tunicates are evolving exceptionally fast and cephalochordates (aka amphioxus or lancelets) are evolving exceptionally slowly. Species of amphioxus are quite similar morphologically and live in similar habitats. Indeed, intergenus crosses of amphioxus can produce viable offspring. In contrast, tunicates are highly diverse morphologically and occupy a wide range of marine environments. Even congeneric species occupying the same habitat rarely interbreed. The present talk asks “Why are levels of diversity and rates of evolution so vastly different in tunicates and amphioxus? Are these differences related to different modes of development with cell fates being determined very early in tunicate development but only gradually in amphioxus? Which came first, a switch in evolutionary rate from slow to fast or a switch from late determination of cell fate to early determination of cell fate?”
Linda Holland is a researcher at the Marine Biology Research Division at Scripps Institution of Oceanography in UC San Diego. She is broadly interested in Chordate evolutionary relationships, developmental genetics of amphioxus, and evolution and development.
If you would like to meet with Linda, please contact Ildiko Somorjai
(Friday) 1:00 pm - 2:00 pm
Bute Lecture Theatre D
Bute Medical Buildings, School of Biology, University of St Andrews, Queen's Terrace, St Andrews KY16 9TS, UK
Ellen Garland & Christian Rutzecg5@st-andrews.ac.uk, firstname.lastname@example.org Dyers Brae, University of St Andrews, St Andrews, Fife, KY16 9TH, UK