Biogeography and Phylogenetics Phylogenetics What did our phylogenetic

Biogeography and Phylogenetics

Phylogenetics • What did our phylogenetic trees from the past week show us? 2

What is biogeography? • The study of the distribution of species and ecosystems in geographic space and through geological time. • How does this compare to what we did in last lab? • What types of trees did we get last week? • What do they show or tell us about the species? 3

Review • What process does this part of a tree represent? • How can speciation occur? • How can we predict where allopatry might have occurred? 4

MEGA – Maximum Likelihood Today we will be using MEGA again, but will be developing trees based on analysis of Maximum Likelihood. • When we used MEGA last week, what was the analysis based on? • How does a MEGA analysis using Maximum Likelihood differ from one using parsimony? • At the end of the analysis what additional information will we have? • What will still be missing? 5 Image source: https: //en. wikipedia. org/wiki/File: Phylogenetic_tree. svg

Geography!! • What program will we use to investigate this? • What does the acronym stand for and what does it do? • Who currently uses this program (as well as MEGA)? • What data do you enter into RASP? • What does RASP do with the data you enter? 6

RASP • Today, you will generate a phylogeny that utilizes the present-day location of the species along with the most-probable phylogenetic relationships to paint a prospective picture of the geographical ancestry for the species in the tree. • Follow the instructions for RASP 7 Image source: https: //en. wikipedia. org/wiki/File: Phylogenetic_tree. svg

Everyone have RASP trees made? • Put your RASP tree on your screen and walk around to see other groups’ trees • Similarities? Differences? • • What do the pie shapes and pieces mean? Why are the graphs so similar? What is missing from this tree? How can we hypothesize more specific times in relation to our tree? 8

Geography!! (and Continental Drift) • Today we’ll be using the Paleobiology Navigator and its ability to track continental drift to examine past relationships of land masses that are currently homes to the species under investigation. Image source: https: //commons. wikimedia. org/wiki/Category: Images 9

• Using the Paleobiology Navigator and other resources from the internet, consider how you can attach tentative dates to your RASP tree. • Do a search – when is the Crassulaceae family thought to have diverged from its closest ancestor? • How does this compare to the information you developed above? • Continue working through your worksheet. 10

Due at the end of lab: • the Maximum Likelihood bootstrap tree made in MEGA • the phylogenetic tree generated in RASP • screenshots of any pertinent geological continental appearances for key periods in the evolution and distribution of Crassulaceae over the planet • hypotheses and citations for how this group of organisms have evolved 11