25. Briefly explain in your own words, the significance of phylogenetic systematics in understanding vertebrate evolution.

2. Draw the branches for the next phylogenetic tree using the matrix below and then map the traits like you did in the last example. Sharks and relatives Ray-finned fishes Amphibians Primates → Rodents and rabbits → Crocodiles and relatives Dinosaurs and birds Vertebrae? Bony YES YES YES YES YES YES YES skeleton? Sharks and Relatives Ray Finned Fishes Amphibians Primates Rodents and Rabbits Crocodiles and Relatives Dinosaurs and Birds no no YES no YES YES YES YES YES YES YES Four limbs? no no no YES YES YES YES YES YES YES Amniotic egg? Hair? no no no YES no 2 2 2 2 2 YES no no no no no YES YES Two post-orbital fenestrae? 1. Name the outgroup of this tree 2. Name a pair of sister taxa 3. Are there any polytomies on this tree? 4. Name a derived trait for primates and rodents: 5. Name 4 ancestral traits for primates and rodents: Vertebrae, Bony Skeleton, Four Limbs, Amniotic Eqa

10. Why are genes that are involved in informational activities, like transcription, translation and replication, the best subjects for determining phylogenetic relationships?

INSTRUCTIONS: 1. On the branches of the phylogenetic tree on the back side of this worksheet, write in a unique derived trait (Autapomorphy), either anatomical or behavioral, that is used to distinguish each primate subgroup from the other taxa of primates. The points where the derived traits should be entered are labelled A1 - A6 and a written description of what is expected for each appears below and to the right of the tree. 2. On the trunk of the phylogenetic tree write in a shared derived trait (Synapomorphy) that unifies the branches (clades) of the tree which sit to the right of the trait marker (S1-S5). Again these traits can be either anatomical or behavioral and a written description of what is expected for each appears below and to the right of the tree. For both #1 and #2 you should write in at least one trait for each trait marker (A1-A6 and S1-S5) that appears on the phylogenetic tree. Make sure all entries are detailed enough to differentiate taxa and written legibly. If…

8. Evolutionary biologists can estimate when major clades probably diverged from each other using molecular clocks. How do they know when these splits happened? 9. Describe how evolutionary reversal and horizontal gene transfer make it more difficult to create an accurate phylogenetic tree

1. How does anatomical fossil evidence helps scientists connect lines of evidence for evolutionary relationships between species? Example and explanation 2 How does anatomical evidence provide clues about the ecological role a species plays in its environment? Example and explanation

1. The clade that includes the common ancestor to the Chordata clade and all the Chordata lineages within that clade represents a. Monophyletic clade b. Divergent evolution of the group c. Homologous traits. d.All of the above