1 / 50

Phylogeny

Phylogeny. The evolutionary history of a group Systematics attempts to reconstruct phylogeny, by analyzing evolutionary relatedness. Uses morphological and biochemical similarities Molecular Systematics uses DNA, RNA, and proteins to infer evolutionary relatedness. Petrified Wood.

jjohn
Download Presentation

Phylogeny

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Phylogeny • The evolutionary history of a group • Systematics attempts to reconstruct phylogeny, by analyzing evolutionary relatedness. • Uses morphological and biochemical similarities • Molecular Systematics uses DNA, RNA, and proteins to infer evolutionary relatedness.

  2. Petrified Wood

  3. Ammonites Became extinct at the end of the Cretaceous Period

  4. “Sue” at the Field Museum in Chicago – T. Rex – 67 million years old

  5. Barosaurus

  6. Systematics • Uses evidence from fossil record and existing organisms to reconstruct phylogeny • Uses branching taxonomic categories such that they reflect phylogeny • Binomial nomenclature (Genus species) keeps identity of organism universal – invented by Linnaeus

  7. Modern Systematics

  8. Taxonomy:scienceof classifyingorganisms

  9. The Connection Between Classification and Phylogeny

  10. Cladistics • Cladogram is a tree with two way branch points • Each branch point represents divergence from common ancestor • Each branch is called a clade • Clades are monophyletic

  11. Monophyletic versus Paraphyletic and Polyphyletic groups

  12. Monophyletic – has the ancestral species and all its descendants Paraphyletic – has the ancestor and some of the descendants Polyphyletic – it lacks the common ancestor of the species in the group

  13. Performing Outgroup Comparison What is the shared primitive characteristic?

  14. Not all Similarities Represent Common Ancestry • Homologous structures indicate shared common ancestry and are therefore evidence of divergent evolution • Analogous structures are similar in function but not in evolutionary history and are evidence of convergent evolution

  15. How would you compare the fins in these 2 organisms?

  16. In what way are these organisms displaying examples of convergent evolution?

  17. How do we differentiate between homologous and analogous structures? • Compare embryonic development of the structures in question • Look for structures that are complex. • The more complex the structures are the more likely that they are homologous. • Compare macromolecules along with anatomical features.

  18. Molecular Clocks • Proteins and mitochondrial genomes have constant rate of change over time • Use these rates to determine relative evolutionary relatedness. • Accuracy of these clocks is still debated • Recently used to date HIV

  19. San Andreas Fault

  20. Figure 25.1 A gallery of fossils

  21. Australopithecus Homo Erectus

  22. Figure 34.39 Upright posture predates an enlarged brain in human evolution Laetoli Footprints Lucy

  23. Lake Turkana Boy Figure 34.40 Turkana boy

More Related