Chapter 26: Phylogeny and the Tree of Life Cont’d Monday, 9/22/2014

Warm-up Which came first, the chicken or the egg? Explain how you would use phylogenetics to solve this puzzle.

Warm-up Which came first, the chicken or the egg? Explain how you would use phylogenetics to solve this puzzle. Hanken. 1998. Eggs first. Trends in Ecology and Evolution. 4: 58.

Blobfish https://www.youtube.com/watch?v=2gidkmWrP4M Blob fish video http://youtu.be/8HvtcVoI0-M Video for some cool prehistoric animals

Objective SWBAT explain, create, and interpret phylogeny using cladograms as graphical representations of evolutionary history

Agenda 1. Warm-up & hand in homework: 10 minutes 2. Science News: 5 minutes 3. Homework for tomorrow: 5 minutes 4. Review Friday’s Homework: 20 minutes 5. Review phylogenetics: 25 minutes 6. Phylogenetics practice: rest of class time ~ 20 minutes

Homework 1. MasteringBiology Questions on Chapter 26: Due Wednesday, 10:45 AM 2. Short Essay: Read this short article and summarize. Instructions posted on wiki. Due Friday, 9/26 http://evolution.berkeley.edu/evolibrary/news/080301_elephantshrew 3. Bring your textbooks, or access to your online textbooks, tomorrow!!!!!!! 4. Phylogeny worksheet from class (with all the animals). Due tomorrow. Interactive activity with phylogenetics (useful as review): http://www.hhmi.org/biointeractive/creating-phylogenetic-trees-dna-sequences

Homework http://www.hhmi.org/biointeractive/creating-phylogenetic-trees-dna-sequences http://evolution.berkeley.edu/evolibrary/news/080301_elephantshrew

Q2. If new evidence were uncovered indicating that taxon E in the figure is the sister taxon of a group consisting of taxa D and F, how would this change the phylogeny below? Answer: c This question is linked to Concept Check 26.1, question 4. 9

Phylogenetics Phylogenetics is the study of evolutionary relatedness among various groups of organisms, which is discovered through molecular sequencing and morphological data. Tucuxi

Cladogram Diagram that shows relationships among organisms

Analogous vs. homologous structures *Convergent evolution produces analogous structures Convergent evolution: evolution of similar features in independent evolutionary lineages Homoplases (analgous features) are when different lineages have the same solutions to ecological problems *Homologous structures are a result of common ancestry

We can also use morphological differences to deconstruct evolutionary relationships Derived Ancestral

Ancestral vs. derived features Ancestral characters: a character that originated in the ancestor of the taxon Derived characters: character that is an evolutionary novelty to a particular clade synapomorphies: derived characters shared with taxon (ex. Hair is a synapomorphy of mammals)

Molecular clock Method for estimating time required for a given amount of evolutionary change, based on the observation that some regions of genomes (genetic material of an organism/virus) evolve at constant rates

The cytochrome c gene reflects a pattern of differences in DNA sequences due to mutations. The changes accumulate at a constant rate, and can be used as a molecular clock to help date evolutionary divergences.

Species: Panthera pardus Genus: Panthera Family: Felidae Order: Figure 26.3 Species: Panthera pardus Genus: Panthera Family: Felidae Order: Carnivora Class: Mammalia Figure 26.3 Linnaean classification. Phylum: Chordata Kingdom: Animalia Domain: Bacteria Domain: Archaea Domain: Eukarya