Evolutionary relationships – classification

1. Evolutionary relationships – classification Should birds be distinct from reptiles? Are pachyderms a good taxonomic group?

2. What are phylogenies good for? • Tracing evolutionary relationships • e.g.: disease transmission (problem set 4) • coevolution (in text) • tree of life • classification • adaptive radiation

3. Evolutionary relationships – adaptive radiation on islands

4. What are phylogenies good for? • Tracing evolutionary relationships • e.g.: disease transmission (problem set 4) • coevolution (in text) • tree of life • classification • adaptive radiation • Studying trait evolution • requires independent data • e.g.: origin of whales (in text) • evolution of viviparity map morphological traits onto molecular phylogeny

5. Trait evolution – origin of whales

6. Trait evolution – evolution of viviparity in Sceloporus Sceloporus (a lizard genus) – some populations lay eggs, others bear live young

7. What are phylogenies good for? • Tracing evolutionary relationships • e.g.: disease transmission (problem set 4) • coevolution (in text) • tree of life • classification • adaptive radiation • Studying trait evolution • requires independent data • e.g.: origin of whales (in text) • evolution of viviparity • Studying evolutionary timing • molecular clock • e.g.: age of clades (in text) • when did fruit flies come to Hawaii? (in text) genetic drift predicts regular change through time

8. Evolutionary timing – Molecular clock

9. Human evolutionary history other Old World monkeys ‘apes’ and humans upright posture loss of tail increased brain size • Humans show similarities with ‘apes’ (gibbons, orang, gorilla, chimps) • shared derived traits: large brain, no tail, more upright posture

10. Human evolutionary history other Old World monkeys gorilla,chimps and humans gibbons orang brow ridge loss of some hair skull elongation upright posture loss of tail increased brain size • Humans show similarities with African ‘great apes’ (gorilla, chimps) • shared derived traits: elongated skull, less hairy, brow ridge

11. Human evolutionary history gorilla,chimps and humans other Old World monkeys gibbons orang ? brow ridge loss of some hair skull elongation upright posture loss of tail increased brain size Which are closer: gorilla & chimps, humans & chimps, human & gorilla?

12. Human evolutionary history gorilla chimps human gorilla chimps human ? knucklewalking morphology similarities in teeth, skull, genitals • Which are closer: gorilla & chimps or humans & chimps? • are traits shared derived versus convergent / lost?

13. Human evolutionary history gorilla chimps human gorilla chimps human  knucklewalking morphology common ancestor ~5 million yrs ago DNA similarities similarities in teeth, skull, genitals Molecular data suggests chimps and human are close relatives

14. Human evolutionary history gorilla chimps human common ancestor ~5 mya hunting, simple tools, complex social behavior DNA similarities similarities in teeth, skull, genitals Molecular data suggests chimps and human are close relatives

15. Human evolutionary history other Old World monkeys gibbons orang gorilla chimps human many unique traits similarities in teeth, skull, genitals brow ridge loss of some hair skull elongation upright posture loss of tail increased brain size • Humans’ closest living relatives are chimpanzees • shared derived traits: morphological: skull, teeth, genitals • behavioral: hunting, tool use, social behaviors