1. Allopatric speciation
Harris’ groundsquirrel
White-tailed ground squirrel

2. Allopatric speciation
Kaibob squirrel
Albert’s squirrel

5. Hawaiian Drosophila

6. Speciation due to dispersal . . .
Fig

7. . . . can give rise to huge numbers of species.
Adaptive radiation.
Fig

8. Speciation in the lab
Fig

9. Fig 23.1

10. Wind direction
high
Tolerance
to metals
low
Adults
Off mine
tailings
Adults
On mine
tailings

11. Sympatric speciation?
Many species in small isolated, bowl-shaped lake.
Schliewen, et al Genetic and ecological divergence of a monophyletic cichlid species pair under fully sympatric conditions in Lake Ejagham, Cameroon. Molecular Ecology 10:1471.  

12. Sympatric speciation ??

14. Sympatric Speciation Closely related species often sympatric
Disruptive selection
Assortative mating

15. Polyploidy Fig 24.13 Self fertilization New species 2n = 6
with 2n = 12
2n = 6
Error during meiosis
makes gametes with n = 6

16. Gametes
Zygote - infertile

17. 2n = 14
2n = 28

18. IV. Macroevolutionary Pattern
A. Tempo of Speciation
1. gradualism
2. punctuated equilibrium
B. Phylogenetic Reconstruction
1. an example
2. the problem of convergent evolution
3. molecular traits

19. Fig

20. salamander
frog
mouse
lizard
snake
bird A E C B D

21. Current species:
salamander
frog
mouse
bird
lizard
snake E D B C A

22. ancestors:
salamander
frog
mouse
bird
lizard
snake E D B C A

23. Fig 22.14
humerus
ulna
radius
carpals
phalanges

24. Some snake species still have non-functional pelvis
bones and little leg bones.

25. Source: Ray Troll, in Matsen and Troll 1994 Planet Ocean
Source: Ray Troll, in Matsen and Troll 1994 Planet Ocean. Ten Speed Press, Berkeley.

26. The problem of convergent evolution: the Tasmanian wolf is more closely related to the kangaroo than it is to the North American red wolf
Tasmanian Wolf
Red Wolf

30. Homeobox (Hox) genes have same order, structure and similar pattern of expression in mouse and fly!