1. Integrative taxonomy Gustav Paulay Florida Museum of Natural History University of Florida

2. BSC and ESU Biological species concept –No gene flow –Independent evolutionary tracks –Reproductive isolation –Tested experimentally or sympatric Evolutionary Significant Unit –No gene flow –Independent evolutionary tracks –Untested for reproductive isolation, allopatric

3. Speciation Formation of species Requires isolation of two populations leading to no/little mating between them Leads to divergence of populations Divergence of genotype Mutations – changes in DNA Fixation of mutations: –Genetic drift or selection Mutations accumulate –interbreeding becomes impossible –or leads to poor hybrids –speciation

4. ESU: demonstrate lack of gene flow Defined as reciprocally monophyletic populations –i.e. fixed for different traits

5. ESU: demonstrate lack of gene flow Reciprocally monophyletic in at least independent 2 traits

6. Any two independent traits w/ genetic basis Morphological characters Genetic characters –Independent loci (mtDNA – all one) Geography Any combination of these ESU: 2 independent traits

7. Integrative taxonomy Use of multiple lines of evidence Field - museum - lab Ecology - behavior - morphology - genetics - geography Distinguishing between morphs and species Two or more independent characters showing distinction between species

8. Integrative taxonomy: Actinopyga mauritiana - guamensis

9. Two major types of challenges Not seeing species where there are Seeing species where there aren’t Cause: rate of evolution varies among traits –phenotype: morphology, behavior, color pattern... –genotype: sequence divergence –reproductive isolation

10. Not seeing species where there are unequal rates of evolution –phenotype divergence - SLOW –sequence divergence –reproductive isolation cryptic species

11. Cukes vs. primates Different foci for sensory perception Humans – visual cues Cukes - chemical cues Do cukes care about each other’s colors or ossicles when meeting?

12. Supposed distribution of Scutellastra flexuosa and exusta Powell, 1968

13. but what is really going on... NJ K2P COI

14. Synapta maculata

15. unequal rates of evolution –phenotype divergence –sequence divergence –reproductive isolation - FAST Not seeing species where there are

16. Actinopyga obesa complex

17. Echinometra mathaei complex Rapid secondary sympatry Facilitated by rapid evolution of fertilization proteins? ~1 Ma COI Bindin Landry et al. 2003 Proc Roy Soc COI Bindin

18. Seeing species where there aren’t ecophenotypic variation ontogenetic variation geographic variation ecological variation - depth, habitat, etc polymorphism paralogous loci former divergence now united

19. Polymorphism / phenotypic variation

20. Paralogous loci: mitochondrial genes gone nuclear in Alpheus Williams & Knowlton 2001 Mol Biol Evol

21. ESU vs. BS Need demonstration of no possibility for reuniting into one species No problem when sympatric as gene flow is tested Can’t assume reproductively isolated in allopatry – need test experimentally – mating essays

22. Cypraea tigris a species differentiated, then united 15% divergence in COI Type A – Indian only Type B – mostly Pacific –some Indian A and B in Indian identical in all other characters

23. BS test – marginal overlap

24. ESU - reciprocal monophyly DNA - gene flow - BSC reciprocal monophyly implies lack of recent genetic connections need several samples of each form to test reliability of conclusion depends on depth of intra- vs. inter-specific variation in sympatry - separate biological species in allopatry - separate ESUs, species status subjective

25. Where are the species limits?

28. Lack of reciprocal monophyly morphs rather than species distinct species, but: –introgression –insufficient time for sorting deep coalescent rapid speciation

29. Introgression in Astralium

30. Introgression in Bohadschia argus? Unusual form only in W Pacific; never seen in Polynesia, etc. Need compare independent markers to test

31. Insufficient time for sorting Gene trees vs. species trees: coalescence theory Avise 1999 Phylogeography

32. Evolution of reproductive isolation Slow –most gastropod –deep divergence among allopatric ESUs –clear reciprocal monophyly –slow to secondary sympatry / biological species Rapid –echinoids, holothuroids –shallow divergence among sympatric species –potential paraphyletic species –rapid to secondary sympatry / biological species

33. 1.Two deeply divergent clades: A & B sympatric on 8 island groups 2.30 ESUs so far 3.Pigmentation separates major and minor clades. Astralium rhodostomum complex

34. Geographic signal no signal 94% divergences < 10 Ma retain signal (115 of 122) Persistence of allopatry - Cypraeidae 94% divergences < 10 Ma retain allopatry (115 of 122)

35. Echinometra mathaei complex Rapid secondary sympatry Facilitated by rapid evolution of fertilization proteins? ~1 Ma COI Bindin Landry et al. 2003 Proc Roy Soc COI Bindin

36. Stichopus variegatus complex

37. Advantages of sequence data Directly test genetic connections Very large number of characters Independent markers - independent sources “Independent” of morphology - so can trace evolution of form, etc on gene tree without circularity

38. Potential problems with sequence data depth of coalescent vs. interspecific divergence paralogous sequences introgression –selective sweeps –homogenization through drift