phylogenetic niche conservatism

1. Phylogenetic Niche Conservatism Lorelei E. Patrick

3. Review by Wiens and Graham 2005Why is PNC Important? Allopatric speciation Historical biogeography Patterns of species richness Community structure Spread of invasive species Response to global climate change Human history

4. Why is PNC Important? a) Allopatric speciation A geographic barrier consisting of inhospitable environmental conditions limits gene flow between populations potentially resulting in speciation PNC limits adaptation to the environmental conditions at the barrier

5. Why is PNC Important?b) Historical biogeography Limitation of clades to particular climatic regimes has resulted their distributions being limited to particular climates or continents.

6. Why is PNC Important?c) Patterns of species richness One potential explanation for greater species richness in tropical regions; �tropical conservation hypothesis�: Many groups originated in the tropics and have had more time for speciation there Lack of adaptations for cold climates has limited these species dispersal to temperate climates More extensive tropical climates in the past explain why many groups originated in the tropics Another explanation is that there are higher rates of diversification Much of this species diversification occurs because of montane endemism and limited dispersal

7. Why is PNC Important?d) Community Structure Assemblage membership can be determined by dispersal limitation of guilds between regions. Ecological structure of communities not due strictly to ecological characteristics or phylogeny In this figure each circle represents a species. The size and color indicate similar phenotypes. The squares represent different communities. In both a and b, phylogenetic niche conservatism is the evolutionary process acting on the clades; each clade consists of species that are phenotypically similar to each other. Phylogenetic niche conservatism is assumed in most phylogenetic community structure studies. When communities are phylogenetically clustered as in a, the likely cause is habitat filtering. Habitat filtering means that only species with the functional traits capable of using the resources in a particular habitat are capable of surviving, so the communities are phenotypically clustered. When communities are overdispersed as in b, it is assumed that species interactions, such as competition, are leading to phenotypically overdispered communities. In this figure each circle represents a species. The size and color indicate similar phenotypes. The squares represent different communities. In both a and b, phylogenetic niche conservatism is the evolutionary process acting on the clades; each clade consists of species that are phenotypically similar to each other. Phylogenetic niche conservatism is assumed in most phylogenetic community structure studies. When communities are phylogenetically clustered as in a, the likely cause is habitat filtering. Habitat filtering means that only species with the functional traits capable of using the resources in a particular habitat are capable of surviving, so the communities are phenotypically clustered. When communities are overdispersed as in b, it is assumed that species interactions, such as competition, are leading to phenotypically overdispered communities.

8. Why is PNC Important?e) Spread of Invasive Species If fundamental niches are conserved, species will only be able to invade regions with appropriate climatic conditions. These conditions can be modeled and used to predict the extent of species invasions

9. Why is PNC Important?f) Response to global climate change Given PNC of environmental tolerances, species are likely to shift their ranges to more hospitable temperatures Many species that are unable to shift their ranges are likely to become extinct However, some species are likely to benefit from global warming

10. Why is PNC Important?g) Human history PNC of domesticated plants and animals may have facilitated their spread throughout Eurasia but kept similar exchanges from occurring on other continents

11. Causes of PNC Natural selection Ecological conditions reduce fitness outside of the niche Gene flow Gene flow from individuals from the population center to the populations at the distributional edge can prevent peripheral populations from adapting to conditions outside the range Pleiotropy Traits that allow for range expansion could be linked to traits that reduce fitness Lack of variability Species may not be able to evolve traits to tolerate different environmental conditions

12. Tools to Test for PNC:Ecological Niche Modeling (ENM) Used to test if climatic factors limit the distribution of species Modeling requires three things: Georeferenced locality information for the focal species (available from museum collections) Climatic data for the geographic area in question (available from many online databases) Computer program to construct the climatic niche envelope of the species based on the climate at the collection localities (several programs available to do this) Projection of the model onto the species range map can help to determine if climatic or other factors are important in shaping the species distribution

13. Tools to Test for PNC: ENM Peterson, Soberon, and Sanchez-Cordero 1999 One of the first papers to use ENM to infer PNC Used climatic data of collection localities for pairs of bird, mammal, and butterfly species on either side of the Isthmus of Tehuantepec to see how well one taxon predicted to range of the other taxon These results indicate PNC of the climatic niche since there has been ample time for evolutionary diversification

14. Case Study 1: Stephens and Wiens 2009 In eastern North America there is a latitudinal gradient of species and ecology in emydid turtles Northern semi-terrestrial species don�t disperse south Southern aquatic species do not disperse north Is competitive exclusion or niche conservatism responsible for this pattern?

16. Case Study 1: Methods Testing for competitive exclusion Used locality data to determine if northern and southern species ranges were sympatric or abutted closely Divided each northern species range into 10 longitudinal bins and compared the southernmost band to the northernmost locality of each southern species that occurred in that band

17. Case Study 1: Results No parapatric ranges indicating no competitive exclusion

18. Case Study 1: Methods, con�t Testing correlations with environmental variables Chose 5 minimally correlated climatic variables representing precipitation and temperature Logistic regression to determine which variables were correlated with presence/absence across localities of each species Constructed ENM to determine successful prediction of species range based on the climatic variables

19. Case Study 1: Results Significant correlation between presence/absence and climatic variables

20. Case Study 1: Results Smaller percentage error for Bio5 in niche models

21. Case Study 1: Methods, con�t Testing environmental variables for phylogenetic conservation Using a phylogeny, calculated phylogenetic signal (?) for each variable for each species Used ancestral trait reconstruction to determine ancestral state for 2 temperature variables

22. Case Study 1: Results Phylogenetic signal apparent for several climatic variables.

23. The northern clade temperature reconstructions are ancestrally lower than the remaining clades

24. Case Study 1: Conclusions Results indicate PNC of climatic niche, not competitive exclusion, structure the turtle communities Therefore, the northern semi-terrestrial species are not physically capable of dispersing southward

25. Case Study 2: Lovette and Hochachka 2006 Set out to assess whether co-occurrence of wood-warblers was correlated to phylogenetic relatedness

26. Case Study 2: Methods Used Breeding Bird Survey data to determine presence and co-occurrence of 43 wood-warbler species Assigned each species to terrestrial or arboreal forager categories Generated genetic distance matrices from mitochondrial genes Used linear quantile regression to quantify the relationship between genetic distance and co-occurrence distribution Compared observed phylogenetic and ecological co-occurrence relationships to randomly generated datasets

27. Case Study 2: Results and Discussion

28. Case Study 2: Results and Discussion Conservatism of foraging niche apparent in tree Thick branches= terrestrial foragers Remaining are arboreal

29. Case Study 2: Conclusions Divergent selection resulting from competition has not erased the phylogenetic signal of habitat specialization PNC of the foraging category is important in community structure Co-occurring species are phylogenetically distantly related and ecologically differentiated

30. Losos 2008Controversy Surrounding PNC Distinction must be made between �phylogenetic signal� and PNC Phylogenetic signal: tendency of more closely related species to have similar characteristics PNC: closely related species are more ecologically similar than expected under Brownian motion evolution Presence of phylogenetic signal is not enough to prove PNC but absence is enough to rule out PNC Researchers should not presume that phylogenetic signal much less PNC are universal PNC is a pattern, not a process

31. Need better methods than case studies and phylogenetic signal to prove PNC (Losos 2008) New approaches are being developed that are more statistically rigorous For example, Warren et al. 2008 have modified existing statistics and null models to test for PNC and niche equivalency Controversy Surrounding PNC

32. Controversy Surrounding PNC A critical assumption of ENM is that environmental niche is stable through time (Losos 2008, Pearman et al. 2008) ENM can only model the realized niche, not the fundamental niche (Losos 2008, Pearman et al. 2008)

33. Controversy Surrounding PNCImplications for Community Ecology It is important to note that the same ecological patterns can be manifested through different evolutionary pathways. In this example, communities a and c are phylogenetically clustered and b and d are phylogenetically overdispersed. However, the species in c and d have undergone convergent evolution so that each clade has a member of each phenotype. Therefore, the phylogenetically clustered communities in c are phenotypically overdispersed and are likely structured by species interactions not habitat filtering as in a. The communities in d are phylogenetically overdispersed but phenotypically clustered indicating they are likely structured by habitat filtering not species interactions as in b. These patterns are opposite those that would be assumed if morphology were not considered indicating the need for morphological verification of PCS results. Since convergent evolution is known to occur at least in the genus Myotis, I predict that I will observe patterns c or d in my datasets.It is important to note that the same ecological patterns can be manifested through different evolutionary pathways. In this example, communities a and c are phylogenetically clustered and b and d are phylogenetically overdispersed. However, the species in c and d have undergone convergent evolution so that each clade has a member of each phenotype. Therefore, the phylogenetically clustered communities in c are phenotypically overdispersed and are likely structured by species interactions not habitat filtering as in a. The communities in d are phylogenetically overdispersed but phenotypically clustered indicating they are likely structured by habitat filtering not species interactions as in b. These patterns are opposite those that would be assumed if morphology were not considered indicating the need for morphological verification of PCS results. Since convergent evolution is known to occur at least in the genus Myotis, I predict that I will observe patterns c or d in my datasets.

34. Subgenera of the genus Myotis

35. Subgenera of the genus Myotis

36. Conclusions Phylogenetic niche conservatism is a pervasive assumption in many aspects of ecology and evolution However, PNC should be rigorously tested before being invoked for particular taxa or communities

37. References CAVENDER-BARES, J., K. H. KOZAK, P. V. A. FINE, AND S. W. KEMBEL. 2009. The merging of community ecology and phylogenetic biology, Ecology Letters 12:693-715. EMERSON, B. C., AND R. G. GILLESPIE. 2008. Phylogenetic analysis of community assembly and structure over space and time, Trends in Ecology & Evolution 23:619-630. KEARNEY, M., B. L. PHILLIPS, C. R. TRACY, K. A. CHRISTIAN, G. BETTS, AND W. P. PORTER. 2008. Modelling species distributions without using species distributions: the cane toad in Australia under current and future climates, Ecography 31:423-434. LOO, S. E., R. M. NALLY, AND P. S. LAKE. 2007. FORECASTING NEW ZEALAND MUDSNAIL INVASION RANGE: MODEL COMPARISONS USING NATIVE AND INVADED RANGES, Ecological Applications 17:181-189. LOSOS, J. B. 2008a. Phylogenetic niche conservatism, phylogenetic signal and the relationship between phylogenetic relatedness and ecological similarity among species, Ecology Letters 11:995-1003. LOSOS, J. B. 2008b. Rejoinder to Wiens (2008): Phylogenetic niche conservatism, its occurrence and importance, Ecology Letters 11:1005-1007. LOVETTE, I. J., AND W. M. HOCHACHKA. 2006. Simultaneous effects of phylogenetic niche conservatism and competition on avian community structure, Ecology 87:14-28. PEARMAN, P. B., A. GUISAN, O. BROENNIMANN, AND C. F. RANDIN. 2008. Niche dynamics in space and time, Trends in Ecology & Evolution 23:149-158. PETERSON, A. T., SOBER, OACUTE, J. N, AACUTE, AND V. NCHEZ-CORDERO. 1999. Conservatism of Ecological Niches in Evolutionary Time, Science 285:1265-1267. STADELMANN, B., L. K. LIN, T. H. KUNZ, AND M. RUEDI. 2007. Molecular phylogeny of New World Myotis (Chiroptera, Vespertilionidae) inferred from mitochondrial and nuclear DNA genes, Molecular Phylogenetics and Evolution 43:32-48. STEPHENS, P. R., AND J. J. WIENS. 2009. Bridging the gap between community ecology and historical biogeography: niche conservatism and community structure in emydid turtles, Molecular Ecology 18:4664-4679. WARREN, D. L., R. E. GLOR, AND M. TURELLI. 2008. Environmental niche equivalency versus conservatism: quantitative approaches to niche evolution, Evolution 62:2868-2883. WIENS, J. J. 2008. Commentary on Losos (2008): niche conservatism déjà vu, Ecology Letters 11:1004-1005. WIENS, J. J., AND C. H. GRAHAM. 2005. Niche conservatism: Integrating evoluton, ecology, and conservation biology, Annual Review of Ecology, Evolution, and Systematics 36:519-539.