Research

Phylogeny & Infectious Diseases

Infectious diseases cause 1 in 5 human deaths and are responsible for 51% of years of life lost globally. In a study on the global distribution of human diseases, the best predictor of disease richness is the number of animal species within a region (Dunn, Davies et al. 2010 PRS 277:2587). In part, this correlation may be explained by diseases shifting from wildlife to humans. Humans share parasite communities with wild animals in proportion to their phylogenetic relatedness (Davies & Pedersen 2004 PRS 275:1695). We might, therefore, predict hotspots of parasite host-shifts to humans, and thus centres of zoonotic disease emergence, to be located in regions of high primate diversity (Pedersen & Davies 2009 EcoHealth 6:496).

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Representation of the interaction between phylogeny and geography that may determine the frequency of host shifts within host communities. In the maps, warmer colors represent areas with many overlapping species ranges (geographically clumped distributions). In the phylogeny, red branches represent samples of closely related taxa (phylogenetically clumped).
Pedersen, A.B. & Davies, T.J. EcoHealth (2009) 6: 496. https://doi.org/10.1007/s10393-010-0284-3

Identifying the potential for transmission of parasites among hosts will be important for directing surveillance of animal parasites before they successfully emerge in humans, and increasing the efficacy of programs for the control and management of zoonotic diseases (Farrell, Berrang-Ford & Davies 2013 Environ. Res Lett 8:015036).

Read more about our work on phylogeny and infectious diseases here.

Phylogeny & Conservation

There is growing scientific consensus that we are experiencing an extinction crisis. The International Union for Conservation of Nature has documented the slide toward extinction of many groups in its Red List publications. In mammals, 21% of species are currently listed as threatened with extinction and similar proportions seem threatened in other taxonomic groups. Global biodiversity may thus change considerably in our lifetime. With a core group of collaborators, I have worked to better integrate phylogenetic diversity metrics into conservation thinking (see Rolland, Cadotte, Davies et al. 2012 Biol Lett 8:692; Vernon, Davies et al. 2017 Biol Rev 92:271). By considering dimensions of diversity that capture species properties rather than just numbers, such approaches might be especially relevant for maintaining the provisioning of important ecosystem functions and services (Forest et al. 2007 Nature 445:757; Thompson, Davies & Gonzalez 2015 PLOSONE 10:e0117595. Davies et al. 2016 Ecology 97:221). It was rewarding, therefore, to see phylogenetic diversity included in the National Academy of Sciences colloquium on Biodiversity & Extinction (Davies et al. 2008 PNAS 105:11556).figures_davies_etal.jpg

This body of work has helped extend conservation thinking beyond the traditional focus on species. Read more here.

Phylogeny & Climate Change

Plants and animals are responding to climate warming in various ways, and average responses have been well-documented in the literature. However, in a large meta-analysis we suggest that predicted ecosystem changes—including continuing advances in the start of spring across much of the globe—may be far greater than current estimates based on data from experiments, and that individual species’ responses are highly variable (Wolkovich et al. 2012 Nature 485:494). These findings question our ability to accurately predict species responses to future change.

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Phylogenetic distribution of day of year for first flower across angiosperms.
Davies, T.J., Wolkovich, E.M., Kraft, N.J., Salamin, N., Allen, J.M., Ault, T.R., Betancourt, J.L., Bolmgren, K., Cleland, E.E., Cook, B.I. and Crimmins, T.M. [2013]. Phylogenetic conservatism in plant phenology. Journal of Ecology, 101: 1520-1530.

Over the past decade, we have developed increasingly sophisticated models that have allowed us to predict extinction risk in various taxonomic groups (see above). We currently lack equivalent robust models for predicting responses to climate change. Phylogeny provides one avenue forward. For example, because phenology is evolutionarily conserved (Davies et al. 2013 J Ecol 101:1520), it might be possible to estimate species sensitivities from taxonomic membership (Mazer et al. 2013 Am J Bot 100: 1). It is also possible to use phylogenetic methods to identify key traits and environmental cues triggering flowering (Lessard-Therrien, Bolmgren & Davies 2014 Botany 92:749; Lessard-Therrien, Davies & Bolmgren 2014 Int J Biometeor 58:455), to help better understand interspecific variation in species’ responses.

Read more about our work here.

Several key review papers synthesise our current knowledge but also identify important knowledge gaps (Wolkovich et al. Ecol Lett 2014 17:1365; Wolkovich, Cook & Davies 2013 New Phytol 201:1156; Pau et al. 2011 Global Change Biol 17:3633).

This research has been widely reported in the media, and informed the Fifth Assessment Report from Working Group II of the IPCC.