Biosciences Seminar Speaker 05 June 2019

Biosciences Seminar Series - Spring 2019
05 June 2019 - 3pm - Zoology Museum

Toward a Periodic Table of Niches, or Exploring the Lizard Niche Hypervolume

Prof Eric Pianka

(University of Texas at Austin, USA)

Our Biosciences Seminar Series terminates for the 2019 spring term with a talk by Prof Eric Pianka from the University of Texas at Austin, USA. Eric is the Denton A. Cooley Centennial Professor of Zoology at UT Austins. He is an evolutiionary ecologist and a world authority on the ecology, biology and evolution of lizards. He has done the most comprehensive surveys of lizard assemblages carried out anywhere in the world, which forms the basis of major ecological work.

Abstract

Widespread niche convergence suggests that species can be organized according to functional trait combinations to create a framework analogous to a periodic table. We compiled ecological data for lizards to examine patterns of global and regional niche diversification, and we used multivariate statistical approaches to develop the beginnings for a periodic table of niches. Data (50+ variables) for five major niche dimensions (habitat, diet, life history, metabolism, defense) were compiled for 134 species of lizards representing 24 of the 38 extant families. Principal coordinates analyses were performed on niche dimensional data sets, and species scores for the first three axes were used as input for a principal components analysis to ordinate species in continuous niche space and for a regression tree analysis to separate species into discrete niche categories. Three-dimensional models facilitate exploration of species positions in relation to major gradients within the niche hypervolume. The first gradient loads on body size, foraging mode, and clutch size. The second was influenced by metabolism and terrestrial versus arboreal microhabitat. The third was influenced by activity time, life history, and diet. Natural dichotomies are activity time, foraging mode, parity mode, and habitat. Regression tree analysis identified 103 cases of extreme niche conservatism within clades and 100 convergences between clades. Extending this approach to other taxa should lead to a wider understanding of niche evolution.

  

Hope to see many of you - everyone most welcome to attend!


For the list of forthcoming seminars see here