Overview

Our work addresses the processes that link morphological evolution, phylogenetic diversification, and community sorting over space and time. Most of this work is quantitative, including morphometrics, functional morphology, geographic analysis, phylogenetics, and quanitative evolutionary modeling.

Vertebrates, Climate Change, and Ecometrics

Anthopogenically induced climate change is now an established reality, and current questions concern only the scale of its impacts (IPCC 2007).  It has been predicted, for example, that a third of the globe will experience faster change in climates than the fastest rates at which plant species can migrate without human assistance. One of the least well-developed areas of climate change biology is the comparison between the changes we observe happening now and the changes that occurred historically inthe palaeontological and geological past.  That past record contains data on how species have interacted with changing climates and environments, on how those interactions have resulted in the transformation of ecological Carnivore Locomotion Mapcommunities and extinction, and on the geographic and temporal magnitudes at which climatic and environmental processes operate.

We are using ecometrics, species distribution modelling, and other tools to better understand how species and ecological communities have interacted with changing environments in the past. Ecometrics is the study of the phenotypic traits that are an animal's (or plant's) interface with its environment. A key to understanding how biotas and climates interact on many spatial and temporal scales are those ecometric traits. We are studying how ecometric traits evolve, how they function in the environment, and how they contribute to the geographic and climatic sorting of species. This map, for example, shows the average locomotion in mammalian carnivore communities across North America as measured by the ratio of the in- and out-lever of the calcaneum, one of the main bones of the ankles. The average of this measurment taken from bones in all the species living in an area is correlated with the type of vegetation dominant in the area because the species that live there tend to have locomotor specializations that are compatible with living in dense tropical forests, open grasslands, or whatever the local landscape offers.

Grants: National Science Foundation Research Grant EAR-0843935.  2009-2012. Environmental Sorting of Vertebrate Faunas: Are Guild-Level Locomotor and Dietary Ecomorphology Indicators of Paleoclimate?; Leverhulme Trust Multi-Institution Exceptional Grant F/00 696/Q.  2009-2012.  Dispersals of early humans: adaptations, frontiers and new territories (AHOB3). Chris Stringer, Programme Director.

Collaborators: Michelle Lawing, Jussi Eronen, Jason Head, Mikael Fortelius, Nils Christian Stenseth, Kaj Johnson.

Website: http://iccbio.org/


Ancient Human Occupation of Britain (AHOB)

AHOB is a multi-institutional programme that has brought together archaeologists, palaeontologists and earth scientists who aim to build a calendar of human presence and absence in Britain during the Pleistocene (1.8 million to 12,000 years ago) and to study the environmental and faunal context of humans in northern Europe.

Grants: Ancient Human Occupation of Britain, Leverhulme Trust Programme Grant, 2001-2006; Ancient Britain in its European Context: AHOB2, Leverhulme Trust Programme Grant, 2006-2009.

Collaborators: Chris Stringer, Nick Ashton, Ian Candy, Andy Currant, Simon Lewis, Will Roebroeks, Jim Rose, Danielle Schreve, Rebecca Scott, Mark White, Roger Jacobi, Simon Parfitt, Silvia Bello, Mark Lewis.

Website: http://www.ahobproject.org/


Evolution of Snakes

The unusual limbless body plan of snakes presents unusual opportunities for the study of functional and developmental biology and unusual challenges for the interpretation of the fossil record. We are using quantitative methods to study vertebral differentiation in functional, developmental, and phylogenetic Titanoboa cerrejonensis. (c) 2009 Jason Bourquecontexts. We applied these methods in the reconstruction of Titanoboa cerrejonensis, the giant snake from the Paleocene of the Cerrejon Coal Mine in Colombia (image right).

Grants: An eigenshape analysis of snake axial skeletons:  evolution, development, and locomotion, University of London Central Research Fund, 1999.

Collaborators: Jason Head, Marty Cohn, Michelle Lawing, Jon Bloch, Carlos Jaramillo, Edwin Cadena, Fabiany Herrera, Jason Bourque, Alex Hastings.


Morphological Variation at the Level of Metapopulations

Paleophylogeography is the study of the geographic context of speciation using morphological markers to link fossil population samples with one another and with living populations. Analysis of the historical data from the paleontological record provide a means to test phylogeographic hypotheses that are founded on genetic variation in living species. We are studying paleophylogeography in small Quaternary mammals, especially shrews, marmots, and voles. For paleophylogeography to be useful, the relation between genetic differentiation and morphological variation in fossilizable traits, such as teeth and skeletons, must be understood. We are studying variation in shrews, bats, ground squirrels, marmots, snakes, mice, and voles.

Grants: Molecular and fossil evidence for the effect of migration on bat evolution, Leverhulme Trust (F/07476/Q), 2003-2007; Development, Variability, and Evolution, UK Natural Environment Research Council (GR8/03692), 1998-2001. Morphological markers for mammal populations? Variation in molar shape, its correlation with population structure, and comparative post-glacial recolonization in Sorex shrews and marmots, UK Natural Environment Research Council (G3/12996).

Collaborators: Tamsin Burland, Andrea Cardini, Radha Caumul, Sara Churchfield, Anjali Goswami, Islam Günduz, Steve Le Comber, Orin Mock, Andrei Polyakov, Leszek Rychlik, Jeremy Searle, Heidi Schutz, Jan Wójcik, Anna Wójcik.


Geometric Morphometrics, Evolutionary Modelling, and 3D Analysis

Geometric morphometrics, which measure the shape of biological structures using coordinate points that can be used to visually display the structure as well as analyze it, are useful for all kinds of evolutionary questions, including modelling phenotypic evolution. We are working on methods of modelling and methods for the analysis of 3D surfaces, an interesting extension to typical landmark and outline methods.

Collaborators: Anjali Goswami, Aida Gomez Robles, Norman MacLeod,Michelle Lawing.


Phylogenetic Systematics of Carnivora and Creodonta

Grants: Phylogeny of early carnivorans: basicranial anatomy revealed by CT-scanning, A.G. Side Grant, Linnean Society of London, 1998-1999; The phylogeny of the Creodonta and a study of their carnivorous adaptations, US National Science Foundation Dissertation Improvement Grant, 1991-1993.

Collaborators: Anjali Goswami, Ron Heinrich, Gina Wesley-Hunt, Graham Davis, Brigitte Lange-Badré.

 

Indiana University Bloomington