Ever since working with Dr. Thomas Hansen as a post doc, I have become enthralled with the phylogenetic comparative method and how it can be used to evaluate and compare the evidence for and against different hypotheses of trait evolution.
In a long term collaboration with Thomas Hansen, Kzrysztof Bartozek, Jesualdo Fuentes Gonzalez, Staffan Andersson and others, we continue to develop comparative methods based on processes that are compatible with
trait adaptation over macro evolutionary time scales. We also use these methods on a variety of organisms, and in the process get to learn about so many different biological systems and collaborate with a variety of specialists for organisms and traits ranging through plant genomes, fish body shapes, lizard thermobiology, trade-offs between bird tail lengths and patch sizes (see figure above), primate brain sizes and so on.
relevant publications
Styga JM, Pienaar J, Scott PA & Earley RL (2019). Does body shape in Fundulus adapt to variation in habitat salinity? Frontiers in Physiology (Aquatic Physiology) 10: 1400.
Kopperud BT, Pienaar J, Voje KL, Orzack SH, Hansen TF, Grabowski M. (2019) SLOUCH: Stochastic linear Ornstein–Uhlenbeck Comparative Hypotheses. R package version 2.1.2
Kopperud BT, Pienaar J, voje KL, Orzack SH, Hansen TF. (2018) SLOUCH Stochastic linear Ornstein‐Uhlenbeck comparative hypotheses. R package version 2.1.1.
Pienaar, J., Ilany, A., Geffen E., & Yom-Tov, Y. (2013) Macroevolution of life history traits in passerine birds: adaptation and phylogenetic inertia. Ecology Letters 16: 571-576.
Bartozek, K, Pienaar, J., Hansen, T.F. & Mosstad, P (2012) A multivariate comparative method for studying adaptive optimality. Journal of Theoretical Biology 314: 204-215.
Davis, R. B., Javois, J., Pienaar, J., Ounap, E. & Tammaru, T. (2012) Disentangling determinants of egg size using an advanced phylogenetic comparative method: Maternal body size is the primary factor in geometrid moths. Journal of Evolutionary Biology 25: 210-219.
Uyeda, J. C., Hansen, T. F., Arnold, S. J. & Pienaar, J. (2011) The million year wait for macroevolutionary bursts. Proceedings of the National Academy of Sciences 108: 15908-15913.
Labra, A., Pienaar, J. & Hansen, T. F. (2009) Evolution of thermal physiology in liolaemus lizards: adaptation, phylogenetic inertia and niche tracking. The American Naturalist 174: 204-220.
Hansen, T. F., Pienaar, J. & Orzack, S. H. (2008) A comparative method for studying adaptation to a randomly evolving environment. Evolution 62: 1965-1977.
Butler, M; O’Meara, B.C. & Pienaar, J. Comparative methods and data analysis in R (2008) University of Hawaii, online publication