Department of Biology
Queens College, CUNY
Can a Learned Behavior Evolve?
Monday, September 19, 2011
AA-G008, 5:00 PM
Studying animal behavior from an evolutionary perspective has led to the realization that genes and environment, nature and nurture, cooperate to guide the development of traits. This is true even of very plastic or changeable traits, such as those that involve learning. However, we still have a limited understanding of behavioral evolution. Behavior is often so developmentally distant from the genes, and controlled by so many genes, that we cannot very easily determine whether and how it can evolve. Birds are valuable study organisms for this purpose because they have relatively short generation times for a vertebrate, have many traits that involve significant learning, and are easily studied both in the wild and (for some species) in the laboratory. I describe two studies that show how complex traits that involve learning can evolve by natural selection. The first deals with African weavers, whose eggs are distinctively colored and patterned in order to avoid being fooled by the eggs of a parasitic cuckoo. In the other case study, male swamp sparrows sing to attract mates and repel intruders, and their songs are more effective when they are faster. Both egg recognition in weavers and song production in sparrows are heavily dependent on learning, and yet experimental studies demonstrate how they can evolve by natural selection. These examples show how closely inheritance and learning can work together to guide both the development and the evolution of behavior.
David Lahti received a BS in biology and history from Gordon College. He pursued a Philosophy PhD at the Whitefield Institute Oxford, studying the relationship between natural science and the foundations of morality. He then earned a PhD in Ecology and Evolutionary Biology at the University of Michigan for the study of rapid evolution in an introduced bird. During two postdocs, one as Darwin Fellow at the University of Massachusetts and the other as an NIH NRSA Fellow, he studied the development and evolution of bird eggs and songs, and continued to explore the relationship between evolution and human moral psychology. In 2009 he joined the faculty of the City University of New York, and now runs a Behavior & Evolution laboratory at Queens College. He lives in rural Putnam County with his wife and two young children.
- Lahti, David C. “Evolution of bird eggs in the absence of cuckoo parasitism.” PNAS. 102. 50 (2005): 18057-18062. [PDF]
- Lahti, David C.; Moseley, Dana L.; and Podos, Jeffrey. “A Tradeoff Between Performance and Accuracy in Bird Song Learning.” Ethology 117 (2011) 1-10. [PDF]
- Lahti, David C., et al. “Relaxed selection in the wild.” Trends in Ecology and Evolution. 24. 9 (2009): 487-496. [PDF]
At noon on Monday, 9/19, in S3-214 David will give a brief talk and host a discussion on the evolutionary origins of moral tension in humans. The following readings are provided for anyone interested in that aspect of his work.