What lizard sex tells us about behavioral evolution

Michele Johnson wonders how different parts of an animal's body work together to produce behavior. She has zoomed in on an area of behavior at the center of evolution—courtship and copulation—and a group of species where just a few body parts are used. In male anole lizards, a single muscle controls courtship displays, and just two muscles control the paired copulatory organs called hemipenes. Johnson is studying this simple system in depth to connect muscles, nerves, hormones and brain responses. The variation in these behaviors across species allows her to link genotype and phenotype and trace evolutionary patterns. A series of field observations, clever experiments and data analysis ranging from molecular analysis of brain tissue to video analysis will, she hopes, allow her to test a number of ideas about the physiological basis of how behavior evolves.

Social media hashtag: #lizardsex