Abstract: Observations of remarkable conservation of basic developmental programs across taxa, such as the organization of the invertebrate and vertebrate body plan, or the mechanisms that direct axons to and connect them with their targets, have become commonplace. These conserved developmental programs not only produce stability but also coordinate variation in adults. I will explore how the features of a conserved pattern of neurogenesis may have been exploited to allow graceful scaling of various classes of photoreceptors in primate eyes of varying sizes, and for the coordinated variation of multiple features of the eye for nocturnality and diurnality. The same conserved pattern of neurogenesis produces the predictable and disproportionate enlargement of the cortex when brains become larger in absolute size. I will argue that such conservation does not represent constraint, but the outcome of an evolutionary filter for robust solutions to repeatedly encountered challenges.
Biographical Sketch:Barbara Finlay has been professor of psychology, neurobiology and cognitive science at Cornell University for over 30 years. She received her Ph.D in Brain and Cognitive Science at MIT in 1976, working in visual system physiology and development. Having never taken an evolution course before, she was evangelized by Glenn Northcutt in a week-long course in brain evolution in 1979, and has organized her work in brain development in an evolutionary context ever since. Her long tenure at Cornell has allowed shorter appointments over the years in the University Laboratory of Physiology at Oxford, the University of New South Wales, at “INSERM” in Lyon, at the University of Western Australia and at the Wissenshachftskolleg in Berlin, and an ongoing collaboration with Luiz Carlos Silveira in the Federal University of Parà, Belèm, Brazil since 1996. She was chair of the Department of Psychology at Cornell for five years, and has been co-editor of Behavioral and Brain Sciences with Paul Bloom since 2002. She has two grown children, one just beginning graduate studies in developmental biology (no idea what that represents conservation of). She remains a rather incompetent but always enthusiastic equestrienne.
Readings
2) Comparative aspects of visual system development