March 27, 2012

The Scientist: Prof. Finlay Examines Primate Visual System Evolution

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Deep in the Brazilian rainforests, Prof. Barbara Finlay, psychology, observes the behavior of various species of primates in order to understand the evolution and development of the how primates see. Finlay takes an “evo-devo” approach to understanding and analyzing the visual system, building from the basic concept that all evolution comes from development. Her work with primates explores the intricate relationship between evolution and development.

Her work has taken her all over the world–London, Berlin, New Zealand–but her most significant work has been in Belém, Brazil. Since 1995, she has collaborated with Luiz Carlos de Lima Silveira, the Federal University of Pará, researching the evolution of monkey vision through a comparative study of the different kinds of New World primates found there, ranging from pygmy marmosets to capuchin monkeys.

One particularly interesting subject in this project is the owl monkey because it is the only monkey that has regained nocturnal sight. The owl monkey’s eyes are similar to those of their nocturnal lemur ancestors in that they are relatively large and contain a substantial amount of rods, which are receptors in the eye that enable night vision. Finlay’s team set out to determine the cause of this divergence by examining the monkeys’ embryos at specific points of development; it discovered that a variety of different cell structures could be caused by just one very early developmental change, like tampering with the timing of cells leaving the ‘stem cell pool’ and becoming specialized.

These findings begin to tackle the larger question of how evolution is able to occur in seemingly evolved creatures. Development is a means of building on current resources and environmental challenges, and organisms have to evolve in order to exploit certain niche opportunities. “Anyone belonging to a species that’s still here has gone through the filter of being evolvable,” Finlay said.

Growing up, Finlay was not particularly interested in science, but as a teenager she enrolled in a summer program with the National Science Foundation as “a way to get away from my strict parents in the suburbs of Pittsburgh.” There, she was assigned to an ophthalmology laboratory where she read James J. Gibson’s Perception of the Visual World. “I was really hooked at that point. That’s when I really got interested in vision.” Finlay said.

She pursued this interest as a graduate student at MIT, where she worked in Peter Schiller’s visual physiology lab. Her work entailed recording single neurons in an attempt to figure out how the visual system worked; after long nights recording brain activity of primates, Finlay found that this work was approaching a dead end. Finlay then decided to switch into developmental neurobiology, where she was able to look at how the visual system is wired.

Finlay teaches BIONB 4230: Cognitive Neuroscience, where she explores the relationship between neurobiology and psychology. Typically, the class draws an even mix of students from both disciplines.

“Both sets of students have a bit of culture shock,” Finlay said. The psychology students are typically taken aback by the amount of neuroanatomy and biology-related vocabulary taught in the class, while neurobiology students tend to be nonplussed by psychology concepts like multidimensional scaling or connectionist networks, according to Finlay.

For aspiring neuroscientists, Finlay advises, “You have to keep in touch with the biology, and the evolution, and all the basic functions of the brain when you’re thinking about things, and don’t specialize in a little chunk of some particular tissue in some particular animal.”

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Original Author: Sherri Couillard

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