The PROUST hypothesis: the evolution of olfactory systems to map the meaning of odors across space and time


April 11, 2017 - 12:00pm
Northwest Building, Room 243
About the Speaker
Lucia Jacobs
Speaker Affiliation: 
UC Berkeley

Vertebrates have evolved two major olfactory
systems: the first evolved and almost universal main olfactory system (MOS) and
the secondarily evolved vomeronasal system (VNS). Unlike the MOS, the VNS is
often lost, notably in birds, whales, most bats and all Old World primates,
including humans; VNS receptor gene families are also more variable than those
of the MOS. It is still unclear why this second system evolved and exactly how
it complements the MOS. If a major function of the MOS is the mapping of odors
across space (Jacobs, 2012), this may offer a new perspective on VNS function
as well. Here I propose the PROUST hypothesis: that the VNS evolved as an
adaptation to the colonization of land, in response to the MOS becoming
specialized for air-borne odors. I will further propose that this in turn led
to a conflict between respiration and olfaction in air-breathing tetrapods,
which led to further novel adaptations in respiration, olfaction and
locomotion. In short, I will propose that the mechanisms by which vertebrates
use odors to track resources across space and time may be key to understanding
the evolution of the vertebrate body.