Release from bats: genetic distance and sensoribehavioural regression in the Pacific field cricket, Teleogryllus oceanicus.
The auditory thresholds of the AN2 interneuron and the behavioural thresholds of the anti-bat flight-steering responses that this cell evokes are less sensitive in female Pacific field crickets that live where bats have never existed (Moorea) compared with individuals subjected to intense levels of bat predation (Australia). In contrast, the sensitivity of the auditory interneuron, ON1 which participates in the processing of both social signals and bat calls, and the thresholds for flight orientation to a model of the calling song of male crickets show few differences between the two populations. Genetic analyses confirm that the two populations are significantly distinct, and we conclude that the absence of bats has caused partial regression in the nervous control of a defensive behaviour in this insect. This study represents the first examination of natural evolutionary regression in the neural basis of a behaviour along a selection gradient within a single species.
Department of Biology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada. james.fullard@utoronto.ca
James H
JH
Fullard
Hannah M
HM
ter Hofstede
John M
JM
Ratcliffe
Gerald S
GS
Pollack
Gian S
GS
Brigidi
Robin M
RM
Tinghitella
Marlene
M
Zuk
D000818:Animals; D001309:Auditory Threshold; D001315:Australia; D001522:Behavior, Animal; D002685:Chiroptera / Q000502:physiology*; D004247:DNA / Q000235:genetics; D017931:DNA Primers; D017753:Ecosystem; D056228:Feedback, Sensory / Q000502:physiology; D005260:Female; D005426:Flight, Animal / Q000502:physiology; D006580:Genetic Carrier Screening; D006135:Gryllidae / Q000235:genetics / Q000502:physiology*; D006309:Hearing / Q000502:physiology*; D015810:Linkage Disequilibrium; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D010139:Pacific Islands; D011156:Population Density
D017931:DNA Primers; D004247:DNA