CAS BI 107 Lecture Notes - Lecture 3: Reproductive Isolation, Sympatric Speciation, Fixed Action Pattern
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Early ethologists came up with the instinct theory model. Key stimuli in the environment are perceived by an innate releasing mechanism and trigger a fixed action pattern (behavior; what we can actually see individuals doing) Assumes that animal behavior is response entirely by instinct to environmental stimuli. Ethologists did(cid:374)"t u(cid:374)dersta(cid:374)d the i(cid:374)(cid:374)ate releasi(cid:374)g (cid:373)e(cid:272)ha(cid:374)is(cid:373) at the ti(cid:373)e (cid:271)e(cid:272)ause the(cid:455) did(cid:374)"t know a lot about how genetics could influence behavior or neural biology (i. e. this terminology is archaic, but the analysis is still relevant) For example, the idea that behavior is genetically or neurally controlled comes from the idea that there"s a fi(cid:454)ed patter(cid:374) to (cid:271)ehavior. Most frequently used e(cid:454)a(cid:373)ple: egg retrieval i(cid:374) geese; it"s instinctive behavior because if you pull egg away the goose will continue its behavior, behavior has to (cid:862)pla(cid:455) through to (cid:272)o(cid:373)pletio(cid:374)(cid:863) Analysis of stimulus and response, started with work on the stickleback. Olfactory/chemical communication (sex attractants, trail and alarm pheromones)