Class Notes (837,999)
Canada (510,615)
Sociology (2,430)
SOCC11H3 (26)

ANTC23 W7.docx

3 Pages
Unlock Document

Joyce Parga

ANTC23 L6 Sexual dimorphism - Morphological differences between males and females in: o Body size and shape o Color: sexual dichromatism - Not all primates show sexual dimorphism o Sexual monomorhism: sexes are the same size, color, etc. - In many primates, if sexes differ in body size, usually the males are bigger o Why? Male-male physically aggressive contest competition over females.  Larger body size in males has been “selected for” because this trait has been adaptive in these species 2 types of competition - Contest competition: when a resource can be monopolized by a single individual or group and can be fought over o Hanuman langurs o Size and strength is an advantage - Scramble competition: when a resource is exploited by the individual that arrives and uses it first o Small nocturnal prosimians that don’t live in social groups o Gelada baboons, aye-aye, Howler monkey, gorilla o It can become a contest competition Sexual dimorphism and mating systems - Which mating system is most frequently associated with sexual dimorphism in the form of larger males? o Polygyny i.e. gelada baboon, Hamadryas baboon o Polygynandrous species sometimes have sexual dimorphism (with larger males) i.e. common chimps o Monogamous species are usually sexually monomorphic in body size. i.e. titi monkey Sexual dimorphism and taxonomic groups - Most apes are sexually dimorphic in body size, with larger males o Except for gibbons and siamangs. They do have sexual dichromatism but pretty much the same size. - Many OW monkeys are sexually dimorph9ic in body size with larger males - Many NW monkeys and prosimians are NOT sexually dimorphic in body size. i.e. marmosets o Exception: in some nocturnal prosimians with dispersed mating systems, males are larger than females. i.e. galagos Sexual dimorphism in canine size - Males with larger canines than females – indicates male-male physically aggressive contest competition. o Many polygynous and polygynandrous mating systems Secondary sexual characteristics - External traits that help dis
More Less

Related notes for SOCC11H3

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.