Class Notes (837,698)
Canada (510,399)
Biology (6,824)
Biology 1001A (1,727)
Tom Haffie (1,170)
Lecture 17

Lecture 17-biology.docx

3 Pages
24 Views
Unlock Document

Department
Biology
Course
Biology 1001A
Professor
Tom Haffie
Semester
Fall

Description
Biology November 11 2013 Lecture 17: Before: Mates as a resource:  Mating systems have evolved to maximize reproductive success o Due to extra level of parental care for offspring o Also due to other aspects of a species ecology Monogamy:  Male and female form a pair bond  For a mating season or for reproductive lives  Usually occurs when young require a great deal of care that both parents can provide o White-crowned sparrows are altricial (naked and helpess) when hatched o The young must beg for food that both parents can provide  Rates of reproduction higher  Mammals is slightly different because mother provides food (milk) o Monogamy occurs because males indirectly feed the children by feeding the mother Polygamy  Polygyny o One male is with many females o Males often contribute nothing to reproduction but sperm o If males have high-quality territories then females can raise young on there own o The males role is a sperm donor who protects the territory as opposed to actually playing a role in the raising of the offspring  Red-winged blackbirds, males often hold large resource filled territories that support several females  females are still attracted to males even if other females are already present in the territory o polygyny is prevalent among mammals because females have a much larger investment in the care of young then males  Polyandry o One female is with many males o Females contribute nothing but eggs to reproduction Promiscuity  Males and females have no pair bonds beyond the time it takes to mate  Females only stay long enough to receive sperm  These males make no contribution to raising young o Sage Gouse and hammer-headed bats form leks  Leks are congregations of displaying males where females go to mate Biology November 11 2013 Viviparous animals (the animals that get pregnant)  May bear the costs of housing and feeding developing young Sexual Selection: Competition for access to mates coupled with mate choice sets the stage for sexual selection Sexual dimorphism  One gender is larger and more colorful than the other  Can be an outcome of sexual selection Males compete for Females  Males are often larger  May have ornaments and weapons used to attract females and to butt, stab or
More Less

Related notes for Biology 1001A

Log In


OR

Join OneClass

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

Sign up

Join to view


OR

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.


Submit