Class Notes (808,385)
Canada (493,173)
Biology (2,097)
BIO318Y5 (33)

BIO318 Lecture 21 (Nov 25).docx

3 Pages
Unlock Document

University of Toronto Mississauga
Sanja Hinic- Frlog

BIO318 Lecture 21 - Last day: plants can assess their environments to o Increase chemical defences when eavesdropping on the “chemical screams” of other species o “call in” enemies of their own natural enemies o Assess operational sex ratios to adaptively adjust their own sex ratios (monoecious species) o When detecting close kin neighbours, restrain their own “competitive root expansion” - Selective thinking o “No theory about anything extrinsic in the universe will ever hold so much intrigue or encounter as much resistance as a theory about ourselves” R.D. Alexander - D. Gwynne’s ancestral fertility o More than 50% drop in fertility rate (from 7 offsprings to about 2-3) - “the demographic transition” o Same trend is going on around the world o First decade in last century started dropping by more than half to present day o Correlates with industrial revolution - Are our modern environments so different from those of our ancestral hunter/gatherer ancestors that much of our behaviour is no longer adaptive? - An example of recent selection o In monogamous populations in Finland (1760-1849) o Most of the opportunity for selection = survival to adulthood and offspring – production success (fertility) o Variance in mating success contributed more to reproductive success in males than females o (HOW did they estimate male mating success?) - Graph of relationship between number of marriages and number of children in males and females o Male slope is greater than female slope o Conclude that there were sexual selection on males over females o What was under sexual selection?  Not mentioned in the article - Lactose tolerance in humans is higher in societies that milk o A lot of groups are lactose tolerant o Lactose intolerance are in adults and based on ancestry o Lactose tolerance example = gene
More Less

Related notes for BIO318Y5

Log In


Don't have an account?

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.