1. Homework 2 due today
Bonus 1 due W 2/28

2. Evolution: A species’ genetic component changes as the individuals reproduce. These changes are based on how the DNA changes and who reproduces.

3. How does monogamy work?
from “The Myth of Monogamy” by Barash and Lipton

4. Mating pairs share genetic information and possibly help in child-rearing

5. 10-40% of offspring in a socially monogamous bird species are fathered by an extra-pair male

6. Social Monogamy = pair lives/works together, but not “faithful”
Sexual Monogamy = pair raise young and only copulate with each other

7. Do males and females have different attitudes towards reproduction
Do males and females have different attitudes towards reproduction? (results from class survey)

8. Would you have dinner with a boy/girl you met today. Male “yes” 76%
Would you have dinner with a boy/girl you met today? Male “yes” 76% Female “yes” 57%

9. Would you have dinner with a boy/girl you met today. Male “yes” 76%
Would you have dinner with a boy/girl you met today? Male “yes” 76% Female “yes” 57%
2. Would you go to a boy’s/girl’s house who you met today? Male “yes” 76% Female “yes” 15%

10. Would you have dinner with a boy/girl you met today. Male “yes” 76%
Would you have dinner with a boy/girl you met today? Male “yes” 76% Female “yes” 57%
Would you go to a boy’s/girl’s house who you met today? Male “yes” 76% Female “yes” 15%
Would you sleep with a boy/girl who you met today? Male “yes” 28% Female “yes” 0%

11. Eggs require large resource input.
A clutch of bird eggs can be ~20% of bird’s weight.
Sperm are cheap.

12. Human Females:
~1 egg/month
Human Males:
250,000,000 sperm/ ejaculation

13. What are the consequences of the different male and female attitudes toward sex and relationships?

14. The female reproductive system

15. Sperm competition: = sperm competition.
Sperm can survive for several days in a woman’s reproductive tract.
In Great Britain in a survey of 4,000 women…
0.5% had sex with 2 different men within 30 minutes…
30% within 24 hours
= sperm competition.

16. The female reproductive system

17. Zebra Finch

18. Zebra finch pairs were allowed to mate ~9 times

19. Then a new male was brought in and allowed to mate with the female once.

20. Last male advantage
Original male (mated 9 times) fathered 46% of offspring
The last male that only mated once fathered 54% of offspring

21. Last male advantage
To ensure fatherhood males mate guard and produce copious quantities of sperm

22. After successfully mating, male purple martins call and attract younger males

23. The older males then cuckold the younger male’s females
Younger males with nests near older males only father 29% of eggs in their nests.

24. Older males produce 4. 1 offspring with their mate and 3
Older males produce 4.1 offspring with their mate and 3.6 by younger neighbor’s mate.
Younger males with nests near older males only father 29% of eggs in their nests.

25. What advantage is their for females to accept or solicit EPCs?
Older males produce 4.1 offspring with their mate and 3.6 by younger neighbor’s mate.
What advantage is their for females to accept or solicit EPCs?

26. Gunnison’s Prairie Dogs
Sexually monogamous female squirrels have a 92% chance of successfully giving birth.

27. Gunnison’s Prairie Dogs
Sexually monogamous female squirrels have a 92% chance of successfully giving birth.
Non-monogamous females have a 100% chance of giving birth

28. Mating pairs may be genetically incompatible
Cystic Fibrosis: F= normal, f= cystic fibrosis
Mom=Ff F f F FF Ff
Versus
Dad=Ff
Mom=Ff f Ff ff F f F FF Ff
Dad=FF F FF Ff

29. How can a female know which male has successful genes?

30. Females may choose traits, like large displays, that are disadvantageous for male survival.

31. How can females determine “good” males?

32. Color:
Bright coloring can be correlated with health…

33. But a male with a mate is judged as being high quality even if he is less colorful

34. better off helping with these kids or should I mate with someone else?
Am I the only one? Am I
better off helping with these
kids or should I mate
with someone else?
Is this the best I can do?
Maybe I can find someone
with better genes or
more genetic diversity.