The Biology of Love *

1. The Biology of Love* *Please note. This discussion in no way attempts to discuss love in a religious context. Rather it is merely an entertaining way to learn about the sometimes comical world of biological reproduction.

2. “If not for sex[ual reproduction], much of what is flamboyant and beautiful in nature would not exist.”–Olivia Judson, Dr. Tatiana’s Sex Advice to All Creation

3. Why Sex?

4. A sexual organism has only 50% of the “fitness” of an asexual organism. In a game between sex and "asex," asex always wins -- other things being equal. That's because asexual reproduction is easier, and it's guaranteed to pass genes on to one's offspring. 1 2 1 2 3 4

5. A sexual organism has only 50% of the “fitness” of an asexual organism. asexuality is more common in species that are little troubled by disease: boom-and-bust microscopic creatures, arctic or high-altitude plants and insects. 1 2 1 2 3 4

6. So, I ask again… Why Sex?

7. You Have to Find and Woo a Mate This takes ATP!!

8. You Have to Fight to Win Their Love This takes ATP!!

9. You'll Be More Conspicuous to Predators Male Superb Bird of Paradise This takes ATP!!

10. Sex Increases Risk of Diseases That Lead to: SicknessInfertility Death

11. So, Why Sex?

12. b/c it gives us BIG benefits against ANTIGENS!!!!

13. WHAT???????? I don’t get it --

14. The Red Queen Hypothesis

15. The Red Queen's Hypothesis is an evolutionary hypothesis ~ 1983. • The term is taken from the Red Queen's race in Lewis Carroll's “Through the Looking-Glass”. • The Red Queen said: "It takes all the running you can do, to keep in the same place." • The Red Queen Principle can be stated thus:

16. "For an evolutionary system, continuing development is needed just in order to maintain its fitness relative to the systems it is co-evolving with. • When one changes… (prey) so does the other have to (predator)!

17. The hypothesis is intended to explain the advantage of sexual reproduction at the level of individuals. • By making every individual an experiment, when mixing mother's and father's genes, sexual reproduction may allow a species to evolve quickly- • …just to hold onto the ecological niche that it already has in the ecosystem.

19. First coined by Leigh Van Valen of the UniversityofChicago, it refers to Lewis Carroll's Through the Looking Glass, in which the Red Queen tells Alice, "It takes all the running you can do, to keep in the same place." • This never-ending evolutionary cycle describes many natural interactions between hosts and disease, or between predators and prey: As species that live at each other's expense coevolve, they are engaged in a constant evolutionary struggle for a survival advantage. They need "all the running they can do," because the landscape around them is constantly changing.

20. The Red Queen hypothesis for sex is simple: SEXISNEEDEDTOFIGHTDISEASE!! • Diseases specialize in breaking into cells, either to eat them, as fungi and bacteria do, or, like viruses, to subvert their genetic machinery for the purpose of making new viruses. • To do that they use protein molecules that bind to other molecules on cell surfaces. The arms races between parasites and their hosts are all about these binding proteins.

21. The Red Queen hypothesis for sex is simple: SEXISNEEDEDTOFIGHTDISEASE!! • Parasites invent new keys; For if one lock is common in one generation, the key that fits it will spread like wildfire. • So you can be sure that it is the very lock not to have a few generations later.

22. The Red Queen hypothesis for sex is simple: SEXISNEEDEDTOFIGHTDISEASE!! • According to the Red Queen hypothesis, sexual reproduction persists because it enables host species to evolve new genetic defenses against parasites that attempt to live off them.

23. Sex is the best strategy for winning the lottery… keeping your genes afloat!! Lucky in Love

24. Increasing Variety = Greater Success

25. TheDifference Between Males and Females

26. Between 1725-1765, the Wife of Feodor Vassilyev had 69 Children In Her 27 Pregnancies: she Gave Birth to *16 Pairs of Twins *7 Sets of Triplets *4 Sets of Quadruplets

27. 1,042 Children

28. Love is Like a Game of Chess It's All About Strategy

29. Make the Choice That Will Lead to the Greatest Number of Successful Offspring! Base Your Decisions on the Environment in Which You Live

30. Monogamy... My Heart Beats Only For You

31. Polygamy... I Love You and You and You and You and

32. MonogamyPolygamy Less disease risk More diversity in offspring Can guard your mate Produce more offspring Lower infanticide Less commitment Form social bonds Less male competition

33. How Many Offspring Should You Have?

34. If You Decide to Have Few...

35. You Must Provide Parental Care This takes ATP!!

36. If You Decide to Have Many... You Won't Have to Provide Parental Care

37. But, You'll Probably Be So Exhausted That You'll Die Soon Afterwards

38. Are You a Desperate Male?

39. Commit Sexual Suicide It's Better to Have Loved and Lost Then to Have Never Loved at All!

40. Or Allow Yourself to Be Exploited And Persist as a Tiny Blood-Sucking Parasite Attached to the Female's Body

41. What if a Member of the Opposite Sex is Not Available? Get a SexChange!

42. But, What if You're Alone?

43. Shy?

44. Rejected?

45. Unable to find a mate?

46. All is Not Lost

48. GoAsexual But, Remember You Lose the Benefits of Sex So Switch Back When Possible

49. Arguably the MostExquisitelyEvolved Mating Behaviors Belong to Class Aves

50. Arguably the MostExquisitelyEvolved Mating Behaviors Belong to Class Aves