This is the updated version of the lecture I give to my biology students each year on Valentine's Day. Please leave me a comment if you enjoyed it. If you download it for your own use, please leave me a comment telling me how you will be using it.

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. By Miss Baker missbakersbiologyclass.com

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.

5. You Have to Find and Woo a Mate

6. You Have to Fight to Win Their Love

7. You'll Be More Conspicuous to Predators

8. Sex Increases Risk of Diseases That Lead to Sickness Infertility Death

9. So, Why Sex?

10. The Red Queen Hypothesis

12. Lucky in Love Sex is like the best strategy for winning the lottery

13. Greater Success Increasing Variety =

14. The Difference Between Males and Females

15. Between 1725-1765, the Wife of Feodor Vassiyev had 69 Children In Her 27 Pregnancies She Gave Birth to 16 Pairs of Twins 7 Sets of Triplets 4 Sets of Quadruplets

16. 1,042 Children

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

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

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

20. Polygamy... I Love You and You and You and You and

21. Monogamy Polygamy Less disease risk More diversity in offspring Can mate guard Produce more offspring Lower infanticide Less commitment Form social bonds Less male competition

22. How Many Offspring Should You Have?

23. If You Decide to Have Few...

24. You Must Provide Parental Care

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

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

27. Are You a Desperate Male?

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

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

30. What if a Member of the Opposite Sex is Not Available? Get a Sex Change!

31. But, What if You're Alone?

32. Shy?

33. Rejected?

34. Unable to find a mate?

35. All is Not Lost

37. Go Asexual But, Remember You Lose the Benefits of Sex So Switch Back When Possible

38. Arguably the Most Exquisitely Evolved Mating Behaviors Belong to Class Aves

39. The Greatest Human Mating Behavior of All Time And Now for the Finale Drumroll Please

41. The End

42. Photo Credits http://upload.wikimedia.org/wikipedia/commons/thumb/0/08/Callorhinus_ursinus_and_harem.jpg/300px-Callorhinus_ursinus_and_harem.jpg M. Boylen 20 http://www.flickr.com/photos/wtlphotos/1045750850/ WTL 19 Found on Creative Commons Flickr Search Can you identify? 18 http://www.flickr.com/photos/poppyw/348928452/ PoppyW 17 http://en.wikipedia.org/wiki/Image:Moulay_Ismail.jpg Unknown 16 Found on Creative Commons Flickr Search Can you identify? 15 http://www.flatrock.org.nz/topics/society_culture/assets/sex_differences.jpg Steven Rhoads 14 http://cache.gizmodo.com/assets/resources/2007/05/dpuzzle_640.gif Unknown 13 http://bp3.blogger.com/_92E8fZ0HCXg/Rx5CWQhSyxI/AAAAAAAABJQ/t-P_NSFEcyo/s1600-h/lottery+balls.jpg Unknown 12 http://www.proteusadvisors.com/uploaded_images/Red-Queen-733514.jpg John Tenniel 11 http://www.alice-in-wonderland.net/alicepic/disney-movie/alice-with-queen-of-hearts.jpg Unknown 10 http://www.scienceagogo.com/news/img/sperm_egg_1is.jpg Unknown 9 http://www.health2know.com/images/herpes.jpg Lampron 8 http://l.yimg.com/img.tv.yahoo.com/tv/us/img/site/81/22/0000038122_20070301141540.jpg Billy Campbell 7 http://cache.viewimages.com/xc/3290720.jpg?v=1&c=ViewImages&k=2&d=C06051C8BA2A5A2C4196C3EDFEC0E7E6A55A1E4F32AD3138 Unknown 6 http://www.birdsasart.com/Royal-terns-courtship-feeding-DeSoto-FL-_H2D8575.jpg Arthur Morris 5 http://upload.wikimedia.org/wikipedia/commons/f/fc/Evolsex-dia1a.png Michael Reeve 4 http://www.scienceagogo.com/news/img/sperm_egg_1is.jpg Unknown 3 URL Photographer Slide #

43. http://www.flickr.com/photos/ucumari/427035041/ ucumari 41 http://www.moviewallpapers.net/images/wallpapers/1977/saturday-night-fever/saturday-night-fever-1-1024.jpg Unknown 40 http://www.flickr.com/photos/ryanwhisner/363966960/ Sailing Nomad 38 http://homepage.mac.com/wildlifeweb/reptile/komodo_dragon/komodo_dragon_04tfk.jpg Tim Knight 37 http://www.rivalryrecords.com/BAND_LOGOS/logo_GoItAlone_LP.jpg Unknown 36 http://images.jupiterimages.com/common/detail/96/47/23494796.jpg Mike Kemp 35 http://www.flickr.com/photos/arnar/95116503/ Arnar Valdimarsson 34 http://photomediamagazineonline.com/wp-content/uploads/2006/10/JG-monkeysuitff.jpg Jill Greenberg 33 http://www.flickr.com/photos/ucumari/580865728/ ucumari 32 http://www.flickr.com/photos/lindenbaum/360684002/ tlindenbaum 31 http://www.flickr.com/photos/the_road_ahead/130768000/ Kawa0310 30 http://rmbr.nus.edu.sg/news/images/20050129-photocorynus_spiniceps-male_female.jpg T.W. Pietsch 29 http://www.flickr.com/photos/tarynmarie/233251372/ TarynMarie 28 Found on Creative Commons Flickr Search Can you identify? 27 http://www.anvious.com/archive/photoblog/061026.jpg Anvi 26 http://www.bpa.gov/corporate/BPANews/Library/images/fish/Chinook_eggs.jpg Unknown 25 Found on Creative Commons Flickr Search Can you identify? 24 http://www.flickr.com/photos/marthaenpiet/2093911204/ Martha de Jong-Lantink 23 Found on Creative Commons Flickr Search Can you identify? 22 http://www.flickr.com/photos/jamespreston/88920149/ http://www.flickr.com/photos/brianscott/283824665/ James Preston Brian Scott 21 alb 21 lion URL Photographer Slide #