BIOEE 1780 1st Edition Lecture 19Outline of previous lectureI. The evolution of sexA) Paradox of sexII. Sexual selectionA) AnisogamyB) Certainty of paternityOutline of current lectureI. Sexual selectionA) Sperm competitionB) General patterns of sexual selectionII. Sexual selection: the game showCurrent lectureI. Sexual selection*A form of natural selection involving differential reproductive success among individuals*Can occur via competition between members of the same sex or via attraction of the other sex*Sex differences in reproductive investment cause:-females to be more picky-males to have to compete more for mating opportunities*Sexual dimorphism-morphology-size-ornamentation-behavior*Females choose males based on benefits-direct benefits: food, shelter, protein, help, etc-indirect benefits: “good genes,” arbitrary choice (“runaway”), “sexier” sons, etc*Sometimes the females don’t really choose… the males fight amongst themselvesA) Sperm competition-Special kind of sexual selection that happens after mating-Females can hold sperm from many males, so they then compete-Leads to strange structures: some males can scoop other males’ sperm out of the female, some evolve huge testes so they can flood the female’s reproductive system*Sexual conflict: when the interests of the two sexes are oppositeThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.B) General pattern of sexual selection-usually stronger for males than females-females tend to have the same number of offspring, regardless of if they mate with a hundred males, or just one-males have more offspring if he mates with more females-intrasexual selection (male-male competition)-intersexual competition (female choice)-intrasexual can be female-female, and intersexual can be male choice in a few casesII. Sexual selection: the game show*Jeremy is up on stage in the spotlight doing a mating ritual*He just read a bunch of super cheesy biology pickup lines*Can we turn this loser into a super male?1) Should we give him antlers, horns, or rooster spurs?-Answer: all of the above-Jeremy is now wearing horns, antlers, and rooster spurs2) Let’s give Jeremy giant blue testes-Jeremy is now wearing giant blue testes3) Now he has male-male competition covered… how about female choice?-Let’s give Jeremy a long tail-Jeremy now is wearing a long tail4) Time to add flashy coloring-Jeremy is now wearing some sort of strange shiny red jacket-Jeremy is now wearing a feathered fan on his head5) Morphology is covered, but we still have 10 minutes left-There must be a balance between sexual selection and natural selection-In Jeremy’s current form, he will be immediately killed if there are a lot of predators-However, there aren’t so let’s keep going6) Finale: COURTSHIP DANCE-Jeremy is now dancing to “Sexy and I Know It”-Vote: still a loser, average, or super male-Consensus: super