Evolution: Basic PrinciplesEvolution: Change over time; decent with

modificationNatural Selection: Primary mechanism

producing evolution (change over time). There are other mechanisms such as: sexual selection, social selection, drift.

Basic principles of NS:1. Variability: stuff varies2. Heritability: variation is passed on

genetically3. Competition: limited resources4. Selection: some variations are

advantageous in securing limited resources and tend to passed on more than others = change over time

Sexual selection

Some traits may actually be detrimental to survival but provide an advantage in mating.

Sexual selection: intra-sexual competition

• Typically male-male competition for mates, resources, and status.

Intra-sexual coalitional competition

• Chimpanzees are especially well-known for forming male coalitions to challenge other males for dominance.

Evolutionary basis for male competition

• Gamete size (cheap sperm vs. expensive eggs)

• Parental investment (mating vs. parenting effort)

• Parental certainty (paternal vs. maternal certainty)

Social Selection

• Some traits help animals get along better in their social groups which in turn increases their survival and reproduction. Ex: more socially skilled female baboons tend to have more surviving offspring.

Female competition

• Usually less one on one physical than male competition. Typically relational, social exclusionary, sexually targeted.

Human mate attraction: Long term mates• Males: young, beautiful,

sexually modest• Reproductive value;

paternity certainty

• Females: older, high-status (or potential), robust

• Good genetics, stable secure source of resources,

Brain and social selection

• Larger groups select for more neocortex.

Ten Politically Incorrect Truths About Human Nature

1. Men like blond bombshells (and women want to look like them)

• Why? Beauty is a indicator of fertility. Blonde is an indicator of honest signally (modesty)

• See my webpage for full discussion• Excerpted from Why Beautiful People Have More Daughters, by Alan S. Miller and Satoshi Kanazawa, to be published by

Perigree in September 2007.

2. Humans are naturally polygamous

• Males want harem of young fertile females

• Females want good genes and lots of resources

• However both want some reproductive success more than none so both usually have to compromise (monogomy)

• 3. Most women benefit from polygyny, while most men benefit from monogamy

• Females: Better to have 10% of Bill Gates than 100% of Homer Simpson

• Males: share the babes!

• 4. Most suicide bombers are Muslim

• Polygyny increases ‘loser’ males• Islam promises loser males

reproductive success in afterlife

• 5. Having sons reduces the likelihood of divorce

• Resources/status inheritance more critical for son’s reproductive success (reproductive variance)

• 6. Beautiful people have more daughters

• Beauty is a more valuable trait for female reproductive success than for male, especially among lower economic status couples (Trivers-Willard Hypo). Good-looking, non-rich couples tend to have more females. (I have four daughters, beauty + lower status)

7. What Bill Gates and Paul McCartney have in common with criminals

Young male risk-taking behavior

• 8. The midlife crisis is a myth—sort of

• Male midlife crisis is real but cause by their wife’s age not their own.

• 9. It's natural for politicians to risk everything for an affair (but only if they're male)

• Power is a means to achieve reproductive success for males. It actually makes no sense (genetically) to not have affairs once you have achieved power!

• 10. Men sexually harass women because they are not sexist

• Wrong motivation – it’s not men treating women differently its men treating women as they do other men. That is using their power to achieve advantage for purposes of reproductive success.