1. Natural Selection

2. Effects of Selection
Driving changes in a population

3. Natural Selection
Selection acts on any trait that affects survival or reproduction
predation selection
physiological selection
sexual selection

4. Predation Selection Acting on predator & prey behaviors & habits
camouflage (mimicry)
speed
defenses (physical & chemical)

5. Physiological Selection
Acting on body functions
fitness (food-gathering)
physiology efficiency (oxygen, food, water)
disease resistance
protection from injury
biochemical versatility
HOT STUFF! Some fish had the variation of producing anti-freeze proteins
5.5 mya The Antarctic Ocean freezes over

6. Physiological selection
Dogs pee on trees…Why don’t trees pee on dogs?
NH3
plant nutrient
animal waste

7. Survival doesn’t matter if you don’t reproduce!
Sexual Selection
Acting on reproductive success
attractiveness to potential mate
fertility of gametes
successful rearing of offspring
Survival doesn’t matter if you don’t reproduce!

8. It’s FEMALE CHOICE, baby!
Sexual selection
It’s FEMALE CHOICE, baby!

9. The lion’s mane…
Females are attracted to males with larger, dark manes
Correlation with higher testosterone levels
better nutrition & health
more muscle & aggression
better sperm count / fertility
longer life
But imposes a cost to male
HOT! Worth it??
Even though it’s very hot to have a large mane the benefit of attracting mates and successfully producing & rearing young since you have that large mane outweighs the costs.
Females who chose these males were more “successful” (more, healthier young) and therefore had a greater opportunity to pass on the trait of being attracted to longer darker manes to their daughters and the trait of having longer, darker manes to their sons.

10. Is there a testable hypothesis in there?
Sexual selection
Sexual selection acts in all sexually reproducing species
the traits that get you mates
it influences morphology & behavior
it acts on both males and females
Is there a testable hypothesis in there?
Jacanas

11. Evolution is "so overwhelmingly established that it has become irrational to call it a theory."
Born in 1904 in Germany, Mayr trained as a medical student but realized he had a greater passion for studying birds and biology. Emigrating to the United States, he became a curator at the American Museum of Natural History, working on bird classification while formulating his key ideas about evolution. In 1942 he published his most important work, Systematics and the Origin of Species. Mayr moved to Harvard University in 1953 and served as director of the school's Museum of Comparative Zoology from 1961 to Since then, he has published a number of books and chapters and received the prestigious Japan Prize for Biology in 1983.
In his landmark 1942 book, Mayr proposed that Darwin's theory of natural selection could explain all of evolution, including why genes evolve at the molecular level. On the stubborn question of how species originate, Mayr proposed that when a population of organisms becomes separated from the main group by time or geography, they eventually evolve different traits and can no longer interbreed.
It's this isolation or separation that creates new species, said Mayr. The traits that evolve during the period of isolation are called "isolating mechanisms," and they discourage the two populations from interbreeding.
Moreover, Mayr declared that the development of many new species is what leads to evolutionary progress. "Without speciation, there would be no diversification of the organic world, no adaptive radiation, and very little evolutionary progress. The species, then, is the keystone of evolution."
-- Ernst Mayr What Evolution Is 2001
Professor Emeritus, Evolutionary Biology
Harvard University
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12. Any Questions??