1. Evolution and Natural Selection

2. What are traits?
What is DNA and how does is it affect species’ traits?

3. What is Evolution?
Evolution is the concept that plants and animals (species) existing today came from preexisting species and that species change physically through time.

4. Founders of Evolution
Two founders of evolution were Charles Darwin and Alfred Russell Wallace
Charles Darwin is credited for this theory of evolution because he provided massive evidence for it in a book he published. (Scott Freeman, 2003, pg.495)
Wallace
Darwin

5. Darwin’s Theory
Darwin published the theory in 1859 in a book called On the Origin of Species by Means of Natural Selection.
He gathered evidence for his theory in the Galapagos Islands on a voyage in the HMS Beagle.
Darwin collected mockingbirds from different islands were distinct species, based on differences in coloration, beak size and shape.

6. Similar mockingbird species on different Galapagos islands

7. What does this all mean?
Each finch were adapted to particular ways of eating.
Islands had different things to eat.
Birds with the more adapt beak were able to survive.
Originally there was only one type of finch, but finches adapted to their environment.

8. Evidence for Change through Time
Fossils help support the theory because rocks and fossils from rocks underneath other rocks are older than the fossils found above them.
Fossils show species that are extinct.
Darwin theorized that extinct forms and living forms were related.
Transition forms are species that are in between those of older and younger species

9. Evidence for Evolution Continued…
Development of species
Many Species have gone extinct.
Fossil species frequently resemble living species found in the same area
Earth’s environment is always changing
Genetic similarities in DNA

10. What is Natural Selection?
Organisms vary in traits (size, shape, structure).
Traits are passed on from parents to offspring.
Example tall parents will have tall parents.
Only some offspring will reproduce. Those that don’t reproduce their genetic traits will not be passed on
The population that reproduces will most likely have offspring that will resemble them.

11. Mutation, Harmful or Beneficial?
Mutations can be harmful and some can leave no effect.
Mutations that harm an organism will most likely lead to it dying so it can’t reproduce.
Mutations can also give an organism an advantage over organisms of its same species.
Organisms that have a beneficial mutation will more likely survive and be able to reproduce.

12. Darwinian Fitness
Ability of an individual to produce offspring compared to other individuals in the same population.
Those that are able to adapt to an environment will be able to reproduce
Those that are dead will not be able to create their own offspring.
Courtship rituals and status amongst populations

13. Examples of Darwinian Fitness
Male stickleback fish swim in a stereotypical manner as they court potential mates.
Male bowerbirds build elaborate towers of vegetation to entice females.
Female moths release pheromones that attract males from up to a mile away.
Male African elephants use low-frequency sounds to find females who are sexually receptive.

14. Misconceptions on Evolution
Individuals do not change during the process of evolution; the population changes
Evolution does not favor any individuals, it simply favors individuals that happen to be better adapted to their environment.
Not all traits are adaptive

15. References
Scott Freeman, S. (2003). Biological science. (2 ed., pp ). Upper Saddle River, New Jersey: Pearson Prentice Hall.