Maddie Fetsko & Austin Futrell

Who is Charles Darwin?

English naturalist who traveled to the Galapagos in 1831 studying finches and turtles. He made conclusive theories about evolution of species.

What is Evolution?

Change in population over time.

What is natural selection?

Organism with favorable variations survive and reproduce, passing on their favorable variations onto their offsprings. The organisms in the species with less favorable traits must either adapt or die off. When they adapt, this often causes the creation of new species.

Homologous vs. Analogous Stuctures

We can see the past ancestors of current day animals by analyzing their body parts. Many animals have either Homologous or Analogous structures on their bodies. Homologous structures are structures that are similar in shape and function, and also share a common origin.

Analogous structures share a common appearance, but do not share a common origin.

Evidence of Evolution

Fossils- We can look at fossils from the past and determine what they could have possibly evolved into by the structures on their body and their location on the globe.

Embryology- We can look at the physiological comparisons between the fertilized embryos to determine if they are related.

Molecular Evidence- We can compare the DNA of two organisms to determine how closely related they are.

Anatomy- We can compare the anatomical structures of organisms to determine whether or not they are related.

What is "Survival of the Fittest?"

Natural selection is looked at as a struggle for life in which only those organisms best adapted to existing conditions are able to survive and reproduce.

Convergent and Divergent Evolution.

These two patterns of evolution causes diversity and variations in species over time.

Convergent evolution is evolution in which distantly related organisms evolve similar traits.

Divergent evolution is evolution in which species that once were similar to an ancestral species diverge.


Adaptations are any variation that helps an organism to survive. There are two types of adaptations, structural and physiological. Structural adaptions arise slowly and is seen on the outside of the body (ex. rose bush thorns). Physiological adaptations can arise slowly and occur in the inside of the body (ex. producing venom). Adaptations are important because they are changed variations that help organisms survive.

Geographic and Reproductive Isolation.

Both of these isolations can result in speciation.

Geographic isolation is when species are isolated geographically (ex. tree frog population with a river separating them).

Reproductive isolation can be either genetic or behavioral. Genetically, genetic material becomes so different that fertilization can't occur (ex. geographically separated populations of California salamanders). Behaviorally, populations don't mate at the same time of year (ex. one population of tree frogs mate in the fall and the other in the spring).