Chapter 13

Questions :

What are fossils and why do we need them ?

Fossils are preserved remains or traces of animals, plants and other organisms from past. We use fossils to date the different periods in Earth's life evolution. They are essential prove of Darvin's evolution theory.

Who is Darwin and where did he travel ?

Charles Darwin is an English naturalist. He established what we know today as an evolution theory. He published his theory with evidence in 1859 in book called On the Origin of Species.

His most known research comes from Galapagos Islands even though he traveled throughout the world to acquire his evidence.

What is adaptation ?

Adaptation is evolutionary process whereby a population becomes better suited to its habitat. This process takes place over many generations. It's also one of the basic phenomena of biology.

Diagram :

This diagram shows an example of evolution and natural selection in a specific animal specie.

5facts:

Individuals do not evolve, populations evolve.

Natural selection can amplify or diminish only heritable traits.

Evolution is not goal directed and does not lead to perfection.

Living organisms are adapted to their environment.

Favorable traits accumulate in a population over generations.

Key terms :

extinction - irrevocable loss of species

fossil record - sequence in which fossils appear within layers of sedimentary rocks

strata - rock layers

paleontologist - scientist who studies fossils

homology - similarity in characteristics resulted from common ancestry

vestigial organs - structures of marginal or perhaps no importance to the organism

population - group of individuals of the same species

mutation - change in the nucleotide sequence of DNA

gene pool - total collection of genes in a population at any one time

sexual selection - form of natural selection in which individuals with certain characteristics are more likely than other individuals to obtain mates

Video :

Sexual selection

Summarize :

Chapter 13 introduce deeper informations about Darwin's theory of evolution and little bit of history behind this big scientific theory. Also we learned about fossils and their study. Since we talked in this chapter about Darwin we also talked about evolution theory and learned some new terms. For example Hardy-Weinberg equation etc.. At the end we learned mechanisms of microevolution.