Evolution Notes Chapter 7

5 Fingers Of Evolution A shrinking population changes the gene pool. The gene pool can be changed by characteristics which make an individual more or less likely to mate. M for mutations – the gene pool is changed when mutations occur. Movement of individuals in or out of an area changes the gene pool. The gene pool is changed by thumbs-up adaptations and by thumbs-down adaptations.

Myth Truth Evolution is organisms adapting to their environment. Mutations might give individual organisms a better chance to survive Survival of the fittest Fitness means best adapted to the environment, and survival is not as important as reproduction Some ways of developing make it more likely for the organism to reproduce Evolutionary Purpose

Vocabulary Acquired traits, such as knowledge or muscular development, are not inherited. Inherited traits, such as height or immunity to disease, are genetically passed down

Newest Rock Middle Rock Oldest Rock

Bozeman science explains relative dating: http://www.bozemanscience.com/law-of-superposition/

Chapter 7, Section 1 DO NOT COPY Do changes ever happen in 2 organisms at the same time? Analogous structures – parts of 2 species that are different than those same parts in their last common ancestor Example: Coevolution – when 2 or more species change in order to adapt to each other. Example:

Chapter 7, Section 2 Why do traits change? Some organisms have “fitness”, which means they are able to survive and reproduce

Chapter 7 Notes, Section 3

What are ways in which living things change? Speciation Variation Changes occur so that the new types of organisms cannot breed with the older types of organisms Change occur within the species (different colors, different nesting habits, etc.) but interbreeding can still happen

Geographic Speciation is when geographical features such as rivers, canyons, or mountains cause new species to be formed .

How much time does it take for changes to happen? DO NOT COPY Two Theories: Punctuated equilibrium: species have sudden, big changes, followed by staying the same for a long time Gradualism: species change constantly, in very small ways.