The Theory of Evolution Video Clip – Isn’t Evolution just a Theory?

Evolution The theory that species change over time A change in the genetic make-up of a population over a period of time.

Misconceptions Individuals do NOT evolve! Populations evolve. Evolution occurs at conception when new combinations of DNA are made. The only role you have left in evolution will be when you have children.

Evidence for Evolution Indirect & Direct Evidence Indirect Evidence: Evidence for evolution by observing the history of the Earth “Indirect” = not seeing a creature change before our eyes, but studying change over millions of years

Examples of Indirect Evidence 1. Fossil Record 2. Comparative Anatomy Homologous structures Analogous structures Vestigial structures 3. Comparative Embryology 4. Biogeography

1-Pager (pgs. 423-428) Label the top of the drawing paper - “Indirect Evidence of Evolution” Fold paper into 4 sections For each type of indirect evidence: Describe how this evidence supports the theory of evolution (include key vocab) Give an example of what is meant by each topic Draw a picture to represent the topic or example given

1-Pager (pgs. 423-428) Title: Indirect Evidence for Evolution For each type of evidence: Describe the Evidence Give an example Draw a related picture Define 3 vocab words on back of paper

Indirect Evidence for Evolution

Fossil Record Dating Fossils The Law of Superposition: oldest fossils found at bottom and newest on top Radioactive Carbon Dating: C14 can be used to age fossils

Comparative Anatomy Homologous structures: A common limb that has evolved to perform a different function. Ex: Bird wing, human arm, whale fluke all have similar bone structure *Same structure different function

Analogous structure: Different structures that perform the same function Ex: Bird wing vs. fly wing *Different structure, same function

*Other examples: appendix & coccyx Vestigial structures: A structure that is reduced in function (snake hips) *Other examples: appendix & coccyx

Wisdom Teeth http://health.howstuffworks.com/human-body/parts/no-wisdom-teeth1.htm

Comparative Embryology: Comparing the embryos of different species can give clues to evolutionary relationships. http://www.pbs.org/wgbh/nova/beta/evolution/guess-embryo.html

Biogeography Study of the distribution of plants and animals on Earth Life & where life is found Example: Island species most closely resemble species on the nearest mainland

Direct Evidence for Evolution Evidence of evolution that one can visually observe over time (a.k.a Microevolution)

1. Observations in Nature Peppered Moth

Adaptations Favorable traits that make an organism more likely or “fit” to survive Traits are controlled by genes

Examples of Adaptation Camouflage – blending in Peppered moth Mimicry – an individual gains an advantage by looking like the individuals of a different species Monarch is poisonous and Viceroy is not

2. Changes in Genetic Make-up The organism whose genetic make-up will aid in its survival will reproduce and pass on those traits

Example Taking antibiotics will kill most of the bacteria causing you a problem. If just 1 bacterium is resistant to the antibiotics (different genetic make-up), it will survive and reproduce more bacteria resistant to the antibiotic… They have evolved!!