EVIDENCE OF EVOLUTION Chapter 15-2 Unit 8 Part 2: Notes #1 Turn in Warm-ups from 1/29- 2/6 (Pass towards middle) Warm-up 2/12: What is Struggle to Survive? Give an Example. Why is struggle to survive key to Natural Selection? Give two examples of Evidence that scientist have to support evolution. (You should have learned some in middle school) EVIDENCE OF EVOLUTION Chapter 15-2 Unit 8 Part 2: Notes #1

Evolution defined… Evolution is a process of gradual modifications Darwin called this descent with modification

Ancestor Organism 1 Organism 2 Many animals and plants shared common ancestors and deviated from that common ancestor overtime Organism 1 Ancestor Organism 2

Fossils Fossils provide geologic evidence of evolution Fossils in older layers are more primitive than those in the upper layers

Transitional Species: Descent with modification states that newer species are modified versions of older species - Fossil record contains the intermediates

Anatomy Vestigial organs - a group of organs with no particular use now but may have been useful in ancestors (tailbone coccyx or hip bones in whales)

Anatomy cont. Homologous Structures: body parts that are similar in structure may have different functions Indicating at some point way in the past they did the same job and came from a common ancestor

Anatomy cont. Analogous Structures: same functions but different development ex. a butterfly wing and a bat wing Indicates that populations evolved to be better suited to the environment

Warm-up 2/13 What is the difference between Homologous and Analogous Structures? Name 3 ways that the fossil record gives evidence for evolution. Evidence for Evolution Part b (continuation of Tuesdays notes)

Biogeography Certain animals in one location share similar traits (I.E. marsupials in Australia)

Embryology Similar likenesses in embryos of organisms is evidence of descent with modification

Biological Molecules DNA  RNA Proteins Similar proteins means similar DNA The longer it’s been since they shared a common ancestor the more differences in protein

EVOLUTION IN ACTION Chapter 15-3 pp. 308-311

Evolution defined… Evolution of a population is due to environment and the interaction of other species Evolution acts on phenotype, not genotype

Artificial Selection Humans breed for specific traits causing differences in species (i.e. dog breeding)

Examples of Evolution Convergent evolution: Organisms with very different ancestors become more alike due to a common environment Ex. fish and whales- compare analogous structures

Divergent evolution: populations become more and more dissimilar to adapt to the environment-compare homologous structures Appearance of birds with different sized beaks that are specific for size of bird seed

Adaptive radiation Population undergoes divergent evolution until it fills all areas of the environment

Co-evolution: as one species evolves another does (parasites and hosts)