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Presentation Transcript
Do Now • What “theories” are you using to determine the evolution of your fossils?
How did this happen? • Wolf ----------------------> Poodle
Types of Theories • Wolf ----------------------> Poodle
Evolution Diversity of Life
Contributor’s to Darwin’s thinking included: : • John Baptiste Lamarck – Inheritance of acquired CharacteristicsandLaw of Use and Disuse • Alfred Russel Wallace – organisms evolved from common ancestors
Lamarck’s Theory of Evolution (WRONG!) • Idea called Law of Use and Disuse • If a body part were used, it got stronger • If body part NOT used, it disappeared.
Lamarck’s Theory of Evolution • Inheritance Of Acquired Traits • Traits Acquired During Ones Lifetime Would Be Passed To Offspring Clipped ears of dogs would be passed to offspring!
Hutton’s Theory of Geological Change • Changes in Earth’s crust due to slow continuous processes • Ideas Known as Uniformitism and Gradualism based on fossil record
Principles of Geology • Provides evidence to support evolution of life • Explained Geological Processes That Shaped The Earth • Helped Darwin Understand Sea Shells In The Andes Mountains At 12,000+ Feet • Expanded Earth’s Age to billions of years
Do Now • Grab your survivors poster by the window • Explain your results from the survivors lab for the Do Now for today • Get out your planner
Charles Darwin • Born Feb. 12, 1809 • Joined Crew of HMS Beagle, 1831 • Trained in Theology and a Naturalist • 5 Year Voyage around world • Avid Collector of Flora & Fauna • Astounded By Variety of Life
Darwin’s Observations • variation of traits among similar species • Species found on one island looked different from those on nearby islands • Island species looked different from those on the mainland • Differences seemed well suited to animals’ environment
Darwin’s Observations • Both Living Organisms & Fossils collected • Fossils included: • Trilobites • Giant Ground Sloth of South America This species NO longer existed.What had happened to them?
Gradualism: Long time scale events that gradually create and destroy species. Charles Darwin
Punctuated Equilibrium: Short periods of time with “rapid” leaps in evolution. Usually after a major extinction event. Steven Gould
Parallel Evolution: • Different Animals On Different Continents But Similar Adaptations To Shared Environments
Do Now • Get out your fossil lab material • What is the difference between gradualism and punctuated equilibrium
Convergent Evolution • Evolution toward similar characteristics in unrelated species • resulting from adaptations to similar environmental conditions
Divergent Evolution • Evolution of one or more closely related species into different species; • resulting from adaptations to different environmental conditions
Changes in Allele Frequency • how traits were inherited (Traits are passed through genes) • Genes Are NOT Changed By Activities In Life • Change Through Mutation Occurs Before An Organism Is Born
Evolution Principles What Pressures Cause Evolution ?
Definition • Evolution is change in a population of organisms over time
1. Overproduction: - More offspring produced than can survive - Only a small fraction of offspring survive and reproduce.
- 2. Competition: - food, water, space and mates are limited - Competition within the species and with other species
3. Variation - There is variation within populations. • Individuals of a population have different genetic traits. • No two individuals are exactly alike.
4. Adaptations Because of variations some individuals are better adapted to survive in their environment “Survival of the Fittest”
Adaptations • Those that survive and reproduce have the fittest genetic variations.
5. Descent with Modificationthrough Natural Selection • Some genetic traits are selected for by environmental conditions. • Those selected for survival live and pass on their beneficial genes. • Others die and genes are lost. .
6. Extinctions • Some species disappear due to a catastrophic event in nature (humans, asteroid, earthquake…)
6. Extinctions • Some species disappear due to a catastrophic event in nature (humans, asteroid, earthquake…)
Descent with Modification Over time favorable adaptations gradually accumulate in a species and unfavorable ones disappear. Eventually the accumulated changes result in a new species.
Genes create evolution! • The mutation or combination of alleles has to already be there by chance. Populations do not decide to adapt or mutate after an environmental change • Only beneficial mutations lead to evolution!
Selective Breeding • Artificial Selection • Selective Breeding To Enhance Desired Traits Among Stock or Crops • Dogs, horses, fruits, corn etc..
Wild Mustard was artificially selected to become broccoli! Yum!
Natural Selection • Cannot Be Seen Directly • It Can Only Be Observed As Changes In A Population Over Many Successive Generations • Radiation • Fossil Record
