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Evolution by Natural Selection. Part 1: Darwin Part 2: Adaptations. Who is Charles Darwin?. Part 1. An English naturalist in the 1800’s Studied to be a minister Did most of his research while working on the HMS Beagle as the science officer Voyage took 7 years
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Evolution by Natural Selection Part 1: Darwin Part 2: Adaptations
Who is Charles Darwin? Part 1
An English naturalist in the 1800’s • Studied to be a minister • Did most of his research while working on the HMS Beagle as the science officer • Voyage took 7 years • Sailed along the coast of South America • Explored the Galapagos Island chain • Collected thousands of specimens (plants and animals), collected data on weather and ocean currents
Proposed The Theory of Evolution By Natural Selection • Based on 5 key observations • those organisms best adapted to the environment will most likely survive; “survival of the fittest” • those organisms that survive will mostly likely reproduce • genetic traits are passed on from parents to offspring who usually look similar to parents • more offspring are produced than can survive – the idea of overproduction to ensure some will survive to reproduce • organisms compete for needed resources: • a. food • b. water • c. shelter d. space / territory e. mates
What are Adaptations? Part 2
Traits that help an organism survive • Helpful, positive physical or behavioral characteristics • Allow organisms to: 1. get food 2. protect themselves 3. reproduce/find a mate 4. withstand environment
structural: • a body part or coloration that aids survival • 1.) wings, beak shapes, long legs, antlers, etc. • 2.) camouflage or protective coloration • * allows an organism to blend in or hide in its surroundings • 3.) mimicry or protective resemblance • * organism looks like or acts like something it’s not
Physiological • the ability to control life functions to aid survival • 1.) hibernation (slowing down metabolism, breathing, heart rate) • 2.) marine mammals holding breath for long time • 3.) certain plants in extreme conditions (salty, dry, underwater)
Behavioral: • actions that aid survival • learned behaviors 1.) behaviors taught to or learned by experience 2.) example: knowing where the water hole is or knowing what to eat • Instincts 1.) behaviors genetically inherited from parents; “just know how” 2.) example: knowing when to migrate, sensing danger, mating season