Evolution Notes: Charles Darwin

Evolution The changes of populations over time

Population Population – group of organisms all of the same species

Naturalist Scientist who studies the natural history of living organisms

Natural Selection a mechanism (method) for change in populations.

Charles Darwin Charles Darwin was a naturalist (studied living things from around the world). In 1831, he traveled on board HMS Beagle to Galapagos islands

Studying Animals on the Island Darwin spent time studying all the types of animals on the island. He looked specifically at sizes and shapes of the animals.

Finches Darwin studied birds called finches. He collected finches from all over the island (near water, near mountains, in the forest, etc.) Darwin realized that the same kind of bird had different shaped beaks (What the heck?)

Darwin realized that different beaks helped the birds eat different things (nuts, berries, nectar). He realized that the finch with beak #1 was better at cracking open nut shells, and it survived in the area where there were a lot of nuts available. Finches

Natural Selection Darwin later wrote a book called On the Origin of Species. Darwin proposed an idea called Natural Selection. Natural Selection - a mechanism (method) for change in populations. Natural selection occurs when organisms (with favorable variations) 1) survive, 2) reproduce, and 3) pass their variations to the next generation.

Natural Selection The individuals with the “better” characteristics” will survive and reproduce…the others DIE Small, subtle variations (like beaks) can eventually lead to whole new species

EVOLUTION: Small Variations that help organisms survive

Peppered Moth

Wholly Mammoth to Elephant Natural Selection

Homework Questions 1) Who is considered the “father of evolution? 2) What idea did Darwin come up with after studying Finch beaks? 3) If you lived in a cold environment, would you survive better with or without a lot of hair? 4) In order for natural selection to work what three things must happen? 5) Explain the statement “Survival of the Fittest”