Evolution Notes:

Charles Darwin

EvolutionThe changes of populations

over time

PopulationPopulation – group of

organisms all of the same species

NaturalistScientist 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 SelectionThe 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 Questions1) 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”