Evolution

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Charles Lyell

Proposed theory of Uniformintarianism

Geological processes at uniform rates building & wearing down Earth’s crust

Proposed that the Earth was millions of years instead of a few thousand years old

Slide 14

Principles of Geology

Published by Lyell Just Before The Beagle Set Sail & read by Darwin

Explained Geological Processes That Shaped The Earth

Helped Darwin Understand Sea Shells In The Andes Mountains At 12,000+ Feet

Expanded Earth’s Age

Slide 15

Lamarck’s Theory of Evolution

Jean-Baptiste Lamarck, 1809

One Of First Scientists To Understand That Change Occurs Over Time

Stated that Changes Are Adaptations To Environment acquired in an organism’s lifetime

Said acquired changes were passed to offspring

Slide 16

Lamarck’s Theory of Evolution

Idea called Law of Use and Disuse

If a body part were used, it got stronger

If body part NOT used, it deteriorated

Slide 17

Lamarck’s Theory of Evolution

Inheritance of Acquired Characteristics

Proposed That By Selective Use Or Disuse Of Organs, Organisms Acquired Or Lost Certain Traits During Their Lifetime

These Traits Could Then Be Passed On To Their Offspring

Over Time This Led To New Species

Slide 18

Lamarck’s Theory of Evolution

Use & Disuse - Organisms Could Change The Size Or Shape Of Organs By Using Them Or Not Using Them

Blacksmiths & Their Sons (muscular arms)

Giraffe’s Necks Longer from stretching)

Slide 19

Slide 20

Lamarck’s Theory of Evolution

Inheritance Of Acquired Traits

Traits Acquired During Ones Lifetime Would Be Passed To Offspring

Clipped ears of dogs could be passed to offspring!

Slide 21

Lamarck’s Theory of Evolution

Tendency Toward Perfection

Organisms Are Continually Changing and Acquiring Features That Help Them Live More Successfully In Their Environment

Example: Bird Ancestors Desired To Fly So They Tried Until Wings Developed

Slide 22

Lamarck’s Mistakes

Lamarck Did NOT Know how traits were inherited (Traits are passed through genes)