Development of the modern theory of how evolution happened History The Beagle Darwin’s Research

Early ideas on evolution: Lamarck He thought salamanders lost their legs because they didn’t use them. Legless salamanders (snakes) then passed on this trait to offspring. Logic errors: Not supported by DNA No experimental evidence

Charles Darwin: “Father of Evolution” Traveled extensively Familiar with breeding (genetics) Published his ideas in Origin of Species in 1859.

Published in 1859:

Darwin’s Voyage on the HMS Beagle Where it went His Observations

Darwin’s Voyage on HMS Beagle

Darwin’s observations gave him an idea. Then he did his homework!

Darwin’s observation: 1. Variation exists in all living things Structural variation (what they look like) Behavioral variation (how they act) Biochemical variation (how they function) 2. Species compete for resources: Food Water Mates Shelter

Darwin’s Inferences: Theory of Natural Selection 1. Due to variations, some organisms have characteristics which help them survive. 2. These organisms reproduce, passing on their genes. Over time, more and more organisms will have this great trait, making them “different” from previous generations. Natural selection explains how new organisms will appear over time. This is called speciation.

Vocabulary Adaptation An inherited variation that increases the chance of survival. Fitness Measure of the ability to survive and produce more offspring. Survival of the Fittest Sometimes used as another phrase for natural selection, it means that species that can reproduce can survive