Chapter 13 – Theory of Evolution Evidence & Examples

Lamarck Hypothesis Over the lifetime of an individual, features enlarge based on use and reduce in size based on no use “Physical conditions of life” = the organism’s natural environment’ conditions

Darwin & Galápagos Islands Observations of Finches – originally from South America and adapted after the move This change is known as “descent with modification”

Natural Selection and Evolution Natural selection plays a major role in passing on favorable traits to the future generations These traits become adaptations needed for the population to survive

Inherited variation exists in every population Darwin’s Theory Inherited variation exists in every population Some species are better suited to survive and reproduce Favorable traits spread over time in a population through reproduction Fossils provide evidence of evolution

Reproductive Isolation The condition where two populations of the same species do not breed with each other because of geographic separation They are now considered separate species

Punctuated Equilibrium Tempo of Evolution Gradualism Species formation from gradual changes Punctuated Equilibrium A model of evolution with rapid changes with little or no change in between periods

Factors of Natural Selection Based off Darwin’s original ideals Emphasis on changes in the environment Stronger traits = longer survival

Lung disease from bacterium Tuberculosis (TB) Lung disease from bacterium Epidemic in 1993 – bacteria became resistant to antibiotics DNA from non-resistant evolved to adapt to antibiotic environments

Darwin’s Finches