Transcript Evolution and Natural Selection

Evolution and Natural Selection
9.4-9.5
Darwin Identified Selection as a
Force in Evolution
Darwin had observed that animal breeders could
accentuate desirable characteristics by carefully
selecting animals for mating.
This process is known as artificial selection.
He suggested that animals in nature were
somehow selected by their environment.
Individuals with characteristics that helped them
survive in their environment could produce more
offspring than those that lacked characteristic.
He called this process natural selection.
The characteristics that enable some members
of a species to survive and reproduce are called
adaptations.
Darwin’s Theory Changed Biology
Darwin published a book entitled the Orgin of
Species based on his observations and travels
on the Beagle.
Darwin’s theory of evolution by natural selection
was met with protest and opposition.
Darwin’s theory of evolution by natural selection
has been supported by the findings of thousands
of biologists.
One example concerns the peppered moths
found in Britain.
In the 1700’s trees in Britain were covered in
gray-green lichens.
Gray moths were commonly found here.
Dark moths were less common because they
were eaten by birds due to their high visibility.
Later during the Industrial Revolution, soot
darkened the trees and gray moths became less
common.