Lecture 2 Flashcards
Prior to 1857, what did the majority of naturalists believe about evolution?
That species existed in their current form without the ability to change.
What did Darwin point out in his book “The Origin of Species” about evolution?
He postulated that species change over time and are not immutable.
What 3 primary features did Darwin observe about living things?
Variation
Heredity
Differential Reproduction
Describe variation?
Every individual is unique and vary in appearance and behavior.
Describe heredity?
Some of the distinct differences between individuals is passed onto offspring.
Describe differential reproduction?
Due to inherited characteristics, individuals reproduce at different rates.
When you combine variation, heredity and differential reproduction, what do you get?
Natural selection
Define natural selection?
Traits that compromise lifetime reproductive success will diminish over time while traits that favor reproductive success will increase.
What is artificial selection?
Humans purposefully breed individual animals to produce desired traits. Traits don’t have any desired survival advantage.
When did artificial selection start?
In 1959, Russian scientist Dmitriy Belyaev wanted to produce a tame fox.
What is natural selection?
Individuals that express specific characteristics are afforded a survival or breeding advantage.
Describe a survival advantage
Allow individuals to live long enough to procure mates and produce offspring.
Describe a breeding advantage?
Allow individuals to produce more offspring than individuals that lack these characteristics.
Give an example of natural selection from the peppered moth.
The amount of speckling in the moth varies from moth to moth and is a heritable trait.
How did the peppered moth survive the industrial revolution?
A differential survival advantage was switched from light colored moths to dark colored moths. And the occurrence of dark moths increased.
