Lecture #27 - Natural Selection

Question 1

What is all you require for natural selection? (4)

Answer 1

1. Variation: individuals in a population vary from one another
2. Inheritance - parents pass on their traits to their offspring
   genetically
3. Selection - some variants reproduce more than others
4. Time - successful variations accumulate over many generations

Question 2

What does evolution act on?

Answer 2

• Evolution doesn’t just act on shape or colour, it also acts on biological molecules
• Natural selection works not just on pigeons, but on the molecules that make pigeons.
• So DNA, the store of information in an organism, should show some evidence for evolution and natural selection.
• Our bodies aren’t designed - they’re evolved so we fail at so many things

Question 3

Natural selection in 4 steps?

Answer 3

1. Population with varied inherited traits
2. Elimination of individuals with certain traits
3. Reproduction of survivors
4. Increasing frequency of traits that enhance survival

Question 4

Random ish from lecture #1 about Darwin

Answer 4

He said organisms change overtime

His father wrote a book about evolution

He actually got his understanding of natural selection from reading books - not actually from his voyages. All he got from a voyage was, “The two turtles on two different islands.”

Question 5

If have less reproductive success……

Answer 5

……natural selection working against you - process of selection happens in nature

Question 6

Darwin said that all life comes from….

Answer 6

…one single point and all diversity on earth has been and is being evolved - evolution doesn’t stop.

Question 7

Sexual selection

Answer 7

Modification of natural selection driven by female choice (most of time) - all just based on choice. Not successful in real world…..peacocks are vulnerable because stand-out-ish