Natural selection plays a key role in evolution as it allows those individuals with certain characteristics
to adapt to their environment. These characteristics allow the individuals to have greater survival and a
greater reproductive rate.
Natural selection is a process in which individuals that have certain inherited traits tend to survive and
reproduce at higher rates than other individuals because of those traits.
An example of Natural Selection:
Example: The finches various beaks and behavior are adapted to the specific food available on the
island.
Evolution: is the change in the genetic composition of a population from generation to
generation.
A common picture depicting macro-evolution:
A gene is a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA.
Gene Pool consists of all copies of every type of allele at every locus in all members of the
population.
Hardy- Weinberg Principle describes the gene pool of a population not evolving.
Equation: p^2+2pq+q^2= 1
5 conditions for Hardy- Weinberg Equilibrium: 1. No mutations 2. Random Mating 3. No natural selection 4. Extremely large populations 5. No gene flow
Relative Fitness: the contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals/
Adaptions:are inherited characteristics of organisms that enhance their survival and reproduction in
specific environments.
Example: Moths change from a white color to a black color through natural selection to adapt to
their new environment.
A picture example:
Darwin: (1809-1882) made an hypothesis about evolution and his explanation of how adaptions arise centered on natural
selection.
Mutation: a change in the nucleotide sequence of an organism's
DNA.