11a Flashcards
What are the 5 mechanisms of evolution?
Natural selection, variation, genetic drift, gene flow, sexual selection
What can generate new alleles?
Mutation
When bacteria change so antibiotics no longer work in people who need them to treat infections
Antibiotic resistance
Inherited change in the frequency of characteristics in a population over time
Biological Evolution
Characteristics must be inherited via …
Gene alleles
Different versions of the same gene
Alleles
A group of individuals of the same species living in the same geographic area
Biological population
Any change in the frequency of alleles within a population from one generation to the next
Evolution
The differential survival and reproduction among individuals in a population
Natural Selection
What is the most common process by which populations adapt to varying environments?
Natural selection
What is an example of natural selection?
Natural selection
Selection for the average traits (birth weight of human babies)
Stabilizing selection
Change in population traits that favor individuals of one extreme of a phenotype that have the advantage over others
Directional Selection
What is the most common type of selection?
Directional Selection
Selection for extremes, the average condition is the least fit
Disruptive selection
Traits that increase reproductive output…
Adaptations
A single nucleotide change in DNA
Single Nucleotide Polymorphism
Chromosomes after crossing over contain information from maternal and paternal chromosomes
Crossing over
Parent cell has two complete copies of the manual
Recombination
Structure grows in place of another
Hox gene mutations
A change in allele frequencies in a population due to random differences in survival rates
Genetic drift
Occurs when a new colony is started by a few members of original population
The Founder Effect
Occurs when a population undergoes an event in which a significant percentage of a population or species is killed or otherwise prevented from reproducing
Population bottleneck
The exchange of alleles among populations
Gene flow
