Animals and Outdoors Flashcards
What is evolution?
The change over time in the proportion of individuals in a population differing in one or more inherited traits
What is genetic drift?
The change in frequencies of alleles in a population that occur RANDOMLY
What does genetic drift do?
Usually changes neutral traits, effects smaller populations and makes the population less genetically diverse
What is natural selection?
The NON RANDOM increase in frequency of DNA sequences that increase survival
What is sexual selection?
Increase of allele frequency through sexual favouritism
What do you call the differences between males and females?
Sexual dimorphism
What does directional selection favour?
An extreme
What does stabilising selection favour?
The average phenotype
What does disruptive selection favour?
Favours both extremes
What is the founder effect?
A decrease in genetic variation that occurs when a new population is established by a very small number of individuals from a larger population
What is the bottleneck effect?
A decrease in genetic variation caused by a natural disaster which leaves a a small number of individuals who aren’t representative of the larger population
What does the term fitness describe?
A term used to measure how successful a particular genotype has been in surviving from one generation to the next
What is absolute fitness?
Ratio of frequencies of a particular genotype from one generation to another
What is relative fitness?
Ratio of surviving offspring of one genotype compared to another
How do you calculate relative fitness?
Absolute fitness of genotype/ absolute fitness of most successful genotype
