-Genetics&EvolLEC11 Flashcards
What is one common misconception about evolution?
That individual organisms evolve, in the Darwinian sense, during their lifetimes.
Natural selection acts on individuals, but what evolve?
Populations!
What do genetic variations allow populations to do?
Ex. Snail shell color
Evolve more rapidly!
What does the Dobzhansky’s modern synthesis do?
It intergrates Mendel’s and Darwin’s ideas, and focus on populations as units of evolution.
What is population genetics?
The study of how populations change genetically over time.
Main way to study evolution.
What is a population?
A group of individuals that can interbreed and produce fertile offspring.
What is evolution?
Change in allele frequencies of a population from one generation to the next.
What is a gene pool?
The total group of genes in a population.
What are mutations?
Ex. horse’s fur colors
Changes in sequence of nucleotides or “stairsteps” of DNA that produce new alleles.
What is point mutation?
A change in one nucleotide in a gene that may impact survival
What is nondisjunction?
Chromosomal error that can affect many genes. Almost always harmful.
Mutation rates are low in animals like humans, but are high in what?In humans one mutation happens per how many genes per generation?
Microorganisms!
100,000
What is far more important than mutation in producing genetic differences that allow us to adapt?
Sexual recombination!
What is the three major factors that change allele frequencies and cause most adaptation?
- Natural selection
- Genetic drift
- Gene flow
What does differential reproductive success cause?
Ex. cat’s fur
It causes some alleles to be passed to the next generation more than others.
