Evolution Flashcards
Mutation
A permanent change in an organisms genetic information
Variation
Differences between individuals which may be structural functional or physiological
Adaptations
A structure, behaviour or physiological process that helps an organism survive and reproduce in a particular environment
Selective pressure
Environmental conditions that select for certain characteristics of individuals and select against other characteristics
Selective advantage
A genetic advantage that improves an organisms chance of survival, usually in a changing environment
Survival of the fittest
The organisms in the population with the most genetic advantages from variation are the ones who survive and reproduce
Fitness
The relative contribution an individual makes to the gene pool of the next generation by producing offspring that will survive long enough to reproduce.
Descent with modification
Organisms that survive long enough to reproduce have traits that are good for their environment pass these traits to their offspring
Natural selection v artificial selection
Natural selection is the process by which characteristics of a population change over many generations as organisms with advantageous heritable traits survive and reproduce, passing their traits to offspring while artificial selection is when organisms are bred by humans to improve desirable traits (selective pressure)
Genetic drift
The change in distribution of alleles due to chance events in a breeding population
Smaller the population less likely it is that the parent gene pool will be reflected in the next generation. Vice versa for large population
Gene flow
The net movement of alleles from one population to the other due to the migration of individuals
If organisms come from other populations and mate diversity is increased
Sexual selection
Natural selection for mating based, in grneral, on competition between males and choices made by females
Natural selection
The process by which characteristics of a population change over many generations as organisms with advantageous heritable traits survive and reproduce passing their traits to offspring
Synpatric speciation
Individuals within a population develop different preferences within the same geographical area
- one section of a population of bees likes starch foods and one likes sugar foods
- behaviour of individuals isolates them from the rest of the population and new niche(habitat role in ecosystem) moves to speciation
Allopatric speciation
Occurs when populations become geographically separated (physical barrier from one another
- environmental conditions can cause natural selection to occur differently
Cuvier
Studied palentology (fossil evidence) - theory of catastrophism in which catastrophes result in quick changes in geology and species changes.
Hutton
Proposed that geological processes are slow
Darwin said that evolution was slow because of this