Evolution - Unit 3 Flashcards
Definition of mutation
a random change to genetic material
What effects can mutations have?
neutral , advantage, disadvantage
Mutations are the only…
sources of new alleles
What is a variation ?
Differences in characteristics that can be seen in individual members of a species
name two mutagenic agents
radiation , chemicals ( mustard gas )
What is an adaptation ?
A inherited characteristic that makes an organism well suited to it’s environment
What does survival of the fittest mean ?
the individual with the most adapted characteristics will live long enough to reproduce to pass its genes onto the next generation
What is natural selection ?
- more offspring is produced than the environment can sustain
-organisms with the best characteristics will survive long enough to reproduce, passing on their genes to a new generation - this is called having a selective advantage
What is speciation ?
a formation of a new species, natural selection causes this to happen
What are the three factors of speciation
isolation barriers, different random mutations, natural selection
What are the three catagories of isolation barriers?
Geographical
Ecologial
Behavioral
Give examples of each of the isolation barriers
G - river, mountain, sea
E - pH, salinity, different habitats
B - different mating calls, sleeping patterns
What is the process of speciation ?
- speciation occurs after part of a population becomes isolated
- different mutations occur in each sub-population
- natural selection selects different mutations in each group
-each sub population evolves untill they become so genetically different they are 2 species
