Evolution Of Species Flashcards
What is a mutation
is the random change to an organisms genetic material
Mutations are the source of new what in a population
only source of new alleles in a population
mutations are spontaneous
they result in variety within a population
what can increase mutations
mutagenic agents
Radiation
Some chemicals
Why is Variation good
Variation within a population makes it possible for a population to evolve over time in response to changing environmental conditions
what is an adaptations
an inherited characteristic that makes an organism well suited to survival in its environment
adaptions give an organism an advantage which increase their chances of survival
what are physiological adaptions
snakes produce venom to ward off predator and to capture prey
Behavioural adaptions
things organisms do to survive
what causes a struggle for survival
when a species produces more offspring than the environment can sustain
when does natural selection occur
when there are selection pressures
describe the circumstances in which variation exists
between members of the same species and they compete for survival
decribe survival of the fittest
the best adapted individual in the population survive and reproduce to pass on their favourable alleles to offspring and the alleles increase in frequency within the population over time
state the stages of natural selections
-more offspring than environment can handle results in a struggle for survival
-survival of the fittest occurs
- the best adapted individuals survive and reproduce
- they pass on advantageous allele
- overtime alleles increase in frequency within the population
What is speciation
the formation of new species
when does speciation occur
when a population becomes isolated from other populations of the same species and mutation occurs
What are the three types of isolation barriers
- geographical river, mountain
- ecological ph, habitat, salinity
- behavioural mating rituals, mating calls
