Life on Earth - 3.6 Evolution of species Flashcards
Examples of behavioural barrier ?
Preference to mate with an individual with a particular allele
Examples of different geographical barriers ?
River or Mountains or Ocean
What is mutation ?
A mutation is a random change to genetic material
Mutation can be ?
Neutral + advantage +disadvantage
What is a neutral mutation ?
Neutral mutations have no impact on the organism
Mutations are spontaneous and are only source of ….. ?
New Alleles
New Alleles produced by mutation can result in ?
plants and animals becoming better adapted to their enviroment
What can increase rate of mutation ?
Environmental factors such as
radiation and some chemicals
Variation in a population makes it possible for ?
Population to evolve over time in response to changing environmental conditions
What is an adaptation ?
An adaptation is an inherited characteristic that makes an organism well suited to survival in its environment/ niche
What do species produce more than the environment can sustain ?
Offspring
Natural selection or survival of the fittest occurs when there are ?
Selection pressures
What are the best-adapted individuals in a population ?
Survive to reproduce, passing on the favourable alleles that confer the selective advantage
These alleles increase in frequency with in the population
Speciation occurs after ?
part of a population becomes isolated by an isolation barrier
What are the types of isolation barriers ?
Geographical
Ecological
Behavioural
Different mutations occur in each ?
Subpopulation
Natural selection selects for different mutation in ?
each group, due to different selection pressures
Each sub-population evolves until they become ?
so genetically different that they are 2 different species
Examples of ecological barrier ?
PH
Salinity
