Evolution Flashcards
What is a mutation?
A random change in genetic material
What are 3 possible consequences of a mutation?
neutral, positive or negative
What is a positive mutation?
increase the chances of survival
What is a neutral mutation?
Neither increases or decreases the chances of the organism surviving
What is the only source of new alleles?
Mutations
Give an example of something that can increase the rate of mutations?
UV light, X-rays and some chemicals (mustard gas, cigarettes)
What do we call inherited characteristics that make an organism well suited to survive in its environment?
adaptation
Why is variation in a population important?
It allows the population to adapt to changing environmental conditions over time
Do species produce more or fewer offspring than the environment can support?
more
Give 3 examples of selection pressures.
predation, food shortage, disease
What name is given when the best adapted survive, reproduce and pass on alleles that gives a selective advantage?
Natural selection
What happens to the number of favourable alleles in a population over time?
They increase in number
During the process of speciation, what stops the 2 populations breeding together?
isolation barrier
Give an example of an isolation barrier.
sea, ocean, mountain range, geographical, ecological, behavioural
What name is given to the formation of 2 or more species from one original species?
speciation
