Evolution of species Flashcards
What is a mutation?
A RANDOM CHANGE TO GENETIC MATERIAL
Mutations are the only sources of new…
ALLELES
The three types of mutation
ADVANTAGEOUS, DISADVANTAGEOUS, NEUTRAL
Examples of factors which can
increase the rate of mutation
MUTAGENIC AGENTS E.G.RADIATION
AND SOME CHEMICALS
What is an adaptation?
AN INHERITED
CHARACTERISTIC THAT MAKES AN ORGANISM WELL SUITED IN ITS ENVIRONMENT
What is meant by the term ‘natural selection’
THE SURVIVAL OF THE
FITTEST / BEST ADAPTED
SURVIVE
Examples of selection pressures
DISEASE
What is meant by the term ‘speciation’
THE FORMATION OF TWO OR MORE SPECIES FROM ONE
ANCESTRAL SPECIES
What must happen to a population to allow speciation to occur
THE POPULATION MUST BE ISOLATED AND SPLIT INTO 2 SUB POPULATIONS
What is meant by an ‘isolation
barrier’
A FACTOR WHICH PREVENTS THE INTERBREEDING OF
POPULATIONS
Examples of isolation barriers
ECOLOGICAL, BEHAVIOURAL, GEOGRAPHICAL
The 4 main steps in the formation of new species
ISOLATION, MUTATION, NATURAL SELECTION,
SPECIATION
How it is possible to tell if
speciation has occurred
ORGANISMS CAN NO LONGER INTERBREED TO PRODUCE
FERTILE OFFSPRING
