Better adapted organisms survive to produce
a greater number of adapted offspring
Demonstrate the process of natural selection
In all species more offspring is produced than
actually survive, some individuals are stronger and
theya re more likely to survive and breed. This is
called natural selection
Outline the key steps in the process of natural selection
1. Individuals within a population show variation:
due to: sexual reproduction, random assortment,
crossing over
2. Overproduction: populations produce to many
young
3. Selection pressures: certain conditions within
enviroment affect chances for survival e.g.
predators
4. Struggle for survival: organisms must compete
to survive due to overproduction and selection
pressure
5. Survival of the fittest: organisms with best
adaptations will survive
6. Inheritance of favourable traits: best adapted
organisms pass there favourable traits onto
offspring.
Explain Darwin and Wallace's contribution to
the theory of evolution by natural selection
In the mid 1800's, two scientists Charles Darwin and
Alfred Wallace were working on similar theories to
explain how the earth come to be populated by such a
broad variety of organisms. Though Charles Darwin got
the credit for his discovery first.
Outline the theory of evolution by natural selection
'Its the gradual change in organisms over a long period of
time'. This theory is based upon the collection of evidence
noted by Charles Darwin.
Two forms of evidence for evolution and provide examples
1. Fossil evidence of ancient organism
remains - e.g dinosaurs, are not alive today
2. Similarities among living organisms - e.g has evolved over
time, similar but different e.g. humorous bone found in bird,
whale.