Revision Evolution MC Answer 5

Revision Evolution MC Answer 5

Taken from 2007 midyear

The five steps of Darwin's theory of evolution by means of matureal selection can be summaried as follows:
- There is variation in every population.
- Organsims must competer for limite resources
- Organisms have more offspring than can survice.
- Organisms with themost beneficial traits are more likely to survive and reproduce
- Organisms pass beneficial traits on to their offsprin..

Of the steps describing Dariwn's Theory of Evolution which of the steps listed below would indicate that there would be an increase in the population if there is abundance or food avaliable.

a) There is variation in every population
Variation means that each individual will be different. This arrises due to mixing of the genes and traits of the mother and father. You will note that brothers and sisters of the same parents are different because each egg and sperm mix in a different way. There is also mutations or random variation in genes. The most commonly suggested way people think off is due to radiation, however long term studies of the survivors of Hiroshima show that deterioration of male sperm with age is the major factor causing mutations. It is not surprising that 25% of human conceptions end in miscarrage of a embryo that is not viable


b) organisms must compete for limited resources
Abundant food means less competition.

c) organsims have more off spring that can survive
This means that 2 adults, produce more that 2 to replace them. For example 2 makes 4 makes 8 make 16 etc. This drives the population upto the maximum that the enviroment can support.

d) organisms with the most beneficial traits are more likely to survive and reproduce.
This is key to driving the emphasis of traits in a population