Evolution Flashcards
What is the theory of evolution?
More than tree billion years ago life on earth began as simple organisms from which all the more complex organisms evolved
How are plants, animals and microorganisms classified?
Plants- make their own food (by photosynthesis) and are fixed into the ground
Animals move but can’t make their own food
Microorganisms are different to animals and plants e.g. Bacteria are singled cells
What is an evolutionary relationship?
Species with similar characteristics having similar genes due to the sharing of a recent common ancestor, they tend to look alike and live in similar habitats
What affect does how recent the common ancestor was have?
The more recent the common ancestor the closer the two species are related
What is ecological relationships ?
Seeing organisms in the same environment with similar characteristics suggests they may be in competition
Differences between organisms in the same environment can show predator prey relationships
Who came up with the theory of natural selection?
Charles Darwin
How does natural selection work?
Individuals within a species show variation because of the differences in their genes
Individuals with characteristics that make them better adapted to the environment have a greater chance of survival so are more likely to breed successfully
So the genes of the useful characteristics are more likely to be passed on to the next generation
What is a mutation?
A change in an organisms DNA
What happens when a useful mutation takes place?
The mutation may give a useful characteristic
This characteristic may give an organism a better chance of surviving and reproducing
The mutation is likely to be passed on to future generations by natural selection
Overtime the beneficial mutation will accumulate in a population
Why did many people not agree with Darwins theory?
It went against religious beliefs about how life on earth developed
Darwin couldn’t give a god explanation about where the mutation came from and how it was passed on as genes and mutation were not yet discovered
There wasn’t enough evidence to convince many scientists
What was Lamarcks theory?
If a characteristic was used a lot by an organism then it would become more developed in its lifetime
These acquired characteristics would be passed onto the next generation
Why was Lamarcks theory eventually rejected and Darwins accepted?
Experiments didn’t support his hypothesis
The discovery of genetics supported Darwin’s idea and it provided an explanation of how organisms born with beneficial characteristics can pass them on
