Evolution Flashcards
Looking at similarities and differences between organisms allows us to classify them into groups:
Plants are fixed in the ground and make there own food by photosynthesis.
Animals move around the place and so can’t make there own food.
Microorganisms are different to plants and animals.
How do species have similar genes?
Species with similar characteristics tend to have similar genes because they share a recent common ancestor, so they’re closely related. They often look very alike and live in similar types of habitats.
Why do some species sometimes look alike when they are genetically different?
Although they are not closely related they look alike due to growing up and adapting in the same habitat.
The more recent common ancestor, the more __ ____the two species are
Closely related
If organisms live in the same environment with similar characteristics, what can happen?
They could end up competing for the same food source.
What does the organisms that live in the same environment but are different show?
Differences between organisms in the same environment can show predator to prey relationship.
Explain Darwin’s theory of natural selection
Individuals of the same species shows variations due to their genes. They can have characteristics that makes them better adapted to the environment they are living in making them have a bigger chance of survival and so are more likely to breed successfully. The genes are responsible for the useful characteristics and are more likely to be passed on to the next generation.
Evolution can only occur due to mutations. What is a mutation?
It is a change in the DNA of an organism.
What can mutations do the the organism?
Most of the time, mutation has no effect on the organism but sometimes it can produce useful characteristics that can help them survive and reproduce. The organisms offspring is likely to get the mutation through its parents genes and so it is passed on to the next generation by natural selection.
Why did people not agree with Darwins theory/ why was it very controversial at the time?
1- it went against common religious beliefs about how life on earth developed. It was the first explanation for our existence without the need for god.
2- he couldn’t give a good explanation for why these new, useful characteristics appeared or how it was passed onto the offspring as he didn’t know about genes or mutations since they were not discovered.
3- there wasn’t enough evidence to convince many scientists as not many studies have been done to see how they changed.
What was the name of the person who had another idea about evolution?
Lamarck
Explain how lamarcks hypothesis was different from darwins
He argued that if a characteristics was used a lot by an organism, then it would become more developed during it’s lifetime so for eg if a rabbit used its legs to run a lot, then the legs would get longer.
He believed that these acquired characteristics would be passed on to the next generation.
Why might scientists develop different hypotheses about evolution
Because they have different beliefs, they think differently or they have been influenced by different people.
How could you find out whos hypothesis is right?
Find evidence to support or disprove each one.
Why was lamarcks hypothesis wrong?
Experiments that happened didn’t support his hypothesis. If you dyed an animals hair blue, the offspring would be the parents natural hair colour because the new characteristics won’t have been passed on.
