B1.8 Evolution Flashcards
What is the theory of evolution?
More than 3 billion years ago, life on Earth began as simple organisms from which all the more complex organisms evolved
What is natural selection?
Individuals in a species show variation due to their diff. genes, these individuals can therefore be better adapted to their environment and can be more likely to survive, these useful characteristics are then passed on to the next generation
What is example of natural selection?
Rabbits being born with bigger ears than other -> They can hear predators from further away than rabbits with smaller ears can, this means they can escape sooner and survive, whereas the smaller eared rabbits are eaten
How does variation spread across a population of a species?
Useful characteristics which help the organism to survive will be passed on to offspring - this is evolution
What happens when the changes in a population of species are great enough?
A new species will evolve
Evolution can occur due to mutation, what is mutation?
A change in an organism’s DNA (genes)
Why was there controversy when Darwin released his theory of evolution? (3)
It went against the belief of God, he was unable to explain mutations or how characteristics were passed onto offspring as genes were not yet discovered and there wasn’t enough evidence to convince scientists as not many studies had been done
What was Lamarck’s theory?
He believed that as organisms used a characteristic a lot, then it would become more developed over, and this development of characteristics would be passed onto offspring e.g. a rabbit gaining longer legs as they continue to escape predators
Why do scientists have different hypotheses? (2)
Because they have different beliefs, or they have been influenced by different people
How can you prove or disapprove hypotheses?
By finding enough evidence to support or disapprove it
What classifies a plant? (2)
They can make their own food and are fixed to the ground
What classifies an animal? (2)
They can move around and can’t make their own food
What classifies a microorganism?
They are very different to animals and plants, and can be single-celled
What are evolutionary relationships?
How living things are related
What are ecological relationships?
How living things interact with each other
