Topic 6 Speciation Flashcards
What is speciation
The development of a new species
What is a species
A group of similar organisms that can reproduce to give fertile offspring
When does speciation occur
When populations of the same species become so different that they can no longer successfully interbreed to produce fertile offspring
What can lead to speciation
Isolation and natural selectiom
What is isolation and why might it happen
Where populations of a species are separated apart. This can happen due to physical Barriers e.g floods and earthquakes
Why will there characterises change
Conditions on either side of the barrier will be slightly different so different characteristics will become more common in each population due to natural selection operating differently on the populations
How does each population show variation
Have a wide range of alleles
Why are some individuals better adapet3 to the environment
So they have a better chance of survival and so are more likely to breed successfully
Why are beneficial characteristic more likely to be passes on to the next generation
Because that generation had more chance of survival and reproduction
What does it mean if individuals have changed so much they can no longer breed
They have become separate species
Who was Alfred Russel Wallace
A scientist working at the same time as Charles Darwin
What did Alfred Russel Wallace study
Idea of speciation
What did Alfred Russel Wallace do
Independently came up with the idea of natural selection and worked on the subject together with Darwin in 1858 and promoted him to publish “on the origin of species” in 1859
What observations did Alfred Russel Wallace make whilst travelling the world
Evidence to support theory of evolution by natural selection
Warning colours are used by some species (butterflies) to deter predators from eating them and this was an example of beneficial characteristics that evolved due to natural selection
