Learning Objectives and Key points
How much have organisms changed over time?
We can learn from fossils how much or how little organisms have changed as life has developed on Earth. This understanding is limited though due to the evidence left behind apart from for a few animals including the horse there is a very complete fossil record. Fossils show us that not all animals have changed very much over time e.g. the shark as their environment hasn't changed much as they developed and adapted early they have remained the same.
What is extinction?
Extinction- the permanent loss of all members of a species. As conditions change new species evolve which are better suited/more adapted to the environment. The older species can not cope with the changes and die out as they are not able to compete for things e.g food as well. This is how evolution happens and the…