Biodiversity on Earth
How has it changed?
Biodiversity has fluctuated over the past millions of years. This is because of geological changes and extinctions that have occurred forcing the environment to adjust. As you can see, angiosperms have the greatest number of evolutionary families in its lineage. Following angiosperms are insects and mammals.
Mass extinctions are where biodiversity has changed the most. There have been multiple mass extinctions, but the most common one resulted in a very large meteorite hitting the earth. This caused the dinosaurs to go extinct and the chemicals found in the meteorite affected the environment making the climate completely change.
Because of the high demand of timber, the habitats of many animals are being destroyed. This is causing the extinction of many different species. Scientists say that there are thousands of species that they have studied and many species they haven't studied could be on the verge of extinction.
Cyanobacteria appeared and was produced by photosynthesis and any free oxygen was chemically captured. The cyanobacteria made so much oxygen that it could not be captured and therefore filled the atmosphere. The Great Oxidation produced aerobic organisms.