Why should we have a helathy envionment explain

The deserts of the sahara and australia are associated with

Classify the structures as homologous or analogous, depending on their structure and function.

Need an answer asap 45 points and brainlest to the first person to answer why do scientific theories, such as biological and chemical evolution, represent the strongest explanation of the changes observed in the fossil record. must be in sentence form how can scientific theories on evolution and the fossil record change over time? must be in sentence form