Differentiate between deforestation and desertification

deforestation = cutting down of trees in large scale due to which it causes soil erosion. desertification = a process by which fertile land become desert ,typically as a result for drought, deforestation etc. Deforestation is defined as the cutting down or clearing of trees from a wooded area. ... If trees are removed, the area can become much warmer and drier, which may result in desertification, which is a transformation of once fertile land into desert.

Explanation:

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?