Recall how alfred russel wallace theory compared to darwin's theory of evolution by natural selection. *who ever answers correctly hey answer*

Alfred Wallace and Charles Darwin where both the theorists behind the natural selection mechanism by which animals evolve to adapt in their environment. Distinctively, Wallace was the co-author of the theory by which his expeditions made him discover the processes that act on how evolution occurs which he relayed to Darwin. However, as both peers in the theory of evolution it seems to have arose that Wallace never became popular on this idea unlike Darwin. 

what subject is this

satellites are frequently used to make observations of the orbit on earth