What was the first animal to appear on earth, according to MIT researchers?

a. Sea Algae

b. Sea Sponge

c. Sea Bacteria

d. None of the above

ANSWER: Sea Sponge

Explanation:

The first animal to appear on earth was the sea sponge, according to MIT researchers, as they predate the Cambrian explosion during which large number of new animals came about. MIT studied the discovery through analysis of molecular fossils which are trace amounts of molecules found in ancient rocks surviving till current times.