The answer is Alfred Wallace.
Darwin began formulating his theory of natural selection in the late 1830s but he went on working silently on it for twenty years. He wanted to amass a wealth of evidence before publicly presenting his idea. During those years he corresponded briefly with Wallace (right), who was exploring the wildlife of South America and Asia. Wallace supplied Darwin's help publishing his own ideas on evolution. He sent Darwin his theory in 1858, which, to Darwin's shock, nearly replicated Darwin's own.
2 is the answer I THINK look at other ones first
Thymine and cytosine are classified as "Pyrimidines" and have one ring of carbon and nitrogen atoms for each base.