Input (grade 13): Other lectures grew into Huxley's most famous work Evidence as to Man's place in Nature (1863) where he addressed the key issues long before Charles Darwin published his Descent of Man in 1871.
Output (grade 7): Huxley's public lectures grew into his most famous work Man's place in Nature (1863). There he deals with the evolution of man, before Charles Darwin published his Descent of Man in 1871.