In the summer of 1858, a lesser-known 35-year-old naturalist named Alfred Russel Wallace mailed Charles Darwin a 20-page letter from the Indonesian jungle outlining the theory of evolution by natural selection — a theory Darwin had been quietly developing for 20 years without publishing — forcing Darwin to hastily share the credit with a man he had never met

In the summer of 1858, a lesser-known 35-year-old naturalist named Alfred Russel Wallace mailed Charles Darwin a 20-page letter from the Indonesian jungle outlining the theory of evolution by natural selection — a theory Darwin had been quietly developing for 20 years without publishing — forcing Darwin to hastily share the credit with a man he had never met

The letter’s author, Alfred Russel Wallace, was 35 years old, the seventh of nine children of a financially declining English family, largely self-educated, working at the time as a specimen-collector in what is now eastern Indonesia, financing his expeditions by shipping insect and bird specimens back to British natural-history dealers who sold them on to collectors and museums. He had spent eight years in such fieldwork — four years in the Ama…