Early theories of the origin of life included spontaneous generation from non-living matter and panspermia, the arrival of life on earth from other bodies in space. The question of how life originated became urgent when Charles Darwins 1859 On the Origin of Species' became widely accepted by biologists. The evolution of new species by splitting off from older ones implied that all life forms were derived from a few such forms, perhaps only one, as Darwin had suggested at the end of his book. Darwin suggested that life could have originated in some "warm little pond" containing a suitable mixture of chemical compounds. The question has continued to be debated into the 21st century.
Nick Lane is a biochemist at University College London; he researches "evolutionary biochemistry and  bioenergetics, focusing on the origin of life and the evolution of complex cells." He has become known as a science writer, having written four books about evolutionary biochemistry.