Universal Common Ancestor Quotes

“If a single cell, under appropriate conditions, becomes a man in the space of a few years, there can surely be no difficulty in understanding how, under appropriate conditions, a cell may, in the course of untold millions of years, give origin to the human race.”
― Herbert Spencer, The Principles of Biology, Vol 1

“The uniformity of the earth's life, more astonishing than its diversity, is accountable by the high probability that we derived, originally, from some single cell, fertilized in a bolt of lightning as the earth cooled. It is from the progeny of this parent cell that we take our looks; we still share genes around, and the resemblance of the enzymes of grasses to those of whales is a family resemblance.”
― Lewis Thomas, The Lives of a Cell: Notes of a Biology Watcher

“All of today's DNA, strung through all the cells of the earth, is simply an extension and elaboration of [the] first molecule.”
― Lewis Thomas, The Medusa and the Snail: More Notes of a Biology Watcher