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

“An irrefutable proof that such single-celled primaeval animals really existed as the direct ancestors of Man, is furnished according to the fundamental law of biogeny by the fact that the human egg is nothing more than a simple cell.”
― Ernst Haeckel, The History Of Creation V2: Or The Development Of The Earth And Its Inhabitants By The Action Of Natural Causes

“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