Billions Quote by Robert Jastrow

Every creature alive on the earth today represents an unbroken line of life that stretches back to the first primitive organism to appear on…

— George Wald

Consider: Life arose on Earth close to four billion years ago. Four billion years of slithering, swimming, and soaring life forms. But only in…

— Seth Shostak

Life began three and a half billion years ago, necessarily about as simple as it could be, because life arose spontaneously from the organic…

— Stephen Jay Gould

“600 million years ago, the monopolizing grip of the algae was broken and an enormous proliferation of new lifeforms emerged, an event called the…

— Carl Sagan

Life existed on Earth for nearly four billion years before anything remotely resembling a human being showed up. And even then, when we started…

— Neil deGrasse Tyson

The question of the origin of life is essentially speculative. We have to construct, by straightforward thinking on the basis of very few factual…

— John Desmond Bernal

“Life on earth evolved gradually beginning with one primitive life form – perhaps a self-replicating molecule – that lived more than 3.5 billion years…

— Jerry A. Coyne

The record of the rocks contains very little, other than bacteria and one-celled plants until, about a billion years ago, after some three billion…

— Robert Jastrow

“Life, in short, just wants to be. But—and here’s an interesting point—for the most part it doesn’t want to be much. This is perhaps…

— Bill Bryson

All of us who study the origin of life find that the more we look into it, the more we feel it is too…

— Harold Urey

The Earth has been lawned with life for something over 3.5 billion years. That's a span of time great enough to encompass some honest-to-goodness…

— Seth Shostak

The physical fabric of the world had to be such as to enable that ten billion year preliminary evolution to produce the raw materials…

— John Polkinghorne