The content you've requested is available without charge only to active Sigma Xi members and
If you are an active member or an individual subscriber, please log in now in order to access this article.
If you are not a member or individual subscriber, you can:
Four billion years ago, back when life began, our planet was a very different place. Earth spun more rapidly on its axis—a day lasted only four or five hours. The Moon was much closer, and giant meteorites pelted the planet. Under these conditions of constant, chaotic change, there was only one place of constancy—a warm spring in the relative safety of the deep ocean floor. There, protected from ultraviolet radiation, existed a place that never dried out, never got too hot or too cold, never became too acidic or too alkaline. Life began there, inside the membranous froth of minerals that surrounded these hydrothermal springs, and the minerals themselves catalyzed the first chemical reactions that made proteins and nucleic acids—precursors to the earliest living things. Every kind of life, including us, carries the mark of that first catalysis in the form of tiny mineral clusters at the centers of our enzymes, still doing the jobs they began so long ago.
Connect With Us:
An early peek at each new issue, with descriptions of feature articles, columns, and more. Every other issue contains links to everything in the latest issue's table of contents.News of book reviews published in American Scientist and around the web, as well as other noteworthy happenings in the world of science books.
To sign up for automatic emails of the American Scientist Update and Scientists' Nightstand issues, create an online profile, then sign up in the My AmSci area.
JSTOR, the online academic archive, contains complete back issues of American Scientist from 1913 (known then as the Sigma Xi Quarterly) through 2005.
The table of contents for each issue is freely available to all users; those with institutional access can read each complete issue.
View the full collection here.
Receive notification when new content is posted from the entire website, or choose from the customized feeds available.