I sort of wish Arch was still here.
All life on Earth evolved from a single-celled organism that lived roughly 3.5 billion years ago, a new study seems to confirm.
The study supports the widely held "universal common ancestor" theory first proposed by Charles Darwin more than 150 years ago.
(Pictures: "Seven Major 'Missing Links' Since Darwin.")
Using computer models and statistical methods, biochemist Douglas Theobald calculated the odds that all species from the three main groups, or "domains," of life evolved from a common ancestor—versus, say, descending from several different life-forms or arising in their present form, Adam and Eve style.