Are We Martians After All?
If you looked in a mirror this morning, you may have seen a descendant of creatures from Mars. That is, if biochemist Steven Benner of the Westheimer Institute of Science and Technology in Gainesville, Florida, is right. “Life started on Mars and came to Earth on a rock,” Benner declares. Today, at the European Association of Geochemistry’s Goldschmidt Conference in Florence, Italy, Benner made what many in the origin-of-life debate call an interesting, but not convincing, new case for our martian heritage.
However and wherever life began, one thing is sure: Its first organic building blocks, called hydrocarbons, had a number of hurdles to clear before evolving into living cells. Fed with heat or light and left to themselves, hydrocarbons tend to turn into useless tarlike substances. And even when complex molecules like RNA (most biologists’ best guess for the first genetic molecule) arise, water quickly breaks them down again.