various simes times like fluffy mattresses (stromatolite comes from ttress”), sometimes tens of metersabove ter—sometimes as ers. In all tations, ted tcooperative venture, ies of primitive organism living just at t underneataking advantage of conditions created by ts first ecosystem.

    For many years, scientists kne stromatolites from fossil formations, but in 1961t a real surprise y of living stromatolites at Se nort coast of Australia. t unexpected—so unexpected,in fact, t it ists realized quite oday,ourist attraction—or at least as mucourist attraction as a place all can ever be.

    Board into t visitors can stroll over ter to get agood look at tromatolites, quietly respiring just beneaterlessand gray and look, as I recorded in an earlier book, like very large cos. But it is acuriously giddying moment to find yourself staring at living remnants of Eart : “truly time traveling, and if ttuned to its real  he pyramids of Giza.”

    Alt, timated (imated) three billion individual organisms on every square yard of rock.

    Sometimes rings of bubbles rising to tions raised tmospo 20 percent, preparing t, more complex cer inlife’s ory.

    It ed t teria at S-evolvingorganisms on Eartainly no.  of existence nearly every at Sers are too saline for tures t  on took so long to gro to  until ted tmosply. “Animals could not summonup to ey  it. It took about tory, for oxygen levels to reacration in tmosp once tage , and apparently quite suddenly, anentirely neype of ce