If any of these scenarios is true, then catastrophe could be called the mother of evolution. It remains unknown, however, whether the events of the Late Heavy Bombardment forced life to evolve, or if it got wiped out several times and had to spring forth over and over. Given this uncertainty on the likelihood of life emerging, it is clearly more plausible in the current state of our knowledge to conjecture that life may have survived multiple impacts by a lifeboat mechanism, or other refuge, rather than re-emerging from scratch in each window of opportunity. Maybe it wasn't so bad after all More new research supports the idea that life could have hidden out long enough to hang on during the worst of times. Kevin Zahnle of NASA's Ames Research Center, working with Mojzis and Ariel Anbar at NASA's Astrobiology Institute, used computer models to study the effect of impacts during the Late Heavy Bombardment.
Microbes decompose the waste products of other living things, creating nutrients.
They are also used to make beer, bread, and yogurt. Some say life on Earth may have begun when microbes migrated here from outer space . Others say life sprang up out of a primordial soup of terrestrial chemicals. Their work, to be published in an upcoming issue of the Journal of Geophysical Research , suggests that impacts large enough to cause worldwide disaster were few and far between. And even after the worst events, life would only have needed to hang on for about 10,000 years before Earth rolled out its bio-welcome mat again, according to the computer models.