the rise and fall of microbes

Rise: Bacterial co-evolution has might have made you what you are today:

"If animals from an omnivorous background have moved into a more herbivorous lifestyle they have absolutely needed bacterial partners and microbes to allow that to happen," Gordon says.

David Relman, a microbiologist at Stanford University in California agrees that microbes could have played an important part in mammalian evolutionary history.

"It's possible that our microbial makeup has guided and played a major role in defining who we are and what we do, but it could also be the flip side," he says. Gut microbe populations could passively respond to changes in host physiology and diet.

To answer that question, researchers need a better grasp on the factors that determine an animal's gut flora – including genes and diet. To make things even more complex, other studies have shown that gut microbe populations change over the course of months and years.

"It's a daunting set of potential variables, only some of which you can control," Relman says.

Should make for interesting research. In similar news, "If cells could vote, people would be a minority in their own body." We've mentioned this before, but it's worth repeating: you are a superorganism.

Fall:

Life has been found 1.6 kilometres beneath the sea floor, at temperatures reaching 100 °C.

The discovery marks the deepest living cells ever to be found beneath the sea floor. Bacteria have been found deeper underneath the continents, but there they are rare. In comparison, the rocks beneath the sea appear to be teeming with life.

John Parkes, a geobiologist at the University of Cardiff, UK, hopes his team's discovery might one day help find life on other planets. He says it might even redefine what we understand as life, and, bizarrely, what we understand by "age".

Parkes has been hunting for deep life for over 20 years. Recently, he and his colleagues examined samples of a mud core extracted from between 860 metres and 1626 metres beneath the sea floor off the coast of Newfoundland.

It's possible that some of the freshly-discovered prokaryotes could be several million years old--their metabolism is so slow, that they live almost in a sort of permanent hibernation. Parkes figures that the mass of these undersea prokaryotes could equal that of all other life on earth.