Lack of Molybdenum May Have Delayed Life on Earth

esocid writes "Scientists from around the world have reconstructed changes in Earth's ancient ocean chemistry during a broad sweep of geological time, from about 2.5 to 0.5 billion years ago. They have discovered that a deficiency of oxygen and the heavy metal molybdenum in the ancient deep ocean may have delayed the evolution of animal life on Earth for nearly 2 billion years. Bacteria cannot fix nitrogen efficiently when they are deprived of molybdenum. And if bacteria can't fix nitrogen fast enough, then eukaryotes — a kind of organism that includes plants, pachyderms and people — are in trouble because eukaryotes cannot fix nitrogen themselves at all. Ariel Anbar, a co-author of the research of Arizona State University, stated that "eukaryotes depend on bacteria having an easy enough time fixing nitrogen that there's enough to go around. So if bacteria were struggling to get enough molybdenum, there probably wouldn't have been enough fixed nitrogen for eukaryotes to flourish.""

Comments

Re:42

[Silicon Jedi]

Holy crap! There are 42 protons in its nucleus!

Re:terraforming and other things

[dokebi]

Nitrogen is part of both DNA and amino acids. Therefore all life as we know it requires it. We can speculate about other types of lifeforms that doesn't use DNA, but as far as we know the, nitrogenases are the only enzymes that takes nitrogen gas to a usable form (ammonia).

It is important to realize that life on earth didn't all come to existence at once. Animals cannot breath CO2 not because it can't evolve for it but because our metabolism depends on oxygen. Without plants fixing CO2 and putting out O2, *for millions of years*, animals couldn't exist. Plants couldn't evolve to fix nitrogen in the similar way. Read up on the nitrogen cycle.

BTW, IMAB (I am a biologist).