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).

Re:Excitement

[mikael]

Not necessarily. The use of bitumen/tar was documented in biblical times. The Romans were thought to have used coal for metalwork. A Greek by the name of Heronas, developed a prototype steam engine. They might have advanced faster technologically, if they weren't afraid of making the slaves unemployed

You can also read the history of the combustion engine . The first combustion engines were based on gunpowder, then coal powered steam engines, coal gas, and finally petroleum. At the same time, engineers experimented with one stroke, two stroke and four stroke engines with vertical and V slant pistons.

Re:Excitement

[sm62704]

The Romans were thought to have used coal for metalwork

I didn't know that there was any other way besides coal/coke for the ancients to have done blacksmithing, although wikipedia says it can be done with charcoal. I have no idea how charcoal would work. The Wikipedia article isn't quite accurate:

Blacksmiths work by heating pieces of wrought iron or steel in a forge until the metal becomes soft enough to be shaped with hand tools, such as a hammer and chisel. Heating is accomplished by the use of a forge fueled by propane, natural gas, coal, charcoal, or coke.

You can't blacksmith using just coal; the coal is turned to coke by oxygenating it with a blower, and pouring water on it. At least that's what they taught in my college blacksmithing class. I can't remember the fellow's name, unfortunately, but he was 72 at the time and travelled to different universities teaching his dying art to the younger generation. This was some time in the late 1970s. He'd smithed Gerald Ford's wrought iron fence, at the time of the class Carter was president.

I really should build a forge.