Could living things that evolved from metals be clunking about somewhere in the universe? Perhaps. In a lab in Glasgow, UK, one man is intent on proving that metal-based life is possible.
He has managed to build cell-like bubbles from giant metal-containing molecules and has given them some life-like properties. He now hopes to induce them to evolve into fully inorganic self-replicating entities.
"I am 100 per cent positive that we can get evolution to work outside organic biology," says
Lee Cronin (see photo, right) at the University of Glasgow. His building blocks are large "polyoxometalates" made of a range of metal atoms – most recently tungsten – linked to oxygen and phosphorus. By simply mixing them in solution, he can get them to self-assemble into cell-like spheres.
Cronin and his team begin by creating salts from negatively charged ions of the large metal oxides bound to a small positively charged ion such as hydrogen or sodium. A solution of this salt is squirted into another salt solution made of large, positively charged organic ions bound to small negative ones.
When the two salts meet, they swap parts and the large metal oxides end up partnered with the large organic ions. The new salt is insoluble in water: it precipitates as a shell around the injected solution.
Cronin calls the resulting bubbles inorganic chemical cells, or iCHELLs, and says they are far more than mere curiosities. By modifying their metal oxide backbone he can give the bubbles some of the characteristics of the membranes of natural cells. For example, an oxide with a hole as part of its structure becomes a porous membrane, selectively allowing chemicals in and out of the cell according to size, just like the walls of biological cells. This property gives the membrane control over the range of chemical reactions that can happen within – a key feature of specialised cells (
Angewandte Chemie, DOI:
10.1002/anie.201105068).
The team has also made bubbles within bubbles (
see images), creating compartments that mimic the internal structure of biological cells. Better yet, they have started imbuing the iCHELLs with the equipment for photosynthesis by linking some oxide molecules to light-sensitive dyes. Cronin says early results suggest he can create a membrane that splits water into hydrogen ions, electrons and oxygen when illuminated – the initial step of photosynthesis.
"We've [also] got an indication that we can pump protons across the membrane" to set up a proton gradient, says Cronin – another key stage in harnessing energy from light. If he can assemble all these steps, Cronin could create a self-powered cell with elements of plant-like metabolism.
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This still seems to require liquid water to work. Right now, searching for possible life bearing planets doesn't involve much more than looking for rocky planets, with atmospheres, within a given distance range from their sun that they would support water.
So... no. I am pretty sure in this specific context it would not change much.
Very neat though. I am sort of missing where these metal bubble jobbies would gain the ablity to replicate or pass along the genetic information(the term would still be genetic if we are not dealing with dna/rna right?) required for evolution.
I thought this thread was about science, not anti-science.
Rock Band DLC | GW:OttW - arrcd | WLD - Thortar
Polar solvents will do won't they, liquid ammonia and the like as well? Or at least they can support life even if there's some tricks involved in getting there.
These are actually my favorite ones.