The slime chronicles

We see that the Australians who specialize in spotting fossilized slime in early terrestrial rock have performed another coup in Greenland. One might need to be a palaeobotanist to fully appreciate a stromatolith bouquet, but there it is (see here), inscribed into the Isua greenstone belt through the hills behind Nuuk, where volcanic rocks of 3,700 million years’ antiquity are to be found (by radiometric dating). We have pushed back the frontier of life on Earth another 200 million years plus, from similar findings in Western Australia, according to pop-science media — moving ever closer to some imagined evolutionary interface between physics and biology.

Alternatively, we are looking at ancient mineral accretions from evaporating sea water; but there you go. It could be biotic slime, of the sort we can observe today, microbially cementing layers of sediment to construct stone pillows in exotic shapes. And it might do for an image of the primordial gunge which, ever since Darwin, has served for a quasi-explanation of how Evolution got started.

The Earth is hypothesized to be 4,600 million years old (give or take a few ten-millions). Our proto-planet was bombarded from space continuously, and is supposed to have collided with another spinning proto-planet about the size of Mars, creating the mess that was finally resolved as Earth-and-Moon. Tranquillity was not to be had for some time, according to this cosmology, and metamorphic processes within the planet continue to the present day. All trace of life prior to, say, 4,000 million years ago, will have been cooked beyond the possibility of recognition.

The find in Greenland pertains to a little patch exposed by melting snow, smaller than a football field, which hypothetically escaped the intense baking, and floated through all later geological subductions. Well spotted, indeed!

A human body contains many trillion (millions of millions) of fairly cooperative living cells. Each of these cells contains a few million protein-coding genes. The microbial life imputed in this case is simpler, to be sure, but still incredibly complex. The degree of this complexity is under-appreciated.

We are often told that we share 98 percent of our genes with monkeys; but did gentle reader know that we also share around 60 percent with their bananas? I mention this otherwise pointless little fact, and compound it with the observation that genes can express themselves in myriad ways, to suggest the amount of choreography required to get anything reproductively genetic. As Nutman et al. acknowledge in their Nature piece, the ancestral slime imputed to their Greenland stone would already need to have been so biologically sophisticated as to require a very long previous evolutionary process.

Alternatively: the metamorphoses can happen rather quickly. This would be consistent with the entire known fossil record, in which we nowhere find creatures that are awkward. The closer we can investigate any one, the more we find it beautifully adapted to its spatial and temporal niche — coming into the geological record as a distinct item for aesthetic contemplation, and then making off; each with its entrance and its exit, from the cosmic dance. Here is its curtsy, there is its bow.

It was an Australian — a certain Lance Endersby from Hobart, Tasmania — who first introduced me to the powers of a microscope, and the thrill of examining smears of slime from the pond in his tropical (Bangkok) garden, whenas I and his two sons were wee boys. I saw things there, on the microscope slides, that blew my little head clean away, and I cannot say it has since had a chance to reassemble.

Later, I encountered this passage from Isaiah:

For thus saith the Lord that created the Heavens,
God himself that formed the Earth,
And made it, the very maker thereof.
He did not create it in vain:
He formed it to be inhabited!