Saturday, March 22, 2014

Tangerines and String Quartets

The origin of life eludes us. The leap from organics to organisms isn't definitively understood.
I believe a leaf of grass is not less than the journey-work of the stars.
Walt Whitman, Song of Myself
The desire for us to understand existential unknowns produces limits on the range of possibilities. The range of possibilities provide the guideposts to inquiry. Within possibilities emerge the paths of plausibility, some more fruitful than others.

The origin of life, and the nature of the living, remains elusive. Still there are established characteristics, like heredity — the self-replicating passing on of information — that links all organisms to the simplest cells and the most basic elements on the periodic chart.
What do they call it…the primordial soup? The glop? That heartbreaking second when it all got together, the sugars and the acids and the ultraviolets, and the next thing you knew there were tangerines and string quartets.
Edward Albee, Seascape
The microcosmic gods of life seem to be nucleic acids and proteins. The earliest detectable life arrived 3.6 to 3.8 billion years ago in the form of simple cells.

Over billions of years, simple replicating cells evolved into complex organisms. This came about against the deterministic cleave of natural selection.
The one thing we have in common with all other living things is that for nearly four billions years our ancestors have managed to slip through a series of closing doors every time we needed them to.
Bill Bryson, A Short History of Nearly Everything
Humans are comparative newcomers arriving 200,000 years ago, yet our organic and earlier inorganic ancestry, is traceable to cosmic stardust.

Years Ago
4.6 billionEarth began circling the sun
3.6 billionArrival of simple cells - Prokaryotes
3.4 billionArrival of cyanobacteria performing photosynthesis
2 billionArrival of complex cells - Eukaryotes
1 billionArrival of multicellular life
600 millionArrival of simple animals
550 millionArrival of bilaterians, animals with a front and a back
500 millionArrival of fish and proto-amphibians
475 millionArrival of land plants
400 millionArrival of insects and seeds
360 millionArrival of amphibians
300 millionArrival of reptiles
200 millionArrival of mammals
150 millionArrival of birds
130 millionArrival of flowers
66 million years agoDeparture of the pterosaurs and non-avian dinosaurs, in the CretaceousPaleogene extinction event.
60 millionArrival of primates
20 millionArrival of Hominidae or great apes
2.5 millionArrival of the genus Homo - human predecessors
200,000Arrival of anatomically modern humans

An insatiable curiosity and judicious hypothesis testing will eventually lead us to many of the answers we seek. But the satisfaction of each answer will be momentary. The side effect of each aha! moment is a set of new questions. This is the quest of science.

The Existential Ledger

On the known side of the ledger, is the precedence, preponderance and rigor of established science. On the unknown side, it must suffice that the nature of life will reveal itself in fits and starts.

We're continually pinged with incoming data. Revelations necessitate reconciling of our existential accounts. We only know what we know at a given time. What remains is pontification or poetry.