The Beginning and Evolution of life on Planet Earth


It’s miraculous – well almost. The chances are possibly trillions to one – certainly. I find thinking about it all absolutely awesome. It boggles the mind with its immensity. I am incredulous.

Yet if something is possible; in an infinite universe it will inevitably happen an infinite number of times. We are exceedingly precious and rare but I am certain that we are not alone. Out there, beyond any possibility of contact, there will be other life on other planets in other galaxies. Not only life – but consciousness too.

I do not care how incredibly unlikely, how preposterous, how stupendous; we are here to prove it is possible.

What is so hard to understand is the sheer immensity of the universe. The galaxies are more numerous than all the grains of sand on every beach on this planet. Each galaxy has more stars than grains of sand on every beach on this planet. I think it is too vast and staggering for human minds to comprehend.

For us to understand is as ridiculous as the bacteria in your toilet bowl not only understanding the nature of the huge backside descending on them dispensing nutrient but the whole nature and purpose of the barely glimpsed bathroom beyond.

They, like us, simply do not have either the senses or brain power to grasp its meaning.

Our primitive ancestors invented deities to attempt to comprehend the bewildering spectacle. I wouldn’t be surprised if the bacteria don’t worship the big arse in the heavens that provides all nourishment. Lol.

We have done remarkably well in such a short while. We are miniscule units of protein scum on the surface of the planet yet we have exercised our grey matter and gained immense understanding of the laws of physics, nature of the universe and life. We have invented instruments to augment our limited senses. It is impressive.

This is what we understand:

5 billion years ago the Earth coalesced under the influence of gravity from the gas and debris of our solar system.

It cooled and seething in heat, radiation, Ultra-violet and electricity for two billion years. (Again it is worth remembering that a billion is a number too big for us to understand. We think of it as being much smaller than it is).

During that two billion years the amino acids, nucleotides and a range of other organic molecules built up in the boiling oceans. They were manufactured naturally from the poisonous atmosphere.

The proteins and molecules grouped together into coercervates with some characteristics of living things. The important jump was the incorporation of a replicable RNA/DNA molecule into the structure to become an organising focus and provide stability and the ability to reproduce. The chances of this happening are infinitesimal. It probably happened on trillions of planets and never got off the ground. It did here. It will have done elsewhere. I know this because there is enough time and planets to ensure that anything that is possible will happen.

Earth was in the goldilocks zone (everything was just perfect for life to emerge). So are countless trillions of other planets in our and other galaxies.

I have no need to manufacture an even more fabulous god (a ready-made super-being coming out of nowhere, ready-formed with the ability to create universes beyond our comprehension and somehow create a tiny species of protein scum on a single insignificant planet which somehow gives purpose to the whole thing. That is too silly for words). I am happy to accept that my inception (life) is stupendous and probably beyond our understanding but scientific none-the-less. We do not need to extend the laws of the universe to create life.

The first life was a single cell with a single strand RNA. DNA followed and the double helix was our mother. All life came from this one amazing instance.

For millions of years it reproduced and evolved. The big leap forward was the incorporation of other bacteria-like organisms as energy producing mitochondria. The organic molecules became used up. Other forms of energy were needed and first chemosynthesis and then photosynthesis evolved.

Photosynthesis produced oxygen which enables more efficient respiration, more energy and also changed the atmosphere; producing an ozone layer that protected against the hard radiation from the sun.

The single celled organisms with chlorophyll gave rise to the full spectrum of plants.

The single cells began to group into colonies. The colonies formed loose organisms like sponges (You can liquidise a sponge and it will reform). The sponges gave rise to multi-celled organisms – first flat-worms, true worms and then arthropods and molluscs. The vertebrates formed from neotonous larvae of sea-squirts. The fish gave rise to amphibians then reptiles who gave rise to the birds and mammals.

The mammals started as small furry rodent-like creatures. We evolved out of monkeys that gave rise to apes. We are apes closely related to chimps. We share 99% of our genes with the chimps.

The important thing is that we all came from the miraculous first cell. It only occurred once. Its inception was spectacularly unlikely.

We are all family. All life is related. It should be respected.

The good thing is that whatever mess we make (and we are making one almighty mess) life will prevail. Even if we manage to cleanse all life off the planet in a nuclear holocaust some bacteria will survive and given a few million years or so will evolve into as equally spectacular spectrum of higher life. It may even produce intelligent life again. If that happens let us hope that the life that evolves is more intelligent than us.

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