The Genetic Book of the Dead — II. A Book Written Without a Writer

If the genome is a book of the dead, who wrote it?

No one did.

There was no author deciding what future generations needed to know. There was no ancestral organism recording its experiences for its descendants.

The book was written by survival.

An environment presents countless conditions and challenges. Organisms vary. Some variations leave their bearers better able to survive and reproduce under those conditions. Others do not persist as successfully.

Across generations, the distribution of variations changes.

Nothing needs to understand this process.

Yet the result is historical.

A population becomes different because of what happened to its ancestors.

This gives natural selection a peculiar capacity to preserve traces without preserving experiences.

Suppose an ancestral population repeatedly encountered a particular environmental condition. Individuals whose inherited organisation happened to cope better with that condition left more descendants. Over many generations, the resulting population can become well adapted to it.

The environment has disappeared.

Its consequences remain.

The genome therefore does not need to contain a description saying, this is what our ancestors encountered. Its organisation has been altered by the differential persistence of organisms that encountered it.

The “writing” is statistical.

It accumulates across generations.

And the reader is not the organism consciously consulting its genome. The organism simply develops and acts according to an organisation that already embodies part of its lineage's history.

This makes evolutionary memory very different from ordinary memory.

A remembered event says, in effect, this happened.

An evolved adaptation says something closer to organisations shaped by conditions like these have persisted.

The distinction is profound.

Evolution does not remember the past because the past was recorded.

It remembers the past because the past changed which forms remained available to the future.

That suggests a broader principle.

Whenever differential persistence allows past conditions to alter the organisation of what comes later, history has acquired a material form.

The genome is one extraordinary example.

But the deeper phenomenon is older than genes.

And that raises our next question:

Could history become organised before there was a genome to carry it?