# The Evolution of Memory

## Titles

Why we like what we like

## Titles

Why we like what we like

## Titles

Why we like what we like

Computers and evolution

## Titles

Why we like what we like

Computers and evolution

Computers and the theory of evolution

## Titles

Why we like what we like

Computers and evolution

Computers and the theory of evolution

Memory, Computers, Evolution, Sex (not necessarily in that order).

## Titles

Why we like what we like

Computers and evolution

Computers and the theory of evolution

Memory, Computers, Evolution, Sex (not necessarily in that order).

The Computer as Extended Phenotype

## Titles

Why we like what we like

Computers and evolution

Computers and the theory of evolution

Memory, Computers, Evolution, Sex (not necessarily in that order).

The Computer as Extended Phenotype

Why cats lick themselves

## Backtracking

This is very like a certain style of computer problem-solving program.

Imagine trying to find a route through a forest: at each fork in the path, you try one direction, and if that doesn't lead to where you want, you backtrack and try another.

There are several possible variants:

• Serial/Parallel
• Find one solution/find all
• Complete/Heuristic.

## Backtracking

This method can solve an amazing range of problems.

```HOW TO RETURN (route, state) path.to aim:
IF state = aim:
RETURN ("success", route with state)
IF state in route OR deadend state:
RETURN ("failure", {})
PUT route with state IN new.route
FOR option IN options state:
PUT (new.route, state altered.for option) path.to aim IN result, route
IF result = "success":
RETURN ("success", route)
RETURN ("failure", {})```

In an article I wrote, I used this to solve the Farmer and the Produce problem, the Two Jugs problem, and even the Towers of Hanoi (just for two disks, it found 12 solutions!), but it will also solve the Eight Queens problem, Sudoku, and many others.

## Evolution

Backtracking is comparable to how evolution works

• Heuristic
• Parallel
• Similar definition of failure
• Different definition of success

## Evolution

See the original interactive version here: evogeneao

## The Requirements for Evolution

The 3 requirements for evolution:

• Variation
• Competition
• Replication with inheritance

### Requirement: Variation

In early evolution, the only source of variation was mutation, and mutation is only rarely successful, more likely leading to deleterious effects. (Compare with changing one ingredient at random in a recipe.)

Once sex evolved, there was more source of variation (and they were combinations of things that were already successful).

Which explains the success of sex.

### Requirement: Competition

If everything survived, then there would be no selection of advantageous genes.

However, there is a guarantee of competition, because in the long run there aren't enough resources to support an ever increasing population.

Death is evolution's backtracking, that is: death without offspring.

(Later we will see how the definition of offspring has changed).

### Requirement: Inheritance (Genetic Memory)

You can see the accretion of successful genes as a form of learning, or a form of memory.

It is similar to the 'route' in the backtracking program earlier.

## Examples of genetic memory in humans

People like sugar and fat: in the past calories were in short supply. Our bodies rewarded us for eating them.

Sex being fun: creatures that enjoy sex are more likely to reproduce.

Age differences in couples: you are more likely to find couples where the man is older than where the woman is older.

## The Effect of Environment

The environment changes (and therefore redefines success).

This is how species happen.

It is interesting to consider that since cats and dogs have a common ancestor, that common ancestor had two children, one of which was the first cat, and one that was the first dog.

(If you wonder what a cat-dog would look like, you might like to know that the hyena is actually a cat, not a dog)

It is also interesting to contemplate that humans may already have speciated without us knowing it (yet).

## The Evolution of Memory

After Sex, true memory was a major development, and allowed learning behaviours: you no longer needed genetic memory to survive, you could use recent outcomes to decide how to act.

An example of a creature with no memory can be seen in the Sphex Wasp behaviour.

## Awareness of Why We Do Things

Hypnosis experiments show that you may not always be aware of the reasons you do things. You may rationalise them differently to the 'true' reason.

Example from Surely You're Joking, Mr. Feynman! "All the time you're saying to yourself, "I could do that, but I won't" – which is just another way of saying that you can't."

Some think that there may not even be conscious free will at all, but that we always rationalise after the action.

## Interpretation of What We Do

We get vitamin D from sunlight, and yet light doesn't contain vitamins

This is because the oil that our skin produces breaks down in sunlight into vitamin D and a different oil, and our skins have the ability to reabsorb the vitamin D.

## Why Cats Lick Themselves

Cats produce the same oil, and their skins don't have the ability to reabsorb. So what do they do? They lick it off.

Probably it tastes good to cats (which would be evolutionarily advantageous), and so they lick themselves all over. This has three advantages for the cats:

1. They get vitamin D.
2. They get clean.
3. The remaining oil gets spread over their fur, which waterproofs it.

So what we interpret as "the cats cleaning themselves" is actually "the cats consuming vitamin D", which has the side effect of them getting clean.

## What people like

It is fun to watch out for things that people apparently love (because they cluster round it, for instance) and try to postulate the evolutionary advantage that it represents.

### Liking Water

People love water.

Children are happy playing for hours by water.

### Liking Heights

In Paris there is a beautiful cathedral on the Montmartre hill, the Sacre Coeur.

### Liking Heights

People visiting it will go in for a brief visit, and then sit for hours on the steps in front of it looking out over Paris.

### Liking Fire

Most animals flee from fire, which makes a lot of sense.

But, strangely, not humans, who are attracted by it, and can stare into fire for hours, in a sort of trance.

And that leads to my flashing red light story...

## What else do people stare at for hours?

My hypothesis is that we like fire not because it is warm, or that it frightens off wild animals, but just because it flickers.

The genetic advantage we got was that it was warm and frightened off predators, but that wasn't the reason we liked it in the first place.

## What else do people stare at for hours?

This may have consequences for the success of e-ink, and that people will prefer the flickering LED screens without knowing why.

## Phenotype and Extended Phenotype

The visable manifestations of genes (as affected by environment):

• Body shape and size
• Hair colour
• Strength
• Aggression

Extended phenotype: created by genes, but not a part of the body. E.g.:

• Bird nests
• Beaver dams
• Spider webs
• ...

## Language

A major development for humans was language.

It allows evolution with planning: survival techniques that you can pass on, memories that last longer than a lifetime.

It creates the concept of Memes, in analogy to genes, carriers of information that may (or may not) help survival.

Examples: Clothes. Houses, washing your hands, ...

An example of bad memes that died: blood letting as a cure; miasma theory.

Having ideas is now just as important as having babies.

## Writing

Writing was another major development, because it allowed ideas and memories to survive your death in a permanent form.

Printing extended this by making it easier to spread the ideas.

## The Extended Human Phenotype

Using memes, not genes, to extend our abilities, and help us survive.

Protection: Helmets, clothes, raincoats, houses.

Memory: writing, photography, video.

Repair: Glasses, medicine, hospitals, deafness.

Abilities: Bicycles, cars, planes, boats, submarines.

Sensing: Telescopes, weather radar, satnav - we were the last generation of people who could get lost.

Each major change in any area is a paradigm shift in that area.

## The Computer as Extended Phenotype

The computer is being used in so many ways to extend our abilities, I can see no other possibility than to regard it as part of our extended phenotype, an external extension of our brain.

## The Singularity

Ray Kurzweil has observed that 'paradigm shifts' have been happening over human history faster and faster.

Compare society now with that of my grandparents as children: they had no hot water in house, no toilets, no electricity. There were no films, radio, television, cars. The only 'modern' technologies they had were trains and photography.

We are now seeing new shifts: mobile telephones, cheap computers that can understand and talk back, self-driving cars, ...

The accelerating rate of change is pointing to a time in the near future where paradigm shifts will occur daily. This is referred to as the singularity.

## Closing the loop

DNA is a sort of memory → Evolution of true memory → Language, passes memories → Writing records memories that outlive you.

Now researchers have found a way to use DNA as a (very slow) storage medium.

DNA storage breakthrough: 700TB of data in one gram (That would require 140,000 DVDs, or 150kg of hard disks).

## Conclusion

The reason that humans have succeeded so well in comparison with many other life forms is the development of language, and therefore of memes that make us much more flexible in our ability to survive.

Particularly successful memes have caused paradigm shifts in human society, fueling the next generation of memes. Evidence shows that the rate of change of change has been increasing exponentially over hundreds of thousands of years.

Possibly within our lifetimes, we will be confronted with a very interesting time, when we may have to contend with six new paradigms before breakfast every day.

(The slides are online)