Natural history of the present

Artificial selection on Music and on Rappers

Evolution has plenty to say about the evolution of music and other art forms. For one thing, music may draw much of its sublime power from its ability to push our evolved sensory buttons. But music itself is always evolving, and an exciting new paper illustrates how.

Dr Bob MacCallum, a bioinformaticist at London’s Imperial College, and colleagues have been running a project they call DarwinTunes where they ask visitors to rate loops of music. The first loops comprised random suites of notes - each a jarring cacophony. Visitors rated each on a five-point scale, from “Can’t Stand It” to “Love It”.

The DarwinTunes software discards the least appealing tunes and allowed the most appealing ones to mate with each other. Sex is really just the business of combining genes from two individuals to make a genetically unique offspring; so you could say the artificial musical tracks had sex with one another.

Within about 3000 generations, the loops evolved into something recognisably musical, combining both pleasing chords and rhythms. The rate of change eventually slowed because new mutations and the process of recombining tracks was causing more disruption than the gain from the “selection” by listeners.

The DarwinTunes experiment provides a cute illustration of how natural selection works in an entirely artificial ecosystem. But can we learn anything more profound? I believe we can.

Similar processes operate on music, visual art and even consumer products all the time. Appealing songs, when played on the radio or in a live set, get a great response from the audience. And so they get played again and again. And soon enough, someone else will imitate that song or some of its features in the hope of imitating its earning power. Likewise with great products - or great brands.

But this process isn’t exactly the same as natural selection. For one thing, it lacks the Darwinian feature of variation introduced at random by mutation. For another the raters knew exactly what they wanted to make - a better sounding loop. Whereas in nature, natural selection operates simply because some individuals - and their genes - are better at reproducing.

The aspect of evolution that these tracks illustrate is selection. And that is what happened in the market. Failed tunes, just like failed products and marketing campaigns, get discarded (“selected out”) and “good” ones are preserved and embellished. In this respect, market forces resemble artificial selection - the partially inadvertent and partially deliberate process of shaping domestic plants and animals to become more useful to us.

I was lucky enough, last week, to meet the incredibly talented Canadian rap artist Baba Brinkman who has established himself as a world-leading science communicator. At the Human Behaviour and Evolution society Conference in Albuquerque, Baba gave us both an impromptu sample from his Canterbury Tales Remixed as well as an hour-long show combining material from his Rap Guide to Evolution and Rap Guide to Human Nature.

Baba opened with a track, Artificial Selection, that captures the essence of the DarwinTunes experiment. It compares the way humans have domesticated plants and animals - the subject of the first chapter of Darwin’s Origin of Species - with the way audience feedback and response gets rid of the least proficient rappers and moulds those who remain in the game.

The fact that there are “Too many MCs, not enough mics” is ultimately responsible for the evolution of rap.

Baba Brinkman: Artificial Selection.

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