Black holes belay bird Bentleys

Following that marvellous Aeon piece on how Phineas Gage didn't suffer a horrible personality disorder after taking a bolt to the brain (see previous post), here's a couple more from them.

.... what, TWO ? Yes, two ! On related topics, obviously. But one of them isn't much good at all, so I'm going to reduce it to the bits I found interesting and ignore the rest.

This first piece is a bit of a meandering rant about how humans learned culture from animals. I mean, yeah, sure, maybe, but how do we know we wouldn't have figured it out anyway ? Being animals ourselves, surely we evolved with a much greater tendency to act on instinct rather than reasoning and therefore didn't start off as such "blank slates" as modern babies are. So we'd have had animal-like tendencies because we were, well, actually animals.

The main problem with the essay is that the author seems hung up on an earlier bias against the idea of animal cultures. I don't think this is nearly such an issue today; it's obvious to anyone watching nature documentaries that many animals possess something akin to culture (even if we might not usually use the word). But there are a couple of interesting points. One is highly specific :

In several caves in France, such as Bara-Bahau, Baume-Latrone and Margot, human-made finger flutings or ‘meanders’ follow earlier cave bear scratches. Some of these long lines of finger-combed grooves are superimposed directly over claw marks. Others are located near the bear-made traces, echoing their orientation. 

In Aldène cave in the south of France, human artists ‘completed’ earlier animal markings. More than 35,000 years ago, a single engraved line added above the gouges left by a cave bear created the outline of a mammoth from trunk to tail – the claw marks were used to suggest a shaggy coat and limbs. In Pech-Merle, the same cave where Lemozi mistook cave bear claw marks as human carvings of a wounded shaman, a niche within a narrow crawlway is marked by four cave bear claw marks. These marks are associated with five human handprints, rubbed in red ochre, that date to the Gravettian period, about 30,000 years ago. 

For Lorblanchet and Bahn, the association between the traces of cave bear paws and human hands is no accident: ‘It is remarkable (and the Gravettians doubtless noticed it),’ they wrote, ‘that a rubbed adult hand, with fingers slightly apart, leaves a trace identical in size to that of an adult cave bear clawmark.’

And that's a very interesting case in which humans may indeed have been directly influenced by animals. Still, it doesn't mean that the claw marking were the bears attempting to do line drawings* – the innovation here is all human (unlike, say, the bower bird). I don't find the other examples nearly as persuasive, however.

* If you go down to the woods today....

The second interesting point is more conceptual. When the author talks of "culture", I think they're really referring to history. That is, remembered culture, a transmitted knowledge of how things used to be in the past : specific events, old traditions, different mindsets of what the ancestors believed. The author does imply this sort of definition, but more by accident than anything else :

This is based on a well-established belief: humans make and do things because only we have culture, and when those things we make and do change over time, we call it history. When animals make and do things, we call it instinct, not culture. When the things they make and do change over time, we call it evolution, not history. Anthropologists have pointed out that this is an unusual way of thinking: at what point did we stop merely evolving from our long line of hominid ancestors, cross an irreversible threshold from nature to culture, and kickstart history ?

... as the British anthropologist Tim Ingold argues, we never speak of ‘anatomically modern chimpanzees’ or ‘anatomically modern elephants’ because the assumption is that those species have remained entirely unchanged in their behaviours since they first took on the physical forms we see today. The difference, we assume, is that they have no culture.

And surely it's interesting to think of animals as having this kind of historical culture. So far as I know, no animal shows evidence for this kind of thinking – episodic memories and old knowledge, sure, but nothing approaching human history.

The second article is very much better. It asks the provocative question as to why other animals don't possess a culture as rich as humans – that is, in the Pratchettian sense of extelligence, of highly complex physical objects like Bentleys and nuclear reactors. Specifically, birds. Plenty of animals are intelligent and even have culture, but many have other factors which readily explain why they don't have sophisticated devices (short lifespans in the case of cephalopods). But birds, quoth the author, appear to have an awful lot of the basic necessities :

• Large brains with strong intelligence and learning capabilities
• Long lives, so that understanding of the world can be learned and refined over time
• Highly overlapped generations, so that information learned can be transmitted through time
• Meticulous rearing of offspring, for the same reason
• Refined intra-species communication, so that high-fidelity transmission of information can be communicated.

So why no Bentley-driving birds ? For this the author develops a very nice metaphor of evolution. They imagine a 2D landscape where the x, y position represent general parameters of a species and the height is how well they're adapted to current conditions. Then we can think of evolution as a blind mountaineer, only able to react to the local gradient and never to make any long-term plans at all :

This is why evolution can get ‘stuck’ at the local maximum – the blind mountaineer will never go ‘down’ in the service of getting to a higher peak on the other side of a valley, because he doesn’t know the peak is there; he senses only that in that direction lies a valley of death.

Now the neat trick is to invert this and make the troughs, not the peaks, represent local suitability. Instead of a blind mountaineer, imagine a ball rolling under gravity – something like the old physics classic of a rubber sheet deformed by a heavy ball, but with the sheet much more complex. The ball itself can deform the sheet but it can also change in response to external stimuli : for example, a cheetah evolving to run faster than its prey sinks the trough a little deeper, but a changing climate may either deepen the trough or fill it in. And since most local minima won't be all that deep, random chance mutations or external changes (both of which happen continuously) usually ensure that animals do keep evolving; only a few get stuck in such extreme minima that they're not likely to change any further.

The useful bit about this for the lack of bird culture is it helps to show that birds aren't a case of a cultural near miss :

Unlike objects flying through space, an evolving species isn’t rapidly whizzing by in a straight line – it is wibbling and wobbling about in evolutionary space, taking a drunkard’s walk in the general vicinity of its current landscape. If birds were simply almost-cultural, with all the predispositions they have, they wouldn’t ‘miss’ cultural evolution and sail off into the distance, they would continue to wobble about the rim, always one small deviation away from falling in to join us in the valley of cultural plenty [i.e. they'd fall in and evolve culture eventually].

Instead, they fell into a black hole called flight. Once birds as a group had flight, their future was sealed – flight would be their defining trait, and would delimit the futures available to them. Flight resolved a huge amount of the pressure that drove humans to seek cultural efficiencies in feeding themselves, fighting predators, hunting prey, transmission of information, and all of the other complicated things that we do to be successful. Birds, by comparison, live on Easy Street – they fly away. They fly away from predators, they fly away from food shortage, they fly away from environmental change. There is no pressure on them to evolve the means to establish agriculture. They can fly away instead.

Flight, says the author (developing this in more detail in the essay) is such a powerful advantage that it removes most of the selection pressure. A bird with culture wouldn't have a significant advantage over one without, because the solution to all its problems would still be the same : fly. It would even have a substantial disadvantage, because the extra intelligence would be biologically expensive. And of course, it would need to have grasping hands, which bird's wings are ill-suited to providing.

Conversely :

It is probably the case that our cultural abilities are also a black hole in evolution. Everything that is true about flight’s incredible selection benefit is true about human culture. We have also fallen down an impossibly steep slope of selection to arrive at the incredible complexity of human life today. I cannot fathom what set of circumstances would cause us to evolve away from this complexity. But at the bottom of our two black holes, we and the birds are separated.

We will both meander about the infinite space of our black holes but will not leave them. They will not play canasta, and we will not fly. Our futures are expansive, but point interminably to our respective singularities – theirs to flight, and ours to culture. For each to have the other would be splendid, but evolution doesn’t aim at splendid. It rolls, unthinkingly, away from pressure, and our respective pressures have been released by our respective all-defining traits.

I think this is an extremely clever and well-thought-out piece, but I still think the picture is incomplete. The author mentions flightless birds as evolving due to exceptional circumstances (e.g. lack of local predators), but what's prevented flightless birds from developing culture ? After all, flightlessness has been a thing for tens of millions of years, possibly longer. I can't believe the wing structure is that big of a deal-breaker.

Of the other apes I suppose the situation is more complex – clearly some of them did develop human culture ! And even human-like culture, considering we know of Neanderthal art and the like. I think we still don't know enough about how our own thought processes really got going to say exactly why the other great apes aren't driving motorcycles, let alone why birds aren't reading Shakespeare. 

Still, it's thought-provoking stuff. I remember many short stories by Stephen Baxter in which humans of the far future, trapped in specific circumstances, lose intelligence as a result of selection pressure and biological expense (often, amusingly, while retaining a level of advanced technology). But one thing he never explored though are the evolutionary consequences of jetpacks. Give everyone a cheap, simple, reliable jetpack, let them simmer for about half a million years... what would the result be ? A whole new expanded way of thinking, or just the opposite – idiocracy but in the clouds ? If the Aeon logic is correct, giving everyone a jetpack should mean the end of history.

... nah, I still want a jetpack, dammit.