Mapping Biology’s Purposes
You must address what a device does before aiming to comprehend how it does it." As obvious as this is for everyday devices, it is not well-appreciated within the biological and brain sciences. We must build the "teleome," which refers to an organism's entire suite of powers. Only then will we be able to crack the mysteries of the human brain and build artificial brains.
See this Science Moment on the topic.
What's it do?
Imagine that you find some mysterious device under your bed. What's your next thought? It's to wonder what the device does. Could it be a hand vacuum, a kid toy? ...a bomb? Notice that your first thought does not concern how the device works. It's premature to get to the "how it works" without having figured out the "what it does".
In much of the biological and brain sciences, however, there appears to be something of an inversion to this. In many scientific circles questions about "what it does" are deemed intrinsically unscientific or meaningless, and explanations in that domain are necessarily "just so" stories rather than science. Only questions concerning the biological mechanisms -- i.e., concerning "how it works" -- are truly kosher. And this attitude is reflected in funding priorities: "how" funding dominates the "what it's for" funding by a mile.
Yes, it's all bass-ackward in the biological and brain sciences! As a community, it's the fellow that sees the device under the bed and says, "Never mind what it does, I'm going to figure out how it works!" Good luck with that.
But, you might ask, isn't there an obvious difference? Devices do things because people made them to do things; they have purpose imbued upon them by human engineers. Organisms, on the other hand, evolved, and there is no purpose -- no design.
It's not true, however, that evolution doesn't design. On the contrary, it is a fantastic designer! It also happens to be quite unintelligent, and super-glacially slow. But the mechanistic process of evolution amounts to an algorithm of sorts, one that, despite its unthinkingness, leads to brilliant designs.
If you don't "get" this, then you don't "get" biology. If you're unable to utter the words, "Eyes are for seeing," then you've argued yourself into some far-away philosophical corner for the birds.
Before we can understand "how it does it," then, we need to grasp "what it does."
We need a "teleome," the ultimate catalog of an animal's what-it-does-es. The teleome is something along the lines of the set of all the capabilities our brains and bodies were selected to carry out. It is our set of powers, or the set of things we can do, or our function list.
The Terminator's teleome sits somewhere back in the lab, and somewhere within his teleome it describes his power to ride motorcycles and mimic human voices.
Where's our human teleome? Or the teleome for any organism, for that matter?
There are ideas that are seemingly similar to the teleome. Ethologists catalog behavioral repertoires for animals. But the entries in such lists are not the sort of thing we imagine in the Terminator’s list, nor in real function lists in the instruction manuals of devices we might buy. The behaviors in ethology are descriptions of (usually whole-body) behaviors, not capabilities. A stapler-behavior might be “being squeezed onto a pack of papers,” but the stapler function is “for fastening papers together.”
Another close candidate is the “phenome,” which refers to the set of phenotypes of an organism. The behaviors of ethologists might plausibly be part of a phenome, although the phenome is more general, referring to all sorts of traits. But traits aren’t quite the same thing as functions, capabilities, or powers. The teleome is unapologetically heavy on teleology, or purpose.
I don't want to give the impression that there aren't biologists who appreciate the "what it does." The adaptive, functional powers of animals has a long and continuing history among the more naturalist variety of biology. Some snakes are capable of spitting venom at predators. Certain fish have the power to blow up like a balloon and become difficult to eat. Hummingbird beaks are for reaching deep into flowers. And work continues, such as recent work by Marc Egeth showing that headless flies behaviorally respond to light, and work by Anders Garm and colleagues demonstrating that jellyfish can see up and out of the water for navigation.
But this naturalist sort of biology has waned, and we need to re-engage it with gusto.
It is not enough to grasp just one or several salient powers of an animal -- the powers an encyclopedia might mention. Organisms are teeming with powers, and most of them are entirely unknown to us (and, thus, also unknown are how they implement those powers).
Why is the teleome important?
Do we really need a teleome? Really? Yes, and here's why...
First, and most importantly, a teleome is important because science should be aiming to comprehend the full catalog of powers of each sort of organism. That is, we should be doing it for its own sake!
Second, and something I have already talked about above, one cannot make sense of mechanisms without knowing what they are for -- mechanisms are for implementing certain capabilities. For example, if natives were to find a stapler, then without knowing it is for fastening paper together, they may spend years examining the specific mechanisms underlying its ability to be used as nunchucks. Their resultant insights into the nunchuck-swinging mechanisms would, however, be incidental to the actual device.
Third, the teleome is crucial for grasping how animals mesh with their natural habitat. If you don’t know why an organism is the way it is, then you won’t know which aspects of natural habitats are important for it. If it ends up in a habitat that’s not its own, it may go extinct, or, in time, changed by natural selection into something else.
Finally, the teleome is needed for advances in artificial intelligence. The principal aim of AI is not to mimic the mechanisms of human brains. Rather, it is to mimic or surpass the power of human brains. And most researchers wouldn’t mind if they could achieve it via an utterly different implementation. (See also this piece about Kurzweil and AI.)
Building the teleome will be difficult
There are tremendous challenges ahead in building the teleome.
To begin with, it is not yet clear what it would even look like. Surely it would not simply be a list. Instead, it would probably be a hierarchically tiered structure of some kind, with powers built out of sub-powers, and so on.
One of the difficulties is that uncovering the teleome requires comprehending not just organisms, but how they plug into the habitats they belong in. …it requires being a consummate ethologist as well as a biologist or neuroscientist. Unlike the genome, we won't be able to pour an organism into a vat and get a teleome print-out on the other side. To get the teleome, the organism along with its entire habitat would have to be placed within a very very large petri dish.
[Another difficulty comes from the famous undecidability results of the 20th century. For any computable function (think: biological capability), it is not generally possible to determine if some specific program (think: biological mechanism) actually computes that function (think: implements that capability).]
I do believe there is hope. Through my own experiences as a theorist, I have found that the ecological regularities governing nature tend to be relatively simple, and that once I have wrapped my head around them, I can make sense of our powers and answer why we are as we are in some particular respect, whether illusions and optic flow, forward-facing eyes and cluttered habitats, color vision and hemoglobin, writing shapes and opaque objects in 3D space, speech sounds and solid-object physical events, music and the sounds of humans behaving, or pruney fingers and grip in the rain [coming soon]).
This is a cause for both optimism and pessimism. There's optimism because it suggests it may be possible to incrementally build the teleome. But it suggests pessimism too, because even supposing my research mentioned above is all true, it took me a decade and lots of luck to do it, and it would only serve to fill out half a dozen spots in a teleome that must have, in total, tens of thousands or more entries.
But there are stumbling blocks besides the theoretical and conceptual ones. They are sociological, and I hinted at them earlier. There is a strong streak of anti-adaptationism in certain swathes of the biological sciences, where they have gotten the impression that it is somehow not scientific to address questions of “what it’s for.” There have certainly been poor arguments within this domain, but one can find large numbers of embarrassing "how it works" arguments as well. Like any area of science, hypotheses about capabilities and powers must make testable predictions, and will acquire credibility to the extent they acquire empirical support. This “anti-adaptationist” streak has, in my opinion, been particularly detrimental to the advance of the neurosciences, where understanding function, design, and fit with the natural ecology will be most important in making theoretical advances.
Building the teleome will be difficult, much more difficult than building the genome. But there is no alternative. ...not if we wish to make sense of organisms, what they do, how they do it, and how we might artificially do it.
(Original published in Forbes, 2011.)