'More like rainbows and mirages than raindrops or boulders'

You and I are mirages who perceive themselves, and the sole magical machinery behind the scenes is perception -- the triggering, by huge flows of raw data, of a tiny set of symbols that stand for abstract regularities in the world...

We human beings are macroscopic structures in a universe whose laws reside at a microscopic level. As survival-seeking beings, we are drive to seek efficient explanations that make reference only to entities at our own level. We therefore draw conceptual boundaries around entities that we easily perceive, and in so doing we carve out what seems to us to be reality. The "I" we create for each of us is a quintessential example of such a perceived or invented reality, and it does such a good job of explaining our behavior that it becomes the hub around which the rest of the world seems to rotate. But this "I" notion is just a shorthand for a vast mass of seething and churning of which we are necessarily unaware...

But our own unfathomability is a lucky thing for us! Just as we might shrivel up and die if we could truly grasp how miniscule we are in comparison to the vast universe in which we live, so we might also explode in fear and shock if we were privy to the unimaginably frantic goings-on inside our bodies. We live in a state of blessed ignorance, but it is also a state of marvelous enlightenment, for it involves floating in a universe of mid-level categories of our our creation -- categories that function incredibly well as survival enhancers.

-- Douglas Hofstadter (2007)

Quietus

In A Long, Melancholy Roar, Olivia Judson reflects on the role of predation by other animals on Man has had on the human psyche, observes that Man is the greatest predator on Man, and that no animal besides Man commits suicide. Here is my comment:

I think I've read that some data indicates suicide rates fall during war time. If true, this is interesting, and may be significant.

There's a remarkable account by the late Australian philosopher Val Plumwood of being attacked and almost killed by a crocodile.

Another 'wild' animal that still kills humans is the elephant. The authorities in the Indian state of Orissa report 180 deaths by trampling in the last 5 years (humans had encroached on elephant territory with mining and other operations).

One commonly reads that fewer than a dozen people are killed each year by sharks. Humans, by contrast, slaughter tens of millions of sharks each year.

I'd add that some (e.g. Richard Barry) claim that dolphins have deliberately committed suicide because they are being held captive by humans in conditions that they find unbearable. (Dolphin 'suicides' such as these may be a distinct, perhaps involuntary, phenomenon.)


In The Ecocidal Moment, Rowan Williams notes that Alastair McIntosh speaks of:

"ecocidal" patterns of consumption as addictive and self-destructive. Living like this is living at a less than properly human level – McIntosh suggests we may need therapy, what he describes as a "cultural psychotherapy" to liberate us. That liberation may or may not be enough to avert disaster. But what we do know – or should know – is that we are living inhumanly.

Inhumanely, perhaps; but all too humanly.

Space cadets

Give us a century or two and we may turn the whole planet into a place from which many people might be happy to depart.

Lawrence Krauss proposes sending astronauts to Mars on a one way ticket. [1] It's good to hear an argument that pushes on some boundaries, but a flaw in this one emerges through a comparison that Krauss makes to the European colonists and pilgrims to North America who "seldom set off for the New World with the expectation of a return trip, usually because the places they were leaving were pretty intolerable anyway."

It's obviously true that many early settlers sought greater economic opportunity, but it's less clear that what they created was better than what they left behind. Quakers were not lynched in England just for being a Quakers, as they were in colonial Massachusetts. Slavery was illegal in England while it remained a keystone in large parts of the colonial and then early U.S. economy. We might also recall, among other things, the attitude of the founding fathers to the people who happened to have been there before the Europeans arrived. [2] And U.S. culture and economic practice today, undergirded by world wide military deployment, is still shot through with hateful magical thinking and debased bronze age mythology.

In sum, we cannot just walk away from the past, and unless we can sort things out on Earth we're unlikely to do any better in a 'New World', whether it be across the seas or interplanetary space.




Footnotes

[1] (added 16 Sep) See also Paul Davies: Fly me to Mars. One way.

[2] As George Washington put it, "the immediate objectives are the total destruction and devastation of their settlements. It will be essential to ruin their crops in the ground and prevent their planting more." Quoted by Jared Diamond in The Third Chimpanzee, along with a series of other incitements to genocide issued by presidents and powerful figures through much of U.S. history.

The second question

...assuming that the answer to the first one is "to be", is:

What do we want to be when we grow up?

-- or so suggests Andy Revkin.



P.S. 22 Aug: Robert Wright believes growing up is possible

Fire creature, fire planet

Reviews by Saswato Das and Christine Keneally of two books on how fire 'made us human' focus on cooking. [1]

But it's not just food, and thereby ourselves, that we have transformed through fire. It's also the planet -- through what Stephen Pyne calls 'second fire', the deliberate use of fire by Man to foster ecological regimes to its [his] benefit. If we are 'the cooking ape' then it is more than food we cook.


In Fire: a brief history, Pyne writes:

It is particularly true for agriculturalists: the saga of first contact takes the form of a great fire. The Malagasy call it afortroa. Maori myths record how the first arrivals lit fires everywhere, burned off forests and wiped out moas. Madeirans preserved the legend of a Seven-Year Fire that drove the first settler into the sea for protection and then, smoldering, let the isle as malleable as a lump of white iron drawn from a furnace. The cosmology of the Stoics was built around a recurring world conflagration. The Aztecs performed a New Fire ceremony, symbolically rekindling the world, every 52 years. Modern myth-making has continued the trope. Star Trek's Wrath of Khan features a "genesis device" capable or remaking planets. The "genesis effect" begins with a fiery blast and spreads its "new matrix" over cold-dead rock with a flaming front. More slowly and bumptiously, that is precisely what humans did with the Earth. [2]

Footnotes

[1] Fire: The spark that ignited human evolution by Frances D. Burton and Catching Fire: How cooking made us human by Richard Wrangham. Seed has an interview with Wrangham. See, too, blog post in this series The raw and the cooked.

[2] See earlier post Fire.

Towards the 'Ecozoic'

We have indeed become strange beings so completely are we at odds with the planet that brought us into being. We dedicate enormous talent and knowledge and research to developing a human order disengaged from and even predatory on the very sources whence we came and upon which we depend at every moment of our existence. We initiate our children into an economic order based on exploitation of the natural life systems of the planet. To achieve this perspective we must first make them autistic in their relation with the natural world about them. This disconnection occurs quite simply since we ourselves have become insensitive toward the natural world and do not realize just what we are doing. Yet, if we observe our children closely in their early years and see how they are instinctively attracted to the experiences of the natural world about them, we will see how disorientated they become in the mechanistic and even toxic environment that we provide for them.

-- from The Meadow Across the Creek by Thomas Berry.


In a biographical note, Mary Evelyn Tucker links Berry to Teilhard de Chardin:

to have become conscious of evolution means something very different from and much more than having discovered one further fact… It means (as happens with a child when he acquires the sense of perspective) that we have become alive to a new dimension. The idea of evolution is not, as sometimes said, a mere hypothesis, but a condition of all experience.

For Teilhard and for Berry, writes Tucker

the perspective of evolution provides the most comprehensive context for understanding the human phenomenon in relation to other life forms. This implies for Berry that we are one species among others and as self reflective beings we need to understand our particular responsibility for the continuation of the evolutionary process. We have reached a juncture where we are realizing that we will determine which life forms survive and which will become extinct. We have become co-creators as we have become conscious of our role in this extraordinary, irreversible developmental sequence of the emergence of life forms.

(The photo of shipping container houses is from Poverty in America. The lily is in Glacier National Park, Montana. The boy swims in water at Cilincing, Jakarta.)

The origin of laughter

Ed Yong has the story:

It didn't arise out of nowhere, but gradually developed over 10-16 million years of evolution by exaggerating the acoustics of our ancestors. At the very least, we should now be happy to describe the noises made by tickled apes as laughter without accusations of anthropomorphism, and to consider "laughter" as a trait that applies to primates and other animals.

See also BBC report

As we to Floresiensis

On the wilder shores, perhaps, Michael Anissimov wonders whether the only way to escape a scenario in which billions of people are killed by toxins deliberately engineered and delivered by micro-robotic scorpions, parasitic wasps, fairyflies and the like [1] is to create a "benevolent singleton", an "Intelligence Amplified fundamentally considerate and kind human whose intelligence is actually improved above Homo sapiens to the tune that H. sapiens is above H. heidelbergensis."

Para eso habeis nacido

To be contrary, and with only a bit of tongue in cheek, couldn't there be more room for beings a little less intelligent, perhaps a little like H. floresiensis, which in a slower world might persist for millions of years?

Footnote

[1] On insects as weapons, insect cyborgs and roboflies see Jeffrey Lockwood.

The raw and the cooked

I haven’t eaten a mammal in about 30 years, except a couple of times during the 1990s, when I ate some raw monkey the chimps had killed and left behind.

-- Richard Wrangham, who says early humans were able to evolve because cooked foods were richer, healthier and required less eating time:

Homo erectus, our...immediate ancestor, ha[d] long legs and a lean, striding body. In fact, he could walk into a Fifth Avenue shop today and buy a suit right off a peg.

Image: H. ergaster by Viktor Deak

P.S. 27 May: Why Are Humans Different From All Other Apes? It’s the Cooking, Stupid

Human kindness

Humans have a special combination of co-operative instincts, prosocial motives, high level intention attribution and moral propensities.

-- says N J Enfield. [1] And how far back might that sophistication go?

Among my favourite humans are Homo erectus: ancestors closer to us than the jugular vein and yet in so many ways totally unknown.

Some ape mothers may carry the body of a deceased infant for days after its death. But early humans may have been able to do much more than other apes in some cases to actually keep ailing infants and children alive. [2], [3]  And there is intriguing but inconclusive evidence of well-developed caring strategies for severely handicapped individuals as long as 530,000 years ago. [4]


Footnotes

[1] This is from a review in Science, 3 April 09, of Origins of Human Communication by Michael Tomasello. Enfield is the co-editor of Roots of Human Sociality: Culture, Cognition, and Interaction.

[2] (Added 20 April) The empathy of our closest evolutionary relatives [i.e. chimpanzees] exceeds even their desire for bananas, says Frans de Waal. 

[3] (Added 23 April) It may be that allomaternal care is required once adult brain size reaches about 1000 cubic centimetres, or about Homo erectus size.

[4] The brain-damaged child, of the species Homo heidelbergensis, would probably have needed special treatment and care over a long period of time. See Did Early Humans Really Care?.

Birdsong of the Eremezoic

It seems feasible that over the coming century human nature will be scientifically remodelled. If so, it will be done haphazardly, as an upshot of struggles in the murky realm where big business, organised crime, and the hidden parts of government vie for control. If the human species is re-engineered it will not be as a result of humanity assuming a godlike control of its destiny. It will be another twist in man's fate.

Thus John Gray (2002) in pessimism of the grand style, which sweeps along so boldly that you may sometimes question if it sweeps away too much. [1]

For Gray, the prospect of conscious human evolution evoked by E O Wilson is a mirage.

Further extensions for Freud's prosthetic (brutal infant) god(s) are likely. Whatever is coming down the track may not be godlike in the sense Gray means, but it may be as arbitrary and unpredictable, as kind and as cruel as the gods in Ovid's Metamorphosis.


Footnote

[1] So, for example, Man may well be "a highly inventive species that is also one of the most predatory and destructive"; but it may be more than that. Man, and especially women, may also be "naturally" cooperative and compassionate. Pity, like a naked new-born babe, striding the blast...shall blow the horrid deed in every eye, that tears shall drown the wind.

Part human

In an opinion piece on the consequences of "our ongoing inability to see animals outside our own fraught frame of reference", Charles Siebert mentions an image made by Nicolaes Tulp of a chimpanzee landed at the Hague in 1641

The creature — seated atop a boulder with its mostly hairless torso and limbs, tapered elfin hands and feet, and sweetly smiling face — looks like a potbellied forest nymph dreamily sleeping off a good drunk. Not a chimpanzee so much as an ape-human hybrid.

I haven't found a copy of this on the web (only this) but did find the image above by the late 17th century physician Edward Tyson.

Tyson's engraving is included in a set of materials about Mary Shelley's Frankenstein. His Philological essay concerning the pygmies of the ancients was republished in 1894 with a preface by Bertram C. A. Windle which suggests that while in Tyson's day it may have been reasonable to suppose that apes were the pygmies of ancient times, human imagination can make create stranger things from less evidence.

P.S 9 March: Siebert's starting point is behaviour in chimps that humans find horrendous but which is occasioned by the way chimps have been treated by humans. An interesting but less dramatic example would be 'planned' stone attacks

What remains

The tracks were confined to two layers of sediment, vertically separated by 15 feet and about 10,000 years. The upper layer contained three footprint trails, two of two prints each and one of seven prints, as well as several isolated prints. The lower layer preserved one trail of two prints and a single isolated print.

Homo Erectus walks and runs across huge continents for a million years. About a dozen footprints survive.

(The quote is from a report on Early Hominin Foot Morphology Based on 1.5-Million-Year-Old Footprints from Ileret, Kenya DOI: 10.1126/science.1168132 . The image is Flower Clouds by Odilon Redon.)

Like mind

[It] is hard to say what is instinct in animals & what is reason, in precisely the same way [it] is not possible to say what [is] habitual in men and what reasonable. …as man has hereditary tendencies, therefore man's mind is not so different from that of brutes.

-- Charles Darwin (1838 a), quoted in Baboon Metaphysics (2007).

Interest in the idea of a herd mentality [in humans] has been renewed by work into mirror neurons - cells that fire when we perform an action or watch someone perform a similar action. It suggests that our brains are geared to mimic our peers. "We are set up for 'auto-copy'," says the psychologist Jonathan Haidt...[who] thinks this research helps explain why fascist leaders, amongst others, use organised marching and chanting to whip crowds into a frenzy of devotion to their cause, though these tactics can be used just as well for peace, he stresses.

-- from How to control a herd of humans.

This notion of the autonomous individual who is in charge of his or her fate is one that I couldn't really subscribe to.

-- W G Sebald quoted by Will Self.

On not crashing the planet

The discovery [that these jellyfish are spreading almost everywhere] underscores "our remarkable underestimation of the extent to which the ocean has been reorganized." 

-- says the marine biologist James Carlton in a report about "immortal" jellyfish swarming the world's oceans. [1]

Humans, it appears, may be learning ever more about ecosystems and our impacts upon them, but we often do so as a by-product of what looks (with hindsight) like blind stumbling. [2] An example may be the transportation of billions of gallons of sea water around the world as ballast, which Craig Venter calls: 

a giant ecological experiment we have been doing irrationally for decades and decades. [3]

It turns out that, absent human influences, 85% of the DNA sequence in oceanic bacteria, archaea and viruses is (was) unique every two hundred miles.  The consequences of mixing the seas up are not known.

Venter's assertion is reminiscent of Roger Revelle's momentous observation in 1957:

human beings are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future.

Inadvertent 'experiments' -- involving jellyfish, oceanic micro-organisms, the global climate and much else -- arise from a global economy driven by huge social forces on which ecosystem science has to date had only a tiny influence.

Redressing the 'clumsiness' of those forces would probably require huge changes in awareness, among other things. [4] Tools like Google oceans (and, one day, more sophisticated ones) may play a useful role, perhaps more than we presently imagine; but they will have limits. In a reflection from Andy Revkin, Stephen Kellert cautions:

The sad reality is that while more abstract, vicarious/representational awareness of nature and its conservation via the video and computer have grown enormously, concurrently, there has been a profound decline in more commonplace, everyday experience and contact with nature and the often deeper and more realistic and lasting appreciation and action that comes from this personal involvement.

Footnotes:

[1] Here's another story on Tracking jellyfish blooms.

[2] (added 4 Feb) In a talk at the Zoology faculty at Oxford University relating to the paper Maximum Entropy and the State-Variable Approach to Macroecology, John Harte suggested that ecology is progressing beyond the gathering of data (the 'Brahe stage') and patterns (the 'Kepler stage' [sic]) towards general laws (the 'Newton stage').

[3] Genomics: from humans to the environment. A lecture at the James Martin 21st Century School. Roughly 34 minutes in to the podcast.

[4] It's not so much that we're riding a tiger, but that we are [part of] the tiger. This is expressed in a way I find compelling but disturbing and partly questionable ("command?") by Roberto Unger (Nature in its place, New writings):

...We are unquiet in nature because the mind concentrates and focuses a quality diffuse in nature: the mind is inexhaustible and therefore irreducible and uncontainable. No limited setting, of nature, society, or culture, can accommodate all we -- we the species, we as individuals -- can think, feel, and do. Our drivenness, including our drive to assert power over nature, follows from our inexhaustibility. We should not, and to a large extent we cannot, suppress, in the name of delight, stewardship, or reverence, the initiatives by which we strengthen our command over nature...

...Nothing should prevent us from tinkering with our natural constitution, inscribed in genetic code, to avoid disease and deformity. The place to stop is the point at which the present seeks to form human beings who will deliver a future drawn in its own image. Let the dead bury the dead is what the future must say back, through our voices, to the present. To let the future go free would show more than power. It would show wisdom.

'Collective self interest'

At the heart of "anthropogenics" [a new discipline, one that could go beyond the work of thousands of ecologists, climatologists, economists, anthropologists, psychologists, political scientists, neuroscientists and the like] would be a synthesis of what we know about our ability to sacrifice private for public good, to take less and give more, and of research into game theory, social psychology, anthropology and evolutionary economics. It will challenge the key western assumption that human behaviour is necessarily selfish.

-- from Niels Röling on Why we need a proper study of mankind

(Image: Banaue Rice Terraces)

Twilight souls

Having proved men and brutes bodies on one type: almost superfluous to consider minds. [1]

Almost but not quite:

He who understands baboon would do more towards metaphysics than Locke. [2]

What, then, to make of the 'new, scientific' study of morality by the likes of Marc Hauser, which may point to something like this:

the science [sic] of morality may bring into doubt some of our most deeply ingrained cultural perceptions about right and wrong. We’ll have new, richer opportunities to examine our actions in the presence of consequences. We probably won’t like what we see. [But] those awkward realizations may be the greatest value of moral science. [3]

How far are we here from:

No man can ever attain to anywhere near a true conception of the subconscious of man who does not know primates under natural conditions. [4]

Carlo Fausto [5] quotes Friedrich Nietzsche:

Our body is, after all, only a society constructed out of many souls.

and Mia Couto:

In Lua-do-Chão, there is no word to say “poor.” One says “orphan.” This is true misery: to have no kin.

Footnotes

1. Charles Darwin, Notebooks on transmutations of species.

2. Darwin, 1838 notebook.

3. Reinventing Morality, a review of Moral Minds (2006).

4. Eugène Marais, in a letter from 1935, republished in an introduction to the The Soul of the Ape by Robert Ardrey. Ardrey was an advocate of the now unfashionable 'killer ape' hypothesis. More popular these days may be the 'kind ape' hypothesis. ('Twilight souls' is a term used by Marais to describe the Chacma baboons of the Waterberg. There is evidence that Australopithecus africanus and, later, Homo erectus lived in the Waterberg.)

5. Feasting on People: Eating Animals and Humans in Amazonia, 2007. DOI: 10.1086/518298

Image: Gaza

Human being

I'm no historian of game theory, but I'm fairly sure that this, from an essay in Nature's series Being Human, has been well understood for a few decades:

Most of our interactions occur in a population of players, and pay-off accumulates over encounters with many different people. Because overall success is proportional to the sum of that pay-off, the other person in any one encounter is more a partner than an opponent. [1]

A more pressing matter, arguably, is how broadly and deeply networks of partnership extend. Historically, it's often argued, the boundaries have been quite narrow and shallow. For example, during the late Pleistocene, writes Samuel Bowles in another essay in the series [2], competition between small hunter-gatherer groups, each of them internally altruistic, was rife. Over seven millennia in the Channel Islands off southern California, for example, "conflict [between groups] accounted for a much larger fraction of deaths than occurred during Europe's just concluded century of total war" [3].


Over time, however, networks have become larger and deeper. Half a millennium of rapid technological advance and intense conflict reforged Europe from some 500 city states, bishoprics, principalities and other sovereign bodies into about 27 states, now acting in union (more or less!). The parochial form of altruism, in which we only co-operate narrowly and are in a state of near permanent war with most other groups, is (Bowles concludes) "part of the human legacy but it need not be our fate." [4]

Right now, however, there are at least three kinds of breakdown and/or incipient conflict that need attention: those internal to particular nations and/or economic groups; those between nations and groups; and those concerning beings, such as future generations, unable to speak for themselves [5].

An example of the first is the breakdown in trust occasioned in part by the privatisation of gains but socialisation losses by financial and corporate elites in rich countries [6]. An example of the second is failure of outside countries to exercise their responsibility to protect large numbers of people at high risk in places like Congo and Zimbabwe [7]. An example of the third is the failure, so far, of world governments to act effectively on climate change [8].


Footnotes

1. Generosity: a winner's advice by Martin Nowak. Nature 456, 579 (4 December 2008). Nowak wants to "add cooperation to mutation and selection as a fundamental force of evolution." Lynn Margulis and many others would probably say they already made the case decades ago. But it's not a view shared by, for example, Steve Jones in Coral.

2. Conflict: Altruism's midwife by Samuel Bowles, Nature 456, 326-327 (20 November 2008).

3. An poignant instance of inter-group conflict and intra-group co-operation seems to come from evidence of the earliest DNA so far discovered of a whole family, buried together about 4,200 years ago near the Saale River in Germany. See report. This example long post-dates the beginnings of agriculture, of course.

4. For optimism see also, for example, Robert Wright. For pessimism see, say, this. And here Gideon Rachman considers the possibility of global government.

5. Something like the three problems identified by Martha Nussbaum in Frontiers of Justice.

6. See, for example Paying the Piper - Frances Cairncross, BBC Radio 4. [ 8 Dec addition: a striking recent small illustration is the case of Marc S. Dreier. 12 Dec: or Bernard Madoff. 13 Dec: comment from Frank Rich. See also Control Fraud.]

7. The 'responsibility to protect', a far-reaching principle that holds that states have a responsibility to protect the lives, liberty, and basic human rights of their citizens and that if they fail or unable to carry this out, the international community has a responsibility to step in. In Terror and Consent, Phillip Bobbit notes that Lee Feinstein and Anne-Marie Slaughter have proposed a corollary that would change international law to recognize a 'duty to prevent' -- that is, to create a legal obligation for outside intervention when a state commits crimes against humanity, develops weapons of mass destruction or shelters terrorists. Bobbit, who was an adviser to John McCain in the recent presidential campaign, argues for something like this, concluding that when 'we' finally get serious in the 'Wars against Terror', "we will face a threat to mankind that is unprecedented and is potentially measureless in its tragedy."

8. Roman Krznaric argues that this can in part be overcome by reducing an empathy deficit, citing Barack Obama as a source of hope. [For the record, I think that while 'denial' is a significant problem hindering effective policies on climate change, it is not the only one. At least as significant, I think, is a simple failure to understand the non-intuitive nature of stock and flow -- or, in simpler terms, that if you stop increasing your credit card debt it doesn't mean that the debt goes away.]

Bounded in a nutshell

A previous post on this blog, Kin, noted five characteristics or behaviours that are still regarded as uniquely human, and I've suggested (as have others) another: the capacity to do science itself. Here is David Deutsch in The Fabric of Reality:

Many other physical systems, such as animals' brains, computer or other machines, can assimilate facts and act upon them. But at present we know nothing that is capable of understanding an explanation -- or of wanting one in the first place -- other than the human mind.

And in What is our place in the cosmos? Deutsch takes this all the way:

one physical system, the [human] brain, contains an accurate working model of the other, the quasar; not just a superficial image of it – though it contains that as well – but an explanatory model, embodying the same mathematical relationships and same causal structure – that is knowledge. And if that wasn't amazing enough the faifthfulness with which the one structure resembles the other is increasing with time. That is the growth of knowledge. So the laws of physics have this special property: the physical structures as unlike each other as they can possibly be can embody the same mathematical and causal structure and do it more and more so over time. ..We are a 'chemical scum' [1] that is different. This chemical scum contains with ever increasing precision the structure of everything. [2]

Footnotes

1. Stephen Hawking’s (jokey) description of humanity: "The human race is just a chemical scum on a moderate size planet, orbiting around a very average star in the outer suburb of one among a hundred billion galaxies."

2. In The Fabric of Reality, Deutsch argues that "we are not heading away from a state in which one person could understand everything that is understood, but towards it".

Images: A Five Quasar Gravitational Lens, Heart and soul nebulae

Self-made Man

Not sure about this:

The most intriguing form of relaxed selection...occurs when an animal actively creates a shield against natural selection. This so-called Baldwinian evolution has played a particularly important role in the evolution of our own species. For example, the technological innovations of producing stone tools and cooking meant that our ancestors no longer had to chew tough vegetation and meat. This reshaped the way we look...[notably] a radical reduction in large flat molars, thick enamel, robust face and jaw structure and powerful jaw muscles...Then came agriculture, which made foods even more palatable, relaxing the selection pressures on our digestive system. As digestion became easier, more energy was available for other purposes, especially for building and running a larger brain. Our ancestors would have used this increased cognitive capacity, in turn, to devise more technological and cultural innovations to further shield them from the pressures of natural selection.

-- from Freedom from selection lets genes get creative by Christine Kenneally New Scientist, 28 Sep.