Why has intelligent life only arisen on the Earth in the last two hundred thousand years?

There are certain readily-filled niches in ecosystems. Even when the slate is wiped clean by some mass-extinction event, the evolutionary process means that animals from wholly different orders are plastic enough to re-fill those niches quickly.

Thus, if terrestrial ecosystems have generally had room enough to tolerate thriving populations of arboreal animals, flying animals, burrowing animals, fast moving carnivores who prey on large lumbering herbivores, carrion eaters in their wake, semi-aquatic animals, and so on, then we have found that such niches are invariably filled.

Velociraptors, Moas, Tigers and Marsupial Lions have occupied one such niche (predatory carnivores) by turns. Apatosaurs, Elephants, Diprotodons another (large herbivores). Pterodactyla, Archaeopteryx, Modern birds, and bats still another, and so on.

When a living can be had as an occupant in one of those niches, it seems applicants have always queued up, regardless of whether they have cold blood, feathers or pouches. These niches must represent enduring evolutionary "sweet spots", since they are filled over and over.

Obviously, intelligence confers a huge survival advantage. It enhances the ability for creatures to plan, and to act in concert through the use of language. Although many other animals are social species, an intelligent individual's ability to survive and reproduce is further multiplied through greater co-operation with the whole. The aggregation of learned survival strategies suddenly can be passed down the generations via a means better than mimicry or instinct. An animal can only mimic what it has seen, but language means the memes for, for example, an improved hunting method, or of rendering a food otherwise poisonous fit for consumption, can be passed across continents and down the centuries by stories, and eventually, writing. Intelligence means an unprecedented ability for a creature change its environment to suit itself, rather than need to continually adapt to suit the environment.

So if nature has continually repeated herself through the repetition of forms and characteristics advantageous to exploit a niche, and intelligence  is manifestly such a characteristic, why is there no indication that intelligent life or civilisation has ever appeared before in the half-billion years that have elapsed since complex life arose?

I just through I'd throw that out there. It's a question I've turned over periodically. If anyone knows if any of the major writers like Dawkins have addressed this question, please point us in the right direction in the comments.

(The picture: Doctor Who's answer to this question. Intelligent life did arise before; the Silurians!

I'm not sure I subscribe to this theory, but my 7YO son may well).

Only the good die young

Rex and I, midnight screening of Star Wars. I was no match for his skill with The Force

Sadness is compounded when you have to bury people before their time. Dr Rex Stubbs OAM was a friend and a mentor to me. He died last weekend and the funeral was Thursday. He was 60.

Rex typified for me the model of a community minded man, a lot like my grandfather did in my earlier life. Rex just seemed to be everywhere. He served on Hawkesbury Council for 26 years, and spent ten of those as Mayor. He was my GP, he was a local historian, and he was a patron of the arts. He was, in a cynical and thankless age, a Good Man. I shall miss him so.

But he was also a friend. I remember on many occasions where he saw my interests in history or local politics overlapping with his, he always offered his quiet and deliberative encouragement. That encouragement will stay with me all my life. Those who knew him well said at the funeral that they never once heard him raise his voice, and I believe it.

But there was a vein of humour as well. Rex was a proud sci-fi buff and I always thought it was a hoot when I was organising midnight screenings of Star Wars premieres for my youth group and there he was, turning up with a bunch of young people (some in dressing gowns), fighting with plastic light sabres, his wry smile winking over the top of his glasses.

It was often like that. Usually when someone was being too pompous, Rex would glance at us, over his glasses, and the wordless look he gave let us in on the joke, and you felt you were with him, and there was... an understanding.

Too much of what passes for politics these days is bled dry of any humanity. It’s all calculation and ambition. Rex genuinely looked down from the mayor’s chair through the lens of history, rather than merely an eye to the next intrigue, with a genuine appreciation for the heritage and history of the shire he served. He was a man of soul in an increasingly soulless avocation. If there's anything I choose to take away from Rex's influence in my life, it's that. People matter. History matters.

I read somewhere recently that all people die three times. We die once when we draw our last breath. We die again when our earthly remains return to the earth and lose their form, and we die a third time when our name is spoken aloud for the last time. This idea affects me very much. When will we all die that last time? When will we be invoked in conversation or recollection a last time, or the cadence of our voice, or the values we transmit to others, be lost to living memory? After how many years? In that sense, many die quickly, and some are still with us centuries on.

I have a hunch Rex will be with us for a very long time.

In which Nathan considers his good fortune

Recently, I was sitting with nine good friends and I was trying to articulate a principle of life.
"I am beset by trials," I began, "but I seek to keep life in proportion by kindling gratitude in my heart for the simplest things."
"Such as?" my friends inquired.
"The smile of my sleeping child; the accident of birth that makes me Australian; the laws of physics and mathematics."
I encountered consternation. "Physics? Maths?"
I explained, "Did you know that you can zoom into a Mandelbrot set so deeply that if the original was as big as the entire universe and you zoomed in so that what you were looking at was smaller than a quark, you would see a tiny little simulacrum of the original shape, repeated anew? There it is, woven into the fabric of reality. Like a signature."
The purpose of our gathering was philosophical, and just as well. Such observations rarely travel well at the pub.

And why not choose to feel some sense of wonder and gratitude at both sunsets, and the laws of physics that make sunsets possible? A few nights ago, I told my son to regard his upraised hand.
"Many of the atoms in your hand, your body and everything you see around you were made in a Supernova, before the Solar system was even formed. What planets did that star keep warm, I wonder?" I explained.
His eyes widened. I love doing that, and we enjoy many such moments as I deliberately inculcate a love of science in my son.
Carl Sagan's observation that "We are made of star-stuff" stands to me as one of the most wonder-inducing and humbling statements we can reflect on. To think that the glint of gold on my wedding band came from the core of an exploding star 5 or more billion years ago is a fine reminder of both our transience, and equally our participation in the Universe. I give thanks for that. That the Universe is interrogable by Human intellect at all (a situation in which the Universe could equally have felt no obligation)... that is grounds for wonder and thanks.

Strangely, these are among the thoughts that sustain me in my earthly trials. Family, yes. Friends, of course, but some sense also that the world is full of hidden joys and marvels that we miss through harried inattention. When my 7YO son has built a Lego model of the Yamato because we're watching Star Blazers on my laptop together at bedtimes (one episode a night. "Hurry, Star Force! There are only 315 more days to save the Earth!"), and he wants to explain how the guns work at exhaustive length; that moment has as much significance as any could in history. Making my son feel listened to is as profound a purpose I have as I can conceive.

How easily I could have missed that. Or to let my other trials wear at my soul until the bone shows. The best philosophy is to expect a better day and to not be idle in the meantime.
To get to that gathering of my friends I recounted, my brother in law had dared me to ride from Oakville to Wilberforce, some 28km round trip, and I had acquitted myself. It was further than I had ridden since High School.
Yesterday, I sang at a good old fashioned Australian bush dance (My big number was The Wild Colonial Boy. Did you know that song was considered seditious in the 1890s and banned?) We wheeled and cavorted, my son partnered by grandmas and aunties alike through the heel-toe polka or the Drongo, now inducted like his immemorial ancestors into the courtesy of bowing and asking girls sweetly if they will dance. I beamed.
 Today, I constructed the frame of a grand new cubby house for my boy while the family gathered in the back yard. Sprinklers were jumped through. Balls were chased by the dippy Spaniel. The BBQ setting was repainted, largely to cover the sins of a previous artistic painting afternoon 7YO son and I had in which the garden furniture came off second best.

Tonight, I cleaned the study. As Satie's Gymnopédies shuffled through iTunes, my hand chanced to rest on the volume of Marcus Aurelius' Meditations I borrowed from my friend Grant years ago and haven't quite managed to return yet. As it fell open, there it was. What I'd been trying to say to my friends that night:

"Be like the headland against which the waves break and break: it stands firm, until presently the watery tumult around it subsides once more to rest. How unlucky I am, that this should have happened to me!' By no means; say rather, 'How lucky I am, that it has left me with no bitterness; unshaken by the present, and undismayed by the future'. The thing could have happened to anyone, but not everyone would have emerged unembittered. So why put the one down to misfortune, rather than the other to good fortune? Can a man call anything at all a misfortune, if it is not a contravention of his nature; and can it be a contravention of his nature if it is not against that nature's will? Well, then: you have learnt to know that will. Does this thing which has happened hinder you from being just, magnanimous, temperate, judicious, discreet, truthful, self-respecting, independent, and all else by which a man's nature comes to its fulfillment? So here is a rule to remember in future, when anything tempts you to feel bitter: not, 'This is a misfortune,' but 'To bear this worthily is good fortune.'"

This neatly encapsulates the view I want to have about life. This is what I would like others to say of me. Stoicism has always had a strong appeal, but this passage is beautiful in its truth. To be sure, recent loss gives my son and I, (and others in the family) a sadness that sometimes verges on the inconsolable, and an anger as well, and a railing at injustice and helplessness. But equally, I carry a sense that if I keep my nerve... if I focus on my family, my community and my study, then our satisfaction and happiness will be inevitable.