Are We Alone?

The Monday Poll is back, but if you're reading this on the Wordpress version, you need to come over to the Blogger version to vote.

The last poll- long forgotten- was on the Channel islands and you lot decided they weren't part of France.

This week, the topic to vote on is simple.
Should we expect intelligent lifeforms like ourselves to exist elsewhere in our galaxy. Emphasis on galaxy, not universe.

You see, what we have here, is what is known as the ET paradox. Sometimes called the Fermi paradox after Enrico Fermi, the physicist of the mid twentieth century who posed it simply 'Where is Everybody?'

Because although the absence of evidence isn't evidence of absence, all the available data is telling us we're alone. At least in this neck of the woods. And always have been.

And yet a lot of scientists say that statistically, we shouldn't be. If a whole set of variables are crunched- and one sees these variables crunched over and over again in books trying to convince us we are not alone and grey headed races are visting us to stick probes in the nostrils of rednecks- the verdict is usually- we should have space-faring neignbours somewhere near enough to get here, and indeed, have got here.
And of course the REAL reason we know they haven't, is that the odds are that if they had got here, it would be long before we appeared and as a result- we'd never have appeared. Or appeared obviously bred by our master who were still here to tell us how they bred us.
Or at least left behind obvious evidence they were here.

Now frankly, I don't want to get into an argument about that. Some of you may feel like championing Erich Von Daniken and Graham Hancock, but I'll post on that some other time and we can debate it then. Those ideas aren't related to the fact that evidence of intelligent life ever having existed in the vicinity of this star system is lacking.

So the only question to really be asked is- can we really know what sort of variables we are working with?
And I think the answer often is; no. These estimates vary so widely, because the variables are so wide.
So; I thought rather than start at the begining, I'd start at the end.

LAST assumptions first.

And the last assumption, is that even with an earthlike flora and fauna, even with land dwelling tetrapodal creatures, even if they were exactly the same as earth dwelling mammals- a mammalian species would evolve that learned how to split the atom. A species would evolve capable of understanding it's environment.

For a species of any kind to get to where we are, it first has to go through the systematic development we did. Once it does, the rest will kind of follow. If anywhere in the universe, any species ever settles down in constructed dwellings, organises crop rotation and smelts metal, then in a matter of time, it will split the atom. So civilisation and splitting the atom are guaranteed. If Rutherford doesn't do it, someone will.
But actually, that isn't the real start.

Human civilisation became inevitable when we started painting animals on the walls of caves. We started farming because the climate changed and we we were able to communicate well enough with eachother to do it. But to do that, you need to have already developed the sort of conceptual understanding needed to communicate an idea when the person whose idea it originally was is dead and gone. Other animals communicate, but not like that. To be able to retain information and keep it, immortality of information, that is what has made it possible for the knowledge of one man to be added to that of another. I see further by standing on the shoulders of giants, etc, etc.
Dolphins never learned to paint animals on the walls of caves. They never learned to share ideas. This is why they may well be intelligent, but they are stuck in the sea swimming around.

So it isn't about a species being intelligent. It's about it mastering advanced communication.
And our history has happened because our species really mastered communication as its basic tool of living, as a carnivorous predatory hunting primate.

The question we need to ask, is if we go back five million years, could it have happened that we didn't?

If you had a planet somewhere which had been a clone of Earth five million years ago, both of us identical in terms of our entire history, might the city dwelling ape never have come to pass?

Quite possibly. We only know our early history through fossils. Our history as a species is clearly extraordinary. Apes are clearly intelligent and clearly communicate. But our species went that extra mile and it did so in a relatively short space of time.

We needn't think that an ape species would naturally do so as a matter of course. The appearance of the ape does not necessarily guarantee our development. In point of fact, ape genera have been on the decline for the last ten million years. Aside from us, apes have not been selected as the great survivors. So had we not flourished, it's possible apekind would be on their way to the dustbin of history.

So you could have a world where history was almost identical to earth- but apes never got smart enough. No ape species ever took on a predatory role and was driven remorselessly to world domination.

By the same token of course, in this rerun world, perhaps that curious run could have happened to another intelligent mammal. We don't know much about the living habits of extinct mammals. The Chalicotheres are extinct, but maybe they were quite bright. Maybe in a rerun Earth, a Chalicothere species might have taken the unusual road we did. They were bipedal, so maybe tool using, a big brain, communication could have come.

So the most we can really say about a parallel Earth, starting from the time the dinosaurs become extinct, is that conditions exist in which an intelligent species could appear, because mammals are innately intelligent. They use intelligence in a way the now extinct rulers of the Earth did not. And if a niche appeared in which exploitation of communicative intelligence became a survival premium, such a species might evolve. But there is nothing inevitable about it. In a hundred such Earths, if one ran from the end of the Cretaceous to thirty five million years into the future- giving us a sweep of a hundred million years- would an intelligent city building species evolve in more or less of them? And in those where it did, in how many cases would that species come from the primates?

We then have to admit that the extinction of the dinosaurs happened at just the right time. For us to exist, dinosaurs have to be extincted. We have to have a world in which Mammalian life becomes dominant. Yet looking at the history of mammals, it is hard to see how mammals COULD have evolved as a dominant species. The intelligence of mammals and their ability to connect with eachother has a lot do with protection of young. In a hostile world. Dinosaurs didn't have to be smart and seemingly weren't. Mammals ended up taking over the world having intelligence as a skill already. And it helped them in their mastery. But it wasn't why they evolved it to begin with. They evolved it to scurry away all the better from brute force and shearlike teeth.

The rudimentary survival skills that meant that a species like us could only come from the Mammal and would never likely appear in cold blooded, egg laying, scaly creatures who really don't even need to bother getting on with eachother- were actually developed when the chances that Mammals would ever inherit the Earth were slim.
So creatures like Mammals would have to inherit the Earth in the first place. After the domination of bigger, stupider, selfish creatures. Because they could only evolve in response to such creatures.



So already, by the time we get back to the first Tetrapod, it would seem that standing back here in the Carboniferous, we might actually need a hundred parallel Earths, all identical up till this point, to be certain of a species appearing on that world that could one day split the atom. Maybe. I'm guessing it would be less. My guess is that periodic extinction events are likely to be a common feature of any world where life lasts as long as it has done on ours. But I still maintain that if one now let these hundred parallel Earths diverge from the time of the Carboniferous onwards, only a small minority would lead to an atom splitting species emerging. And would that species be a Primate or even give birth to live young? Maybe only on the one out of a hundred that was ours. On the rest, we'd find city building Chalicotheres or Rodents driving tanks. Or maybe even a kind of Marsupial biped, who need no prams, post-natal dresses have a slit for the mother's pouch.

Then of course, we have to come out of the sea in the first place. Now, Chordates aren't alone here. It seems that multicellular life will indeed come out of the sea and colonise land. Though only a minority of forms have done so, the fact that most major superphyla of the animal kingdom, as well as Plants and Fungi have done so, suggests that once we have multicellular life, colonisation of the land becomes inevitable.

Multicellullar life will lead to land dwelling life.

The question is, does the fact that life emerges onto land necessarily lead to life of our kind?

Well, no. One would guess that the phyla that do not have land living representatives do not have them, because they did not have structural advantages suited to land based life in the first place. Which is fair. One needs some sort of scaffolding structure to exist on land. Which is why only Chordates, Arthropods and Mollusks have actually made it properly. Others have, but only by living inside us.

Chordates are able to move around without the benefits of an ocean environment, because they have a skeleton. Arthropods and Mollusks have shells. So for phyla to evolve which could come out of the sea, would seem normal once multicellular animals appear.
But shells pose a limit on growth. Arthropods can grown quite large in the sea- witness the extinct sea scorpions- but not on land. Here gravity imposes limits, because they have to shed their skins. And therefore there is only so big they can grow before the process of growing a new skin whilst standing up is not possible. Does this effectively mean that Arthropods COULDN'T have dominated the Earth without Chordate competition?

Could there be worlds out there where New Yorks and Londons and Tokyos exist- but in miniature?

Interesting thought. And not one I'd like to rule out. Insects have shown themselves able to set up co-operative society based on communication. In fact, they've been doing it a lot longer than we have. But it hasn't developed the same way. I guess the difference is, Mammals learned to think, then happily we learned to communicate as well as insects. But insects never went through the basic Mammal stage of learning to think. So for Insect civilisation to emerge, some powerful dynamic would have to happen to make Insects go through our developmental process in reverse; we had Primate instincts, then took on Carnivore instincts, and now have picked up insect tricks. They'd have to pick up our Mammal tricks. And perhaps without Chordate life, Arthropod life would have become so diverse such a species might evolve.

Insects are, in my view, the only example of a mode of life that had as good a chance as Mammals as being, in an alternate Earth, a viable contender for producing an atom splitting species.

But even so, standing back in the Cambrian period, looking at Animal life then consisting of a variety of wormlike and jellyfish like phyla, all giving a vague hint as to their descendants, here a protochordate, there a protoarthropod, I think I'd still have to say that at this juncture, one would need at least a hundred parallel Earths to GUARANTEE an atom splitting species. And as to whether it would be Chordate or Arthropod or other, I wouldn't like to guess.

And I only need to go back one more geological period to be confronted by what may be the uneasiest looking bit of data I need assimilate on this. One that still seems to escape most people's radar. We get excited by the dinosaurs. See them as strange, long gone lords of the Earth. But really, they are familiar. Related to living creatures, Tetrapods like us, with close living relatives, crocodiles and birds still with us.
Trilobites and Ammonites are slightly stranger, further back. Trilobites were Arthropods that lived in the sea, but not so very clearly related to Insects. Arachnids possibly. Strange to us, because the Trilobite eye evolved completely independently. It seems in fact, to have been the most complex eye of all eyes ever. Trilobites are more noticeably a different type of animal to all animals on earth today than Dinosaurs were.

But- what are we to make of Vendobionta?

Back in the Ediacaran, half a billion years ago, the fossils are strange. We know from Molecular biology that back here was the time that the Bilaterian phyla diverged. Back here, the Insects and us find our common ancestor, a kind of worm. And we find wormy creatures in the fossil record. And jellyfish type creatures too. But also- fossils of things unlike anything we now know. At first, they were thought to be jellyfish. Now we think they weren't. Not even- Animals.
Not Plants. Nor Fungi.

What were they related to? We don't know. But they might well have been a form of multicellular life that sprung independently from single celled life just as Animals and Fungi did. But as different from each of those as they are to eachother.

A fourth form of Multicellular life. And in the Ediacaran, more dominant than animals.
Maybe. We're not sure.

Why did it become extinct? Again, we can't know yet, since we don't even know what they were. How they fed. How they gained energy. So we can't know if it's disappearance was inevitable, or a freak of circumstance.

But it raises the possibility of Animal life not being the top of the food chain. Because judging by the SIZE of the fossils, Vendobionta seems to have been the dominant form of life back then. Misleading perhaps, because the biggest life of all is plants.

But it raises the possibility that parallel Earths could exist where life with nerve networks that ultimately allow for a brain to evolve, never become the dominant form of life, worlds where a kind of fleshy sea dwelling fern lookalike is the grand ancestor of the life that eventually becomes top of the food chain on land, are just as likely as this one.
It raises the possibility that life could have existed and flourished to fill niches we'd not thought of. That lives in a way that nothing now lives. But in doing so, ensures that life of the Animal kind will always fill a lower niche.

And there is no guarantee that that niche at the top of this imaginary food chain would ever lead to any form of communicative intelligence. But then again, who knows? After half a billion years, a Vendobiontan species could well have split the atom.

Going back two and a half billion years to the first Eukaryote life and looking at it, one would have to ask the question, here it is, it has eight billion years to cause a species to exist that will learn to split the atom. What are it's chances?
It's chances of producing multicellular life? High. Of that life colonising land? High. Of it splitting the atom? My gut instinct still feels; low. Even when given a clear run for that eight billion years.

Perhaps one in every five hundred worlds where Eukaryote life pulls it off. And really, that's just a wild guesstimate. And that one in five hundred includes the atom splitting Vendobionta, atom splitting insects, atom splitting Chalicotheres, etc.

And that's only the world where it gets time. Time, that's the key. You see, this is where we often go wrong. We're out there looking for Earth like worlds as the only places where life might be found. Which is silly. Earth is Earthlike because life made it so. It didn't start that way.

My guess is viruses are a natural feature of the vast majority of new worlds. Viruses come easy. It's whether they last. Our telescopes are now telling us planets are common, even where we once thought they shouldn't be. The idea that only the Earth is exactly right for life is an Anthropocentric myth. The point is- life here has done something.



My guess is we will find evidence that life of the viral type did once exist independently on Mars. May still do so on Venus. And on the Moons of the Gas Giants. That new world come to life, but it often doesn't last long, relatively speaking. A billion years or two is enough to create Eukaryote cells, but no more. And that's usually as far as it gets before it gets extincted. And most often it doesn't get that far.

I think as knowledge of our solar system increased we'll realise that the truth about life is, it starts a lot of places, it just rarely gets a free run in an environment conducive to wide variations in niches of life. Earth is an unusual planet. It isn't really a lone traveller, it's Moon is not really a satellite, it's the junior partner of a double system. And perhaps that is so much more important than we think. The Moon gives life a shelter against external ravages that not many cosmic bodies possess.

So the question is this.

The galaxy contains 100 trillion stars.

Around 5 trillion of them are stars like ours.

Stars with planetary systems.

In this spiral arm of the galaxy are around 200 billion such stars.

In 20 billion, there has been enough time, taking this planet as an average, for an atom splitting species to have evolved.

Those are the only variable we can really quote accurately- how little we can speculate on the rest has been the topic of this post.

But lastly, we have one more variable.
Once an atom splitting species exists, bearing in mind such a species evolved through intelligence and mastery of its food chain and is by definition, a species that manipulates communication and has blood thirsty instincts- what is the statistical probability that once it know how to split the atom, it extincts itself before it can progress any further?

Because it may well be that that is the determining variable which answer's Fermi's question.

I hope not.

So the question; Is there currently a species within this spiral arm of the galaxy, aside from us, capable of splitting the atom?

Poll is in the sidebar.

Have your say!