Roger asked:

My question has to do with the number of humans in the world versus the number of non-human
sentient animals. It requires a rather lengthy setup, so bear with me.

Imagine that you could somehow catalog every fertilized egg cell (zygote) that would one day grow to
be a sentient animal. That is, pretend that you had a computer database describing every zygote that
ever existed, from that which would become a prehistoric mosquito to one that would become Albert
Einstein. All would eventually mature into a fully conscious being. The database would contain all
kinds of information about the zygote, but you would primarily be interested in the species of the
animal that it would one day become. The reason that the database contains information about only
the zygote and not the animal itself is to underscore the fact that we all start out as such, no matter
how big we become.

Now imagine that you query your database for the total number of homo sapiens egg cells that have
ever existed. Nobody knows what that number would be, but let us say that it is roughly 15 billion.
Now query your database for the total number of all of the zygotes. Obviously, that number would be
much much higher. The number of insects alone would be extremely high. There are 200 million
insects alive for every human on earth (I got that from Hollywood Squares). Multiply that by the
number of years that insects have existed, and you obviously have a very large number.

Divide the number of humans by the total number of animals, and the result is an extremely small
number. It would seem that this number represents the probability of being a member of homo
sapiens, given that you are any sort of sentient animal having been born sometime in the past. Let us
conservatively estimate that number to be one in 10 trillion.

Now let us take a closer look at one in 10 trillion. An event having that probability would be
EXTREMELY unlikely to occur. In fact, I would even describe it as being "freakishly improbable".

The average lottery player would be much more likely to win the jackpot twice during her or his
lifetime. I do not know about you, but I have never won the lottery once let alone twice. It would seem
that, by having been born human, you and I have won the jackpot in the lottery of life. Twice! I cannot
accept this as true. "Freakishly improbable" events just do not happen to you or me!

Now, the following thought comes to mind:

Do the lower animals such as insects really possess a rudimentary consciousness?

Most researchers in the field say yes. Insects and other such animals do indeed possess a
rudimentary consciousness. They are sentient. They are not like zombies, sensing and reacting to
things without having an awareness of them. They have consciousness.

Thus, human consciousness is an extremely rare thing on our planet.

Here is my question:

Are we humans really the unlikely winners in the lottery of life, or is there some other explanation?
Could the probability of being human actually be much greater than I have assumed?

============

The problem with your arithmetic exercise is that numbers as such have no bearing at all on the
situation you are portraying. In calling the likelihood of a zygote to be a human rather than a mosquito
'freakish', you forget that the atoms in the universe that might or might not become part of a living
thing have even more freakish improbability to account for.

Forget numbers and probabilities and look at structures.Everything in the universe has structure, and
thus the only pertinent type of argument along your lines of thought is to consider whether one or
another type of entity is structurally probable (or possible), i.e. whether it makes sense for some type
of structure to exist and how and where it does. In such a context a spiral nebula is easily explained
by gravitational forces; and the entropy that eventually results is equally plausible. The context of your
question is biochemical and biological, however, which entails a different slant or perspective.

Let me get one thing out of the way quickly. What kind of species possess consciousness or not we
can scarcely be certain about, but a default theory is that nerves are the absolute minimum. Now
consider that nerves are themselves living things! Are they conscious of their own consciousness, or
of ours, or of none? You see (I hope) what a futile theory this is! Consider further, just for now, that a
great deal of this theorising is concerned with our place in the sun, and that the pendulum tends to
swing rather wildly between theorists who want to convince us that we're just overgrown apes and
should, perhaps, dismantle civilisation and return to the trees, and those who believe that we have a
destiny to manage this planet before somehow we get ourselves installed as managers of the solar
system or even the whole galaxy. Well, I can tell you I'm not on the side of the former, even if I
reserve the right to remain sceptical about the latter.

Now: In logic (or in the lottery scenario) there was no compulsive reason for bacteria ever to grow into
anything bigger or more complex, seeing that they were (and are) perfectly adapted to survive just
about any calamity short of this planet physically blowing up. Yet it is a plain fact that 'upgrading' is a
also a kind of 'default programme' for organisms: that's what the theory of evolution is all about. A
deep problem in that theory is, however, that they are also lured down the path of numerological
speculation and thus keep stringently to the mechanical doctrine of genetic accident — which is no
answer at all, but a simple causal argument that leaves you looking for more causes right through to
infinite regress.

I can't write a book here, although that's what is really necessary to answer you in depth. All I can do
give you in one paragraph what my conclusions are, and then a couple of titles for you to pursue the
matter on your own bat.

Carbon atoms are capable of forming polymeric chains of immense length and infinite flexibility. They
are the onlyatom so endowed. Now this suggests that carbonaceous structures will be different in
kind from all other molecules, as indeed they are. A specific type of this kind of molecule, called a
macromolecule (i.e. giant molecule) or polymer, given certain temperature conditions, such as prevail
on earth, has the capacity of 'turning itself over' in such a way as to construct an integrated work
cycle without external mechanical push-and-shove. This is difficult for us to come to grips with: we are
still enthralled to the cartesian division between mind and matter and therefore prone to seek
explanations for all structures, including biological ones, by the route of reductionism. This doesn't
work in the present scenario. However, the point to be made is that these latter structures, which we
call 'bacteria', are obviously possible, and given the conditions named, altogether probable. Most
biologists would tell you that the chance of some such form of life arising on any earth-like body in the
universe is quite high. This leaves only the last item to be explained, why do they upgrade?

Now this is where numbers and probabilities get stuck. Remember me saying that it seems not to be
compulsive for sheer survival. This part of the conclusion is therefore totally interimistic. On earth, it
occurred because the atmosphere changed about 2.5 billion years ago to a level of toxicity that was
fatal to microbial survival (I'm talking about the air we breathe!): and it is from this point onward that
'upgrading' sets in. Organisms needed to find a way to detoxify the air; this meant devising respiratory
structures, therefore necessarily an increase in body size and complexity. This process has never
stopped, but greater size and complexity impair survivability in other ways, as will be apparent without
me spelling it out. But it explains why to every billion bacteria, there might be 1 million mozzies, 10
cats and 1 human. But all these structures are implicit from the moment that bacteria were compelled
to follow this path of proliferating organic forms.

Ok, all this is rudimentary. My point is merely that under certain circumstances, as demonstrated by
historical developments which we can easily trace back, this 'upgrading' was already latent in the first
biological polymer when it came into existence. Whether such a path is logical may be another
matter. Whether a human being would arise necessarily in the course of such evolutionary pathways
I'm inclined to doubt — too many other contingent factors might intervene and human are not
necessarily the goal' of these developments. There may no goal at all, of course; or if you're a
believer, you might say that human are the outcome of a directed evolutionary path. One way or
another, however, human-like creatures may not evolve on other planets, even though there is no
logical argument why they should not. What happened here cannot be denied to be possible
elsewhere, since as a possibility it has already occurred. Finally, the argument for 'upgrading', which
includes, eventually, nerves and therefore consciousness, is pretty plausible too. There are (even if I
deny it to mozzies and fleas) enough species on earth with nerves to admit that consciousness is an
almost inevitable adjunct to young upwardly mobile creatures.

Humans? Well, put the question the other way: why dogs and cats and horses? All these are, to
some extent, contingent developments. Human may have development without dogs, cats and
horses. We would not have evolved, however, without the species mammals' making the grade. So
there is a certain hierarchy which cannot be ignored. When one talks about structures, as I did, it is
incumbent to remain aware of the priority of some types of structures before others.

But: the 'movie' of life's evolution on this earth is not a path, it's a bush with thousands and millions of
branching points at every juncture. It's likely to be exactly the same, but different in detail, on any
other life-bearing planet. So I would expect that some structure analogous to earthly life forms to arise
wherever the possibility exists; I would expect (as indeed most of us do from sheer habit) that if there
are mammals, they would also have biaxially symmetrical body forms, because these things don't
happen like that just on a whim; but I would expect that their details might be very, very different. For
example, four different types of eye have evolved on earth, and the lobster's eye is so different from
ours as you wouldn't want to believe (it's made up of little pixel-like rectangles!). Moreover I am of the
belief that, because the mind is a thing with structure, that aliens endowed with a mind would also
show a similar structure of thinking to ours, though obviously different again in detail (namely in the
influence which the environment would have on their intuitions). However, that's enough speculations;
but I hope you get the point that it's not numbers, but structures which are important. Let me add, as a
joke, that the probability of life to arise on earth (mathematically calculated on the chance of certain
amino acids to join up by chance) is 0.0000000000001 or even less: the universe isn't old enough to
see it happen. So: structure and complicity to the rescue!

Something you might like to read: Stuart Kauffman: At Home in the Universe;Graeme Cairns-Smith:
Seven Clues to the Origin of Life;Ian Stewart and Jack Cohen: Figments of Reality.Now these books
are fun;and since they were written by scientists working at the coal face of research, you can rest
assured that they don't push fancy theories without some hard evidence at their back.

Best of luck!

Jürgen Lawrenz

Sydney

Your question is based on an incorrect conception of probability. The probability of humans is either
unanalyzable, or unity. If you want to attempt to analyze the probability of humans, you certainly
cannot do it by counting zygotes. That assumes that all zygotes are in a big barrel, and someone is
picking them out at random. I mean... really.... You mighttry to start with bits of RNA in a puddle and
try to estimate the odds of coming up with human DNA... but how? We don't have the slightest idea of
what conditions were on earth when life started evolving, so there's no way of estimating what the
odds were of some process of which we have no knowledge. Not only that, but you just don't do
statistics this way, I don't care what blather you've read in the papers. You do statistics either by
taking a sample of a population, and estimating from characteristics of that sample how the same
characteristics would be distributed in the population. Or you run a process multiple times and
generate odds by looking at the results of the runs. Or, if you've got lotsof information, e.g., that a die
has 6 sides and it's shape and weight are evenly distributed, you might use that information to predict
odds. Ok? So, which of those do you have for this little question? None.

You're trying to look at all zygotes and estimate from that sample how many should be human. But
that kind of sampling depends on assumptions like: the distribution of the characteristic is random in
the population. If it isn't, then how do you collect your sample? It's like saying, we'll take a random
sample of fish and animals and from that see how likely it is that animals have four legs. What that
ratio would mean would be that if you were an alien from space taking random samples of creatures
on earth you'd get x percent with four legs. But that doesn't tell you how likely it is that animals have
evolved four legs, all it tells you is about alien sampling results.

And you're not going to run evolution multiple times, unless you have a few billion years to spare.

So since you have one sample, and you can only do the run once... then your odds are just the odds
of your spilling your tea, afteryou've spilled it. Absolute certainty. You havespilled the tea. Humans
haveevolved. Alternatively, you can say the odds are unknowable.

Steven Ravett Brown