Monthly Archives: May 2007

Evolution — a guessing game…

Does evolution really work? Has it really made us what we are today? Surely the chance of just randomly creating human life must be “zero many times over”, right?

I’ve read quite a few pages from the more fundamental and lively bunch of Creationists and Intelligent Design aficionados (like for instance this one), and I’ve frankly grown tired of this talk about randomly creating life…

Let me try to explain.

As far as I’ve understood, opponents to Evolution uses two arguments:

  1. Life (humans, humans from apes etc) cannot have happened by chance, neither can evolution from once specie to another happen by chance.
  2. The probability for spontaneous evolution from one specie to another is “zero many times over”

Let’s begin with 1: Life cannot have been created by chance

Not even Darwin says life was created haphazardly or by random. He says life was created by “survival of the fittest”. This means nature gives feedback to life (maybe there’s where we should go look for God?), mostly by killing off those who wasn’t fit enough (which sounds like we’re looking for Old Testament God, right?)

Theories of evolution has never claimed life was created by chance

Let’s compare life developing by survival of the fittest to a guessing competition. Say between our friends Craig and Eve… Craig will think of a number between zero and, oh why don’t we take 30,000,000,000 (which happens to be the number of nucleotides in human, DNA, but for now it’s just a number), and Eve will try to guess it. Craig will only tell Eve if her guess is too low or too high. Eve will get as many attempts as she needs. Now… how many attempts does she need? Well it won’t be like twenty questions, not with 30 billions in the pot…

The actual formula for the number of attempts in this kind of guessing game is:

Formula for max guesses = log10(n_max) / log10(2)
Formula for max guesses

And for guessing a number between 0 and 30 billion:

max number of guesses needed to guess a number between 0 and 30 billion
max number of guesses needed to guess a number between 0 and 30 billion

So… she needs 35 tries. I think 35 tries to guess a number between 0 and 30 billion isn’t unfair…

So, it stands between Craig and Eve then:

Eve:   Think of a number between zero and thirty billion.
Craig: Ooops... okay lemme think.
            (But instead Craig goes to random.org,
            and gets the number, 16,637,597,566)
         Okay.
Eve:   Is it 15,000,000,000?
Craig: Higher.
Eve:   Is it 22,500,000,000?
Craig: Nah, lower.
Eve:   Is it 18,750,000,000?
Craig: Nah, lower.
Eve:   Is it 16,875,000,000?
Craig: Nah, lower.
Eve:   Ah, darn.  Is it 15,937,500,000?
Craig: No.  Higher!
Eve:   Aha!  Is it 16,406,250,000?
Craig: Nope (hehehe).  Higher.
Eve:   I'm sure its 16,640,625,000!
Craig: Millions of numbers wrong!  And lower.
Eve:   Okay.  16,523,437,500?
Craig: Nope.  Higher.
Eve:   Sheesh!  16,582,031,250?
Craig: Nah, Lower... you're flailing allover the place!
Eve:   (Blushes).  Okay, is it 16,611,328,125?
Craig: No. Higher!  (You'll nevva get it...)
Eve:   Is it 16,625,976,563?
Craig: No. Higher!
Eve:   (Sigh!)  Is it 16,633,300,782?
Craig: No. Higher!
Eve:   Oh Shoot!  Is it 16,636,962,892?
Craig: No!  No!  No!  Hiiiiigher!
Eve:   Is it 16,638,793,947?
Craig: Hahahah!  You're sooo lost!  Lower!
Eve:   Is it 16,637,878,419?
Craig: Lower!
Eve:   Is it 16,637,420,655?
Craig: Higher!
Eve:   Is it 16,637,649,537?

Well, those of you who hasn’t realized by now that Eve will manage to nail that number between zero and thirty-billion before long… … read on.

So what happened here? I knew the number beforehand, so I just arranged the guessing competition?

This is exactly what happened:

Eve started off with half the top number (half of 30 bil is 15 bil, right?) And depending on if Craig told her the number she guessed was higher or lower, Eve divided 15 bil in half (7.5 bil) and added or subtracted to 15 bil. In this scenario 15 was lower than 16 so Eve added 7.5 and got 22.5 bil which was way high. Craig told her so, Eve divided 7.5 in two (getting 3.75) and subtracted this from 22.5, getting 18.75). (You can see exactly how this plays out in [1] below).

You can do this as well, but if you don’t have a calculator and pen and paper, choose a lower max, like a thousand or ten-thousand.

Okay, back to the discussion. First off, the higher-lower clue is probably more than nature gives us (it just kills us ;o). And guessing between zero and 30 bil is probably also grossly underestimated. The number should probably be thousands, even millions of times higher, and the clues about as much fuzzier.

So, let’s up the stakes!

How many attempts would it take for Eve to guess a number roughly representative of the human genome? There are some 3 billion base pairs (Functional and Comparative Genomics Fact Sheet) in a human genome. Each of these pairs can consist of a combination of four different bases (usually abbreviated A, C, G, and T for adenine, cytosine, guanine, and thymine, http://www.answers.com/nucleotide), but for the heck of it, let’s assume once we’re done understanding life we’ve realized there’s as many as 100 different bases that can be combined in a pair, and that they can be combined in any order.

Let’s represent a pair as two numbers between 0 and 99 for each base, meaning one pair is a number between 0 and 9999. So, the number we’re looking at is 3 billion x 4 digits long. Minimum 0, maximum 12 billion 9′s. We can describe this number as a power of ten:

The number representing the genome
The number representing the genome

And the maximum number of attempts needed will be:

Number of guesses for the genome
Number of guesses for the genome

That means it will take approximately 3.32×10^13 attempts to get to the right human genome (and that is probably exaggerated since this calculation first says there can be as many as a hundred bases in a nucleotide pair — space taken for future exploration, and no regard has been taken to what nucleotides really can be paired together with which. Also note that this number of attempts are required for a given individual not just any human. If Eve guessed on Craig’s grandpa instead of say Craig, she would still be wrong and have to continue until she guessed on Craig).

If one person were to make one guess per second on an number “roughly” equivalent to the human genome it would take about 1.05 million years to guess the correct number…

What does this number mean? If we were to make one attempt a second it would take us roughly 1,053,000 years to get the right number. There are a lot of factors to take into consideration here. Most of the groundwork was made before nature even managed to produce the first single-cell organism… the number of failures before this happened were probably numerous and recurrent.

Some scientists (Functional and Comparative Genomics Fact Sheet) believe the differences between mammals to be very small (for instance the genes in a mouse not possessed by a human and vice versa may be around 1%). What this probably means is that there are numerous combinations which has never occurred within any animal on earth. Already from the beginning a huge number of combinations were discarded to the benefits of others (or in other words, the kind of life we’re seeing on earth is probably far from the only working combination!)

The kind of life we’re seeing on earth is probably far from the only working combination!

Some bacteria reproduce in about an hour (but rates can vary between 12 minutes and 24 hours or even more http://textbookofbacteriology.net/growth.html), so for those bacteria it would take 3600 times as much time to get the exact genome down…. and that means it would take 3,8 billion years… how… convenient, since scientists believe life occurred on earth some 3.2 – 3.7 billion years ago (How and Where Did Life on Earth Arise?, Carl Zimmer, Science, Vol 309, Issue 5731). However, when talking about bacteria, we’re not talking about one single line of bacteria doing the whole job, we’re talking about billions and billions of them working in parallel, one variant defeating another less “fit to survive” variant, over and over again.

It’s actually a bit hard to see how life could have not evolved, given the circumstances on this planet, but let’s not go further into that duscussion just yet.

Okay, point number 2 above. The probability for this to happen is “zero many times over”

Well, maybe you would have been right if Earth was the only place were life has attempted to evolve. However… you need to take a good look at the universe… (unless you belong to those who think the Sun rotates around the Earth and the stars are small piercings in a black cloth, if that’s the case, I can only give my condolences….)

In the Milky Way alone there are some 200 billion stars (see Ask an Astrophysicist, Size of the Milky Way), and even if only 1% of these have planets, and 1% of those has planets with even a remotely acceptable temperature and only 1% of those have an atmosphere that would sustain life and only 1% of those really had life and only 1% of those had intelligent life it would still be 20 stars in this galaxy alone with intelligent life.

That would equal a 1 in 10 billion chance of intelligent life (0.000000001%).

Given that the universe is estimated to contain some (holes in black cloths disregarded here, sorry) 1,000,000,000,000,000,000,000 stars (10^21) (see Ask an Astrophysicist, The Number of Stars).

The universe is estimated to contain some one thousand billion-billion stars (that’s a one with 21 zeros after it…)

The 1 in 10 billion estimate would give us around 100,000,000,000 (100 billion) star systems with intelligent life in the universe… The part of the universe we can see so far…. However, I believe that number to be grossly exaggerated, I am sure there are no more than say three or four thousand planets with intelligent life in the known universe (which would give us a 1 in 285 million billion chance — or 0.00000000000000035% — for intelligent life in a given solar system).

I believe there are only a few thousand solar systems with intelligent life in the universe…

Very few of these 3-4000 planets probably have societies that has evolved far enough to start making noise we can pick up. Some may take thousands of years before they get that far, some may already have gone past the “radio” era, but since they’re millions of light-years away they would already have come here, seen us, yawned and went home again, when their radio signals finally reaches us…

One of the major failures of ID/Creationism aficionados is the inability to fathom how huge the known universe is. Professor Edwin Conklin is rumored to have said that the probability of life originating from accident is comparable to the unabridged dictionary resulting from an explosion in a printing factory. To put things into perspective, lets contemplate the number of printing factories that can be placed on the planets of one thousand billion billion solar systems, and how many times these factories can explode during some 3.5 billion years.

I am still saying life did not happen by chance, accident or randomness, but I’d like to make a point that the size of the universe does play a significant role when determining the feasibility of evolutionary theories.

So what do I believe….?

I believe if God ever created anything, then God created evolution… >:P

Maybe God created evolution?


[#1] The number guessing, beat-by-beat (Craig thought of the number 16,637,597,566)

Guess # Eve’s guess What she added / subtracted Craig’s reply
1 15 000 000 000 - Too low!
2 22 500 000 000 7 500 000 000 Too high!
3 18 750 000 000 3 750 000 000 Too high!
4 16 875 000 000 1 875 000 000 Too high!
5 15 937 500 000 937 500 000 Too low!
6 16 406 250 000 468 750 000 Too low!
7 16 640 625 000 234 375 000 Too high!
8 16 523 437 500 117 187 500 Too low!
9 16 582 031 250 58 593 750 Too low!
10 16 611 328 125 29 296 875 Too low!
11 16 625 976 563 14 648 438 Too low!
12 16 633 300 782 7 324 219 Too low!
13 16 636 962 892 3 662 110 Too low!
14 16 638 793 947 1 831 055 Too high!
15 16 637 878 419 915 528 Too high!
16 16 637 420 655 457 764 Too low!
17 16 637 649 537 228 882 Too high!
18 16 637 535 096 114 441 Too low!
19 16 637 592 317 57 221 Too low!
20 16 637 620 928 28 611 Too high!
21 16 637 606 622 14 306 Too high!
22 16 637 599 469 7 153 Too high!
23 16 637 595 892 3 577 Too low!
24 16 637 597 681 1 789 Too high!
25 16 637 596 786 895 Too low!
26 16 637 597 234 448 Too low!
27 16 637 597 458 224 Too low!
28 16 637 597 570 112 Too high!
29 16 637 597 514 56 Too low!
30 16 637 597 542 28 Too low!
31 16 637 597 556 14 Too low!
32 16 637 597 563 7 Too low!
33 16 637 597 567 4 Too high!
34 16 637 597 565 2 Too low!
35 16 637 597 566 1 *growl*