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StephenT [userpic]

Evolution's timespan

14th December 2009 (19:19)
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For once, a post that has absolutely nothing to do with fandom...

On another forum, someone was being sceptical of evolution because they couldn't believe that tiny little changes generation by generation could account for the development of bacteria into humans. Of course, if you believe the world was created on 22 October 4004 BC then you're right, there wouldn't be enough time, barring miracles (*cough*). But for those of us who prefer knowledge to revelation in understanding the world, there's still the problem that the human brain can't really cope with numbers in the millions or billions on an intuitive level. Unlike the rabbits in Watership Down, we can at least count above four... but at some point even we switch to "seventy-nine, eighty, many, lots".

So I put together the following as an attempt to communicate just how long a timescale evolution has had to work with, if we accept that life developed about 4 billion years ago. And I thought maybe a few other people might be interested too, so I'm posting it here.

I did get most of the data from Wikipedia, so if anyone in my flist is a paleontologist feel free to let me know more accurate details. :-) Also, apologies to traditionalist hold-outs who still think that a billion should be a million million instead of a thousand million. I'm afraid I've succumbed to creeping Americanisation here.


Four billion is a very big number

The oldest person alive today is a little over a hundred years old. Let's say this dot represents their lifespan:
.

Go back two hundred years - double the limit of human memory - and you're into the era of Napoleon Bonaparte and Thomas Jefferson. Two hundred years is two of our little dots:
..

Now let's go back two thousand years, to the birth of Jesus. That's twenty little dots:
....................

How about the building of the Great Pyramid in Egypt? That was in around 2570 BC, which is 46 dots:
..............................................

The discovery of agriculture is usually estimated to be around 8000 BC. That's 100 dots:
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Before that time, humans lived as stone age hunter-gatherers. The earliest known skeletons which are anatomically fully human have been dated to about 195,000 years ago. That's 1950 dots:
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Those humans evolved out of earlier semi-human ancestors like Homo habilis and Homo erectus. The earliest members of the genus evolved around 2.5 million years ago. That's 25,000 dots. Look at the representation above, with 1950 dots, and imagine it repeated 13 times. If you use an 11-point font with normal spacing, you can just about fit 25,000 dots onto a single sheet of A4 paper. That's how long it took for creatures which looked very much like humans to evolve into humans.

The evolution of humans and chimpanzees diverged around six million years ago, according to most estimates. That's two and a half sheets of paper covered in dots.

How about the first mammals, with fur, warm blood and giving birth to live young? The earliest known such fossil we're aware of - Eomaia - evolved aroud 125 million years ago. That's 50 sheets of paper each covered in 25,000 dots; about the size of a magazine.

How about the first vertebrates? The earliest known fossil with a backbone comes from 505 million years ago - a type of fish resembling a modern lamprey eel. These creatures swam the world's oceans 202 sheets of paper covered in dots ago. That's a 400-page novel composed of nothing but dots, if we allow for the novel to be printed at half-A4 in size.

The first multi-cellular life - a form of algae - appeared 2,100 million years ago. That's 840 sheets of paper. Four 400-page novels.

Finally, go back around 4 billion years and the first primitive cells - equivalent to bacteria - are found. Four billion years would be 1600 of our sheets of paper.


So, if you work in an office, go to the stationary cupboard where they keep the photocopier paper. Take three reams of 500 sheets each and stack them up. With a pen, mark a little dot on the topmost sheet. That's the lifespan of the oldest human alive. Now imagine every one of those 1500 sheets covered in identical dots. You still don't have enough paper there to show how long evolution has been operating...

Comments

Posted by: The Mezzanine (deird1)
Posted at: 14th December 2009 19:28 (UTC)

How very funky...


As fascinating as this post is, I have to say my main reaction was "Ooh! Watership Down! Bunnies! So many bunnies!" ...and I just kinda sat there and kept doing that. Watership Down can distract me from just about anything. :)

Posted by: StephenT (stormwreath)
Posted at: 14th December 2009 19:51 (UTC)

Well, you could also interpret the post to say:

This is two bunnies:
..

This is the same group of bunnies after four years:
............

This is the same group of bunnies after 16 years:
[pageful of dots]

And so on. :-)

Posted by: Lily (lavastar)
Posted at: 15th December 2009 00:10 (UTC)

Posted by: fix me, motherfucker! i'm standing right here. (immortality)
Posted at: 14th December 2009 19:53 (UTC)

I think the problem is, people seem to have this idea that one day there was an ape and the next day there was a human, and well, just, NO. They don't seem to grasp the concept that this happened, like you illustrated, over thousands and thousands of years. It didn't just happen in one day. It took hundreds and hundreds of genetic mutations before we got where we are today. As for the evolution of life itself, well -- again, like you illustrated -- it took billions of years, how is it not possible to understand how this could have worked?

Honestly, the problem is, most people have ZERO grasp of basic biology concepts, so none of this makes sense to them. It's just serious academic fail.

Posted by: StephenT (stormwreath)
Posted at: 14th December 2009 19:58 (UTC)

Exactly. :-) The whole of recorded history takes up less than half the length of the first line of that block of 20 rows of dots... and that's just the history of modern humans... the people that came before that weren't even apes, they were just short humans with bigger bones and sloping foreheads compared to us.

Posted by: 2maggie2 (2maggie2)
Posted at: 14th December 2009 20:10 (UTC)

FWIW, the argument about how big 4 billion is means nothing if you don't put it side by side with the big number of mutations that would be required to get from point a to point b. And it's still begging the question of how life evolved, which AFAIK is still an unsolved question. I would hardly want to take the side of a person who thinks that the Bible requires that we believe that God created the world a few thousand years ago -- but the argument here doesn't go through without a good deal more work.

My own position on the debate between true-believing proponents of evolution and true-believing Bible fundamentalists is to say a pox on both your houses. My God can create in a day or over billions of years, so it makes no difference to me. But there's plenty of sloppy reasoning that happens on the pro-evolution side and when that keeps happening it makes me think there's more going on that just level-headed scientists reporting the facts. See Stephen Gould on both the large questions hovering over received Darwinian doctrine and on the way scientists can deceive themselves and others when they have axes to grind. We're all humans and nobody has a monopoly on clear headed reasoning.

Posted by: The One Who Isn't Chosen (gabrielleabelle)
Posted at: 14th December 2009 20:36 (UTC)

The key difference between science and religion, though, is that science is self-correcting. There's no doubt that science gets things wrong. Horribly wrong (see eugenics). It can be used to validate biases and such. That's why it gets put up for peer review, retesting, criticism, etc. There is no end goal in science.

There is an end goal for religion, though, and anything that doesn't reach that goal must be twisted to follow in line.

Personally, I don't see much point in the science vs religion debate. They're two entirely different things. Plenty of people are able to reconcile their religious beliefs with their scientific beliefs. And as an atheist, I really don't care too much what religion says on anything unless it has decent facts and evidence supporting it (which most of the creationism aka intelligent design stuff doesn't).

Posted by: 2maggie2 (2maggie2)
Posted at: 14th December 2009 21:40 (UTC)

Posted by: The One Who Isn't Chosen (gabrielleabelle)
Posted at: 14th December 2009 22:02 (UTC)

Posted by: flake_sake (flake_sake)
Posted at: 14th December 2009 20:40 (UTC)

Posted by: 2maggie2 (2maggie2)
Posted at: 14th December 2009 21:13 (UTC)

Posted by: StephenT (stormwreath)
Posted at: 14th December 2009 20:42 (UTC)

Posted by: 2maggie2 (2maggie2)
Posted at: 14th December 2009 21:31 (UTC)

Posted by: Nicki (peroxidepirate)
Posted at: 14th December 2009 22:31 (UTC)

Posted by: flake_sake (flake_sake)
Posted at: 14th December 2009 20:30 (UTC)

Very nice piece of making unimaginable imspans imaginable :). I'll have to bookmark it for further discussions.

Just had a very lenghty one with an antievolutionist on the BF.

Posted by: StephenT (stormwreath)
Posted at: 14th December 2009 20:45 (UTC)

Really? I must have missed that (then again, I usually only look in the S8 forum on BF so it's unsurprising I missed it.) Glad it was interesting. :-)

Posted by: flake_sake (flake_sake)
Posted at: 14th December 2009 21:06 (UTC)

Posted by: The One Who Isn't Chosen (gabrielleabelle)
Posted at: 14th December 2009 20:32 (UTC)
vamp willow

Wow. That was hot.

*bookmarks*

Posted by: StephenT (stormwreath)
Posted at: 14th December 2009 20:46 (UTC)

*Files away another reference point in the eternal struggle to fathom the mystery that is Gabs' sexuality.* ;-)

Posted by: alexeia_drae (alexeia_drae)
Posted at: 14th December 2009 21:13 (UTC)
lost in space

Will have to add this to Carl Sagan's Cosmic Calendar as a good way to visualize the enormity of the time that has come before us. I actually like this a bit better because of all the paper that would be involved makes for a better visual IMHO.

Posted by: StephenT (stormwreath)
Posted at: 14th December 2009 21:21 (UTC)

I was tempted to look through online stationery stores for a photo of 1500 sheets of paper stacked up together. ;-)

Posted by: joe_sweden (joe_sweden)
Posted at: 14th December 2009 21:23 (UTC)

Until recently, I was one of those traditionalists. But have finally moved with the times. Bring on the milliard style billions!

Posted by: StephenT (stormwreath)
Posted at: 14th December 2009 21:35 (UTC)

You've been Americanised! I hope it wasn't painful...

Posted by: Beer Good (beer_good_foamy)
Posted at: 14th December 2009 21:50 (UTC)

Very nice outline. I'll always find it fascinating that there are people who think the universe is younger than the oldest currently living organisms.

Posted by: StephenT (stormwreath)
Posted at: 14th December 2009 22:05 (UTC)

God hid fossils in the ground to trick us. :-)

Mind you, given that bacteria reproduce by division, it's surely possible that the same bacterium is alive today that was created 4,000,000,000 years ago?

Posted by: erimthar (erimthar)
Posted at: 14th December 2009 22:03 (UTC)

Unfortunately, the primary arguments of evolution deniers tend to fall into one or both of these categories:

1. The Bible says different, or
2. If I can't wrap my mind around it, it's nonsense.

Posted by: StephenT (stormwreath)
Posted at: 14th December 2009 22:07 (UTC)

I think the person who inspired this was more in the mode of "I've heard both arguments and they both seem to make ssense, can you help?" rather than being an outright denier. The victim of the anti-intellectual climate created by deniers, you might say.

Posted by: none of the above (frogfarm)
Posted at: 14th December 2009 22:05 (UTC)

On my usual tangent, this was one of my favorite childhood books.

Posted by: StephenT (stormwreath)
Posted at: 14th December 2009 22:06 (UTC)

I'd not heard of that. It sounds like the kind of book you'd want to borrow from the library rather than buy. :-)

Posted by: Nicki (peroxidepirate)
Posted at: 14th December 2009 22:32 (UTC)

Neat!

Posted by: StephenT (stormwreath)
Posted at: 14th December 2009 22:36 (UTC)

:-)

Posted by: Lily (lavastar)
Posted at: 15th December 2009 00:17 (UTC)

WAIT. WAIT. WAIT.

Who gives a shit about this evolution stuff, but BILLION DOESN'T MEAN THE SAME TO EVERYONE????

You are like the research Wikipedia explainy man, so please hit me with some knowledge: how the heck do we get around talking about things with a basic numbery thing meaning different stuff to different people?? And how did I not know about this??

Posted by: StephenT (stormwreath)
Posted at: 15th December 2009 02:51 (UTC)

Who gives a shit about this evolution stuff
Lots of people actually. ;-)

Anyway:

In the US, 1 billion = 1,000,000,000 (a thousand million)

In Europe, formerly,
1 billion = 1,000,000,000,000 (a million million)
The number 1,000,000,000 was called a "milliard" instead.

But around, maybe 30 years ago? at least in Britain, we started using the US names instead. For a while you had to specify "an American billion" to make it clear what you meant; but these days, it's just understood.

That's what I meant by the comment about being Americanised. Which sounds painful. Or possibly a lot of fun, depending on the American.

Posted by: Lily (lavastar)
Posted at: 15th December 2009 22:36 (UTC)

Posted by: Peasant (peasant_)
Posted at: 15th December 2009 04:32 (UTC)

This is a great explanation! Far better than the normal 'if man evolved a minute ago...' explanations which end up being just as ungraspable. But thick reams of paper, everyone can imagine thick reams of paper.

I find it also helps in these discussions to also explain just how quickly evolution can work. Here's a nice example: Britain's bird tables changing the path of evolution. People often feel more comfortable knowing that evolution is not just a theory but a directly observable phenomenon.

Now, what have you got on explaining coriolis force...?

Posted by: StephenT (stormwreath)
Posted at: 15th December 2009 13:56 (UTC)

Thanks! Though I do also like the 1 second=1 year, 1 minute= 60 years, 4 billion years = 127 years comparison.

The bird example is neat, thanks for that. It has more cute-appeal than the one I'd thought of, which involves MRSA.

I have to admit I know almost nothing about Coriolis force other than that it's something to do with spinning...

Posted by: candleanfeather (candleanfeather)
Posted at: 15th December 2009 19:08 (UTC)

Did you know that two of most important founders in paleontology and prehistory are priests? Teilhard de Chardin was a Jesuit, a paleotologist and the author of a treaty conciling science and religion; Breuil who worked on many prehistoric sites in France and even in China is a priest (L'abbé Breuil).

"I'm afraid I've succumbed to creeping Americanisation here." Noooooo! But at least you'll keep your sexy British accent? Right? Right? (Panics).

Posted by: StephenT (stormwreath)
Posted at: 15th December 2009 21:29 (UTC)

Did you know that two of most important founders in paleontology and prehistory are priests?

No - but it's not really surprising. The idea that science and religion are incompatible, polar opposites is thankfully resricted to a relatively small cultural milieu so far. :-)

Noooooo! But at least you'll keep your sexy British accent? Right? Right? (Panics).

*blinks* You too? I can understand Americans thinking a British accent is sexy, but French people too? You live next door to us, we've been fighting each other for the last thousand years!

And more to the point, everybody knows that the French accent is the sexiest in the world; you should be too distracted by each other to be listening to us... ;-)

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