
What caused the Cambrian explosion? - tokenadult
http://whyevolutionistrue.wordpress.com/2013/06/20/what-caused-the-cambrian-explosion/
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jofer
It's important to note that in geologic terms, the Cambrian Explosion really
refers to the proliferation of hard-bodied organisms. There's almost
definitely a sudden increase in global biodiversity, but it's an increase in
fossil preservation that gives it the name "Cambrian Explosion".

Fairly complex lifeforms were around well before the Cambrian (e.g. the
Ediacaran Fauna [1]), and even some hard-bodied organisms were around before
(the "small shelly fauna" [2]).

At the start of the Cambrian, though, hard body parts (i.e. biomineralization)
really took off. It's often hypothesized to be an "evolutionary arms race"
with armor and teeth.

In that context, weathering of the continents influencing the chemical
composition of the seas and therefore making it easier for organisms to grow
hard body parts starts to make a lot more sense.

[1]
[http://en.wikipedia.org/wiki/Ediacara_biota](http://en.wikipedia.org/wiki/Ediacara_biota)
[2]
[https://en.wikipedia.org/wiki/Small_shelly_fauna](https://en.wikipedia.org/wiki/Small_shelly_fauna)

Also, I just noticed that the article links to something in New Scientist. The
paper it refers to was published earlier in Nature:
[http://www.nature.com/nature/journal/v484/n7394/abs/nature10...](http://www.nature.com/nature/journal/v484/n7394/abs/nature10969.html)
Google Scholar tells me there's a pdf here, if anyone is interested:
[http://211.144.68.84:9998/91keshi/Public/File/34/484-7394/pd...](http://211.144.68.84:9998/91keshi/Public/File/34/484-7394/pdf/nature10969.pdf)

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barryfandango
The cambrian explosion is really interesting but I'd rather read about the
thing itself, not framed as a polemic against creationism. I don't care about
creationism.

~~~
astrodust
Science education is so damaged in the United States now that a survey of
people on the street would probably find a worryingly high percentage of
people believed either a) the "Cambrian explosion" was an asteroid impact, b)
involved explosives, or c) took place over a matter of hours or days.

~~~
HarryHirsch
It's not only science education; what I see here in the US (and I am saying
that as a practicing Catholic from Europe) is a problem with people's faith.
They think it's under assault and in need of defense, they think God's word
isn't strong enough to hold its own in the world, and that's where these weird
arguments in favour of creationism comes from. I think they have crossed the
line into blasphemy.

You even have this phenomenon of Cleanflix, this Mormon endeavour of beeping
out rude words in Hollywood movies, because they are seen a threat to their
worldview. This is for the same reason; they have weak faith.

~~~
alexqgb
Exactly. If someone's "faith" needs proof, then it's hardly faith anymore, is
it?

You can't really frame conflicts with these people in terms of "science vs.
religion". It's more like blocking trolls who have failed at both, stopping
them from taking violent swings at civilization.

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tokenadult
More about the Cambrian period, from the University of California Museum of
Paleontology:

[http://www.ucmp.berkeley.edu/cambrian/cambrian.php](http://www.ucmp.berkeley.edu/cambrian/cambrian.php)

A book review, titled "Decoding the Cambrian Radiation," of the book _On the
Origin of Phyla_ (2004):

[http://www.americanscientist.org/bookshelf/pub/decoding-
the-...](http://www.americanscientist.org/bookshelf/pub/decoding-the-cambrian-
radiation)

Lecture notes, "The Origin of Phyla and the Cambrian Explosion of Life," with
color slides for an undergraduate course about fossils and evolution:

[http://www.geo.wvu.edu/~kammer/g230/originphylacambrianexplo...](http://www.geo.wvu.edu/~kammer/g230/originphylacambrianexplosion.pdf)

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thaumasiotes
This idea is not original to me. But I still remember a comparison of the
Cambrian explosion to a gardener looking at a major tree on his grounds and
remarking "you know, it's funny that no major boughs have appeared on this
tree for some time. These days, all the growth seems to be at the twig level."

