If the Cambrian is full of these diverse phyla and lifeforms, then why zilch before 580mya?
Please note the Cambrian started 542 mya. That means that there was 38 million years (half the time back to the KT boundary) to get from simpler organisms to what we see early in the Cambrian.
You quote says:
quote:
Before about 580 million years ago, most organisms were simple, composed of individual cells occasionally organised into colonies.
It does NOT support "zilch". It says 'most'. Perhaps there was nothing but that is not what the post says. And it is 38 million years (which is a rather long time) before the Cambrian starts.
There was disolved oxygen in the seas.
The oxygen content of the seas was also low. It has to be in equilibrium with the air. The point is that there wasn't oxygen for most of the vast expanse of time before.
However, the snowball episodes occurred a long time before the start of the Cambrian, and it is hard to see how so much diversity could have been caused by even a series of bottlenecks;[18] the cold periods may even have delayed the evolution of large size.[39]
I didn't make myself clear. It is about this time that multicellular organisms started to appear not the life of the Cambrian. You asked about "why only simple life for so long". This is one thing that
may have influenced it. The timing is just at the end of snowball earth so it may be connected. It is only conjecture that they are connected it may simply have been contingency or the level of oxygen in the air was finally adequate at the same time. Of course, it was a long time before the Cambrian. The build up from mostly single (all?) celled organisms began a long time before the Cambrian. It didn't just "poof" at the Cambrian. That is the point. You've now backed up to about 58 million years before the Cambrian.
And, of course, the Cambrian itself lasted about 29 million years. (abe- 29 being the smallest range I could find. Other sources suggest 50 million years). That gives you a rather long drawn out "poof" doesn't it? It is plenty of time in fact.
It means faith my friend. It is the evidence of things hoped for the conviction of things not seen. (Heb 11:1)
In other words it is a simple-minded god-of-the-gaps argument. This has been demonstrated to be poor theology over and over. So much so that sophisticated theologians and other believers know how foolish it is.
This gap is already a lot more closed that it was a very few decades ago and it is also a lot more closed than you think it is. Your ignorance of facts doesn't mean they are not there.
Edited by NosyNed, : No reason given.