”Over the years, as paleontologists have reflected on the overall pattern of the Precambrian–Cambrian fossil record in light of Walcott’s discoveries, they too have noted several features of the Cambrian explosion that are unexpected from a Darwinian point of view11 in particular: (1) the sudden appearance of Cambrian animal forms; (2) an absence of transitional intermediate fossils connecting the Cambrian animals to simpler Precambrian forms; (3) a startling array of completely novel animal forms with novel body plans; and (4) a pattern in which radical differences in form in the fossil record arise before more minor, small-scale diversification and variations. This pattern turns on its head the Darwinian expectation of small incremental change only gradually resulting in larger and larger differences in form.”
Stephen C. Meyer. ”Darwin's Doubt.”
You are right here. Paleongologist have wondered this a lot, and you failed to mention that they did find answers.
Each era shows an explosion of new life, and era ends when the environment is so full that survival of the fittest OR changing conditions make current forms obsolete, thus most of the living things die out.
Cambrian biota do not mostly fit to later period because most of the life forms died out completelly, no surviving kids to speciate and multiply. They did not adapt. They died.
Same with Ediacaran. Only few animals developed a hard shell giving them HUGE advantage over soft bodied animals, and they DOMINATED the planet for next 40 million years before this happened:
ø The Ordovician Period started at a major extinction event called the Cambrian–Ordovician extinction events some time about 485.4 ± 1.9Mya (million years ago), and lasted for about 44.6 million years. It ended with the Ordovician–Silurian extinction event, about 443.4 ± 1.5 Mya (ICS, 2004) that wiped out 60% of marine genera.
ø Theories[edit]
- Glaciation
- Depletion of oxygen in marine waters
Most of the planet was covered by Ice, so do you really expect "gradual changes" to gradually move one age to another? Catastrophes usually mark the end of an era and the beginning of another!!
You can only wonder the speed of evolution, not Darwin´s theory. And I repeat earlier comments here.
Ediecaran and cambrian eras had faster evolution than now because of short lifespan of biota AND more room to live. Now every corner is filled with animals that have adapted to their own niche. they cannot find new ecological slots to fill because they are filled.
Humanity mixes this by moving biota from one niche area to another, effectly allowing new species to devestate the new area completelly and thus shake the equilibrium and speed up evolution that way.
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