Cambrian Explosion: not from Ediacarans (Introduction)

by dhw, Wednesday, August 13, 2014, 23:03 (2054 days ago) @ David Turell

DAVID: These simple fern-like animals die out and complex Cambrians appear, big jump, the gap still unexplained:

http://www.sciencedaily.com/releases/2014/08/140811170201.htm


QUOTE: "The oceans during the Ediacaran period were more like a weak soup -- full of nutrients such as organic carbon, whereas today suspended food particles are swiftly harvested by a myriad of animals," said co-author Professor Simon Conway Morris.
Starting 541 million years ago, the conditions in the oceans changed quickly with the start of the Cambrian Explosion -- a period of rapid evolution when most major animal groups first emerge in the fossil record and competition for nutrients increased dramatically."

Quote: "As the Cambrian Explosion began however, the rangeomorphs became 'sitting ducks', as they had no known means of defence from predators which were starting to evolve, and the changing chemical composition of the ocean meant that they could no longer get the nutrients they required to feed.
"As the Cambrian began, these Ediacaran specialists could no longer survive, and nothing quite like them has been seen again," said Dr Hoyal Cuthill
."

Simon Conway Morris establishes a clear link between the changes in the environment, the arrival of new species, and the extinction of the hitherto flourishing rangeomorph. The implication is unmistakable: new conditions lead to new modes of survival, and existing organisms must either adapt, innovate, or perish. Here are the four explanations we have considered, the last three of which advocate intelligent design:

1) Darwin's random mutations, which we both reject. (But we do NOT reject natural selection, because that simply decides which changes will or won't survive).
2) Your God preprogrammed both the changes in the environment and the innovations right from the beginning of life. (= Automatized evolution)
3) Your God stepped in to change the environment and to implant all the innovations. (= Creationism)
4) The environment changed, and some organisms had the ability to change their structure in order to survive in and/or exploit the new conditions. (= Evolution)

In 2), since you insist that the innovations were all part of your God's “intricate planning”, and since they depend on environmental change, I am assuming the environmental changes must have been incorporated into his plans.
In 3), I am assuming that your God's plans were not at the mercy of environmental changes outside his control
In 4), the source of the ability of organisms to change is unknown, but it may have been your God.

Of course we are going over the same ground, but there has to be an explanation for the jump. Anyone like to make a choice? Or offer a different explanation?


Complete thread:

 RSS Feed of thread

powered by my little forum