Does the Cambrian Explosion pose a challenge to evolution?https://biologos.org/common-questions/does-the-cambrian-explosion-pose-a-challenge-to-evolution/
The “Cambrian Explosion” refers to the appearance in the fossil record of most major animal body plans about 543 million years ago. The new fossils appear in an interval of 20 million years or less. On evolutionary time scales, 20 million years is a rapid burst that appears to be inconsistent with the gradual pace of evolutionary change. However, rapid changes like this appear at other times in the fossil record, often following times of major extinction. The Cambrian Explosion does present a number of interesting and important research questions. It does not, however, challenge the fundamental correctness of the central thesis of evolution.
The Cambrian Explosion is often posed as a challenge for evolution because the sudden burst of change in the fossil record appears to be inconsistent with the more typical gradual pace of evolutionary change. However, although different in certain ways, there are other times of very rapid evolutionary change recorded in the fossil record—often following times of major extinction. The Cambrian Explosion does present a number of challenging and important questions because it represents the time during which the main branches of the animal tree of life became established.
It does not create a challenge to the fundamental correctness of the central thesis of evolution, the descent of all living species from a common ancestor.
This important period in the history of life extended over millions of years, plenty of time for the evolution of these new body plans (phyla) to occur. Furthermore, the fossil record provides numerous examples of organisms that appear transitional between living phyla and their common ancestors. The ongoing research about the Cambrian period is an exciting opportunity to advance our understanding of how evolutionary processes work, and the environmental factors shaping them.
The major animal body plans that appeared in the Cambrian Explosion did not include the appearance of modern animal groups such as: starfish, crabs, insects, fish, lizards, birds and mammals. These animal groups all appeared at various times much later in the fossil record.3 The forms that appeared in the Cambrian Explosion were more primitive than these later groups, and many of them were soft-bodied organisms. However, they did include the basic features that define the major branches of the tree of life to which later life forms belong.
ANU’s calculations state that Dickinsonia lived 558 million years ago, some 16 million years before the Cambrian explosion is thought to have begun. This will no doubt help shape scientists’ thinking about the Ediacaran biota, which, because individual species were so difficult to classify, had left scientists scratching their heads for many years.As the team writes in the paper, their conclusion about Dickinsonia’s age “supports the idea that the Ediacaran biota may have been a precursor to the explosion of animal forms later observed in the Cambrian, about 500 million years ago.”
What this means is that, although Dickinsonia doesn’t exist today, it is the earliest known part of the evolutionary family tree from which all animals — our unbathmat-like selves included — eventually emerged.
www _ inverse _ com/article/49169-dickinsonia-lived-before-cambrian-explosion