Cambrian Explosion Trick
The Cambrian period 540 million years ago is the period of time when animals developed hard shells that started making clear fossils. This relatively sudden appearance in the fossil record is used by Christian apologists to argue that evolution could not have done this.
Yet the 'Cambrian Explosion' is an eye catching phrase and much is written about it and much of that is distorted to inflate the drama. Large multicellular life is known to exist up to 100 million years earlier.
How Sudden Was It?
The Cambrian period was from 542/528 to 488/485 million years ago. the period itself lasted for around 54 Million years, which is actually a long time. The layer of history got named by paleontologists classified the layer according to a general grouping of the kinds of fossils seen in that age of rocks, and particularly because the layers older than that did not have visible large fossils.
Christian creationists Stephen Meyer wrote a book claiming that all the various life forms appeared in 5 million years. He is a famous proponent of intelligent design and has written a book on the topic. That 5 million years corresponds to the time that trilobites were plentiful: 525 to 520 million years ago, and there appears to have been an extinction event at around 520 million years ago. The Christian apologist claims are always the more dramatic and much shorter period than mainstream science.
This assumption of a sudden appearance of life, although largely propagated among the wider public, is not generally accepted among most scientists, who consider that the ‘explosion’ lasted several tens of millions of years and was thus not by any means ‘explosive.’ The Wikipedia article on the topic cites a number of references saying the period lasted 13 million years, and several more claiming it was 25 million years.
Soft Bodied Life
In doing apologists conflates the appearance of fossils with the appearance of life. The fossil record is incomplete, and sometimes what seems like a sudden appearance is really a consequence of missing information.
The oldest fossils of microscopic creatures are 4.5 billion years so there is a lot of time for soft bodied animals to evolve.
The Ediacaran biota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period (c. 635–538.8 Mya). These were enigmatic tubular and frond-shaped, mostly sessile, organisms. Trace fossils of these organisms have been found worldwide, and represent the earliest known complex multicellular organisms.
It is now clear that the Ediacaran biotas of the latest Precambrian were already highly diverse; some authors indicated that the roots of the Cambrian ‘Explosion’ lie in the Precambrian, and considered that there is possibly no true separation between Ediacaran and Cambrian skeletal biotas
Media Bias
It is obvious today that articles including the words ‘Cambrian Explosion’ are regularly published in the journals that have a large media attention, also because the terminology ‘explosion’ attracts readers in search of eye-catching headlines. Probably also partly for this reason, the idea of an abrupt appearance of life has been popular in the media, attracting many readers and followers, similar to the Biblical idea by implying that life on Earth appeared virtually overnight. Occasionally the exact moment of the ‘explosion’ is even located by some authors precisely at the base of the Cambrian System, about 541 Ma years ago, a gross over-simplification that even appears in articles of high impact research journals.
Environmental Shifts
The Cambrian Explosion was likely driven by a combination of environmental factors, such as increased oxygen levels and changes in ocean chemistry. These changes could have facilitated more active metabolisms and larger body sizes, allowing for greater complexity and new ecological interactions.
The First Predators
Anomalocaris is one of the most famous animals of Canada’s Burgess Shale: a predatory invertebrate with a pair of grasping appendages at the front of its head, a disclike mouth set with plates to help suck in prey, and complex eyes on stalks that could better detect a potential meal.
The rise of such predators during the Cambrian, some paleontologists have suggested, would have kicked off an evolutionary arms race in which prey species would have had to develop armor, a way to escape, or perhaps even complex eyes to see the predators first.