Through the 1990’s the Cambrian period was thought to have began 570 million years ago (mya) and end 510 mya (a 60 million year period). Novel (new) Cambrian animal forms emerged within a 20-40 million year window within this period. Today, radiometric dating of crystals by paleontologists and geochronologist have narrowed the Cambrian period downward to 543 mya through 490 mya (a time period of about a 53 million years). These studies further suggest that the explosion of life (The so called “Cambrian Explosion“) occurred within a narrow window within the Cambrian. The emergence of novel life forms emerged even more suddenly then ever before imagined, in as little as 5 -10 million years.1
“Compared with a 3+ billion year history of life on earth, this period can be likened to one minute in 24 hour day.”“Traditional Theory of Evolution Challenged” Lili pg. 10
This narrowed Cambrian Explosion window further frustrates Neo-Darwinian Evolutionary Theory because novel forms essentially formed in a flash. Now, not only are the precursor forms completely missing in the Precambrian (besides conjecture more detail follows), now evolution must also explain how all these various incredibly complex life forms emerged in less time than ever envisioned, seemingly as if created from nothing within a geologic blink of the eye.
No doubt, some geologists or evolutionary biologists dispute the Cambrian Explosion by claiming life emerged by a series of separate events stretching 80 million years (or longer). Such periods do not match radiometric, geologic, or fossil evidence. Actual Precambrian evidence is limited to perhaps worm trails (likely formed by digging from animals in the Cambrian) and microscopic organisms such as tiny sponges, algae, and cyanobacteria. 2
…the Precambrian…fossil record is poor, with the majority of fossils being stromatolites…(perhaps) some 2.5 billion years ago.”http://www.fossilmuseum.net/Paleobiology/Precambrian-Fossils.htm
Despite the missing Precambrian evidence evolutionary popularizers literally draw elaborate genetic trees on how life must have evolved from these microscopic organisms called a deep divergence. In doing so, they can reason that the incredible trilobite’s seeming “sudden” emergence in the Cambrian is but illusionary because earlier “trilobite-like” forms existed much earlier in the Precambrian– perhaps a billion years ago. 4 They reason that such original life forms such as cyanobacteria existed over 3.5 billion years ago 4 from which all other life forms diverged. Such a theory makes sense within the perimeters of anticipated time lines and mechanisms of evolution, therefore, evidence or not, such deep divergence in the Precambrian must be true.
1 “Calibrating Rates of Early Cambrian Evolution” by Biwrubg et al. pg 1297
3 “Ultrastructure of compacted DNA in cyanobacteria by high-voltage cryo-electron tomography” by Murata, K., Hagiwara, S., Kimori, Y. et al. Sci Rep 6, 34934; Oct 2016 https://doi.org/10.1038/srep34934
4 “Early Archean (3.3 Billion to 3.5 Billion-Years-Ago) Microfossils from Warrawoona Group Australia” by Schopf & Packer; pg. 70