Quotes About Precambrian

As J. B. S. Haldane said when asked what evidence might contradict evolution, 'Fossil rabbits in the Precambrian.

When challenged by a zealous Popperian to say how evolution could ever be falsified, J. B. S. Haldane famously growled: 'Fossil rabbits in the Precambrian.

I confess that the idea of taking off one's boots in a howling squall to safeguard fossils that had survived since the Precambrian had its funny side.

When do nervous systems enter the evolutionary march? One good estimate is the Precambrian period, which ended 540 to 600 million years ago, an old vintage for certain but not that old when we compare it with the age of first life. Life, even multicellular life, managed quite well without nervous systems for about 3 billion years. We should reflect on this time line before we decide when perception, intelligence, sociality, and emotions made their first appearance on the world stage.

Nowadays, and speaking very generally, geological time is divided first into four great chunks known as eras: Precambrian, Palaeozoic (from the Greek meaning "old life"), Mesozoic ("middle life") and Cenozoic ("recent life"). These four eras are further divided into anywhere from a dozen to twenty subgroups

On this scale, according to John McPhee in Basin and Range, the distance from the fingertips of one hand to the wrist of the other is Precambrian. All of complex life is in one hand, "and in a single stroke with a medium-grained nail file you could eradicate human history.

Geologists, however, had found no such myriad of transitional forms leading to the Cambrian fauna. Instead, the stratigraphic column seemed to document the abrupt appearance of the earliest animals. Agassiz thought the evidence of abrupt appearance, and the absence of ancestral forms in the Precambrian, refuted Darwin's theory.

Yet the Precambrian strata of his day showed no signs of providing any obvious transitional forms, much less a well-articulated bottom-up pattern of animals representing lower taxa proliferating into forms exemplifying higher and higher taxonomic categories.

Thus, discovery of an embryo in the earliest stages of cell division shows beyond a doubt that Precambrian sedimentary rocks can, under the right circumstances, preserve soft-bodied organisms.

A PUZZLING PATTERN 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)

Instead, the Precambrian–Cambrian fossil record, especially in light of the Burgess Shale after Walcott, points to the geologically sudden appearance of complex and novel body plans.

Web 2.0 is our code word for the analog increasingly supervening upon the digital—reversing how digital logic was embedded in analog components, sixty years ago. Search engines and social networks are just the beginning—the Precambrian phase. "If the only demerit of the digital expansion system were its greater logical complexity, nature would not, for this reason alone, have rejected it," von Neumann admitted in 1948.

Web 2.0 is our code word for the analog increasingly supervening upon the digital—reversing how digital logic was embedded in analog components, sixty years ago. Search engines and social networks are just the beginning—the Precambrian phase.