Great Fossil Fauna, I: Gunflint Chert Flora

The Gunflint chert is part of a sequence of 1.8 billion-year-old rocks exposed in the Gunflint Range of northern Minnesota and western Ontario along the north shore of Lake Superior.

These rocks contain stromatolites, organo-sedimentary structures formed by cyanobacteria trapping and binding sediment, and when examined under the microscope, small spheres, rods and filaments less than 10 micrometers in size are visible in the chert layers--microfossils preserved in near-pristine 3-D.

The discovery of the Gunflint chert caused a paradigm shift in paleontology, as it proved that under exceptional conditions, even very ancient lifeforms could be preserved.

For its role in opening our eyes to the presence of life in very ancient rocks, the Gunflint chert earns a place on our list of “top 5 fossil lagerstatte”

Photo credit: http://www.fas.org/irp/imint/docs/rst/Sect20/A12.html

Origin, Chapter 14: Last words

Darwin saved his most vivid and poetic language for his concluding paragraph. It is also the only place in the entire volume where a form of the word "evolve" is found (the contemporary term to describe the alteration of one species to another was "transmutation"):

It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us…

There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.

Artwork of a "tangled bank" found at http://neurophilosophy.files.wordpress.com/2006/10/tangled.jpg