Hear the rhapsody in cyan that cyanobacteria composed in bridging the Archaean and Proterozoic eons of geologic history. By "poisoning" the ancient earth's atmosphere through photosynthesis, cyanobacteria converted the reducing atmosphere of the Archaean into the aerobic atmosphere that has prevailed ever since and has supported a wide range of oxygen-loving (or at least oxygen-tolerant) organisms.
Once again, reports Rebecca Bratspies, politically potent forces of ignorance are trying to undermine the teaching of evolution in the United States.
Enlightened voters and policymakers should fight back with precisely the emotional and rhetorical weapons that opponents of evolution have used to foist ignorance upon American children. As Brian Greene recently wrote in the New York Times, science — real science — "really matters" because:
Comet West, as it appeared in 1976, was beautiful to behold. But did it presage yet another deadly bolide from the depths of transneptunian space, headed toward a fatal collision with earth?
Science is a way of life. Science is a perspective. Science is the process that takes us from confusion to understanding in a manner that’s precise, predictive and reliable — a transformation, for those lucky enough to experience it, that is empowering and emotional. To be able to think through and grasp explanations — for everything from why the sky is blue to how life formed on earth — not because they are declared dogma but rather because they reveal patterns confirmed by experiment and observation, is one of the most precious of human experiences.Science empowers humanity — indeed, science morally impels humanity — to seek nothing less from life and to ask nothing less of the universe than the truth. In the poetic idiom of the Hebrew Bible — namely, chapter 38 of the Book of Job:
Humanity, so it seems, demands a story of origins. If we need a creation myth, and the emotional reality of human existence evidently demands no less, then let's tell the greatest story ever told: the real story of earth, from its Hadean origins to the sixth great extinction spasm of the Phanerozoic.
Evolution, the unifying theory of the life sciences, has a rigorous explanation for each of the phenomena illustrated here. It helps humanity unlock the mysteries behind the Book of Job, among other myths that have enchanted humanity throughout its history. In any of its guises, creationism offers no answers whatsoever. Teachers, parents, and citizens, go tell it on the mountain: You shall know the truth, and the truth shall set you free.
Govett's Leap in Australia's Blue Mountains is a spectacular instance of the Permian-Triassic boundary (250 million years ago), which marks the largest mass extinction of the Phanerozoic eon. Triassic sandstone overlies Permian coal; the boundary occurs roughly at the tree line near the base of the waterfall. Charles Darwin wrote about Govett's Leap in The Voyage of the Beagle: "Jan 18, 1836: Very early in the morning, I walked about three miles to see Govett's Leap . . . . These valleys . . . are most remarkable. Great arm-like bays . . . penetrate the sandstone platform; on the other hand, the platform often sends promontories into the valleys, and even leaves in them great, almost insulated, masses."
The Phanerozoic eon has witnessed five mass extinctions: the end Ordovician, the late Devonian, the end Permian, the end Triassic, and the end Cretaceous. Humanity is living through — and largely responsible for — for the sixth: the Holocene mass extinction. Amphibians, a clade 400 million years old, have lived through four mass extinctions. They may not survive a fifth. Will chytridiomycosis, caused by the chytrid fungus, ultimately be responsible for the extinction of evolutionarily distinct, globally endangered amphibians?