Some 19th century geologists assigned the origin of life to the Cambrian Period of geologic history. Rocks younger than the Cambrian contain fossil evidence for life that is striking and abundant. Older formations seemed not to contain fossils of living organisms.
Modern stromatolites in Shark Bay, Western Australia • Paul Harrison (CC BY-SA 3.0)
Artist's conception of comet bombardment • NASA/JPL-Caltech
A constant rain of comets
This week in Baltimore, three Iowa scientists will confront skeptical colleagues with evidence for a radical new theory: that the Earth’s upper atmosphere is continually bombarded by small comets, thousands of them every day, plashing like raindrops into a pond.
Uluru, or Ayers Rock • Photo by Vvfilippov ((CC BY-SA 4.0)
Comets, bandicoots and Dreamland
I recently returned from Australia, where I went to view Halley’s Comet. Every night we watched the comet move among the brilliant stars of the Southern Milky Way. We also experienced a wealth of terrestrial natural history.
Pleistocene fauna • Painting by Mauricio Antón (CC BY 2.5)
The mammoths’ demise
In Jean Auel’s blockbuster novel, “The Mammoth Hunters,” the beautiful Ayla muses on the coming hunt. “How could creatures as small and weak as humans challenge the huge, shaggy, tusked beast, and hope to succeed?” she asks herself.
Countless galaxies • NASA, ESA (Public Domain)
Galactic images
The cluster of white domes on Siding Spring Mountain in New South Wales, Australia, reminded me of the bulbs of the white Aminita mushrooms that spring up overnight in the New England woodlands after an autumn rain.
18th C. engraving of Selborne village (Public Domain)
The world of Gilbert White
Exactly 200 years ago on this date [April 21, 1786], Gilbert White heard the voice of the cuckoo in the woods above Selborne village. Gilbert White was the curate of Selborne, a tiny village nested in a quiet dale about 40 miles southwest of London. The village has changed little since White’s day, and has become a place of pilgrimage for all who love nature.
Photo by John Salzarulo on Unsplash
Evolutionary games on the computer
Those who oppose evolution often claim that the theory is not “scientific.” They say that no hypothesis can qualify as science unless it can be tested by a controlled experiment.
Paradoxides fossil • Photo by James St. John (CC BY 2.0)
Paradox of Paradoxides
Boston, Charlotte, N.C., St. John’s, Nova Scotia, Wexford, Ireland, and Holyhead, Wales, have something in common. All are situated on rocks that contain the fossils of a certain extinct trilobite, or marine arthropod, that are found nowhere else.
Photo by Rama (CC BY-SA 2.0)
Rights of animals
When I was a boy growing up in Tennessee I once snitched my uncle’s .22 rifle and went hunting with my friends. My first shot brought a gray squirrel tumbling down through the branches of a tree. The squirrel lay on the ground at my feet, its belly pierced by a neat red hole, convulsed with pain. I watched, paralyzed by horror at what I had done, until one of my friends dispatched the squirrel with the butt of his rifle.
Photo by dylan nolte on Unsplash
Random numbers that aren’t
Thirty years ago, at about the time I began to study science, I came across a book called “A Million Random Digits.” Here, in a volume as thick as the Boston telephone directory, were page after page of numbers with no apparent pattern. No matter how long you studied the numbers, there was no way to predict what digit would occur next.