Biodiversity on EARTH Magazine

Geomedia: Books: "Half-Earth" is only half-compelling

Tue, 27 Feb 2018 14:14:31 -0500

"Half-Earth: Our Planet's Fight for Life," Edward O. Wilson, Liveright, 2017 (paperback), ISBN-13: 978-1631492525

Edward O. Wilson, professor emeritus and honorary curator in entomology at Harvard, is a scientist of acclaim and renown, a naturalist and experimentalist who has made astounding discoveries about the natural world. These discoveries range from small details about ant communication to much larger ideas related to sociobiology, the co-evolution of genes and culture, island biogeography and biophilia, for example. His work is widely known, in large part, because he’s a talented and prolific writer, and he has twice won the Pulitzer Prize.

Dino deaths cleared the way for frogs

Wed, 15 Nov 2017 14:34:29 -0500

Certain frog lineages, including the family Microhylidae to which this male Microhyla rubra belongs, flourished after the dinosaur extinction left environmental niches open. Credit: L. Shyamal, CC BY-SA 3.0.

Frogs make up almost 90 percent of amphibians, and with 6,775 described species, frogs are considered one of the most diverse groups of vertebrates on the planet. In a new study in Proceedings of the National Academy of Sciences, researchers indicate that frogs’ rapid diversification stems back to the Cretaceous-Paleogene (K-Pg, formerly the K-T) boundary, about 66 million years ago, when nonavian dinosaurs and many other animals went extinct.

Meteorites did not spark Ordovician biodiversification

Mon, 15 May 2017 15:08:48 -0400

Zircon crystals contain trace amounts of uranium and thorium, making them useful for radiometric dating. These highly magnified crystals are about the size of a grain of sand. Credit: Anders Lindskog.

During the Ordovician Period, roughly 470 million years ago, an asteroid the size of a small moon collided with another rocky object in the belt between Mars and Jupiter, shattering the asteroid into billions of pieces. Fragments from the epic collision still occasionally fall to Earth today, making up a large share of the meteorites recovered. But in the immediate wake of the Ordovician event, many pieces rained down on the planet, settling on the surface and in layers of rock forming at the time. In a new study, researchers studying some of these meteorite-rich layers have refined the timescale for the collision. The results bring into question a proposed link between the meteorite bombardment and an evolutionary uptick known as the Great Ordovician Biodiversification Event (GOBE).

Downgrading the Great Dying

Wed, 18 Jan 2017 14:45:23 -0500

Estimates of species losses during six mass extinctions are lower when background extinctions are subtracted from previous estimates. Credit: Steven Stanley.

The end-Permian extinction, nicknamed the “Great Dying,” is thought to be the deadliest mass extinction in Earth’s history. Many textbooks claim that up to 96 percent of marine life died out during this event, but a new study suggests this cataclysmic number has been overestimated.

A Cambrian-like explosion of mammals in the Mid-Jurassic

Tue, 06 Oct 2015 10:14:57 -0400

Mammals, such as the docodonts illustrated here, experienced a burst of rapid evolution in skeletal and dental features in the Middle Jurassic. Credit: April Neander.

Dinosaurs dominated the continents during the Mesozoic, and for a long time, paleontologists assumed our mammalian ancestors kept a low-profile in that era, existing only as small, ground-dwelling, nocturnal insect-eaters. But in the last decade, discoveries of an ever-increasing diversity of mammal fossils have forced a rethink: Mesozoic mammals were also gliders, climbers, diggers and swimmers. Now, scientists looking at mammalian rates of evolution during the time of the dinosaurs have found that this diversity peaked in the Mid-Jurassic, leading to new physical characteristics that would remain for millions of years.

Gulf oil spill threatens subsurface biodiversity

Thu, 05 Jan 2012 06:41:58 -0500

Workers with the International Bird Rescue Research Center clean a brown pelican that was covered in oil from the Gulf of Mexico. IBRCC, Creative Commons Attribution 2.0 Generic

Brown pelicans mired in oily mud along the Louisiana coast are icons of the BP Deepwater Horizon oil spill, daily reminders of the ongoing disaster’s impact on the Gulf coast. Yet, says a leading marine ecologist, the greater long-term danger to wildlife may be occurring out of sight, deep beneath the oily surface of the water.