|The First Art Newspaper on the Net
||Established in 1996
|| Thursday, July 7, 2022
|Asteroid that killed the dinosaurs was great for bacteria|
An illustration provided by Victor O. Leshyk/GEOLOGY/GSA, depicts a theory of events precipitated by the impact of an asteroid on earth some 66 million years ago that extinguished nearly 75 percent of all species. New findings published in the journal Geology reveal that cyanobacteria blue-green algae responsible for harmful toxic blooms moved into the crater just a few years after the impact. Victor O. Leshyk/GEOLOGY/GSA via The New York Times.
by Shannon Hall
NEW YORK (NYT NEWS SERVICE ).- The asteroid moved 24 times faster than a rifle bullet as it struck Earth some 66 million years ago. Its supersonic shock wave flattened trees across North and South America, and its heat wave sparked incomprehensibly large forest fires.
The event lofted so much debris into the atmosphere that photosynthesis shut down. The nonavian dinosaurs disappeared. And nearly 75% of all species were extinguished.
At the point of impact, the picture was even more dire. The space rock left a sterile crater nearly 20 miles deep in what is now the Gulf of Mexico. Not a single living thing could have survived.
But even at ground zero, life managed to return, and quickly.
New findings published in the journal Geology last week revealed that cyanobacteria blue-green algae responsible for harmful toxic blooms moved into the crater a few years after the impact. Thats the blink of an eye, geologically speaking, and helps illuminate how life bounces back on Earth following cataclysmic events, even in the most devastated environments.
In 2016, scientists drilled into the heart of the so-called Chicxulub crater and excavated a 2,750-foot-long core of sediments, allowing scientists all over the world, such as Bettina Schaefer of Curtin University in Australia, to parse the rocks for their own research.
Those samples have answered a number of questions regarding the impact, but Schaefer wanted to better understand how life rebounded at ground zero. Although scientists had seen hints of early life before, the numbers were small and couldnt capture the entire picture.
The issue is that not all microorganisms leave behind fossils. Instead, soft-bodied organisms can be identified by the burrows they make and the molecules they deposit. Cyanobacteria, for example, produce fats that can be preserved in sedimentary rocks for hundreds of millions of years.
So when Schaefers team saw those preserved fats in the core near the time of the impact, they knew cyanobacteria must have been present. Crucially, the fats were deposited atop a layer of fossilized plants that were washed into the crater by the tsunami that followed, but below another layer of iridium that was deposited once the debris in the atmosphere rained back down on Earth after a few years. That suggests the bacteria began to populate the crater after the tsunami hit but before the atmosphere cleared and the suns light had fully returned.
The ones that were able to move in right away, the ambulance chasers, if you will, were these cyanobacteria, said Sean P.S. Gulick, a marine geophysicist from the University of Texas at Austin, a scientist on the drilling expedition and Schaefers co-author.
Moreover, the team was able to detect a host of other organisms that arrived on the scene later, which helped to better characterize the toxic waters that pooled in the crater. Some of the molecular fossils they discovered, for example, can only originate from organisms that live in waters devoid of any oxygen a so-called dead zone similar to what occurs every summer in the contemporary Gulf of Mexico.
Chris Lowery, a paleoceanographer at the University of Texas at Austin and an author of the recent study, suspects that the crater was only partially dead, in part because the team also saw evidence for fossils of plankton that rely on oxygen. Perhaps the craters oxygen-depleted waters existed within only certain layers of its water column. Or, like the dead zone in the modern gulf, maybe those waters were only seasonal.
Knowing that life thrived in the Chicxulub crater while it was still fresh could help scientists better understand how living things adapt to catastrophe today, said Jason Sylvan, an oceanographer at Texas A&M University who was not involved in the study.
Climate change has raised temperatures, depleted oxygen and acidified waters in the worlds oceans. But scientists remain unsure how microbial communities which help control the amount of oxygen in the atmosphere will respond.
To better forecast our future, they will continue to dig up fossils of the past particularly those from one of the greatest extinctions on Earth.
© 2020 The New York Times Company
February 2, 2020
Exhibition looks at the disconcerting phenomenon of statuary polychromy
Asteroid that killed the dinosaurs was great for bacteria
Hester Diamond, passionate art collector, is dead at 91
A gorgeous center for photography, far from picture perfect
LACMA receives $50 million gift from the W.M. Keck Foundation for its Building LACMA campaign
Croatia's Rijeka celebrates capital of culture kickoff
The Morgan brings Jean-Jacques Lequeu Drawings from the Bibliothèque nationale de France
Exhibition surveys the rich range of artistic responses to life during the belle époque
Indiana State Museum opens exhibit on opioid crisis
Exhibition of early European open-air painting reveals new scholarship and recently discovered works
Where did the $9 million cars go?
Bergen Kunsthall features sculptures, drawings, paintings, collages and photographs by Simone Fattal
In former Syria rebel stronghold, nothing was spared
Mary Higgins Clark, queen of suspense and a fixture on bestseller lists, dies at 92
Monica King Contemporary opens the first solo exhibition in New York City of Taylor Anton White
moCa Cleveland announces the new exhibition Temporary Spaces of Joy and Freedom
'Creature Comfort: Animals in the House' opens at Shelburne Museum
New exhibition at Weatherspoon Art Museum highlights "hoops" in the South
Exhibition at Somerset House explores the fascinating world of mushrooms
New group exhibition at Argos loosely inspired by the title of a Chantal Akerman film
Ottocento Art Gallery opens exhibition of important masterpieces
Sikkema Jenkins & Co. opens an exhibition of works by william cordova
Del Pitt Feldman, master of the art of crocheting, dies at 90
Marine Hugonnier unveils a new body of work at Ingleby Gallery
Midcentury Modern, antiques, Abstract art to be offered at Benefit Shop Foundation Feb. 19
Choosing toys for Boys
Museums, Exhibits, Artists, Milestones, Digital Art, Architecture, Photography,
Photographers, Special Photos, Special Reports, Featured Stories, Auctions, Art Fairs,
Anecdotes, Art Quiz, Education, Mythology, 3D Images, Last Week, .
|Royalville Communications, Inc|
Tell a Friend
Dear User, please complete the form below in order to recommend the Artdaily newsletter to someone you know.
Please complete all fields marked *.