The discovery of cracks on the surface of Mars by NASA’s Curiosity rover in early 2017 are evidence of lakes that likely dried up 3.5 billion years ago, confirmed a study, revealing details about the red planet’s ancient climate.
In early 2017 scientists announced the discovery of possible desiccation cracks in Gale Crater, which was filled by lakes 3.5 billion years ago.
“We are now confident that these are mudcracks,” said lead author Nathaniel Stein, a geologist at the California Institute of Technology in Pasadena, US.
Since desiccation mudcracks form only where wet sediment is exposed to air, their position closer to the centre of the lake bed rather than the edge also suggests that lake levels rose and fell dramatically over time.
“The mudcracks show that the lakes in Gale Crater had gone through the same type of cycles that we see on Earth,” Stein added.
Although scientists have known almost since the moment Curiosity landed in 2012 that Gale Crater once contained lakes, “the mudcracks are exciting because they add context to our understanding of this ancient lacustrine system”, Stein explained, in the paper published in the journal Geology.
“We are capturing a moment in time. This research is just a chapter in a story that Curiosity has been building since the beginning of its mission,” he said.
For the study, the team focused on a coffee table-sized slab of rock nicknamed “Old Soaker”.
Old Soaker is crisscrossed with polygons identical in appearance to desiccation features on Earth.
They found that the polygons — confined to a single layer of rock and with sediment filling the cracks between them — formed from exposure to air, rather than other mechanisms such as thermal or hydraulic fracturing, the researchers said. IANS
A group of scientists unveiled the first results Thursday of an ambitious effort to map the genes of tens of thousands of animal species, a project they said could help save animals from extinction down the line.
The scientists are working with the Genome 10,000 consortium on the Vertebrate Genomes Project, which is seeking to map the genomes of all 66,000 species of mammal, bird, reptile, amphibian and fish on Earth. Genome 10,000 has members at more than 50 institutions around the globe, and the Vertebrate Genomes Project last year.
The consortium Thursday released the first 15 such maps, ranging from the Canada lynx to the kakapo, a flightless parrot native to New Zealand.
The genome is the entire set of genetic material that is present in an organism. The release of the first sets is “a statement to the world that what we want to accomplish is indeed feasible,” said Harris Lewin, a professor of evolution at University of California, Davis, who is working on the project.
“The time has come, but of course it’s only the beginning,” Lewin said.
The work will help inform future conservation of jeopardized species, scientists working on the project said. The first 14 species to be mapped also include the duck-billed platypus, two bat species and the zebra finch. The zebra finch was the one species for which both sexes were mapped, bringing the total to 15.
Sequencing the genome of tens of thousands of animals could easily take 10 years, said Sadye Paez, program director for the project. But giving scientists access to this kind of information could help save rare species because it would give conservationists and biologists a new set of tools, she said.
Paez described the project as an effort to “essentially communicate a library of life.”
Three sequencing hubs
Tanya Lama, a doctoral candidate in environmental conservation at the University of Massachusetts at Amherst, coordinated the effort to sequence the lynx genome. The wild cat is the subject of debate about its conservation status in the United States, and better understanding of genetics can better protect its future, Lama said.
“It’s going to help us plan for the future, help us generate tools for monitoring population health, and help us inform conservation strategy,” she said.
The project has three “genome sequencing hubs,” including Rockefeller University in New York, the Sanger Institute outside Cambridge, England, and the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany, organizers said.
The work is intriguing because it could inform future conservation efforts of jeopardized species, said Mollie Matteson, a senior scientist with the Center for Biological Diversity who is not involved in the project. More information about animals’ genetics could lead to better understanding of how animals resist disease or cope with changes in the environment, she said.
“I think what’s interesting to me from a conservation aspect is just what we might be able to discern about the genetic diversity within a species,” Matteson said.
The project has similarities with the Earth BioGenome Project, which seeks to catalog the genomes for 1.5 million species. Lewin chairs that project’s working group. The Vertebrate Genomes Project will contribute to that effort. (VOA)