Tagged: Paleobiology Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 9:19 am on March 24, 2020 Permalink | Reply
    Tags: "Ancestor of all animals identified in Australian fossils", , , Paleobiology, The tiny wormlike creature- Ikaria wariootia is the earliest bilaterian or organism with a front and back two symmetrical sides and openings at either end connected by a gut.,   

    From UC Riverside: “Ancestor of all animals identified in Australian fossils” 

    UC Riverside bloc

    From UC Riverside

    March 23, 2020
    Holly Ober

    1
    An artist’s rendering of Ikaria wariootia. (Sohail Wasif/UCR)

    A wormlike creature that lived more than 555 million years ago is the earliest bilaterian.

    A team led by UC Riverside geologists has discovered the first ancestor on the family tree that contains most familiar animals today, including humans.

    The tiny, wormlike creature, named Ikaria wariootia, is the earliest bilaterian, or organism with a front and back, two symmetrical sides, and openings at either end connected by a gut. The paper is published today in Proceedings of the National Academy of Sciences.

    The earliest multicellular organisms, such as sponges and algal mats, had variable shapes. Collectively known as the Ediacaran Biota, this group contains the oldest fossils of complex, multicellular organisms. However, most of these are not directly related to animals around today, including lily pad-shaped creatures known as Dickinsonia that lack basic features of most animals, such as a mouth or gut.

    The development of bilateral symmetry was a critical step in the evolution of animal life, giving organisms the ability to move purposefully and a common, yet successful way to organize their bodies. A multitude of animals, from worms to insects to dinosaurs to humans, are organized around this same basic bilaterian body plan.

    Evolutionary biologists studying the genetics of modern animals predicted the oldest ancestor of all bilaterians would have been simple and small, with rudimentary sensory organs. Preserving and identifying the fossilized remains of such an animal was thought to be difficult, if not impossible.

    For 15 years, scientists agreed that fossilized burrows found in 555 million-year-old Ediacaran Period deposits in Nilpena, South Australia, were made by bilaterians. But there was no sign of the creature that made the burrows, leaving scientists with nothing but speculation.

    Scott Evans, a recent doctoral graduate from UC Riverside; and Mary Droser, a professor of geology, noticed miniscule, oval impressions near some of these burrows. With funding from a NASA exobiology grant, they used a three-dimensional laser scanner that revealed the regular, consistent shape of a cylindrical body with a distinct head and tail and faintly grooved musculature. The animal ranged between 2-7 millimeters long and about 1-2.5 millimeters wide, with the largest the size and shape of a grain of rice — just the right size to have made the burrows.

    “We thought these animals should have existed during this interval, but always understood they would be difficult to recognize,” Evans said. “Once we had the 3D scans, we knew that we had made an important discovery.”

    The researchers, who include Ian Hughes of UC San Diego and James Gehling of the South Australia Museum, describe Ikaria wariootia, named to acknowledge the original custodians of the land. The genus name comes from Ikara, which means “meeting place in the Adnyamathanha language. It’s the Adnyamathanha name for a grouping of mountains known as Wilpena Pound. The species name comes from Warioota Creek, which runs from the Flinders Ranges to Nilpena Station.

    “Burrows of Ikaria occur lower than anything else. It’s the oldest fossil we get with this type of complexity,” Droser said. “Dickinsonia and other big things were probably evolutionary dead ends. We knew that we also had lots of little things and thought these might have been the early bilaterians that we were looking for.”

    In spite of its relatively simple shape, Ikaria was complex compared to other fossils from this period. It burrowed in thin layers of well-oxygenated sand on the ocean floor in search of organic matter, indicating rudimentary sensory abilities. The depth and curvature of Ikaria represent clearly distinct front and rear ends, supporting the directed movement found in the burrows.

    The burrows also preserve crosswise, “V”-shaped ridges, suggesting Ikaria moved by contracting muscles across its body like a worm, known as peristaltic locomotion. Evidence of sediment displacement in the burrows and signs the organism fed on buried organic matter reveal Ikaria probably had a mouth, anus, and gut.

    “This is what evolutionary biologists predicted,” Droser said. “It’s really exciting that what we have found lines up so neatly with their prediction.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC Riverside Campus

    The University of California, Riverside is one of 10 universities within the prestigious University of California system, and the only UC located in Inland Southern California.

    Widely recognized as one of the most ethnically diverse research universities in the nation, UCR’s current enrollment is more than 21,000 students, with a goal of 25,000 students by 2020. The campus is in the midst of a tremendous growth spurt with new and remodeled facilities coming on-line on a regular basis.

    We are located approximately 50 miles east of downtown Los Angeles. UCR is also within easy driving distance of dozens of major cultural and recreational sites, as well as desert, mountain and coastal destinations.

     
  • richardmitnick 2:27 pm on January 17, 2020 Permalink | Reply
    Tags: "An evolving understanding of extinction", Capetown, Johannesburg, , , Paleobiology, , , South Africa natural wonders,   

    From University of the Witwatersrand, Johannesburg, South Africa via phys.org: “An evolving understanding of extinction” 

    From University of the Witwatersrand, Johannesburg, South Africa

    via

    phys.org

    January 17, 2020
    Christine Steininger
    Bruce Rubidge

    1
    Encyclopædia Britannica, Inc.

    Few things related to science capture the imagination more than the magic of worlds past. This includes the origins of life, dinosaurs, mass extinctions, meteorite impacts, and the evolution of our species. Understanding the evolution of life is central to the way we view ourselves and others and developing this field is thus critical.

    Furthermore, South Africa’s rich palaeontological, palaeo-anthropological and archaeological record provides a unique competitive advantage to local heritage-related scientists.

    2
    3
    4
    Images of the natural wonders of South Africa, various sources.

    5
    Capetown. No image credit

    6
    Johannesburg. Britannica

    Palaeosciences is the only discipline dedicated to understanding the origin and development of past life and its interactions with changing environments. It is the responsibility of these scientists to ensure understanding of the depth of our dependence on Earth as a life support system. Additionally, paleosciences research can provide knowledge of how to manage human interactions with the planet responsibly.

    As our knowledge of the Earth expands, we begin to realise far more synergy and mutualistic relationships with the biological world—built up over millions of years—in many of the fundamental processes to secure biodiversity, soils, water, minerals, energy, and other resources.

    South Africa rocks

    South Africa is poised to become a global leader in an area of geographic advantage.

    Because of the country’s immense diversity, antiquity, and continuity of geological, palaeontological, and archaeological records, and its rich genetic heritage, South Africa is unique in the world.


    The DST-NRF Center of Excellence in Paleosciences. Credit: Wits University

    The country boasts some of the most significant mineral deposits on Earth and preserves, amongst others, the oldest evidence of life on Earth from over 3,500-million years; the most distant ancestors of dinosaurs from 200-million years ago; and a remarkable record of human origins and achievements over four-million years.

    Erasing Earth

    The study of past biodiversity has recognised that five global extinction events have occurred in the last 500-million years, where between 65 percent and 95 percent of species went extinct over a relatively short period. South Africa has a record of four of these five extinction events. Many scientists consider that the Earth has now entered a new epoch—the Anthropocene. Like other transitions between geological eras, the marker for this transition is a mass extinction event, although this one—uniquely—is human-induced. And avoidable.

    The current rate of species extinction is estimated to be 10 to 1,000 times higher than the natural, background rate. This is likely to increase as habitat destruction, global change, and other human-induced stresses on the natural environment accelerate.

    South Africa is the only country in the world with the necessary fossil resources to undertake a research initiative over such an extensive period. Our fossil archives provide case studies throughout Earth’s history to understand how climactic and environmental change affect biodiversity.

    Decoding the mechanisms that lead to population extirpation [localised extinction] and ultimately species extinction under climate change is critical for scenario-planning, interpreting, and possibly predicting its impact on biodiversity and to inform policy to conserve South African biodiversity in future.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The University of the Witwatersrand, Johannesburg (/vətˈvɑːtəsrənt/), is a multi-campus South African public research university situated in the northern areas of central Johannesburg. It is more commonly known as Wits University or Wits (/vəts/ or /vɪts/). The university has its roots in the mining industry, as do Johannesburg and the Witwatersrand in general. Founded in 1896 as the South African School of Mines in Kimberley, it is the third oldest South African university in continuous operation.

    The university has an enrolment of 40,259 students as of 2018, of which approximately 20 percent live on campus in the university’s 17 residences. 63 percent of the university’s total enrolment is for undergraduate study, with 35 percent being postgraduate and the remaining 2 percent being Occasional Students.

    The 2017 Academic Ranking of World Universities (ARWU) places Wits University, with its overall score, as the highest ranked university in Africa. Wits was ranked as the top university in South Africa in the Center for World University Rankings (CWUR) in 2016. According to the CWUR rankings, Wits occupies this ranking position since 2014.

     
  • richardmitnick 1:00 pm on January 17, 2020 Permalink | Reply
    Tags: "In death of dinosaurs it was all about the asteroid — not volcanoes", , Cretaceous-Paleogene extinction event 66 million years ago, , , Paleobiology, , Site of the asteroid strike 66 million years ago is an impact crater buried underneath the Yucatán Peninsula in Mexico. The asteroid doomed the dinosaurs., The Chicxulub crater, , Walter and Luis Alvarez and Iridium,   

    From Yale University: “In death of dinosaurs, it was all about the asteroid — not volcanoes” 

    From Yale University

    January 16, 2020
    Jim Shelton

    1
    (© stock.adobe.com)

    Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs, according to an international, Yale-led team of researchers. It was all about the asteroid.

    3
    K-T boundary (red arrow) along Interstate 25, Raton Pass, Colorado. The Cretaceous–Paleogene boundary of 66 million years ago, marking the temporal border between the Cretaceous and Paleogene periods of geological time, was identified by a thin stratum of iridium-rich clay. During the 1970s, Walter Alvarez was doing geologic research in central Italy. There he had located an outcrop on the walls of a gorge whose limestone layers included strata both above and below the Cretaceous–Paleogene boundary. Exactly at the boundary is a thin layer of clay. Walter told his father Luis that the layer marked where the dinosaurs and much else became extinct and that nobody knew why, or what the clay was about — it was a big mystery and he intended to solve it. A team led by Luis Alvarez proposed in 1980 an extraterrestrial origin for this iridium, attributing it to an asteroid or comet impact. Their theory, known as the Alvarez hypothesis, is now widely accepted to explain the extinction of the non-avian dinosaurs. A large buried impact crater structure with an estimated age of about 66 million years was later identified under what is now the Yucatán Peninsula (the Chicxulub crater)

    3
    The Chicxulub crater is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is located near the town of Chicxulub, after which the crater is named. It was formed by a large asteroid or comet about 11 to 81 kilometers in diameter, the Chicxulub impactor, striking the Earth, and causing the dinosaur extinction.

    In a break from a number of other recent studies, Yale assistant professor of geology & geophysics Pincelli Hull and her colleagues argue in a new research paper in Science that environmental impacts from massive volcanic eruptions in India in the region known as the Deccan Traps happened well before the Cretaceous-Paleogene extinction event 66 million years ago and therefore did not contribute to the mass extinction.

    2
    Deccan Traps at Ajanta Caves. Shaikh Munir

    2
    The hardened lava flows of the Deccan Traps, in western India. Gerta Keller

    Most scientists acknowledge that the mass extinction event, also known as K-Pg, occurred after an asteroid slammed into Earth. Some researchers also have focused on the role of volcanoes in K-Pg due to indications that volcanic activity happened around the same time.

    “Volcanoes can drive mass extinctions because they release lots of gases, like SO2 and CO2, that can alter the climate and acidify the world,” said Hull, lead author of the new study. “But recent work has focused on the timing of lava eruption rather than gas release.”

    To pinpoint the timing of volcanic gas emission, Hull and her colleagues compared global temperature change and the carbon isotopes (an isotope is an atom with a higher or lower number of neutrons than normal) from marine fossils with models of the climatic effect of CO2 release. They concluded that most of the gas release happened well before the asteroid impact — and that the asteroid was the sole driver of extinction.

    “Volcanic activity in the late Cretaceous caused a gradual global warming event of about two degrees, but not mass extinction,” said former Yale researcher Michael Henehan, who compiled the temperature records for the study. “A number of species moved toward the North and South poles but moved back well before the asteroid impact.”

    Added Hull, “A lot of people have speculated that volcanoes mattered to K-Pg, and we’re saying, ‘No, they didn’t.’”

    Recent work on the Deccan Traps, in India, has also pointed to massive eruptions in the immediate aftermath of the K-Pg mass extinction. These results have puzzled scientists because there is no warming event to match. The new study suggests an answer to this puzzle, as well.

    “The K-Pg extinction was a mass extinction and this profoundly altered the global carbon cycle,” said Yale postdoctoral associate Donald Penman, the study’s modeler. “Our results show that these changes would allow the ocean to absorb an enormous amount of CO2 on long time scales — perhaps hiding the warming effects of volcanism in the aftermath of the event.”

    German researcher André Bornemann was co-lead author of the study. Yale researcher Ellen Thomas was a co-author of the study, along with additional researchers from institutions in Germany, the United Kingdom, France, Spain, Japan, Denmark, and the United States.

    The International Ocean Discovery Program, the National Science Foundation, and Yale University helped fund the research.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
  • richardmitnick 1:39 pm on September 26, 2019 Permalink | Reply
    Tags: Clues for search for life on Mars, Drilling deep; looking closely, Paleobiology, the ancient Dresser Formation in the Pilbara region of Western Australia, , Western Australia’s famous 3.5-billion-year-old stromatolites   

    From University of New South Wales: “Earliest signs of life: scientists find microbial remains in ancient rocks” 

    U NSW bloc

    26 Sep 2019
    Isabelle Dubach

    Western Australia’s famous 3.5-billion-year-old stromatolites contain microbial remains of some of the earliest life on Earth, UNSW scientists have found.

    2
    Photomicrograph of pyritized stromatolites from the 3.5 billion-year-old Dresser Formation. The stromatolites are delineated by pyrite, also known as fool’s gold.

    Scientists have found exceptionally preserved microbial remains in some of Earth’s oldest rocks in Western Australia – a major advance in the field, offering clues for how life on Earth originated.

    The UNSW researchers found the organic matter in stromatolites – fossilised microbial structures – from the ancient Dresser Formation in the Pilbara region of Western Australia.

    The stromatolites have been thought to be of biogenic origin ever since they were discovered in the 1980s. However, despite strong textural evidence, that theory was unproven for nearly four decades, because scientists hadn’t been able to show the definitive presence of preserved organic matter remains – until today’s publication in prestigious journal Geology.

    “This is an exciting discovery – for the first time, we’re able to show the world that these stromatolites are definitive evidence for the earliest life on Earth,” says lead researcher Dr Raphael Baumgartner, a research associate of the Australian Centre for Astrobiology in Professor Martin Van Kranendonk’s team at UNSW.

    Professor Van Kranendonk says the discovery is the closest the team have come to a “smoking gun” to prove the existence of such ancient life.

    “This represents a major advance in our knowledge of these rocks, in the science of early life investigations generally, and – more specifically – in the search for life on Mars. We now have a new target and new methodology to search for ancient life traces,” Professor Van Kranendonk says.

    Drilling deep, looking closely

    Ever since the Dresser Formation was discovered in the 1980, scientists have wondered whether the structures were truly microbial and therefore the earliest signs of life.

    “Unfortunately, there is a climate of mistrust of textural biosignatures in the research community. Hence, the origin of the stromatolites in the Dresser Formation has been a hotly debated topic,” Dr Baumgartner says.

    “In this study, I spent a lot of time in the lab, using micro-analytical techniques to look very closely at the rock samples, to prove our theory once and for all.”

    Stromatolites in the Dresser Formation are usually sourced from the rock surface, and are therefore highly weathered. For this study, the scientists worked with samples that were taken from further down into the rock, below the weathering profile, where the stromatolites are exceptionally well preserved.

    “Looking at drill core samples allowed us to look at a perfect snapshot of ancient microbial life,” Dr Baumgartner says.

    Using a variety of cutting-edge micro-analytical tools and techniques – including high-powered electron microscopy, spectroscopy and isotope analysis – Dr Baumgartner analysed the rocks.

    He found that the stromatolites are essentially composed of pyrite – a mineral also known as ‘fool’s gold’ – that contains organic matter.

    “The organic matter that we found preserved within pyrite of the stromatolites is exciting – we’re looking at exceptionally preserved coherent filaments and strands that are typically remains of microbial biofilms,” Dr Baumgartner says.

    The researchers say that such remains have never been observed before in the Dresser Formation, and that actually seeing the evidence down the microscope was incredibly exciting.

    “I was pretty surprised – we never expected to find this level of evidence before I started this project. I remember the night at the electron microscope where I finally figured out that I was looking at biofilm remains. I think it was around 11pm when I had this ‘eureka’ moment, and I stayed until three or four o’clock in the morning, just imaging and imaging because I was so excited. I totally lost track of time,” Dr Baumgartner says.

    Clues for search for life on Mars

    Just over two years ago, Dr Baumgartner’s colleague Tara Djokic, a UNSW PhD candidate, found stromatolites in hot spring deposits in the same region in WA, pushing back the earliest known existence of microbial life on land by 580 million years.

    “Tara’s main findings were these exceptional geyserite deposits that indicate that there have been geysers in this area, and therefore fluid expulsions on exposed land surface,” Dr Baumgartner says.

    “Her study was focused on the broader geological setting of the paleo-environment – lending support to the theory that life originated on land, rather than in the ocean – whereas my study really went deeper on the finer details of the stromatolite structures from the area.”

    The scientists say that both studies are helping us answer a central question: where did humanity come from?

    “Understanding where life could have emerged is really important in order to understand our ancestry. And from there, it could help us understand where else life could have occurred – for example, where it was kick-started on other planets,” Dr Baumgartner says.

    Just last month, NASA and European Space Agency (ESA) scientists spent as week in the Pilbara with Martin Van Kranendonk for specialist training in identifying signs of life in these same ancient rocks. It was the first time that Van Kranendonk shared the region’s insights with a dedicated team of Mars specialists – a group including the Heads of NASA and ESA Mars 2020 missions.

    “It is deeply satisfying that Australia’s ancient rocks and our scientific know-how is making such a significant contribution to our search for extra-terrestrial life and unlocking the secrets of Mars,” says Professor Van Kranendonk.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U NSW Campus

    Welcome to UNSW Australia (The University of New South Wales), one of Australia’s leading research and teaching universities. At UNSW, we take pride in the broad range and high quality of our teaching programs. Our teaching gains strength and currency from our research activities, strong industry links and our international nature; UNSW has a strong regional and global engagement.

    In developing new ideas and promoting lasting knowledge we are creating an academic environment where outstanding students and scholars from around the world can be inspired to excel in their programs of study and research. Partnerships with both local and global communities allow UNSW to share knowledge, debate and research outcomes. UNSW’s public events include concert performances, open days and public forums on issues such as the environment, healthcare and global politics. We encourage you to explore the UNSW website so you can find out more about what we do.

     
  • richardmitnick 7:57 am on March 22, 2019 Permalink | Reply
    Tags: Burgess Shale in Canada, Cambrian explosion of life, , Paleobiology, , Qingjiang and Chengjiang fossils in China,   

    From Science News: “Newfound fossils in China highlight a dizzying diversity of Cambrian life” 

    From Science News

    March 21, 2019
    Carolyn Gramling

    1
    ANCIENT IMPRINTS The newly described Qingjiang biota, a rich fossil site dating to about 518 million years ago, helps document a rapid flourishing of diverse invertebrate life known as the Cambrian explosion. The fossils include abundant jellyfish (left) and comb jellies (middle), as well as a segmented, spiny animal that may be a kinorhynch (right).

    Along the banks of China’s Danshui River lies a treasure trove of fossils that may rival the most famous Cambrian fossil assemblage of all, Canada’s Burgess Shale. The roughly 518-million-year-old site contains a dizzying abundance of beautifully preserved weird and wonderful life-forms, from jellyfish and comb jellies to arthropods and algae.

    So far, researchers led by paleontologist Dongjing Fu of Northwest University in Xian, China, have collected 4,351 specimens at the new site, representing 101 different taxa, or groups of organisms. Of those taxa, about 53 percent have never before been observed, Fu and her colleagues report in the March 22 Science — not even at other well-known Cambrian fossil sites such as the 508-million-year-old Burgess Shale or a 518-million-year-old site known as Chengjiang, also in China.

    “It’s an exciting discovery,” says Jean-Bernard Caron, a paleontologist at the Royal Ontario Museum in Toronto who wasn’t involved in the study. During the Cambrian Period, which began about 542 million years ago, life diversified extremely rapidly. So many new forms appeared in such a relatively short period of time that this diversification is known as the Cambrian explosion. The find “shows that there’s hope for new discoveries” of other Cambrian fossil sites, he says.

    2
    FOSSIL FINDS Researchers discovered the Qingjiang fossils along the bank of China’s Danshui River in Hubei Province. Dong King Fu

    Such sites represent snapshots of life long ago, and no one site can portray the true diversity of life on Earth at any given time, Caron says. “It’s a giant jigsaw puzzle, and we only have a few pieces…. But the more pieces we have, the better chance we have to understand life during that time.”

    The new fossil trove, called the Qingjiang biota, was first spotted in 2007, says coauthor Xingliang Zhang, a paleontologist also at Northwest University. “I have been working on Burgess Shale–type fossils for many years, and know what kind of rocks preserve [them],” Zhang says.

    During a field expedition that year, he and his students were investigating a different rock layer dating to the Cambrian. At lunchtime, he says, he happened to sit on the next lower layer of rocks as it was being lapped by the river’s water — and immediately recognized that the fine clay layer was the perfect preservation setting for fossils. “We split the clay stone and I found a Leanchoilia [a kind of segmented arthropod] quickly.” Many more discoveries soon followed.

    The site is remarkable for the quality of the preservation of the animals, says Allison Daley, a paleontologist at the University of Lausanne in Switzerland who was not involved in the new study but wrote a Science commentary that accompanies it in Science. “There was very little metamorphism or weathering effect, which does affect some other [Cambrian fossil] sites, like Burgess or Chengjiang. We see almost pristine fossils at this site.” She mentions one startlingly clear image of a jellyfish. “I mean, if you were going to smack a jellyfish on a rock, that’s how it would look.”

    ________________________________________________________
    Weird wonders
    The excellent preservation of the Qingjiang fossils reveals fine morphological details of some of the life-forms that lived in Cambrian seas, such as a branched alga (left) and the segmented body of an arthropod called a megacherian (right).
    3
    ________________________________________________________

    Unlike other Cambrian fossil troves, the Qingjiang biota appears to contain a high proportion of jellyfish, or cnidarians, and comb jellies, also called ctenophores. These species, particularly the comb jellies, are extremely rare at other sites.

    With so many ctenophore fossils preserved so well, Daley says, studying their shapes may help to answer a long-standing debate: Whether comb jellies or sponges are the most primitive animal on their family tree. Scientists have thought that sponges appear closer to the base of the tree, based on their very simple shapes. But some molecular analyses have hinted that comb jellies may be at the base of the tree.

    “It’s hard to disentangle the exact relationships of these [creatures],” Daley says. “These early branching groups diverged from each other such a long time ago…. So getting more info on [them] at this new site, where the preservation is really amazing, is really going to fill a gap.”

    The Burgess Shale, a vast deposit of fossil-bearing rocks in the Canadian Rockies, was discovered in 1909. It was this site that first gave scientists a glimpse into the Cambrian explosion, the rapid diversification of life that occurred during that period. The Burgess and Chengjiang sites, separated by 10 million years and half a world today, share only about 15 percent of the same taxa.

    That might be expected, Daley says, given their differences in both space and time. But the Qingjiang and Chengjiang sites, which date to the same time period and are separated by only 1,050 kilometers today, share only 8 percent of their taxa, she says. The researchers, however, suggest that the Qingjiang site may have been a slightly deeper marine environment. If so, that difference in ancient environment may have been the reason why the assemblage of creatures is so different, Daley says.

    The new work is preliminary, representing just the first of what is likely to be a deluge of studies describing fossils found at the site, Zhang says. “We’re just beginning!”

    Even after 110 years of digging in the Burgess Shale region, paleontologists are still turning up rich new sites and bizarre new creatures, adds Caron, of Canada’s Royal Ontario Museum. Just last summer, he and colleagues made new discoveries, including an enigmatic shield-shaped critter that he dubbed “the mothership.” Unlike other Cambrian fossil troves, the Qingjiang biota appears to contain a high proportion of jellyfish, or cnidarians, and comb jellies, also called ctenophores. These species, particularly the comb jellies, are extremely rare at other sites.

    With so many ctenophore fossils preserved so well, Daley says, studying their shapes may help to answer a long-standing debate: Whether comb jellies or sponges are the most primitive animal on their family tree. Scientists have thought that sponges appear closer to the base of the tree, based on their very simple shapes. But some molecular analyses have hinted that comb jellies may be at the base of the tree.

    “It’s hard to disentangle the exact relationships of these [creatures],” Daley says. “These early branching groups diverged from each other such a long time ago…. So getting more info on [them] at this new site, where the preservation is really amazing, is really going to fill a gap.”

    The Burgess Shale, a vast deposit of fossil-bearing rocks in the Canadian Rockies, was discovered in 1909. It was this site that first gave scientists a glimpse into the Cambrian explosion, the rapid diversification of life that occurred during that period. The Burgess and Chengjiang sites, separated by 10 million years and half a world today, share only about 15 percent of the same taxa.

    That might be expected, Daley says, given their differences in both space and time. But the Qingjiang and Chengjiang sites, which date to the same time period and are separated by only 1,050 kilometers today, share only 8 percent of their taxa, she says. The researchers, however, suggest that the Qingjiang site may have been a slightly deeper marine environment. If so, that difference in ancient environment may have been the reason why the assemblage of creatures is so different, Daley says.

    The new work is preliminary, representing just the first of what is likely to be a deluge of studies describing fossils found at the site, Zhang says. “We’re just beginning!”

    Even after 110 years of digging in the Burgess Shale region, paleontologists are still turning up rich new sites and bizarre new creatures, adds Caron, of Canada’s Royal Ontario Museum. Just last summer, he and colleagues made new discoveries, including an enigmatic shield-shaped critter that he dubbed “the mothership.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 11:37 am on March 4, 2019 Permalink | Reply
    Tags: "How Creatures End Up Miles Below the Surface of Earth and Maybe Mars Too", An inevitable and most interesting question that arises is this: If there was robust and adaptable life on early Mars might it have been transported underground in water too?, At the Kopanang mine they had found the roundworm Poikilolaimus oxycercusin in water about a mile underground. What appeared to be the same nematode was also collected from the the Vaal river a few mi, “M. parvella does not have a hibernation stage and cannot survive in fresh water thus it must have been and must be in brackish water all the time” Borgonie said. “The question is did this happe, , , Ecosystems can survive in scalding temperatures in the absence of sunlight at high pressure and without oxygen. Yet they have been found as far down as almost three miles below the surface though in f, H. mephisto, , Paleobiology, Recent reports of another nematode species unaffiliated with South African mines suggests just how robust and adaptable individuals can be — in this case regarding deep freeze hibernation., Round worm Poikilolaimus oxycercus, Salese and colleagues explored 24 deep enclosed craters in the northern hemisphere of Mars with floors lying roughly 4000 meters (2.5 miles) below Martian ‘sea level’ (a level that given the plane, Some potential early Martian life could have migrated into the more protected depths is often discussed as a plausible if at this point untestable possibility   

    From Many Worlds: “How Creatures End Up Miles Below the Surface of Earth, and Maybe Mars Too” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    2019-03-04
    Marc Kaufman

    1
    Poikilolaimus oxycercus is a microscopic nematode, or roundworm, found alive and well more than a mile below the surface in South Africa, where its ancestors had lived for hundreds or thousands of years. (Gaetan Borgonie)

    When scientists speculate about possible life on Mars, they generally speak of microbial or other simple creatures living deep below the irradiated and desiccated surface. While Mars long ago had a substantial period that was wetter and warmer when it also had a far more protective atmosphere, the surface now is considered to be lethal.

    But the suggestion that some potential early Martian life could have migrated into the more protected depths is often discussed as a plausible, if at this point untestable possibility. In this scenario, some of that primitive subsurface life might even have survived the eons in their buried, and protected, environments.

    This thinking has gotten some support in the past decade with the discovery of bacteria and nematodes (roundworms) found as far down as three miles below the surface of South Africa, in water dated as being many thousands or millions years old. The lifeforms have been discovered by a team that has regularly gone down into the nation’s super-hot gold and platinum mines to search for life coming out of boreholes in the rock face of deep mine tunnels.

    2
    Borgonie setting up a water collector for a borehole at the Driefontein mine in the Witwatersrand Basin of South Africa. (Courtesy of Borgonie)

    Now a new paper [below] describes not only the discovery of additional deep subsurface life, but also tries to explain how the distant ancestors of the worms and bacteria and algae might have gotten there.

    Their conclusion: many were pulled down when fractures opened in the aftermath of earthquakes and other seismic events. While many lifeforms were swept down, only a small percentage were able to adapt, evolve and thus survive.

    The is how Gaetan Borgonie, lead author of the paper in Scientific Reports, explained it to me via email:

    “After the discovery of multicellular animals in the deep subsurface up to 3.8 km (2.5 miles) in South Africa everyone was baffled and asked the question how did they get that deep? This question more or less haunted us for more than a decade as we were unable to get our head around it.

    “However during the decade as we made more observations of multicellular organisms we captured in borehole water we found that these were nearly all animals associated with fresh water and not the soil. This indicated the passage to the deep was from a fresh water source on the surface and that animals did not crawl all the way down through the topsoil over millennia.”

    This makes sense because the deepest soil inhabitants live at about six feet below the surface, said Borgonie, formerly of the University of Ghent in Belgium and now with ELi, a Belgian nonprofit that studies extreme life. So another route to their deep subterranean homes was necessary.

    3
    One of six hibernating nematodes found in biofilms from a borehole in the Kopanang mine. Four of the six in this “dauer” or survival state were taken, placed in a petri dish and came back to active life. Several were mated with worms of the same Poikilolaimus oxycercus species and the offspring survived. (Gaetan Borgonie)

    Borgonie and his team conducted a variety of tests — seismic, geological, genetic — but one stands out as most conclusive.

    At the Kopanang mine, they had found the roundworm Poikilolaimus oxycercusin in water about a mile underground. What appeared to be the same nematode was also collected from the the Vaal river, a few miles from the mine.

    The two appeared to be genetically similar, but the best test was to see if they could successfully reproduce. And the answer was that they could.

    It was a smoking gun, though not necessarily a common one. Nematodes from other surfaces and subsurfaces were placed together and were not able to produce young that survived. As explained in the Scientific Reports paper, this may be a function of the once companionable subsurface nematodes having adapted to their environment in ways that broke their connections with surface nematodes of the same species.

    While nematodes can hibernate for long periods in what is called their dauer stage, when they wake up they survive for only 20 to 30 days. Their lines, however, can last in the subsurface for those very long periods.

    4
    Tunnels in South Africa’s Beatrix mine close to where H. mephisto was found. The deeper one goes in the mine, the hotter it gets. And yet life survives in the fracture water and other often tiny pockets of liquid. (Gaetan Borgonie)

    The nematodes collected and tested for this most recent article were but a small part of the zoo of creatures that have been collected from deep underground in South Africa’s Witwatersrand Basin. There was also algae, fungi, bacteria, a crustaceans and even a few insects, the paper reports. The bacteria is important for the nematodes in particular because they are a food source.

    These ecosystems survive in scalding temperatures, in the absence of sunlight, at high pressure and without oxygen. Yet they have been found as far down as almost three miles below the surface, though in far more isolated conditions at that depth.

    5
    Borgonie with Esta van Heerden, who helped gain access to South African mines for researchers including Borgonie and Princeton University geomicrobiologist Tullis Onstott more than a decade ago is part of their research team. She is founder of the mine water remediation company iwatersolutions and was formerly a professor with the University of the Free State in Bloemfontein, where she was a specialist in extremophiles. (Courtesy of Borgonie)

    The age of that life is difficult to determine. While methods exist to determine the age of the fracture water, scientists cannot definitively say when the lifeforms arrived. Still, Borgonie reports that the worms found at the Kopanang mine had been present for between 3,000 and 12,000 years, or rather their ancestors had been there.

    Borgonie and his colleagues had earlier discovered the first multicellular creature at great depth, Halicephalobus mephisto, in mine fracture water .6 to 3 miles down. That discovery, announced in 2011, helped establish that the deep subsurface was more able to support life, even complex life, than expected.

    Often the creatures were living in biofilms, loose collections of bacteria and other life held together in the water by secretions that encase them.

    Another aspect of the deep subsurface nematode story involves specimen found in salty stalactites at the Beatrix gold mine. The worms identified, Monhystrella parvella, are associated with salty environments and so the group inferred that the water and creatures may have come from a sea. There were such seas in what is now South Africa, but it was very long ago.

    “M. parvella does not have a hibernation stage and cannot survive in fresh water, thus it must have been and must be in brackish water all the time,” Borgonie said. “The question is did this happen long ago when that area of South Africa was covered by a sea or did it happen via the salt pans surrounding the Beatrix mine?

    “There is no way to know for now. But the fact is and remains that you have a worm in the subsurface in the middle of South Africa that can only survive in salty water.”

    Recent reports of another nematode species, unaffiliated with South African mines, suggests just how robust and adaptable individuals can be — in this case regarding deep freeze hibernation.

    The longest recorded nematode hibernation was 39 years until Russian scientists announced the discovery of frozen nematodes in deep Siberian permafrost. The worms had been asleep for 42,000 and 34,000 years respectively. A Science Alert article raises the possibility of contamination as an issue, but the scientists maintain they took all possible precautions and are convinced the frozen hibernations were as recorded.

    6
    Using an electron microscope, we see the inside of a stalactite in the Beatrix gold mine, about 1 mile below the surface. The nematodes are of the species Monhystrella parvella. (Gaetan Borgonie)

    That the South African deep subsurface life appears now to have come from the surface — via seismic fractures that could bring rushes or trickles of water filled with life many miles down — does have possible implications for Mars. While no signs of early life on Mars have been discovered, research in recent years has proven that the planet once had substantial water and warmer temperatures. In other words, conditions that might be hospitable to life.

    That theory of a once quite watery Mars was taken a significant step further last week in an article in the Journal of Geophysical Research — Planets , which found evidence of an earlier planet-wide groundwater system. Such a system had been predicted before by models, but now there was significant hard evidence that it had indeed existed.

    “Early Mars was a watery world, but as the planet’s climate changed this water retreated below the surface to form pools and ‘groundwater’,” says lead author Francesco Salese of Utrecht University, the Netherlands.

    “We traced this water in our study — as its scale and role is a matter of debate — and we found the first geological evidence of a planet-wide groundwater system on Mars.”

    Salese and colleagues explored 24 deep, enclosed craters in the northern hemisphere of Mars, with floors lying roughly 4000 meters (2.5 miles) below Martian ‘sea level’ (a level that, given the planet’s lack of seas, is arbitrarily defined on Mars based on elevation and atmospheric pressure).

    The scientists found features on the floors of these craters that could only have formed in the presence of water. Many craters contain multiple features, all at depths of 2.5 to 3 miles – indicating that these craters once contained pools and flows of water that changed and receded over time.

    7
    Researchers said flow channels, pool-shaped valleys and fan-shaped sediment deposits seen in dozens of kilometers-deep craters in Mars’ northern hemisphere would have needed water to form. (European Space Agency)

    So an inevitable and most interesting question that arises is this: If there was robust and adaptable life on early Mars, might it have been transported underground in water too?

    The planet does have seismic activity — some are called Marsquakes — that can open fractures. It seems plausible that if life existed in water on the Martian surface, it would have flowed or trickled down fractures and other porous features to substantial depths.

    Given this hypothetical, many would have died but some may have lived and adapted. Rather like what can be seen on Earth in the South African mines.

    With this possibility in mind, the Borgonie paper recommends that the presence of surface fractures be kept in mind when landing sites are chosen on other planets or moons.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    About Many Worlds
    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 3:23 pm on February 27, 2019 Permalink | Reply
    Tags: A one-stop link allowing earth scientists to access all the data they need to tackle big questions such as patterns of biodiversity over geologic time and the distribution of metal deposits also the w, , British Geological Survey, , Paleobiology, , This network of earth science databases called Deep-time Digital Earth (DDE)   

    From Science Magazine: “Earth scientists plan to meld massive databases into a ‘geological Google’’ 

    AAAS
    From Science Magazine

    Feb. 26, 2019
    Dennis Normile

    1
    Deep-time Digital Earth aims to liberate data from collections such as the British Geological Survey’s. British Geological Survey.

    The British Geological Survey (BGS) has amassed one of the world’s premier collections of geologic samples. Housed in three enormous warehouses in Nottingham, U.K., it contains about 3 million fossils gathered over more than 150 years at thousands of sites across the country. But this data trove “was not really very useful to anybody,” says Michael Stephenson, a BGS paleontologist. Notes about the samples and their associated rocks “were sitting in boxes on bits of paper.” Now, that could change, thanks to a nascent international effort to meld earth science databases into what Stephenson and other backers are describing as a “geological Google.”

    This network of earth science databases, called Deep-time Digital Earth (DDE), would be a one-stop link allowing earth scientists to access all the data they need to tackle big questions, such as patterns of biodiversity over geologic time, the distribution of metal deposits, and the workings of Africa’s complex groundwater networks. It’s not the first such effort, but it has a key advantage, says Isabel Montañez, a geochemist at University of California, Davis, who is not involved in the project: funding and infrastructure support from the Chinese government. That backing “will be critical to [DDE’s] success given the scope of the proposed work,” she says.

    In December 2018, DDE won the backing of the executive committee of the International Union of Geological Sciences, which said ready access to the collected geodata could offer “insights into the distribution and value of earth’s resources and materials, as well as hazards—while also providing a glimpse of the Earth’s geological future.” At a meeting this week in Beijing, 80 scientists from 40 geoscience organizations including BGS and the Russian Geological Research Institute are discussing how to get DDE up and running by the time of the International Geological Congress in New Delhi in March 2020.

    DDE grew out of a Chinese data digitization scheme called the Geobiodiversity Database (GBDB), initiated in 2006 by Chinese paleontologist Fan Junxuan of Nanjing University. China had long-running efforts in earth sciences, but the data were scattered among numerous collections and institutions. Fan, who was then at the Chinese Academy of Sciences’s Nanjing Institute of Geology and Paleontology, organized GBDB around the stacks of geologic strata called sections and the rocks and fossils in each stratum.

    Norman MacLeod, a paleobiologist at the Natural History Museum in London who is advising DDE, says GBDB has succeeded where similar efforts have stumbled. In the past, he says, volunteer earth scientists tried to do nearly everything themselves, including informatics and data management. GBDB instead pays nonspecialists to input reams of data gleaned from earth science journals covering Chinese findings. Then, paleontologists and stratigraphers review the data for accuracy and consistency, and information technology specialists curate the database and create software to search and analyze the data. Consistent funding also contributed to GBDB’s success, MacLeod says. Although it started small, Fan says GBDB now runs on “several million” yuan per year.

    Earth scientists outside China began to use GBDB, and it became the official database of the International Commission on Stratigraphy in 2012. BGS decided to partner with GBDB to lift its data “from the page and into cyberspace,” as Stephenson puts it. He and other European and Chinese scientists then began to wonder whether the informatics tools developed for GBDB could help create a broader union of databases. “Our idea is to take these big databases and make them use the same standards and references so a researcher could quickly link them to do big science that hasn’t been done before,” he says.

    The Beijing meeting aims to finalize an organizational structure for DDE. Chinese funding agencies are putting up $75 million over 10 years to get the effort off the ground, Fan says. That level of support sets DDE apart from other cyberinfrastructure efforts “that are smaller in scope and less well funded,” Montañez says. Fan hopes DDE will also attract international support. He envisions nationally supported DDE Centers of Excellence that would develop databases and analytical tools for particular interests. Suzhou, China, has already agreed to host the first of them, which will also house the DDE secretariat.

    DDE backers say they want to cooperate with other geodatabase programs, such as BGS’s OneGeology project, which seeks to make geologic maps of the world available online. But Mohan Ramamurthy, project director of the U.S. National Science Foundation–funded EarthCube project, sees little scope for collaboration with his effort, which focuses on current issues such as climate change and biosphere-geosphere interactions. “The two programs have very different objectives with little overlap,” he says.

    Fan also hopes individual institutions will contribute, by sharing data, developing analytical tools, and encouraging their scientists to participate. Once earth scientists are freed of the drudgery of combing scattered collections, he says, they will have time for more important challenges, such as answering “questions about the evolution of life, materials, geography, and climate in deep time.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 12:41 pm on May 26, 2016 Permalink | Reply
    Tags: , Paleobiology, Tiny Vampires, ,   

    From UCSB: “Tiny Vampires” Women in Science (No, the women are not the vampires in question) 

    UC Santa Barbara Name bloc

    May 25, 2016
    Julie Cohen

    1
    Susannah Porter. Photo Credit: Sonia Fernandez

    Paleobiologist Susannah Porter finds evidence of predation in ancient microbial ecosystems dating back more than 740 million years.

    2
    The Chuar Group in the Grand Canyon was once an ancient seabed. Photo Credit: Carol Dehler

    Vampires are real, and they’ve been around for millions of years. At least, the amoebae variety has. So suggests new research from UC Santa Barbara paleobiologist Susannah Porter.

    Using a scanning electron microscope to examine minute fossils, Porter found perfectly circular drill holes that may have been formed by an ancient relation of Vampyrellidae amoebae. These single-celled creatures perforate the walls of their prey and reach inside to consume its cell contents. Porter’s findings* appear in the Proceedings of the Royal Society B.

    “To my knowledge these holes are the earliest direct evidence of predation on eukaryotes,” said Porter, an associate professor in UCSB’s Department of Earth Science. Eukaryotes are organisms whose cells contain a nucleus and other organelles such as mitochondria.

    “We have a great record of predation on animals going back 550 million years,” she continued, “starting with the very first mineralized shells, which show evidence of drillholes. We had nothing like that for early life — for the time before animals appear. These holes potentially provide a way of looking at predator-prey interactions in very deep time in ancient microbial ecosystems.”

    Porter examined fossils from the Chuar Group in the Grand Canyon — once an ancient seabed — that are between 782 and 742 million years old. The holes are about one micrometer (one thousandth of a millimeter) in diameter and occur in seven of the species she identified. The holes are not common in any single one species; in fact, they appear in not more than 10 percent of the specimens.

    “I also found evidence of specificity in hole sizes, so different species show different characteristic hole sizes, which is consistent with what we know about modern vampire amoebae and their food preferences,” Porter said. “Different species of amoebae make differently sized holes. The Vampyrellid amoebae make a great modern analog, but because vampirelike feeding behavior is known in a number of different unrelated amoebae, it makes it difficult to pin down exactly who the predator was.”

    According to Porter, this evidence may help to address the question of whether predation was one of the driving factors in the diversification of eukaryotes that took place about 800 million years ago.

    “If that is true, then if we look at older fossil assemblages — say 1 to 1.6 billion years old — the fossilized eukaryote will show no evidence of predation,” Porter said. “I’m interested in finding out when drilling first appears in the fossil record and whether its intensity changes through time.”

    Porter also is interested in seeing whether oxygen played a role in predation levels through time. She noted that the microfossils those organisms attacked were probably phytoplankton living in oxygenated surface waters, but like vampyrellid amoebae today, the predators may have lived in the sediments. She suggests that those phytoplankton made tough-walled cysts — resting structures now preserved as fossils — that sank to the bottom where they were attacked by the amoebae.

    “We have evidence that the bottom waters in the Chuar Group in that Grand Canyon basin were relatively deep — 200 meters deep at most — and sometimes became anoxic, meaning they lacked oxygen,” Porter explained.

    “I’m interested to know whether the predators only were present and making these drill holes when the bottom waters contained oxygen,” Porter added. “That might tie the diversification of eukaryotes and the appearance of predators to evidence for increasing oxygen levels around 800 million years ago.

    “We know from the modern vampire amoebae that at least some of them make resting cysts themselves,” Porter said. “A former student of mine joked we should call these coffins. So one of our motivations is to see if we can find these coffins in the fossil assemblage as well. That’s the next project.”

    *Science paper:
    Tiny vampires in ancient seas: evidence for predation via perforation in fossils from the 780–740 million-year-old Chuar Group, Grand Canyon, USA

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

     
  • richardmitnick 12:17 pm on February 17, 2015 Permalink | Reply
    Tags: , , , Paleobiology,   

    From U Washington: “Ancient rocks show life could have flourished on Earth 3.2 billion years ago” 

    U Washington

    University of Washington

    February 16, 2015
    Hannah Hickey

    1
    The oldest samples are sedimentary rocks that formed 3.2 billion years ago in
    northwestern Australia. They contain chemical evidence for nitrogen fixation by microbes. (R. Buick / UW)

    A spark from a lightning bolt, interstellar dust, or a subsea volcano could have triggered the very first life on Earth.

    But what happened next? Life can exist without oxygen, but without plentiful nitrogen to build genes – essential to viruses, bacteria and all other organisms – life on the early Earth would have been scarce.

    The ability to use atmospheric nitrogen to support more widespread life was thought to have appeared roughly 2 billion years ago. Now research from the University of Washington looking at some of the planet’s oldest rocks finds evidence that 3.2 billion years ago, life was already pulling nitrogen out of the air and converting it into a form that could support larger communities.

    “People always had the idea that the really ancient biosphere was just tenuously clinging on to this inhospitable planet, and it wasn’t until the emergence of nitrogen fixation that suddenly the biosphere become large and robust and diverse,” said co-author Roger Buick, a UW professor of Earth and space sciences. “Our work shows that there was no nitrogen crisis on the early Earth, and therefore it could have supported a fairly large and diverse biosphere.”

    The results were published Feb. 16 in Nature.

    The authors analyzed 52 samples ranging in age from 2.75 to 3.2 billion years old, collected in South Africa and northwestern Australia. These are some of the oldest and best-preserved rocks on the planet. The rocks were formed from sediment deposited on continental margins, so are free of chemical irregularities that would occur near a subsea volcano. They also formed before the atmosphere gained oxygen, roughly 2.3 to 2.4 billion years ago, and so preserve chemical clues that have disappeared in modern rocks.

    Even the oldest samples, 3.2 billion years old – three-quarters of the way back to the birth of the planet – showed chemical evidence that life was pulling nitrogen out of the air. The ratio of heavier to lighter nitrogen atoms fits the pattern of nitrogen-fixing enzymes contained in single-celled organisms, and does not match any chemical reactions that occur in the absence of life.

    “Imagining that this really complicated process is so old, and has operated in the same way for 3.2 billion years, I think is fascinating,” said lead author Eva Stüeken, who did the work as part of her UW doctoral research. “It suggests that these really complicated enzymes apparently formed really early, so maybe it’s not so difficult for these enzymes to evolve.”

    Genetic analysis of nitrogen-fixing enzymes have placed their origin at between 1.5 and 2.2 billion years ago.

    “This is hard evidence that pushes it back a further billion years,” Buick said.

    Fixing nitrogen means breaking a tenacious triple bond that holds nitrogen atoms in pairs in the atmosphere and joining a single nitrogen to a molecule that is easier for living things to use. The chemical signature of the rocks suggests that nitrogen was being broken by an enzyme based on molybdenum, the most common of the three types of nitrogen-fixing enzymes that exist now. Molybdenum is now abundant because oxygen reacts with rocks to wash it into the ocean, but its source on the ancient Earth – before the atmosphere contained oxygen to weather rocks – is more mysterious*.

    The authors hypothesize that this may be further evidence that some early life may have existed in single-celled layers on land, exhaling small amounts of oxygen that reacted with the rock to release molybdenum to the water.

    “We’ll never find any direct evidence of land scum one cell thick, but this might be giving us indirect evidence that the land was inhabited,” Buick said. “Microbes could have crawled out of the ocean and lived in a slime layer on the rocks on land, even before 3.2 billion years ago.”

    Future work will look at what else could have limited the growth of life on the early Earth. Stüeken has begun a UW postdoctoral position funded by NASA to look at trace metals such as zinc, copper and cobalt to see if one of them controlled the growth of ancient life.

    Other co-authors are Bradley Guy at the University of Johannesburg in South Africa, who provided some samples from gold mines, and UW graduate student Matthew Koehler. The research was funded by NASA, the UW’s Virtual Planetary Laboratory, the Geological Society of America and the Agouron Institute.

    See the full article here.

    [*Sorry, not mysterious at all. Everything here, especially metals, comes from the ash of supernovae.]

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.

    So what defines us — the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
  • richardmitnick 9:13 am on February 3, 2015 Permalink | Reply
    Tags: , Microorganisms, Paleobiology, ,   

    From UCLA: “Scientists discover organism that hasn’t evolved in more than 2 billion years” 

    UCLA bloc

    UCLA

    February 02, 2015
    Stuart Wolpert

    1
    A section of 1.8 billion-year-old fossil-bearing rock. The fossils (dark areas) are essentially identical to fossils 500 million years older and to modern microorganisms.
    UCLA Center for the Study of Evolution and the Origin of Life

    Research actually provides further support for Darwin, UCLA professor says

    An international team of scientists has discovered the greatest absence of evolution ever reported — a type of deep-sea microorganism that appears not to have evolved over more than 2 billion years. But the researchers say that the organisms’ lack of evolution actually supports Charles Darwin’s theory of evolution.

    The findings are published online today by the Proceedings of the National Academy of Sciences.

    The scientists examined sulfur bacteria, microorganisms that are too small to see with the unaided eye, that are 1.8 billion years old and were preserved in rocks from Western Australia’s coastal waters. Using cutting-edge technology, they found that the bacteria look the same as bacteria of the same region from 2.3 billion years ago — and that both sets of ancient bacteria are indistinguishable from modern sulfur bacteria found in mud off of the coast of Chile.

    “It seems astounding that life has not evolved for more than 2 billion years — nearly half the history of the Earth,” said J. William Schopf, a UCLA professor of earth, planetary and space sciences in the UCLA College who was the study’s lead author. “Given that evolution is a fact, this lack of evolution needs to be explained.”

    3
    Deep-sea microorganisms are unchanged over more than 2 billion years (UCLA Center for the Study of Evolution and the Origin of Life)

    Charles Darwin’s writings on evolution focused much more on species that had changed over time than on those that hadn’t. So how do scientists explain a species living for so long without evolving?

    2
    UCLA professor J. William Schopf pioneered the techniques used to analyze microscopic fossils preserved inside ancient rocks.(John Vande Wege/UCLA)

    “The rule of biology is not to evolve unless the physical or biological environment changes, which is consistent with Darwin,” said Schopf, who also is director of UCLA’s Center for the Study of Evolution and the Origin of Life. The environment in which these microorganisms live has remained essentially unchanged for 3 billion years, he said.

    “These microorganisms are well-adapted to their simple, very stable physical and biological environment,” he said. “If they were in an environment that did not change but they nevertheless evolved, that would have shown that our understanding of Darwinian evolution was seriously flawed.”

    Schopf said the findings therefore provide further scientific proof for Darwin’s work. “It fits perfectly with his ideas,” he said.

    The fossils Schopf analyzed date back to a substantial rise in Earth’s oxygen levels known as the Great Oxidation Event, which scientists believe occurred between 2.2 billion and 2.4 billion years ago. The event also produced a dramatic increase in sulfate and nitrate — the only nutrients the microorganisms would have needed to survive in their seawater mud environment — which the scientists say enabled the bacteria to thrive and multiply.

    Schopf used several techniques to analyze the fossils, including Raman spectroscopy — which enables scientists to look inside rocks to determine their composition and chemistry — and confocal laser scanning microscopy — which renders fossils in 3-D. He pioneered the use of both techniques for analyzing microscopic fossils preserved inside ancient rocks.

    Co-authors of the PNAS research were Anatoliy Kudryavtsev, a senior scientist at UCLA’s Center for the Study of Evolution and the Origin of Life, and scientists from the University of Wisconsin, NASA’s Jet Propulsion Laboratory, Australia’s University of New South Wales and Chile’s Universidad de Concepción.

    Schopf’s research is funded by the NASA Astrobiology Institute.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: