Right: This Xenophora snail from the Pliocene Epoch shows how it finds a way to survive by incorporating shelly material from other organisms into its own shell. Left: Bulk sample of several ancient bivalves (clams) and gastropods (snails). Credit: University of Cincinnati
Researchers have produced a model of epoch-to-epoch changes in marine bivalves and gastropods during the Cenozoic period (65 million years go to present), providing a view of changes in distribution from tropical latitudes toward the Earth’s poles over time. The results show that climate change through the Cenozoic period had little effect on the migration patterns of ...June 1, 2015 / Posted by: Aaron Gronstal
NJ phylogram, starting with 172 representative taxa, limited to only the 23 taxa found in the agreement subtrees for the 100 replicate trees formed using iterations of six predicted orthologs. Credit: Figure 8, House et. al. (2015)
Astrobiologists studying microbial genomes have found that determining the order of genes in an organism’s DNA could provide insight into how genomes from different organisms are related. The team took a large selection of prokaryotic genomes and developed a method for determining how closely the genomes were related to one another based on the conservation of gene order. In doing so, they ...May 29, 2015 / Written by: Aaron Gronstal
This National Weather Service photo depicts a turbulent sea surface in the North Pacific during a storm. Credit: NOAA/Historic National Weather Service Collection
Current models of ocean redox on Earth suggest that anoxygenic photosynthesis in marine environments was more prevalent during Earth’s earliest time span (Precambrian) than during Earth’s current geological eon (Phanerozoic). To examine this theory, a team of scientists looked at products from carotenoid pigments in rock extracts and oils over a time period ranging from the Proterozoic (just before the rise of complex life) to the Paleogene (roughly 23 million years ago).
Carotenoids are ...May 28, 2015 / Written by: Aaron Gronstal
Rumuruti (R) chondrites have been recognized as a chondrite group since 1994. The first R chondrite was found in Australia in 1977 and is known as the Carlisle Lakes R chondrite. Above are thin sections from Carlisle Lakes in plane-polarized light (left) and cross-polarized light (right). Image Credit: NASA JPL
Many theories about the origins of life involve the delivery of organic molecules to the early Earth by objects from space. Previously, scientists have identified amino acids in carbon-rich meteorites. The abundance and structure of these amino acids can be very different depending on what type of meteorite they come ...May 28, 2015 / Written by: Aaron Gronstal
A molecular dynamics simulations of a transmembrane ion channel. Credit: Pohorille et al. 2010
Scientists supported in part by the Exobiology & Evolutionary Biology element of the NASA Astrobiology Program have used computer simulations and an electrodiffusion model to compute the conduction of simple ion channels.
Ion channels are pore-like structures in cell membranes that regulate how ions move in and out of cells. In humans, everything from brain function to muscle contraction relies on ion channels. They are also essential in lower organisms, and help protect cells from toxins and antimicrobial agents.
Ion channels are a basic mechanism found in all living organisms, and studying them could provide astrobiologists with important information about the origin and evolution of life on Earth. In addition, this research could have many applications in fields like biotechnology and medicine.
The study, “Calculating Conductance of Ion Channels – Linking Molecular Dynamics and Electrophysiology ,” was published in the journal Journal of Physics: Conference Series.
Source: [Journal of Physics: Conference Series]May 27, 2015 / Written by: Aaron Gronstal
It is in dense clouds of interstellar dust, gas, and ice like the Keyhole Nebula (above) that new stars and planetary systems are formed. This image of the Keyhole nebula comes from the Hubble Space Telescope. Credit: NASA and the Hubble Heritage Team (STSci), Hubble Space Telescope WFPC2, STSci-PRC00-06
Glycerol is a key building block of cell membranes, but scientists have not been able to explain its existence on early Earth. A study supported in part by the Exobiology & Evolutionary Biology element of the NASA Astrobiology Program shows that glycerol might form when ionizing radiation interacts with interstellar ices.
Following this radiation-induced formation of glycerol, interstellar grains can then be incorporated into the building material of solar systems. From here, the team believes that comets and meteorites could serve to deliver the glycerol to habitable planets like the early Earth.
The study, “Synthesis of Prebiotic Glycerol in Interstellar Ices,” was published in the journal Angewandte Chemie.
Source: [Angewandte Chemie]May 26, 2015 / Written by: Aaron Gronstal
Derek Briggs awarded Paleontological Society Medal. Credit: YaleNews
The Paleontological Society named Derek Briggs its 2015 Paleontological Society Medalist for his work in the taphonomy, preservation and evolutionary significance of exceptionally preserved fossil biotas.
Briggs is a member of the NAI CAN-6 team at MIT, serving as a Co-I for the Foundations of Complex Life research project. He is also a professor of geology and geophysics at Yale University and curator of the Yale Peabody Museum of Natural History. His previous honors include the Premio Capo d’Orlando, the Lyell Medal, the Boyle Medal, and Humboldt Research Award.
More information ...May 21, 2015 / Written by: Miki Huynh
Astrobiology: The Story of our Search for Life in the Universe. Credit: NASA Astrobiology Program
Today, May 21st, NASA Astrobiology joins The Cartoon Art Museum in downtown San Francisco as they explore the theme of outer space through the medium of comic art. Visitors to this Third Thursday event will be able to pick up copies of the Astrobiology graphic history series by Aaron Gronstal in an exhibit featuring both works of science and science fantasy.
The event takes place 5:00-8:00PM and is free and open to the public.
Established in 1984, the Cartoon Art Museum displays and ...
Sunlight glints off of hydrocarbon seas on Saturn’s moon Titan, as seen here in near-infrared light by the Cassini spacecraft. Credit: NASA/JPL-Caltech/Univ. Arizona/Univ. Idaho
In the search for life beyond Earth, scientists have justifiably focused on water because all biology as we know it requires this fluid. A wild card, however, is whether alternative liquids can also suffice as life-enablers. For example, Saturn’s frigid moon Titan is awash in inky seas of the hydrocarbon methane.
A new study proposes that molecules called ethers, not used in any genetic molecules on Earth, could ...
A eukaryotic cell illustration used to teach students critical thinking skills. Credit: Byung-Ho Kang of the University of Florida
Astrobiology Students Use Art to Develop Critical Thinking Skills
Consider the process that goes into creating a painting — the attention to detail, the need to interpret the world around you. A scientist goes about his or her work using many of the same skills. This concept is the focus of a recent study that describes the development and implementation of a learning module that introduces astrobiology students to the concepts of creative and scientific inquiry.
The study, “Developing ...
Octopus Spring in Yellowstone National Park. Credit: David Strong, Penn State University
Researchers supported in part by the Exobiology & Evolutionary Biology element of the NASA Astrobiology Program have isolated a new 'acid-loving’ microorganisms from cyanobacterial microbial mats associated with Octopus Spring in Yellowstone. Chloracidobacterium thermophilum strain B is an anoxygenic photoheterotroph, a member of the phylum Acidobacteria, and moderately thermophilic.
The paper, “Chloracidobacterium thermophilum gen. nov., sp. nov.: an anoxygenic microaerophilic chlorophotoheterotrophic acidobacterium,” was published in the International Journal of Systematic and Evolutionary Microbiology.May 4, 2015 / Written by: Aaron Gronstal
Scientists are providing new insights into the role mutations play in the evolution of microbial populations. Researchers examined the relationship between different, beneficial mutations in a population, and how organisms survive when one or more of the mutations are present in a single organism.
The study, “ The Valley-of-Death: Reciprocal sign epistasis constrains adaptive trajectories in a constant, nutrient limiting environment,” was published in the journal Genomics.
The research was supported in part by the Exobiology & Evolutionary Biology element of the NASA Astrobiology Program.
Source: [Genomics]May 1, 2015 / Written by: Aaron Gronstal
Scanning electron microscopy image of a MOWS specimen, which is about 4 mm in total length. Image taken by Phoebe Cohen
Researchers supported in part by the Exobiology & Evolutionary Biology element of the NASA Astrobiology Program have discovered new and unusual fossils in Mongolia. The structures, known as macroscopic organic warty sheets (MOWS), could be the remains of fungal biofilms, or even previously unknown organisms that are now extinct. However, the team believes that multiple lines of evidence indicate that the MOWS are the remnants of ancient marine algae.
Regardless of the organisms responsible for their production, the discovery of MOWS increases our understanding of biological diversity during a period of Earth’s history known as the Cryogenian glacial interlude (662–635 million years ago). The discovery also shows that macroscopic and morphologically complex multicellular organisms were present in the Cryogenian.
The study, “Fossils of putative marine algae from the cryogenian glacial interlude of Mongolia,” was published in the journal Palaios.
Source: [Palaios]April 29, 2015 / Written by: Aaron Gronstal
Nathalie A. Cabrol diving and sampling in the Licancabur lake at 5,917 m elevation in the volcano’s crater. Photo Credit: The High Lakes Project: The SETI Institute Carl Sagan Center/NASA Ames/ NAI
Astrobiologist Nathalie Cabrol recently spoke about her work in remote field sites, including high-altitude lakes in the Andes, at the TED2015 conference. In her talk, Cabrol discusses how this work could help scientists search for signs of life on Mars.
Cabrol’s TED Talk, “Nathalie Cabrol: How Mars might hold the secret to the origin of life,” is now available to watch from TED.com ...April 28, 2015 / Posted by: Aaron Gronstal
A hot spring in Yellowstone National Park. Image Credit: Darren Edwards, http://fettss.arc.nasa.gov/collection/details/yellowstone-1/
A study of the Yellowstone hot springs has revealed new clues about how organic materials might have been preserved in similar environments on ancient Mars. Researchers found that iron could either preserve or react with organic material in a way that helps form a fossil record.
The study, supported in part by the Exobiology & Evolutionary Biology element of the NASA Astrobiology Program, was published in the journal Astrobiology.
Source: [astrobio.net]April 27, 2015 / Posted by: Aaron Gronstal