ScienceDaily: All - January 19, 2025
Today's top research news
Three million years ago, our ancestors were vegetarian
Human ancestors like Australopithecus -- which lived around 3.5 million years ago in southern Africa -- ate very little to no meat, according to new research. This conclusion comes from an analysis of nitrogen isotope isotopes in the fossilized tooth enamel of seven Australopithecus individuals. The data revealed that these early hominins primarily relied on plant-based diets, with little to no evidence of meat consumption.
NASA's Hubble traces hidden history of Andromeda galaxy
In the years following the launch of NASA's Hubble Space Telescope, astronomers have tallied over 1 trillion galaxies in the universe. But only one galaxy stands out as the most important nearby stellar island to our Milky Way -- the magnificent Andromeda galaxy (Messier 31). It can be seen with the naked eye on a very clear autumn night as a faint cigar-shaped object roughly the apparent angular diameter of our Moon. A century ago, Edwin Hubble first established that this so-called 'spiral nebula' was actually very far outside our own Milky Way galaxy -- at a distance of approximately 2.5 million light-years or roughly 25 Milky Way diameters.
In the Northeast, 50% of adult ticks carry Lyme disease carrying bacteria
Across most of the Northeast, getting bitten by a blacklegged tick-- also called a deer tick -- is a risk during spring, summer, and fall. A new Dartmouth study, published in Parasites and Vectors, finds that 50% of adult blacklegged ticks carry the bacteria that causes Lyme disease while 20% to 25% of the younger (nymph) blacklegged ticks carry the bacteria.
Bacteria in polymers form cables that grow into living gels
Experiments and modeling reveal the unexpected structure that can be seen in bacteria grown in mucus samples and biofilms.
Astrophysicists reveal structure of 74 exocomet belts orbiting nearby stars in landmark survey
Astrophysicists have imaged a large number of exocomet belts around nearby stars, and the tiny pebbles within them. The crystal-clear images show light being emitted from these millimeter-sized pebbles within the belts that orbit 74 nearby stars of a wide variety of ages -- from those that are just emerging from birth to those in more mature systems like our own Solar System.
Astronomers capture unprecedented view of supermassive black hole in action
Astronomers have now produced the highest resolution direct images ever taken of a supermassive black hole in the infrared, using the Large Binocular Telescope Interferometer.
Reading the genome and understanding evolution: Symbioses and gene transfer in leaf beetles
Scientists explored the evolutionary success of leaf beetles, the most diverse herbivores on Earth. They showed that symbioses with bacteria have evolved repeatedly and independently in different beetle lineages, and contribute significantly to the efficient digestion of plant food. These symbiotic relationships provide clues as to how genetic material was exchanged between bacteria and beetles. Key findings highlight the role of horizontal gene transfer, the incorporation of foreign bacterial genetic material into the beetle genome, which is thought to be the result of earlier symbioses. Overall, the study emphasizes the importance of microbial partnerships and genetic exchange in shaping the dietary adaptations of leaf beetles, which facilitated the evolutionary success of leaf beetles.
Microbial cell factories may help get to the root of understudied plant molecules
A new tool could make it easier to study scarce plant molecules. Researchers have developed so-called microbial cell factories -- using E. coli and yeast -- to produce a special class of plant hormones, known as strigolactones, at unprecedented levels. By amplifying production of strigolactones, which occur in such low amounts in plants, researchers now have the ability to study these elusive plant molecules in much greater depth than before. The work could help improve sustainable agricultural practices by offering deeper insights into how plants make and use their natural hormones to adapt and survive.
Lower access to air conditioning may increase need for emergency care for wildfire smoke exposure
People who have limited access to air conditioning may be at higher risk of seeking emergency care for health problems following exposure to wildfire smoke, according to a new study. The study found that exposure to fine particle matter (PM2.5) from wildfire smoke in California is associated with higher rates of emergency department visits for all causes, non-accidental causes, and respiratory disease. This risk varied by age and race, but was especially high for individuals who lived in areas with lower availability of air conditioning.
Dangerous bacterial biofilms have a natural enemy
Scientists have now discovered a chemical that plants produce when they're stressed prevents dangerous biofilm from forming. The breakthrough offers potential advances in healthcare as well as preventing equipment corrosion in industrial settings.