New research shows that a tiny piece of RNA has an essential role in ensuring that embryonic tissue segments form properly. The study, conducted in chicken embryos, determined that this piece of RNA regulates cyclical gene activity that defines the timing of the formation of tissue segments that later become muscle and vertebrae.
At some point, scientists may be able to bring back extinct animals, and perhaps early...
It’s not entirely clear what caused the end-Triassic extinction, although most...
Swarming is the spontaneous organized motion of a large number of individuals. It is observed at...
The three different formations of South Pacific coral-reef islands, fringing, barrier, and atoll, have long fascinated geologists. The question of how reefs develop into these shapes over evolutionary time produced an enduring conflict between two hypotheses, one from Charles Darwin and the other from Reginald Daly. But in a recently published paper, researchers use modern measurements and computer modeling to resolve this old conundrum.
A carnivorous, cannibalistic tadpole may play a role in understanding the evolution and development of digestive organs, according to research from North Carolina State University. These findings may also shed light on universal rules of organ development that could lead to better diagnosis and prevention of intestinal birth defects.
Researchers at the University of Leeds may have solved a key puzzle about how objects from space could have kindled life on Earth. While it is generally accepted that some important ingredients for life came from meteorites bombarding the early Earth, scientists have not been able to explain how that inanimate rock transformed into the building blocks of life, until now.
Archaeologists recently unearthed a “Black Death” grave in London, containing more than a dozen skeletons of people suspected to have died from the plague. The victims are thought to have died during the 14th century and archaeologists anticipate finding many more as they excavate the site. Results of their reveal a number of factors that show we are still at risk of plague today.
For hundreds of years, naturalists and scientists have identified new species based on an organism’s visible differences. But different species can often show little or no visible differences. Evolutionary biologists have recently combined traditional morphological tests with genetic techniques to distinguish these genetically different but outwardly similar organisms, which are dubbed “cryptic” species.
Chemists have recently shown that conditions in space are capable of creating complex dipeptides—linked pairs of amino acids—that are essential building blocks shared by all living things. The discovery opens the door to the possibility that these molecules were brought to Earth aboard a comet or possibly meteorites, catalyzing the formation of proteins (polypeptides), enzymes and even more complex molecules, such as sugars, that are necessary for life.
New research led by the University of Washington challenges the 140-year-old assumption that finding fossilized remains of prehistoric animals with such teeth meant the animals were living in grasslands and savannas. Instead it appears certain South American mammals evolved the teeth in response to the gritty dust and volcanic ash they encountered while feeding in an ancient tropical forest.
Our ancestors evolutionarily split from those of rhesus monkeys about 25 million years ago. Since then, brain areas have been added, have disappeared, or have changed in function. This raises the question: Has evolution given humans unique brain structures? Previous research has been inconclusive, but by combining different research methods, researchers in The Netherlands now say they have the first piece of evidence that could prove that humans have unique cortical brain networks.
"The sounds uttered by birds offer in several respects the nearest analogy to language," Charles Darwin wrote in "The Descent of Man" (1871), while contemplating how humans learned to speak. Language, he speculated, might have had its origins in singing, which "might have given rise to words expressive of various complex emotions." Now researchers from Massachusetts Institute of Technology, along with a scholar from the University of Tokyo, say that Darwin was on the right path.
RNA bases are thought to have been a part of life from the very beginning. However, RNA don’t form base pairs in water unless they are connected to a polymer backbone, a trait that has baffled scientists for decades. Researchers at the Georgia Institute of Technology have an alternate theory for the origin of RNA. They think the RNA bases may have evolved from a pair of molecules distinct from the bases we have today, and they have demonstrated their theory using self-assembly techniques.
What came first: the bipedal human ancestor or the grassland encroaching on the forest? A new analysis of the past 12 million years' of vegetation change in the cradle of humanity is challenging long-held beliefs about the world in which our ancestors took shape—and, by extension, the impact it had on them.
A series of rapid environmental changes in East Africa roughly 2 million years ago may be responsible for driving human evolution, according to researchers at Penn State University and Rutgers University.
A research team led by biogeochemists at the University of California, Riverside has tested a popular hypothesis in paleo-ocean chemistry, and proved it false. The team has ruled out zinc as a factor in the delayed diversification of single-celled and multicellular organisms.
Two groups—clades—of grasses that once had a common ancestry diverged. The PACMAD clade was predisposed to evolve a more efficient "C4" means of photosynthesis than grasses in the BEP clade. In a new study, a Brown University-led team pinpoints the anatomical differences between the clades that led to the PACMAD's tendency toward C4.
One of the great mysteries of life is how it began. For more than a century, scientists have struggled to reconstruct the key first steps on the road to life. Until recently, their focus has been trained on how the simple building blocks of life might have been synthesized on the early Earth, or perhaps in space. But because it happened so long ago, all chemical traces have long been obliterated, leaving plenty of scope for speculation and disagreement. Now, a novel approach to the question of life's origin attempts to redefine the problem.
Researchers have discovered why plants and animals had a hard time recovering from the largest mass extinction in Earth’s history 250 million years ago. The reason: global warming. Because of environmental consequences of rising temperatures, those species that survived the extinction didn’t fully recover for 5 million years.
Opsins, the light-sensitive proteins key to vision, may have evolved earlier and undergone fewer genetic changes than previously believed, according to a new study that used computer modelling to theorize the evolutionary developments of these structures. The analysis incorporated all available genomic information from all relevant animal lineages.
Bacteria have a bad rap as agents of disease, but scientists are increasingly discovering their many benefits, such as maintaining a healthy gut. A new study now suggests that bacteria may also have helped kick off one of the key events in evolution: the leap from one-celled organisms to many-celled organisms, a development that eventually led to all animals, including humans.
Microorganisms that crashed to Earth embedded in the fragments of distant planets might have been the sprouts of life on this one, according to new research. The research team reports that under certain conditions there is a high probability that life came to Earth during the solar system's infancy when Earth and its planetary neighbors orbiting other stars would have been close enough to each other to exchange lots of solid materials.
Emerging from the investigation of a mysterious nitrogen-fixing microbe that has a very small genome, an international team of investigators has found that certain type of photosynthetic bacteria not only provides nitrogen to its host single-cell algae, it appears now to be the most widespread nitrogen-fixing organism in the oceans.
Several years ago researchers at Michigan State University reported discovering a novel, evolutionary trait in a long-studied population of Escherichia coli . These same biologists have now analyzed this new trait's genetic origins and found that in multiple cases, the bacteria needed more than one mutational step. The finding documents this step-by-step process and highlights the importance of evolutionary changes that alter the physical arrangement of genes, leading to new patterns of gene regulation.
For nearly 260 years, researchers have classified species based on visual attributes like color, shape and size. But some species, such as Symbiodinum , a group of single-celled algae that live inside corals and are critical to their survival, could not have been found using the system that Carl Linnaeus pioneered. Instead, DNA analysis is providing the clue, and many new species are being found as a result.
A new study of giant viruses supports the idea that viruses are ancient living organisms and not inanimate molecular remnants run amok, as some scientists have argued. The study may reshape the universal family tree, adding a fourth major branch to the three that most scientists agree represent the fundamental domains of life.
Scientists have discovered well-preserved frozen woolly mammoth fragments deep in Siberia that may contain living cells, edging a tad closer to the "Jurassic Park" possibility of cloning a prehistoric animal. Russia's North-Eastern Federal University said an international team of researchers had discovered mammoth hair, soft tissues and bone marrow some 100 m underground during a summer expedition in the northeastern province of Yakutia.
Competition is a strong driving force of evolution for organisms of all sizes: Those individuals best equipped to obtain resources adapt and reproduce, while others may fall by the wayside. Many organisms also form cooperative social structures that allow resources to be defended and shared within a population. But surprisingly, even microbes, which are thought to thrive only when able to win the battle for resources against those nearest to them, have a somewhat sophisticated social structure that relies on cooperation, according to Massachusetts Institute of Technology scientists.