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.
Charles Darwin hypothesized in 1880 that most species could not disperse across the Eastern Pacific Barrier, an uninterrupted 4,000-mile stretch of water with depths of up to 7 miles that separates the central from the eastern Pacific Ocean. Scientists have confirmed this hypothesis for many species, but recent research by Penn State University is the first to determine its effect on coral.
Squid’s colorful, changeable skin enables the animal—and their close relatives, cuttlefish and octopus—to display extraordinary camouflage. But how squid control their skin’s iridescence, or light-reflecting property, has been unknown until now. Researchers at the Marine Biological Laboratory report that nerves in squid skin control the spectrum and speed of color change, marking the first time neural control of iridescence in an invertebrate species has been demonstrated.
The start of the universe should be modeled not as a Big Bang, but more like water freezing into ice, according to a team of theoretical physicists at the University of Melbourne and RMIT University. The have suggested that by investigating the cracks and crevices common to all crystals our understanding of the nature of the universe could be revolutionized.
Our family tree may have sprouted some long-lost branches going back nearly 2 million years. A famous paleontology family has found fossils that they think confirm their theory that there are two additional pre-human species besides the one that eventually led to modern humans.
According to two scientific articles published this week, poisoned-tipped arrows and jewelry made of ostrich egg beads found in South Africa show modern culture may have emerged about 30,000 years earlier in the area than previously thought. The findings reinforce the theory that modern man emerged from southern Africa.
Researchers analyzing meteorite fragments that fell on a frozen lake in Canada have developed an explanation for the origin of life's handedness—why living things only use molecules with specific orientations. The work also gave the strongest evidence to date that liquid water inside an asteroid leads to a strong preference of left-handed over right-handed forms of some common protein amino acids in meteorites.
It's a project 500 million years in the making. Only this time, instead of playing on a movie screen in Jurassic Park, it's happening in a laboratory at the Georgia Institute of Technology. Using a process called paleo-experimental evolution, researchers have resurrected a 500-million-year-old-gene from bacteria and inserted it into modern-day Escherichia coli bacteria.
It was a provocative finding: strange bacteria in a California lake that thrived on something completely unexpected—arsenic. What it suggested is that life, a very different kind of life, could possibly exist on some other planet. On Sunday, that same journal, Science , released two papers that rip apart the original research.
Researchers at the Salk Institute for Biological Studies and the Howard Hughes Medical Institute recently speculated that plant chemodiversity results from rapid and sometimes unanticipated evolutionary steps. Their theory aims to help explain why plants evolved their ability to synthesize a vast and diverse array of secondary metabolites.
In most scientific models, genetic mutants have a fitness value which remains constant. Based on this value, they compete, die out, or become established. However, evolutionary game theory considers holds that the fitness of a mutation also depends on the frequency of the mutation. Researchers in Germany have developed a model to address the scenario of mutations being frequency-dependent but having random fitness parameters.
In 1969, an exploding fireball tore through the sky over Mexico, scattering thousands of pieces of meteorite across the state of Chihuahua. More than 40 years later, the Allende meteorite is still serving the scientific community as a rich source of information about the early stages of our solar system's evolution. Recently, scientists from the California Institute of Technology discovered a new mineral embedded in the space rock—one they believe to be among the oldest minerals formed in the solar system.
Dolphins are so distantly related to humans that it's been 95 million years since we had even a remotely common ancestor. Yet when it comes to intelligence, social behavior and communications, some researchers say dolphins come as close to humans as our ape and monkey cousins. Maybe even closer. And they aren’t the only non-primates to show similar brain powers.
University of California, Santa Barbara scientists turned to the simple sponge to find clues about the evolution of the complex nervous system and found that, but for a mechanism that coordinates the expression of genes that lead to the formation of neural synapses, sponges and the rest of the animal world may not be so distant after all.
CT scans of fossilized primate skulls or skull fragments from both the Old and New Worlds may shed light on how these extinct animals moved, especially for those species without any known remains, according to an international team of researchers.
Having mapped the DNA of the bonobo, scientists have found that we are as close genetically to the peace-loving but little-known primate as we are to the more violent and better understood chimpanzee. It's as if they are siblings and we are cousins, related to them both equally, sharing some traits with just bonobos and other characteristics with just chimps.
Identification of the parts of the brain are responsible for the things that reach our awareness is one of the main puzzles in neurobiology today. New findings from researchers in Europe using electrophysiological methods now support the view that the content of consciousness is not localized in a unique cortical area.
In a new study, researchers from the Georgia Institute of Technology used experiments and numerical calculations to show that iron, in the absence of oxygen, can substitute for magnesium in RNA binding, folding, and catalysis. The researchers found that RNA's shape and folding structure remained the same and its functional activity increased when magnesium was replaced by iron in an oxygen-free environment.