Biology articlesEarly-stage sperm cells created from human bone marrow
Human bone marrow has been used to create early-stage sperm cells for the first time, a scientific step forward that will help researchers understand more about how sperm cells are created.
Scientists discover the roots of the fast pace of life in big cities
Humanity has crossed a historic threshold where a majority of people worldwide now live in cities. Yet, even as the debate on how humans impact the natural environment grows, urbanization and its consequences remains poorly understood. For many people, cities are seen as principal sources of social and environmental problems, yet they are also engines of innovation and wealth creation. Recently, Los Alamos scientists studied various features of urbanization in order to better understand their implications for future urban growth.
Females do best if they wait a while
Doubt is cast on one of the biggest assumptions in behavioural ecology.
The emerging fate of the neandertals
For nearly a century, anthropologists have been debating the relationship of Neandertals to modern humans. Central to the debate is whether Neandertals contributed directly or indirectly to the ancestry of the early modern humans that succeeded them.
How dogs don't ape
A distinguishing feature of human intelligence is our ability to understand the goals and intentions of others. This ability develops gradually during infancy, and the extent to which it is present in other animals is an intriguing question.
More nutritious food helps reduce toxins in the food chain
Research led by Dartmouth scientists found that animals fed nutritious, high-quality food end up with much lower concentrations of toxic methylmercury in their tissues. The result suggests ways in which methylmercury—a neurotoxin that can accumulate to hazardous levels—can be slowed in its passage up the food chain to fish.
Cell structures exhibit novel behaviors, mimic red blood cells and liquid crystals
Researchers at the University of Pennsylvania and Yale University have manipulated the internal, structural components of cells, creating a set of simulated cellular structures with novel mechanical properties, including one that acts like a red blood cell and another that mimics the soft, elastic behavior commonly found in novel synthetic materials called liquid crystal elastomers.
Ape gestures offer clues to the evolution of human communication
Researchers at the Yerkes National Primate Research Center, Emory University, have found bonobos and chimpanzees use manual gestures of their hands, feet and limbs more flexibly than they do facial expressions and vocalizations, further supporting the evolution of human language began with gestures as the gestural origin hypothesis of language suggests.
Personality-gene makes songbirds curious
Whether you are an anxious type, or a fearless person - such individual differences in personality could be partly due to the genes you carry. In humans, it is hard to prove the existence of such "personality genes" - there are simply too many factors that influence human behaviour and these factors are hard to control experimentally. Birds are an easier target for research and indeed, they also have different personalities. An international team of researchers have now found evidence for the existence of a "curiosity-gene" in a songbird, the great tit (Parus major).
Fish growth enhanced by climate change
Changes in growth rates in some coastal and long-lived deep-ocean fish species in the south west Pacific are consistent with shifts in wind systems and water temperatures, according to new Australian research published in the United States.
Research team sheds light on diet of early human ancestors
Eight years ago, the field of anthropology was rocked by isotopic evidence that suggested one-third of the diet of early human ancestors consisted of grasses and sedges, or the tissue of animals that ate such plants. The news puzzled scientists, who were unable to reconcile the results with what they knew about the teeth of human ancestors who lived more than 2 million years ago.
Bat flight generates complex aerodynamic tracks
Bats generate a measurably distinct aerodynamic footprint to achieve lift and maneuverability, quite unlike birds and contrary to many of the assumptions that aerodynamicists have used to model animal flight, according to University of Southern California aerospace engineer Geoffrey Spedding.
Wild wheat shows its muscles
A grain of wild wheat has everything required for plant propagation - even tools for drilling into the soil. It uses its two awns for this: in the dry daytime air, these bristles bend outwards. At night, dampened by the dew, they straighten. Over several days, this movement, similar to the swimming strokes of a frog, pushes the grain into the soil. This discovery was made by scientists from the Max Planck Institute of Colloids and Interfaces. The fine, barb-like silica hairs on the outside of the awn ensure that the seed can only move downwards. A similar mechanism could use fluctuating humidity levels to drive micromachines.
Tropical plants go with the flowof nitrogen
Tropical plants are able to adapt to environmental change by extracting nitrogen from a variety of sources, according to a new study that appeared in the May 7 early online edition of The Proceedings of the National Academy of Sciences.
Scientists offer new view of photosynthesis
During the remarkable cascade of events in photosynthesis, plants approach the pinnacle of stinginess by scavenging nearly every photon of available light energy to produce food. Yet after many years of careful research into the exact mechanisms, some key questions remain about this fundamental biological process that supports almost all life on Earth.
Researchers at illinois explore queen bee longevity
The queen honey bee is genetically identical to the workers in her hive, but she lives 10 times longer and – unlike her sterile sisters – remains reproductively viable throughout life. A study from the University of Illinois sheds new light on the molecular mechanisms that account for this divergence. The study appears in the online edition of the Proceedings of the National Academy of Sciences.
Asymmetry due to perfect balance
Cell membranes are like two-dimensional fluids whose molecules are distributed evenly through lateral diffusion. But many important cellular processes depend on cortical polarity, the locally elevated concentration of specific membrane proteins.
Spud origin controversy solved
Molecular studies recently revealed new genetic information concerning the long-disputed origin of the "European potato." Scientists from the University of Wisconsin-Madison, the University of La Laguna, and the International Potato Center used genetic markers to prove that the remnants of the earliest known landraces of the European potato are of Andean and Chilean origin.
Study tracks CO2 pulses released into atmosphere at end of last ice age
A University of Colorado at Boulder-led research team tracing the origin of a large carbon dioxide increase in Earth's atmosphere at the end of the last ice age has detected two ancient "burps" that originated from the deepest parts of the oceans.
Slowing the racing heart
Researchers at the University of Illinois at Chicago explain in the May 11 issue of Circulation Research how an enzyme acts on the heart's pacemaker to slow the rapid beating of the heart's "fight-or-flight" reaction to adrenaline.