Supercomputer simulations of super-diamond suggest a path to its creation
Diamond is the strongest material known. However, another form of carbon has been predicted to be even tougher than diamond. The challenge is how to create it on Earth.
Diamond is the strongest material known. However, another form of carbon has been predicted to be even tougher than diamond. The challenge is how to create it on Earth.
Analytical Chemistry
14 hours ago
0
169
Hydrogen gas is a clean fuel. It burns with oxygen in the air to provide energy with no CO2. Hydrogen is a key to sustainable energy for the future. Though humans are just now coming to realize the benefits of hydrogen gas ...
Cell & Microbiology
15 hours ago
1
176
The development of hair was of central importance for the evolution of mammals and, thus, also of humans. However, the evolutionary origin of the genetic program of hair was previously unknown. An international research team ...
Evolution
17 hours ago
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59
Astronomers from the Nanjing University in China and elsewhere have performed high-resolution observations of a distant galaxy cluster known as CL J1001+0220 using the James Webb Space Telescope (JWST). The observational ...
In non-Hermitian systems, two or more eigenvalues and eigenstates of a resonant system coalesce at Exceptional points (EPs). Dynamic encircling of EPs has received significant interest in recent years, as it leads to highly ...
Optics & Photonics
Mar 15, 2024
0
18
If you look around your bedroom, or in the door pocket of your car, you may have a cool shell you've found and kept. Maybe it's a nice pinky-orange, or has a perfect little hole so that one day you could make a necklace.
Archaeology
Mar 15, 2024
0
27
As people get older, they increasingly focus on their more important relationships, often turning to family and close friends. This active reorientation towards a few, particularly close relationships could explain why aging ...
Plants & Animals
Mar 14, 2024
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1
Hydrogen (H2) is considered a possible alternative to fossil fuels, which are responsible for a large proportion of atmospheric emissions and global warming, but production costs must be lowered if it is to become a viable ...
Analytical Chemistry
Mar 13, 2024
0
2
An international research team led by Dr. Gabriel S. Ferreira from the Senckenberg Center for Human Evolution and Paleoenvironment at the University of Tübingen has described a new species of giant turtle from the late Pleistocene.
Paleontology & Fossils
Mar 13, 2024
3
2232
Transition metal selenides have been considered to be a good choice for electrocatalytic water splitting. In addition, Metal-organic frameworks (MOFs) have been used to make catalysts with good electrocatalytic capabilities. ...
Nanomaterials
Mar 8, 2024
0
1
In biology, evolution is change in the genetic material of a population of organisms from one generation to the next. Though changes produced in any one generation are small, differences accumulate with each generation and can, over time, cause substantial changes in the population, a process that can culminate in the emergence of new species. Indeed, the similarities amongst species suggest that all known species are descended from a common ancestor (or ancestral gene pool) through this process of gradual divergence .
The basis of evolution is the genes that are passed on from generation to generation; these produce an organism's inherited traits. These traits vary within populations, with organisms showing heritable differences (variation) in their traits. Evolution itself is the product of two opposing forces: processes that constantly introduce variation, and processes that make variants either become more common or rare. New variation arises in two main ways: either from mutations in genes, or from the transfer of genes between populations and between species. In species that reproduce sexually, new combinations of genes are also produced by genetic recombination, which can increase variation between organisms.
Two major mechanisms determine which variants will become more common or rare in a population. One is natural selection, a process that causes helpful traits (those that increase the chance of survival and reproduction) to become more common in a population and causes harmful traits to become more rare. This occurs because individuals with advantageous traits are more likely to reproduce, meaning that more individuals in the next generation will inherit these traits. Over many generations, adaptations occur through a combination of successive, small, random changes in traits, and natural selection of the variants best-suited for their environment. The other major mechanism driving evolution is genetic drift, an independent process that produces random changes in the frequency of traits in a population. Genetic drift results from the role that chance plays in whether a given trait will be passed on as individuals survive and reproduce.
Evolutionary biologists document the fact that evolution occurs, and also develop and test theories that explain its causes. The study of evolutionary biology began in the mid-nineteenth century, when studies of the fossil record and the diversity of living organisms convinced most scientists that species changed over time. However, the mechanism driving these changes remained unclear until the theories of natural selection were independently discovered by Charles Darwin and Alfred Wallace. Darwin's landmark work On the Origin of Species of 1859 brought the new theories of evolution by natural selection to a wide audience. Darwin's work soon led to overwhelming acceptance of evolution among scientists. In the 1930s, Darwinian natural selection was combined with Mendelian inheritance to form the modern evolutionary synthesis, which connected the units of evolution (genes) and the mechanism of evolution (natural selection). This powerful explanatory and predictive theory directs research by constantly raising new questions, and it has become the central organizing principle of modern biology, providing a unifying explanation for the diversity of life on Earth.
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