Top cosmologist's lonely battle against 'Big Bang' theory
James Peebles won this year's Nobel prize in physics for helping transform the field of cosmology into a respected science, but if there's one term he hates to hear, it's "Big Bang Theory."
James Peebles won this year's Nobel prize in physics for helping transform the field of cosmology into a respected science, but if there's one term he hates to hear, it's "Big Bang Theory."
General Physics
Nov 14, 2019
34
6358
Researchers have used artificial intelligence to make new discoveries, and confirm old ones, about one of nature's best-known mimics, opening up whole new directions of research in evolutionary biology.
Evolution
Aug 14, 2019
0
489
When Thomas Hertog was first summoned to Stephen Hawking's office in the late 1990s, there was an instant connection between the young Belgian researcher and the legendary British theoretical physicist.
General Physics
May 28, 2023
3
710
A new study led by Adelaide researchers has estimated, for the first time, the rates of evolution during the "Cambrian explosion" when most modern animal groups appeared between 540 and 520 million years ago.
Evolution
Sep 12, 2013
47
1
Darwin's theory of evolution should be expanded to include consideration of a DNA stability "energy code"—so-called "molecular Darwinism"—to further account for the long-term survival of species' characteristics on Earth, ...
Biotechnology
Nov 16, 2020
9
641
Any multicellular animal, from a blue whale to a human being, poses a special difficulty for the theory of evolution. Most of the cells in its body will die without reproducing, and only a privileged few will pass their genes ...
Cell & Microbiology
Dec 15, 2011
7
0
When Charles Darwin first codified the theory of evolution by means of natural selection, he thought of it as a gradual process. "We see nothing of these slow changes in progress, until the hand of time has marked the long ...
Evolution
Feb 16, 2022
1
220
We know the benefits of laughter on health. But why do we laugh? What are the evolutionary origins of laughter and humour? Steven Légaré has asked these questions and has made them the subject of his master's thesis, which ...
Social Sciences
Mar 27, 2013
1
1
Thanks to a generous gift, National University of Singapore study traced historical shipping records and vindicated Darwin from accusations of deceit.
Evolution
Mar 8, 2012
0
1
A link between evolution over short time frames (microevolution) and long time frames (macroevolution) that could open new approaches to understanding some of biology's deepest questions is proposed by Dr. Owen Gilbert of ...
Evolution
Dec 8, 2020
7
601
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.
This text uses material from Wikipedia, licensed under CC BY-SA