News tagged with evolution
NASA's Galaxy Evolution explorer in standby mode
(PhysOrg.com) -- NASA's Galaxy Evolution Explorer, or Galex, was placed in standby mode today as engineers prepare to end mission operations, nearly nine years after the telescope's launch. The spacecraft ...
Space & Earth / Space Exploration
Feb 08, 2012 |
4 / 5 (3) |
1
Neanderthal demise due to many influences, including cultural changes: study
As an ice age crept upon them thousands of years ago, Neanderthals and modern human ancestors expanded their territory ranges across Asia and Europe to adapt to the changing environment.
Other Sciences / Archaeology & Fossils
Feb 07, 2012 |
4.4 / 5 (5) |
8
|
Behavior of parent organisms may influence genes passed on to next generation
Timing is everything, and if there was ever a scientist whose legacy was tarnished by bad timing, it was Jean Baptiste Lamarck. The French naturalist lived from 1744 to 1829 - and published his own evolutionary theory decades ...
Feb 07, 2012 |
not rated yet |
0
Stellar astrophysics explains the behavior of fast rotating neutron stars in binary systems
Pulsars are among the most exotic celestial bodies known. They have diameters of about 20 kilometres, but at the same time roughly the mass of our sun. A sugar-cube sized piece of its ultra-compact matter ...
Feb 02, 2012 |
5 / 5 (7) |
2
|
Elements of ExoPlanets
By looking at the wavelengths of light from nearby stars, researchers have determined the abundance of certain elements for more than a hundred stars. Trace elements in such stars may influence their habitable ...
Space & Earth / Space Exploration
Feb 02, 2012 |
4.9 / 5 (8) |
0
|
Road runoff spurring spotted salamander evolution
Spotted salamanders exposed to contaminated roadside ponds are adapting to their toxic environments, according to a Yale paper in Scientific Reports. This study provides the first documented evidence that a vertebrate has ...
Feb 01, 2012 |
4.5 / 5 (2) |
1
|
Something old, something new: Evolution and the structural divergence of duplicate genes
(PhysOrg.com) -- Gene duplications are arguably the driving force of organismal evolution and if they survive, such duplicate genes will diverge in both regulatory and coding genomic regions. Coding ...
Mouse to elephant? Just wait 24 million generations
Scientists have for the first time measured how fast large-scale evolution can occur in mammals, showing it takes 24 million generations for a mouse-sized animal to evolve to the size of an elephant.
Jan 30, 2012 |
4.6 / 5 (21) |
46
|
Lifelong payoff for attentive kindergarten kids
Attentiveness in kindergarten accurately predicts the development of "work-oriented" skills in school children, according to a new study published by Dr. Linda Pagani, a professor and researcher at the University of Montreal ...
Medicine & Health / Psychology & Psychiatry
Jan 30, 2012 |
4 / 5 (1) |
0
Stress-induced genomic instability facilitates rapid cellular adaption in yeast
Cells trying to keep pace with constantly changing environmental conditions need to strike a fine balance between maintaining their genomic integrity and allowing enough genetic flexibility to adapt to inhospitable conditions. ...
Jan 29, 2012 |
5 / 5 (1) |
0
|
New study of hunter-gatherers suggests social networks sparked evolution of cooperation
Ancient humans may not have had the luxury of updating their Facebook status, but social networks were nevertheless an essential component of their lives, a new study suggests.
Other Sciences / Social Sciences
Jan 25, 2012 |
4 / 5 (3) |
1
|
Examining evolution from a cellular perspective
The evolutionary processes of unicellular and multicellular organisms are continually under debate. John Torday, Ph.D., a lead investigator at Los Angeles Biomedical Research Institute (LA BioMed), has recently co-authored ...
Jan 25, 2012 |
not rated yet |
0
Winged dinosaur Archaeopteryx dressed for flight
Since its discovery 150 years ago, scientists have puzzled over whether the winged dinosaur Archaeopteryx represents the missing link in birds' evolution to powered flight. Much of the debate has focused on the ...
Other Sciences / Archaeology & Fossils
Jan 24, 2012 |
4.8 / 5 (4) |
3
|
The evolution of division of labor
Division of labour is not only a defining feature of human societies but is also omnipresent among the building blocks of biological organisms and is considered a major theme of evolution. Theoretical Biologists Claus Rueffler ...
Other Sciences / Social Sciences
Jan 24, 2012 |
4 / 5 (2) |
0
When it comes to accepting evolution, gut feelings trump facts
For students to accept the theory of evolution, an intuitive "gut feeling" may be just as important as understanding the facts, according to a new study.
Other Sciences / Social Sciences
Jan 19, 2012 |
4.5 / 5 (20) |
184
|
Evolution
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.
For more information about Evolution, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.