Australia battles to save last 11 wild 'earless dragons'
Australia's grassland earless dragon is no bigger than a pinkie when it emerges from its shell, but the little lizard faces an enormous challenge in the years ahead: avoiding extinction.
Australia's grassland earless dragon is no bigger than a pinkie when it emerges from its shell, but the little lizard faces an enormous challenge in the years ahead: avoiding extinction.
Plants & Animals
Mar 27, 2024
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47
To keep lion populations healthy and thriving and to avoid conflicts with local communities, wildlife management is necessary. In Kenya, this is the responsibility of the Kenya Wildlife Service (KWS). Together with scientists ...
Ecology
Mar 20, 2024
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54
Researchers at the Texas A&M School of Veterinary Medicine & Biomedical Sciences (VMBS) collaborated with Australian geneticists to determine whether the country's population of Timor ponies are genetically diverse enough ...
Molecular & Computational biology
Mar 14, 2024
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1
New research has revealed that, despite being scattered across more than a million square kilometers, remote coral reefs across the Seychelles are closely related. Using genetic analyses and oceanographic modeling, researchers ...
Plants & Animals
Mar 12, 2024
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25
The cacao tree (Theobroma cacao), whose beans (cocoa) are used to make products including chocolate, liquor and cocoa butter, may have spread from the Amazon basin to the other regions of South and Central America at least ...
Archaeology
Mar 7, 2024
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72
What's in a name? A lot, actually. For the scientific community, names and labels help organize the world's organisms so they can be identified, studied, and regulated. But for bacteria, there has never been a reliable method ...
Ecology
Mar 4, 2024
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50
Put the word "evolution" into Google images and the results are largely variations on one theme: Ralph Zallinger's illustration, March of Progress. Running left to right, we see a chimp-like knuckle walker gradually becoming ...
Evolution
Mar 3, 2024
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299
After a decade searching for new species of bees in forests of the Pacific Islands, all we had to do was look up.
Plants & Animals
Mar 2, 2024
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52
For more than a decade, invasive Asian honeybees have defied evolutionary expectations and established a thriving population in North Queensland, much to the annoyance of the honey industry and biosecurity officials.
Evolution
Feb 29, 2024
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66
A genetic change in our ancient ancestors may partly explain why humans don't have tails like monkeys, finds a new study led by researchers at NYU Grossman School of Medicine.
Evolution
Feb 28, 2024
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65
In biology, mutations are changes to the nucleotide sequence of the genetic material of an organism. Mutations can be caused by copying errors in the genetic material during cell division, by exposure to ultraviolet or ionizing radiation, chemical mutagens, or viruses, or can be induced by the organism itself, by cellular processes such as hypermutation. In multicellular organisms with dedicated reproductive cells, mutations can be subdivided into germ line mutations, which can be passed on to descendants through the reproductive cells, and somatic mutations, which involve cells outside the dedicated reproductive group and which are not usually transmitted to descendants. If the organism can reproduce asexually through mechanisms such as cuttings or budding the distinction can become blurred. For example, plants can sometimes transmit somatic mutations to their descendants asexually or sexually where flower buds develop in somatically mutated parts of plants. A new mutation that was not inherited from either parent is called a de novo mutation. The source of the mutation is unrelated to the consequence, although the consequences are related to which cells were mutated.
Mutations create variation within the gene pool. Less favorable (or deleterious) mutations can be reduced in frequency in the gene pool by natural selection, while more favorable (beneficial or advantageous) mutations may accumulate and result in adaptive evolutionary changes. For example, a butterfly may produce offspring with new mutations. The majority of these mutations will have no effect; but one might change the color of one of the butterfly's offspring, making it harder (or easier) for predators to see. If this color change is advantageous, the chance of this butterfly surviving and producing its own offspring are a little better, and over time the number of butterflies with this mutation may form a larger percentage of the population.
Neutral mutations are defined as mutations whose effects do not influence the fitness of an individual. These can accumulate over time due to genetic drift. It is believed that the overwhelming majority of mutations have no significant effect on an organism's fitness. Also, DNA repair mechanisms are able to mend most changes before they become permanent mutations, and many organisms have mechanisms for eliminating otherwise permanently mutated somatic cells.
Mutation is generally accepted by the scientific community as the mechanism upon which natural selection acts, providing the advantageous new traits that survive and multiply in offspring or disadvantageous traits that die out with weaker organisms.
This text uses material from Wikipedia, licensed under CC BY-SA