2023-09-20 16:20:34
An international research team led by scientists from the University of Bath in Britain has revealed that flowering plants relatively survived the mass extinction that killed the dinosaurs 66 million years ago, and that this devastating event even helped them become the dominant type of plant today. This event was called the Cretaceous-Paleogene extinction, in which three-quarters of plant and animal species disappeared from the planet Earth, including dinosaurs, but until now it was not clear the extent of its impact on flowering plants. The researchers analyzed mutations in the DNA sequences of thousands of species of flowering plants (Shutterstock) DNA mutations, and the first geological studies of the rocks of that period noted the presence of high levels of the metal iridium, which is rare in the Earth’s crust, but abundant in heavenly rocks. Which led scientists to believe that the extinction was caused by a comet or a huge asteroid with a diameter of 10 to 15 kilometers that struck the Earth in the Chicxulub crater, which is now located on the Yucatan Peninsula in Mexico. According to the study published by this team in the journal Biology Letters, plants do not contain skeletons to leave fossils in the rocks, but analyzing mutations in the DNA sequences of thousands of species of flowering plants, using complex statistical methods, can be used to estimate extinction rates over time. The whole geology, where mutation rates are lower than usual if a large amount of the organism’s population has become extinct and only a small number of them remain, and vice versa. Researchers believe that following the extinction of most plant and animal species on Earth, flowering plants benefited from the availability of food and dominated the surface of the planet, just as mammals did following the extinction of the dinosaurs, as they also became dominant on the surface of the Earth. Of the approximately 400,000 species of plants living today, regarding 300,000 of them are flowering plants (Shutterstock), the kings of adaptation. According to a press release issued by the University of Bath, this is why, of the approximately 400,000 species of plants living today, there are About 300 thousand of them are flowering plants. Among these plants that resisted extinction and remained on Earth are the large-flowered orchid and magnolia, which are now used as ornamental plants, as well as chrysanthemums, potatoes, and mint. Researchers suggest that the reason why flowering plants survive, despite their apparent weakness and inability to move (like animals, for example), is that they are more adaptable, as they use a variety of seed dispersal and pollination mechanisms, and some of them have developed excellent ways to carry out photosynthesis in a sunless world. For a relatively long time. Scientists believe that the blow to the Earth and the subsequent widespread fires caused the release of a huge amount of dust and soot into the atmosphere, blocking the vast majority of the sun’s radiation for a long period starting from months and perhaps extending to years, which in turn caused a global temperature drop. Significantly.
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