{"id":10014,"date":"2021-11-10T00:00:00","date_gmt":"2021-11-10T00:00:00","guid":{"rendered":"https:\/\/www.nextias.com\/current_affairs\/uncategorized\/10-11-2021\/mass-extinctions-on-earth\/"},"modified":"2021-11-10T00:00:00","modified_gmt":"2021-11-10T00:00:00","slug":"mass-extinctions-on-earth","status":"publish","type":"post","link":"https:\/\/www.nextias.com\/ca\/current-affairs\/10-11-2021\/mass-extinctions-on-earth","title":{"rendered":"Mass extinctions on Earth"},"content":{"rendered":"<p><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong><u>In news<\/u><\/strong><\/span><\/span><\/span><\/p>\n<ul>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">A paper published in the journal, Nature Geoscience, has come up with a new reason behind the first mass extinction, also known as the <\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Late Ordovician mass extinction.<\/strong><\/span><\/span><\/span><\/li>\n<\/ul>\n<p><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong><u>About the extinctions<\/u><\/strong><\/span><\/span><\/span><\/p>\n<ul>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Sixth mass extinction<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: Some researchers have pointed out that we are currently experiencing a sixth mass extinction as the result of human-induced climate change.<\/span><\/span><\/span>\n<ul>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">More than 99 per cent of all organisms that have ever lived on Earth are extinct.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">As new species evolve to fit ever-changing ecological niches, older species fade away. But the rate of extinction is far from constant.<\/span><\/span><\/span><\/li>\n<\/ul>\n<\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Several theories<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: There have been several theories behind each of the mass extinction and with advances in new technologies; researchers have been uncovering more intricate details about these events.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Other great mass extinctions<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: Before the Cretaceous mass extinction known for wiping out non-avian dinosaurs, the Earth had witnessed four other great mass extinctions.<\/span><\/span><\/span><\/li>\n<\/ul>\n<p><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong><u>What are these mass extinctions?<\/u><\/strong><\/span><\/span><\/span><\/p>\n<ul>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Rapid decrease in biodiversity<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: An extinction event is a widespread and rapid decrease in the biodiversity on Earth.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Biotic crisis<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: It is also known as a mass extinction or biotic crisis.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Abundance of multicellular organisms<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: Such an event is identified by a sharp change in the diversity and abundance of multicellular organisms.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Increase in rate of extinction<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: It occurs when the rate of extinction increases with respect to the rate of speciation.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Uneven rate<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: Extinction occurs at an uneven rate.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>The Great Oxidation Event<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: which occurred around 2.45 billion years ago, was probably the first major extinction event.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>New forms of life<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: Though mass extinctions are deadly events, they open up the planet for new forms of life to emerge.<\/span><\/span><\/span><\/li>\n<\/ul>\n<p><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong><u>Factors affecting the extinction<\/u><\/strong><\/span><\/span><\/span><\/p>\n<ul>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Change in ocean circulation pattern and climate cooling<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: cooling climate likely changed the ocean circulation pattern. This caused a disruption in the flow of oxygen-rich water from the shallow seas to deeper oceans, leading to a mass extinction of marine creatures.<\/span><\/span><\/span>\n<ul>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">They also noticed a lack of oxygen or anoxia in deep oceans during the period.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Upper-ocean oxygenation in response to cooling was anticipated because atmospheric oxygen preferentially dissolves in cold waters.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">However, we were surprised to see expanded anoxia in the lower ocean since anoxia in Earth\u2019s history is generally associated with volcanism-induced global warming.<\/span><\/span><\/span><\/li>\n<\/ul>\n<\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Major changes in Earth\u2019s carbon cycle<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: such as large igneous province eruptions, huge volcanoes that flooded hundreds of thousands of square miles with lava. These eruptions ejected massive amounts of heat-trapping gases such as carbon dioxide into the atmosphere, enabling runaway global warming and related effects such as ocean acidification and anoxia, a loss of dissolved oxygen in the water.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Humans to be blamed<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: Ever since the beginning of the pollutant-pumping industrial revolution in 1760, humans have been the main contributor to Earth&#8217;s current environmental crisis.<\/span><\/span><\/span>\n<ul>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">From greenhouse gas emissions and ozone depletion to deforestation, plastic pile-up and the illegal animal trade, humans have actively stripped the world of some species and threatened many more.<\/span><\/span><\/span><\/li>\n<\/ul>\n<\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Pandemic perspective<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: 2020&#8217;s lockdowns have led to a 17% global decrease in carbon emissions and a 20% fall in nitrogen oxide levels, according to NASA. Waterways cleared up, and animals were seen venturing into cities and towns around the world.\u00a0<\/span><\/span><\/span><\/li>\n<\/ul>\n<p><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong><u>The other big extinction events<\/u><\/strong><\/span><\/span><\/span><\/p>\n<ul>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Ordovician-Silurian extinction &#8211; 444 million years ago<\/strong><\/span><\/span><\/span>\n<ul>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The Ordovician period, from 485 to 444 million years ago, was a time of dramatic changes for life on Earth. This event killed an estimated 85 percent of all species.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Over a 30-million-year stretch, species diversity blossomed, but as the period ended, the first known mass extinction struck.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">At that time, massive glaciation locked up huge amounts of water in an ice cap that covered parts of a large south polar landmass.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The icy onslaught may have been triggered by the rise of North America\u2019s Appalachian Mountains.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The large-scale weathering of these freshly uplifted rocks sucked carbon dioxide out of the atmosphere and drastically cooled the planet.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">As a result, sea levels plummeted by hundreds of feet. Creatures living in shallow waters would have seen their habitats cool and shrink dramatically, dealing a major blow.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The event took its hardest toll on marine organisms such as corals, shelled brachiopods, eel-like creatures called conodonts, and the trilobites.<\/span><\/span><\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align:center\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><img decoding=\"async\" src=\"https:\/\/lh5.googleusercontent.com\/c53-fmEFAD42dgUXKReLcHnFvL80pplI7L2UmOcTSCrABv1W8f62nIDxcu0oiWYGBW2sfCRFbwBRLIeafQvE_bgDYcVC5pwtY7terJijUT90mSL_3BF8quv6tkLd1BBO0DzcdY8Q\" style=\"height:198px; width:264px\" \/><\/span><\/span><\/span><\/p>\n<ul>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Late Devonian extinction &#8211; 383-359 million years ago<\/strong><\/span><\/span><\/span>\n<ul>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Starting 383 million years ago, this extinction event eliminated about 75 percent of all species on Earth over a span of roughly 20 million years.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">In several pulses across the Devonian, ocean oxygen levels dropped precipitously, which dealt serious blows to conodonts and ancient shelled relatives of squid and octopuses called goniatites.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The worst of these pulses, called the Kellwasser event, came about 372 million years ago.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Rocks from the period in what\u2019s now Germany show that as oxygen levels plummeted, many reef-building creatures died out, including a major group of sea sponges called the stromatoporoid.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The faster rocks weathered, the more excess nutrients flowed from land into the oceans. The influx would have triggered algae growth, and when these algae died, their decay removed oxygen from the oceans to form what are known as dead zones.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">In addition, the spread of trees would have sucked CO2 out of the atmosphere, potentially ushering in global cooling.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The slowdown may have been caused by the global spread of invasive species, as high sea levels let creatures from previously isolated marine habitats mix and mingle, which let ecosystems around the world homogenize.<\/span><\/span><\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align:center\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><img decoding=\"async\" src=\"https:\/\/lh6.googleusercontent.com\/hXSifGrpdT1vH2bEOqfpiOY2Kab03HdvTk3d-9T5WcEOndigeoGPhGer3vwx2RUvjLsaucVC27B6jDfcSeIecKpdiIH4XyIkJyqG2IY1cuZMvlmzy0TeAxHXUMtgiowq5ujQcxb2\" style=\"height:203px; width:259px\" \/><\/span><\/span><\/span><\/p>\n<ul>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Permian-Triassic extinction &#8211; 252 million years ago<\/strong><\/span><\/span><\/span>\n<ul>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Some 252 million years ago, life on Earth faced the \u201cGreat Dying\u201d: the Permian-Triassic extinction.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The cataclysm was the single worst event life on Earth has ever experienced.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Over about 60,000 years, 96 per cent of all marine species and about three of every four species on land died out.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The world\u2019s forests were wiped out and didn\u2019t come back in force until about 10 million years later.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Of the five mass extinctions, the Permian-Triassic is the only one that wiped out large numbers of insect species.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The extinction\u2019s single biggest cause is the Siberian Traps, an immense volcanic complex that erupted more than 720,000 cubic miles of lava across what is now Siberia.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The eruption triggered the release of at least 14.5 trillion tons of carbon, more than 2.5 times what\u2019d be unleashed if every last ounce of fossil fuel on Earth were dug up and burned.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">As temperatures rose, rocks on land weathered more rapidly, hastened by acid rain that formed from volcanic sulfur.<\/span><\/span><\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align:center\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><img decoding=\"async\" src=\"https:\/\/lh5.googleusercontent.com\/cOzX3zbFCdINYPPIiqWNrK1ZotZWpoKp9QW2vkaWcP9vpLBV0gYlSW3yl6WZ_T3567FHgPUoCt3oyh6p8e2XwkvQegYWyJ8ulaf27HWtWKQJow8CLGR29xkAKD9VkZuIH0qaJDHT\" style=\"height:178px; width:281px\" \/><\/span><\/span><\/span><\/p>\n<ul>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Triassic-Jurassic extinction &#8211; 201 million years ago<\/strong><\/span><\/span><\/span>\n<ul>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Life took a long time to recover from the Great Dying, but once it did, it diversified rapidly.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Different reef-building creatures began to take hold, and lush vegetation covered the land, setting the stage for a group of reptiles called the archosaurs: the forerunners of birds, crocodilians, pterosaurs, and the non-avian dinosaurs.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">But about 201 million years ago, life endured another major blow: the sudden loss of up to 80 percent of all land and marine species.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">At the end of the Triassic, Earth warmed an average of between 5 and 11 degrees Fahrenheit, driven by a quadrupling of atmospheric CO2 levels.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">This was probably triggered by huge amounts of greenhouse gases from the Central Atlantic Magmatic Province, a large igneous province in central Pangaea, the supercontinent at the time.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The uptick in CO2 acidified the Triassic oceans, making it more difficult for marine creatures to build their shells from calcium carbonate.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">On land, the dominant vertebrates had been the crocodilians, which were bigger and far more diverse than they are today. Many of them died out.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">In their wake, the earliest dinosaurs\u2014small, nimble creatures on the ecological periphery rapidly diversified.<\/span><\/span><\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align:center\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><img decoding=\"async\" src=\"https:\/\/lh4.googleusercontent.com\/Az4Qthr5w-Suo_tmnB23rfsU06dhGKaSFhOtxjObe9QSUPC_R5mN57k7rCA1zWmItAi84r9sU6D4NmXI0uAmbFvqTI9aCJcTG_mOifMuKVa4DJ5TbpLGX_fw7xArN4Em1G3B8q4Q\" style=\"height:247px; width:306px\" \/><\/span><\/span><\/span><\/p>\n<ul>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Cretaceous-Paleogene extinction &#8211; 66 million years ago<\/strong><\/span><\/span><\/span>\n<ul>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The Cretaceous-Paleogene extinction event is the most recent mass extinction and the only one definitively connected to a major asteroid impact.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Some 76 per cent of all species on the planet, including all nonavian dinosaurs, went extinct.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">The massive impact\u2014which left a crater more than 120 miles wide-flung huge volumes of dust, debris, and sulfur into the atmosphere, bringing on severe global cooling.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Wildfires ignited any land within 900 miles of the impact, and a huge tsunami rippled outward from the impact.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Overnight, the ecosystems that supported nonavian dinosaurs began to collapse.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Global warming fueled by volcanic eruptions at the Deccan Flats in India may have aggravated the event.<\/span><\/span><\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align:center\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><img decoding=\"async\" src=\"https:\/\/lh5.googleusercontent.com\/Ph2_NT3TCRrzYgNYzd3OPs_zXPJRsLpn3XpzybX7eRLQYovowK2_7tZT8IGItcPY-itwTr_0sqVMCDyirbVLBA63PqIsoXDeZwd24ORbISriBmRLRfTZCnQ2QnVT4be6FqCK3xjE\" style=\"height:221px; width:316px\" \/><\/span><\/span><\/span><\/p>\n<p><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong><u>Extinction today (Sixth mass extinction)<\/u><\/strong><\/span><\/span><\/span><\/p>\n<ul>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Biodiversity crisis<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: Earth is currently experiencing a biodiversity crisis.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Various human factors<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: Recent estimates suggest that extinction threatens up to a million species of plants and animals, in large part because of human activities such as deforestation, hunting, and overfishing.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Spread of invasive species<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: Other serious threats include the spread of invasive species and diseases from human trade, as well as pollution and human-caused climate change.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Extinctions are occurring hundreds of times faster<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: If all species currently designated as critically endangered, endangered, or vulnerable go extinct in the next century, and if that rate of extinction continues without slowing down, we could approach the level of mass extinction in as soon as 240 to 540 years.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Climate change presents a long-term threat<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: Humans\u2019 burning of fossil fuels has let us chemically imitate large igneous provinces, through the injection of billions of tons of carbon dioxide and other gases into Earth\u2019s atmosphere each year.<\/span><\/span><\/span><\/li>\n<\/ul>\n<p><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong><u>Various steps to be taken to prevent the mass extinctions<\/u><\/strong><\/span><\/span><\/span><\/p>\n<ul>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Humans can be the driving force<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: The world is awash with scientists, conservationists and environmentalists working in the laboratory, in conservation areas and in political battlegrounds to protect endangered species.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Legislation<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: From tackling global pollution emissions in the 2016 Paris Agreement to the U.K.&#8217;s Global Resource Initiative that combats deforestation, legislation will always be at the forefront of the fight against mass extinction.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Regulating wildlife markets<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: In the wake of the current pandemic, wildlife markets have been thrust into the spotlight as not only being environmentally irresponsible, but potentially dangerous to human health through zoonotic diseases that jump from animals to humans such as COVID-19. These markets, trading live exotic animals or products derived from them, are found throughout the world.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Monitoring species population<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: One of the best ways to help prevent species from becoming extinct is to monitor their populations and identify any problems before it&#8217;s too late to help. Currently camera traps and surveys conducted on foot or from aircraft are the main method of data collection.<\/span><\/span><\/span><\/li>\n<li style=\"list-style-type:disc\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\"><strong>Saved by cloning<\/strong><\/span><\/span><\/span><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">: Another potential solution to combat extinction could be to clone species. In 2021, scientists revealed they had successfully cloned a black-footed ferret from an animal that had died more than 30 years ago.<\/span><\/span><\/span>\n<ul>\n<li style=\"list-style-type:circle\"><span style=\"font-size:12pt\"><span style=\"font-family:'Book Antiqua',serif\"><span style=\"color:#000000\">Native to North America, these small mammals were thought to be extinct until a small colony was found in the early 1980s, which were entered into a breeding program and reintroduced around the United States.<\/span><\/span><\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>In news A paper published in the journal, Nature Geoscience, has come up with a new reason behind the first mass extinction, also known as the Late Ordovician mass extinction. About the extinctions Sixth mass extinction: Some researchers have pointed out that we are currently experiencing a sixth mass extinction as the result of human-induced [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":10015,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[21],"tags":[26,33],"class_list":["post-10014","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-current-affairs","tag-gs-3","tag-science-technology"],"acf":[],"jetpack_featured_media_url":"https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2023\/07\/628725Screenshot.png","_links":{"self":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/10014","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/comments?post=10014"}],"version-history":[{"count":0,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/10014\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/media\/10015"}],"wp:attachment":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/media?parent=10014"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/categories?post=10014"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/tags?post=10014"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}