самая богатая страна в европе по природным ресурсам
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самая богатая страна в европе по природным ресурсам, History of Earth’s Life Forms | Earth Science - Lumen Learning, A Grim 'Huge Extinction Event' Happened 30 Million Years Ago , A Brief Account of Human Evolution for Young Minds, New Evidence Shows How Human Evolution Was Shaped by Climate, The largest mammals have always been at the greatest risk of , Rise of the dinosaurs | MIT News | Massachusetts Institute of , Going up: Birds and mammals evolve faster if their home is .
Between the Mesozoic and the Cenozoic, about 50% of all animal species on Earth died off. This mass extinction, 65 million years ago, is the one in which the dinosaurs became extinct. Although there are other hypotheses, most scientists think that this mass extinction took place when a giant meteorite struck Earth with the energy of the most powerful nuclear weapon. The impact kicked up a massive dust cloud. When the particles rained back onto the surface they heated the atmosphere until it became as hot as a kitchen oven, roasting animals. Dust that remained in the atmosphere blocked sunlight for a year or more, causing a deep freeze and ending photosynthesis. Sulfur from the impact mixed with water in the atmosphere to form acid rain, which dissolved the shells of the tiny marine plankton that form the base of the food chain. With little food being produced by land plants and plankton, animals starved. Carbon dioxide was also released from the impact and eventually caused global warming. Life forms could not survive the dramatic temperature swings., However, life on Earth is very different today than it was 540 million years ago. This lesson covers some of the history of life on Earth. It will show you how living things have developed and changed over the last 540 million years of the Phanerozoic Eon. You will learn about how species adapt and evolve over time. Lesson Objectives, The close of the Eocene roughly 33 million years ago marks a time of great change on Earth. In a slow reversal of what we're seeing today, temperatures dropped and glaciers stretched their icy fingers towards the equator. The loss of life across the Asian continent was profound. But Africa's .
Primates, like humans, are mammals. Around ten to twelve million years ago, the ancestral primate lineage split through speciation from one common ancestor into two major groups. These two lineages evolved separately to become the variety of species we see today., The first evolutionary shake-up happened between 2.9 million and 2.4 million years ago. The famous ancestral lineage of “Lucy” and her ilk ( Australopithecus afarensis ) became extinct, and , We see a steep decline in the average mass of hunted mammals over time. Over the last 1.5 million years, the mean mass of hunted mammals decreased by more than 98%. 2. 1.5 million years ago, our Homo erectus ancestors roamed the earth with mammals weighing several tonnes., Previously discovered fossils in North America have prompted speculation that dinosaurs didn’t appear there until about 212 million years ago — significantly later than in South America. Scientists have devised multiple theories to explain dinosaurs’ delayed appearance in North America, citing environmental factors or a vast desert barrier., The rise and fall of Earth's land surface over the last three million years shaped the evolution of birds and mammals, a new study has found, with new species evolving at higher rates where the , .