EARTH SCIENCE
FOSSILS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Changes in the oceans
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Increase in oxygen in the atmosphere
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Key features of living things started to appear, like hard shells
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The increased population of specific organisms
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Detailed explanation-1: -Some think that a steep rise in oxygen sparked the change, whereas others say that it sprang from the development of some key evolutionary innovation, such as vision. The precise cause has remained elusive, in part because so little is known about the physical and chemical environment at that time.
Detailed explanation-2: -Cambrian explosion, the unparalleled emergence of organisms between 541 million and approximately 530 million years ago at the beginning of the Cambrian Period. The event was characterized by the appearance of many of the major phyla (between 20 and 35) that make up modern animal life.
Detailed explanation-3: -The oxygen concentration in Earth’s atmosphere rose sharply around 300 million years ago. Some scientists believe that an expansive, continental shelf with numerous shallow lagoons or pools provided the necessary living space for larger numbers of different types of animals to co-exist.
Detailed explanation-4: -increased oxygen concentrations in the atmosphere-oxygen is required to fuel metabolism, increased oxygen allowed for greater size and complexity. end of glaciation-Ice limits the number of niches available on earth. More items