Theory Of Macroevolution: The Timeline Of Life

Jack Leidlein
Science
2-15-17 The timeline of life according to the theory of macroevolution is life major evolutionary changes over a long period of time. Precambrian time began 4.6 billion years ago and ended 543 million years ago. During Precambrian time life is thought to have developed and started from simple chemicals. Reactions from energy and radiation created the first complex molecules that eventually created cells. The first organism on Earth is thought to be cyanobacteria. One reason is because cyanobacteria does not need oxygen to survive. Cyanobacteria use sunlight to produce their own food. This cycle releases oxygen which eventually formed the ozone layer, giving the Earth the ability to hold in oxygen and other gasses. …show more content…
The Mesozoic era began 248 million years ago and ended 65 million years ago. During this era there were three periods, Triassic, Jurassic, and Cretaceous. The Triassic period began 248 million years ago and ended 206 million years ago. The Jurassic period began 206 million years ago and ended 144 million years ago. The Cretaceous period began 144 million years ago and ended 65 million years ago. The Mesozoic era is often referred to as the Age of Reptiles because of the domination of dinosaurs. Many dinosaurs adapted and gained things such as duck like bills or large spines on their bodies. Conifers and flowering plants appeared and became important during the Mesozoic era. Every era ends with mass extinction. The end of the Mesozoic era is thought to have ended when a giant meteorite struck the Earth. This caused giant dust clouds to form and worldwide fires. The dust clouds blocked out the sun causing many plants to die out. Then many plant eating animals died out because of a lack of food. This caused the meat eating animals to died because there weren't enough animals around to eat. there weren't enough animals around the meat eating animals also died out. Some organisms adapted well enough and managed to …show more content…
The Cenozoic era began 65 million years ago and is still the current era. The Cenozoic era contains two periods, Tertiary and Quaternary. The Tertiary period began 65 million years ago and ended two million years ago. The Quaternary period began two million years ago and is still the current period. The Cenozoic era is often referred to as the age of mammals. Recently formed fossils from the Cenozoic era are found in rock layers near the Earth's surface. Humans appeared and are living in the Cenozoic era. Many kinds of birds, insects, mammals and flowering plants were found during the Cenozoic era. The climate was also changing a lot of the time. Cold periods were called ice ages. This forced many organisms to migrate, adapt, or become extinct.
Macro and micro evolution are two separate, common, worldviews. Macroevolution is major evolutions over a long period of time. Microevolution is smaller evolutions over a short period of time. Macroevolution is the main scientific worldview while micro evolution is the main Christian

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Theory Of Macroevolution: The Timeline Of Life

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