Earth's Timeline and Emergence of Life Lesson 3.1 PDF

Lesson 3.1 Earth's Timeline and Emergence of Life General Biology 2 [1/2] Science, Technology, Engineering, and Mathematics  Learning Competency At the end of the lesson, you should be able to do the following: Describe general features of the history of life on Earth,...

Lesson 3.1 Earth's Timeline and Emergence of Life General Biology 2 [1/2] Science, Technology, Engineering, and Mathematics  Learning Competency At the end of the lesson, you should be able to do the following: Describe general features of the history of life on Earth, including generally accepted dates and sequence of the geologic time scale and characteristics of major groups of organisms present during these time periods (STEM_BIO11/12-IIIc-g-8). 2  Learning Objectives At the end of the lesson, you should be able to do the following: Describe Earth’s geologic time scale. Identify theories on the emergence of life on Earth. Enumerate early life forms present during the primitive Earth. 3  Earth’s Geologic Time Scale Earth has been around for billions of years and the way that scientists make an estimate is through the geologic time scale. This refers to a system of dating the history of Earth in a chronological manner using geological data. 4  Earth’s Geologic Time Scale The geologic time scale reflects the entire geological history of our planet. The geologic time scale is divided into eons, eras, periods, and epochs. 5  Earth’s Geologic Time Scale Eon Era Period Epoch Phanerozoic Eon (542 MYA) Precambrian Eon (4 BYA) means ‘visible life’ that was represents the period between the constructed through rock units that birth of the planet and the bear abundant fossils. appearance of life forms. 6  Earth’s Geologic Time Scale Eon Era Period Epoch Phanerozoic Eon (542 MYA) Precambrian Eon (4 BYA) Proterozoic Archean Hadean 7  Earth’s Geologic Time Scale Eon Era Period Epoch Phanerozoic Eon (542 MYA) Precambrian Eon (4 BYA) Proterozoic Archean Hadean 8  Earth’s Geologic Time Scale Eon Era Period Epoch Phanerozoic Eon (542 MYA) Precambrian Eon (4 BYA) Cenozoic era Mesozoic era Paleozoic era Proterozoic is also known is also known is also known as the ‘age of as the ‘age of as the ‘age of Archean mammals reptiles’ invertebrates’ Hadean 9  Earth’s Geologic Time Scale Eon Era Period Epoch Phanerozoic Eon (542 MYA) Cenozoic era Precambrian Eon (4 BYA) Mesozoic era Quaternary Tertiary Proterozoic Period Period human mammals Archean evolution diversity Plaeozoic era Hadean 10  Earth’s Geologic Time Scale Eon Era Period Epoch Phanerozoic Cretaceous Period Eon (542 MYA) Cenozoic era extinction of dinosaurs, first primates, first flowering plants Precambrian Eon (4 BYA) Jurassic Period Mesozoic era first birds, dinosaurs diversity Proterozoic Archean Plaeozoic era Triassic Period Hadean first mammals, first dinosaurs 11  Earth’s Geologic Time Scale Eon Era Period Epoch Phanerozoic Permian Eon (542 MYA) Cenozoic era Carboniferous Precambrian Eon (4 BYA) Devonian Mesozoic era Proterozoic Silurian Archean Ordovician Paleozoic era Hadean Cambrian 12  Earth’s Geologic Time Scale Eon Era Period Epoch Phanerozoic Eon (542 MYA) Cenozoic era Epochs are the shortest Precambrian subdivision unit in the Earth’s Eon (4 BYA) geologic time scale that is Mesozoic era characterized by the changes in Proterozoic life forms and may vary from Archean continent to continent. Plaeozoic era Hadean 13 Tips To recall the geologic periods from oldest to most recent, just remember the mnemonics “Can Old Senators Demand Copious Power Than Junior Congressmen? Tough Question!” The first letter of each word represents the first letter of each period in order. 14 Tips The periods in geological time scale from oldest to most recent are Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous, Tertiary, Quaternary. 15 How do you think scientists tried to explain their early ideas regarding the origin of life on Earth? 16  Theories on the Origin of Life on Earth spontaneous generation theory Theories regarding the primordial soup theory origin of life on Earth theory of panspermia 17  Theories on the Origin of Life on Earth Spontaneous Generation The experiment of Needham 18  Theories on the Origin of Life on Earth Spontaneous Generation Pasteur’s experiment disproved spontaneous generation. 19  Theories on the Origin of Life on Earth Theory of Panspermia The theory of panspermia (exogenesis) suggests that building blocks of life came from another planet. Origin of life on Earth according to the panspermia theory 20  Theories on the Origin of Life on Earth Primordial Soup Theory Suggests that life started in a primordial soup of organic molecules. It tries to explain how catalysts for nonliving things became living cells. 21  Early Evidence of Life on Earth One of the earliest known evidence of life on Earth includes the stromatolite fossils collected from various samples of metasedimentary rocks in western Greenland and were aged 3.7 billion years Stromatolite fossils on the old. rock near the shore 22  Early Evidence of Life on Earth In 2015, fossils of the microbial mat (primitive microbial colony) that may represent potential biotic life dated 4.1 billion-year-old were collected in Western Australia. Microbial colony-forming mats or biofilms 23  Check Your Understanding Write the word true if the given statement is correct and false if otherwise. 1. Abiogenesis states that living organisms originate from preexisting living organisms. 2. First life forms are believed to have emerged 3.7 billion years ago. 3. The spontaneous generation theory is still considered as a valid theory even today. 24  Check Your Understanding Complete the table below by providing the important events that happened during the given time period. Period Events Paleozoic Era (ancient life) Cambrian Ordovician Silurian Devonian Carboniferous Permian 25  Check Your Understanding Complete the table below by providing the important events that happened during the given time period. Period Events Mesozoic Era (middle life) Triassic Jurassic Cretaceous Cenozoic Era (recent life) Tertiary Quaternary 26  Let’s Sum It Up! The geologic time scale is divided into eons, eras, periods, and epochs. Early theories regarding the origin of life on Earth started during the 16th century in Europe. These theories include the spontaneous generation theory, primordial soup theory, and theory of panspermia. 27  Let’s Sum It Up! The primordial soup theory suggests that life started in a primordial soup of organic molecules. It tries to explain how catalysts for nonliving things became living cells from chemical compounds abundant on early Earth. 28  Let’s Sum It Up! The theory of spontaneous generation states the idea that life comes from lifeless or nonliving material through a mysterious process. The theory of panspermia states that the building blocks of life come from outside Earth. 29  Let’s Sum It Up! Present-day organisms share common ancestors that evolved through time. First life forms are believed to have emerged 3.7 billion years ago. 30  Let’s Sum It Up! The geologic time scale of Earth 31 Photo Credit Slide 23.: Panspermie by Silver Spoon Sokpop is licensed under CC BY-SA 3.0 via Wikimedia Commons. 32 Bibliography Johnson, G.B., and Raven, P.H. 2001. 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