General Biology 2 L2.1 PDF

GENERAL BIOLOGY 2 Ms. Clarie Ann Manalo EVOLUTION AND ORIGIN OF BIODIVERSI Lesson 2.1 History of Life on Earth TY MOST 1 Describe the general ESSENTIAL features of the history of life on Earth, LEARNING including generally accepted da...

GENERAL BIOLOGY 2 Ms. Clarie Ann Manalo EVOLUTION AND ORIGIN OF BIODIVERSI Lesson 2.1 History of Life on Earth TY MOST 1 Describe the general ESSENTIAL features of the history of life on Earth, LEARNING including generally accepted dates and COMPETEN sequence of the geologic time scale CY and characteristics of major groups of organisms present during these time periods. LEARNING 1 Identify dates and OBJECTIVES sequence of the periods in the geologic time scale. 2 Characterize the major events in each period. 3 Explain the characteristics of major groups of organisms present during these time periods.  A. 4.5 Million Years What is the 4.5 Billion Old age of the Years B. 45 MillionOld Years Earth? Old C. 4.5 Billion Years Old D. 45 Billion Years Studying the age of the Earth involves looking at fossil records and the Theory of Evolution. The Earth has an extensive calendar where many events and changes have occurred, called WHAT IS GEOLOGIC TIME SCALE? It is a system used by scientists to describe the timing and relationships of events in Earth’s history. It divides Earth’s 4.5-billion-year history into hierarchical units based on significant geological and biological events. These units are eons, eras, periods, and  GEOLOGIC TIME EON SCALE ERA A subdivision of an eon, lasting Largest division of geologic hundreds of millions of years. time, spanning billions of years. Marked by major changes in Earth’s life forms and geology. PERIOD EPOCH A subdivision of an era, lasting Smallest division of geologic tens to hundreds of millions of time, lasting several million years. years. Defined by a significant rock Used to describe finer details of Geologic Time Scale Hadean Eon 4.5 bya to 4.0 bya Marks the formation of crust and oceans. Some rock fossils like detrital zircon dating ~4 bya revealed associations with magmatic crust that cooled down and interactions with water.  Archaean 4.0 byaEon to 2.5 bya Earth cooled down enough for the first signs of life to appear. Stromatolites date back ~3.7 bya, the oldest identifiable fossils ever recorded.  Proterozoic Eon 2.5 bya to 541 mya Formation of stable regions due to active tectonic plates. Oxygen level in the atmosphere rose. Eukaryotic cells appeared. Glaciation occurred followed by slow Phanerozoic Eon 541 mya to 0 mya Began with the Cambrian explosion. It is divided into three eras: Paleozoic, Mesozoic, and Cenozoic.  Camels Often Sit Down Carefully. Perhaps Their Joints Creak? Plentiful Early Oiling Might Prevent  Paleozoic Era 541 mya to 252 mya The name means “old life”. Multicellular organisms diversified, but ended with a 90% mass extinction.  Cambrian Ordovician 541 Period mya to 485 mya Period 485 mya to 444 mya The Cambrian Marine ecosystems explosion gave rise to flourished. major groups of Ends with a mass animals such as extinction caused by arthropods, mollusks, glaciation. invertebrates, and echinoderms.  Silurian Devonian 444 Period mya to 419 mya Period 419 mya to 359 mya Emergent of first land “Age of Fishes” with plants and animals. rapid diversification of Stabilization of Earth’s fish. climate. Appearance of first forests and land vertebrates.  Carboniferous Permian 359 mya to 299 mya Period Vast coal-forming Period 299 mya to 252 Formation of the mya forests of ferns and supercontinent other plants. Pangaea. Evolution of first Ends with the largest reptiles and amniotic mass extinction. eggs.  Mesozoic Era 252 mya to 66 mya The name means “middle life”. Age of reptiles, including dinosaurs, and the first mammals.  Triassic Jurassic Cretaceous 252 mya to 201 201 mya to 145 145 mya to 66 Period Period Period mya mya mya Recovery after Golden Age of Flowering plants the Permian dinosaurs. emerged. extinction. First birds Ends with a Early dinosaurs appeared. mass extinction and mammals caused by an evolved. asteroid. The relationship between extinction and diversity Adaptive Radiation Rapid diversification of species and groups after extinction.  Cenozoic Era 66 mya to 0 mya The name means “new life”. Age of mammals and humans. More mountains uplifted as continents and plate tectonics move, revealing rocks and fossils along the slopes. Paleogene Period Paleocene Epoch 66 mya to 56 mya Recovery from the mass extinction of dinosaurs. Mammals diversified, with many small species emerging. Earth's climate was warm and humid. Paleogene Period Eocene Epoch 56 mya to 34 mya First modern mammals like early horses, whales, and bats appeared. Tropical forests spread to higher latitudes. Ends with global cooling, leading to the Antarctic ice sheet. Paleogene Period Oligocene Epoch 34 mya to 23 mya Grasslands expanded, leading to grazing mammals. Earth's climate continued to cool and dry. Modern primates began to evolve. Neogene Period Miocene Epoch 23 mya to 5.3 mya Proliferation of grasslands and large herbivores like elephants. Early apes evolved, ancestors of modern humans. Climate remained warm, but cooling trends began. Neogene Period Pliocene Epoch 5.3 mya to 2.6 mya Ice caps formed at the poles. Early human ancestors, such as Australopithecus, appeared. Further expansion of grasslands and savannas. Quaternary Period Pleistocene Epoch 2.6 mya to 11,700 ya Known as the Ice Age; extensive glaciation shaped landscapes. Megafauna like mammoths and saber-toothed cats thrived. Early modern humans (Homo sapiens) evolved and migrated globally. Quaternary Period Holocene Epoch 11,700 ya to present Current epoch; marked by the development of agriculture and human civilization. Rapid technological advancements and population growth. Human activities significantly impact Earth's climate and ecosystems. Fossil is a preserved evidence of an organism or object that lived in the past. Fossil Record is the total collection of fossils found and stored privately or How fossils are formed? More than 90% of the organisms that lived are now extinct. When a part or the whole organism is buried in mud, ash, sand, or another type of sediment, fossil can possibly form over time. Intact Fossils in Amber An intact fossil with unaltered preservation can be trapped in amber, a sticky resin or sap that hardened over time, and both the organism and the amber didn’t decompose. Intact Fossils via Freezing Permafrost, or soil that remained below 0º for a long time, can be a barrier against decomposers and weathering agents, slowing down decomposition and create intact frozen fossils. Intact Fossils via Mummification Desiccation or Mummification is the removal of moisture from the organism’s body, leading to an aseptic state and stalling decomposition, keeping even the skin and hair. Petrified Fossils Petrification happens when groundwater carrying minerals slowly fills the spaces or cells in the organism’s body, then very slowly dissolves and replaces the organic matter with stone, assuming its shape. Molds and Casts When a deceased organism decays, its physical features could be imprinted on the sand and ground and to form a hole or mold. The filling of mold or hollow part of an organism with sediments The Abundant Fossil Fuel A mass extinction of swamp forests and other flora and fauna eventually turned into rich deposits of coal through a process known coalification. Compression of Fossils into Carbon Film Compression of organic material due to pressure and heat, as sediments build up over time, removes all the other components except for a carbon film or residue on the rock’s surface. Impressions of Movements Become Trace Fossils Trace Fossils are trackways, tooth marks, fossilized dungs, nests, and burrows that were preserved in sediments.  Carbon Dating It is a method of determining the age of fossils by comparing the amount of Carbon-14, a weak isotope that decays over time, remaining in the fossils versus a standard. Carbon-14 accumulates in organisms and stops after death. A half-life is the time it takes for an isotope to decay by half of its previous amount. “Success is not final; failure is not fatal: It is the courage to continue that counts.” ~ Winston S. Churchill