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Prehistoric Time Line, Geologic Time Scale, Photos, Facts, Maps, and More

Prehistoric Time Line, Geologic Time Scale, Photos, Facts, Maps, and More
Humans have walked the Earth for 190,000 years, a mere blip in Earth's 4.5-billion-year history. A lot has happened in that time. Earth formed and oxygen levels rose in the foundational years of the Precambrian. The productive Paleozoic era gave rise to hard-shelled organisms, vertebrates, amphibians, and reptiles. Dinosaurs ruled the Earth in the mighty Mesozoic. And 64 million years after dinosaurs went extinct, modern humans emerged in the Cenozoic era.

http://science.nationalgeographic.com/science/prehistoric-world/prehistoric-time-line/

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Geologic Time Scale I Title: Geologic Time Scale IAuthor: Tamara McDaniel, Lake Geneva Middle School 600 Bloomfield Rd. Lake Geneva, WI 53147Tamara.mcdaniel@badger.k12.wi.us Grades: 7-8 (Spiraled) (See Geologic Time Scale II for the 8th grade activity) Overview of Lesson: Students will research the geologic time scale. Evolution: Second Edition Home This website is a companion to the textbook Evolution, Second Edition, by Douglas J. Futuyma, published by Sinauer Associates. PREHISTORY When men and women started to live in villages, there was a specialization of work. Some people cultivated fields, other people looked after the animals and others made weapons, fabrics, and other objects. There were two important technical innovations in the Neolithic Age: fabrics and pottery. They produced fabrics from animals’ wool using tools like bone spindles, and rudimentary looms. Pottery was made by hand and baked in a bonfire. New objects were invented such as vessels to hold the grain, bowls for eating and cooking, etc.

Prehistory Prehistory (meaning "before history", or "before knowledge acquired by investigation", from the Latin word for "before," præ, and historia) is the span of time before recorded history or the invention of writing systems. Prehistory refers to the period of human existence before the availability of those written records with which recorded history begins.[1] More broadly, it can refer to all the time preceding human existence and the invention of writing. The notion of "prehistory" began to surface during the Enlightenment in the work of antiquarians who used the word 'primitive' to describe societies that existed before written records.[2] The first use of the word prehistory in English, however, occurred in the Foreign Quarterly Review in 1836.[3] The occurrence of written materials (and so the beginning of local "historic times") varies generally to cultures classified within either the late Bronze Age or within the Iron Age.

Geologic time scale Online exhibits Geologic time scale Take a journey back through the history of the Earth — jump to a specific time period using the time scale below and examine ancient life, climates, and geography. You might wish to start in the Cenozoic Era (65.5 million years ago to the present) and work back through time, or start with Hadean time (4.6 to 4 billion years ago)* and journey forward to the present day — it's your choice. [Note: "mya" means "millions of years ago"] Geologic Time Projects/Labs: lewiston Radiometric Dating Atom Decay and Half-Life Simulation. Click Link: Alpha Particles = 2 protons and 2 neutrons bonded together into a particle identical to a helium nucleus.

Evolution Resources from the National Academies In the News: Your Inner Fish – A Scientific Adventure Have you ever wondered why people look the way they do? Why our hands and feet have five digits instead of six? Why we stand on two legs instead of four? Geology Entrance You might wish to start in the Cenozoic Era (65 million years ago to the present) and work back through time, or start with Hadean time (4.5 to 3.8 billion years ago) and journey forward to the present day. No matter "when" you start, don't forget to stop along the way to learn about the stratigraphy, ancient life, fossil localities, and tectonics of the various time periods. Here are three links that can help to speed your journey: 1) Get helpful hints on navigating the Geology Wing. 2) Read about the history of the geologic time scale, and find out more about how it is organized.

Geologic time scale The geologic time scale (GTS) is a system of chronological measurement that relates stratigraphy to time, and is used by geologists, paleontologists, and other earth scientists to describe the timing and relationships between events that have occurred throughout Earth's history. The table of geologic time spans presented here agrees with the nomenclature, dates and standard color codes set forth by the International Commission on Stratigraphy. Evidence from radiometric dating indicates that the Earth is about 4.54 billion years old. Halflife The applet lists a "halflife" for each radioactive isotope. What does that mean? The halflife is the amount of time it takes for half of the atoms in a sample to decay. The halflife for a given isotope is always the same ; it doesn't depend on how many atoms you have or on how long they've been sitting around. For example, the applet will tell you that the halflife of beryllium 11 is 13.81 seconds. Let's say you start with, oh, 16 grams of 11Be.

Evolution of Evolution - 150 Years of Darwin's "On the Origin of Species" Text-only | Flash Special Report Evolution of Evolution - 150 Years of Darwin's "On the Origin of Species" Introduction Charles Darwin Essays Darwin as Ichthyologist: Lessons for Our Future — Daniel Pauly Rethinking the Birdtree of Life — Shannon Hackett & Sushma Reddy What If Darwin Hadn't Written "On the Origin of Species?" History of the Earth The history of the Earth concerns the development of the planet Earth from its formation to the present day.[1][2] Nearly all branches of natural science have contributed to the understanding of the main events of the Earth's past. The age of Earth is approximately one-third of the age of the universe. An immense amount of biological and geological change has occurred in that time span. The first life forms appeared between 3.8 and 3.5 billion years ago. The earliest evidences for life on Earth are graphite found to be biogenic in 3.7 billion-year-old metasedimentary rocks discovered in Western Greenland[3] and microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia.[4][5] Photosynthetic life appeared around 2 billion years ago, enriching the atmosphere with oxygen.

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