SIGN-283 Lecture Notes - Lecture 30: Written Language, Arabian Peninsula, Gerardus Mercator

• School: Diablo Valley College
• Department: Sign Language
• Course: SIGN-283
• Professor: Moudiu

Document Summary

First estimate between 75,000-168,000 years came from. French scholar georges-luis leclerc based on degree of heat lost by earth since its beginning. First increase of estimate in nineteenth century lord kelvin. Same time, charles darwin thought earth had to be 300 million years for all geological and evolutionary processes to have taken place. The different stages in the history of the earth. Geology: studies surface of earth and tries to understand its past by analyzing many layers of sediments that have been formed. First big distinction: between before 542 million years ago and period after around this time lot of macroscopic, hard- shelled animals started to appear, which left plenty of fossils in rocks. Cambrian explosion: sudden presence of fossils in geological records starting 542 million years ago; often presented as beginning of real" life. Cambrian explosion named after place where fossils were found in nineteenth century.