FC: Yousef Mohammad 7-4 March 20
1: Topic : Archean Eon Table of Contents Topic: Pages: plants 4 animals 6 climate 8 summary 10 Bibliography 12 The End 14 | Introduction 2
2: Introduction | The Archean eon was when life probably first emerged. The Archean eon is divided into four eras:Neoarchean, Mesoarchean, Paleoarchean, and Eoarchean.
3: The Archean means ancient. The Archean eon was bacterial for one billion years. It lasted for 3.8 billion years.
4: Plants | Before 3.5 billion years ago the Cynobacteria or (blue green algae) was found. The Cynobacteria are considered the earliest living cells formed on Earth. The place that they are found in is the ocean.
5: Cynobacteria evolved and used sunlight, water, and carbon dioxide to get its energy and excreted oxygen. Cynobacteria are still around and they are considered one of the largest groups of prokaryotic bacteria.
6: Animals | In the Archean eon the first living micro-organisms that existed were called Archea. These microbes are single celled and have no nucleus. They didn't need oxygen to survive which is good because in the Archean eon there was little oxygen in the atmosphere.
7: These micro-organisms are similar to bacteria but different then bacteria. The Archea lived in salty hot water and the guts of animals. They excrete methane gas as a waste product.
8: Climate | Earth during the Archean eon was three times hotter than today’s temperature. The estimated temperature was about 45-85 Celsius degree. There was a lot of volcanic activity, which provided new molecules for the atmosphere. However the Archean eon was cooler than the previous eon, which was the Hadean eon. The Earth’s atmosphere at that time consisted mainly of carbon dioxide and very little oxygen. Also there was no ozone layer; therefore, life on Earth was unprotected from UV rays. The ozone layer appeared hundred of millions of years later after there was higher oxygen layers.
9: This is the period where continents began forming. The first continent appeared during the middle Archean eon. However plate tectonics and continental plates did not exist until the end of the Archean eon. During the Eoarchean era (which is the first era of the Archean eon) the earth was covered by water and volcanoes. The ocean was green and the sky was orange. In the Neoarchean era, which was during the end of the Archean eon oxygen began increasing. The first large continent appeared on the Earth.
10: Summary | Before 3.8 billion years ago the first micro-organism which Is Archea formed. The archea are single celled micro-organisms. It doesn’t need oxygen to survive. The Archean eon climate is three times hotter than today. Cynobacteria produced oxygen through the process of photosynthesis. They live in hot salty water.
11: They are similar but different to bacteria. Cynobacteria is considered to be the earliest prokaryotic organisms. Cynobacteria is considered to be the origin of the plants. At that time earth had very little oxygen but levels increased.
12: Bibliography | Source 1: *Website URL:http://www.ucmp.berkeley.edu/precambrian/archean_hadean.php *Page Title:The Archean Eon and the Hadean *Web Site Title:UCMP - University of California Museum of Paleontology
13: Source 2: *Website URL:http://forces.si.edu/atmosphere/02_02_02.html *Page Title:The Archean Eon *Web Site Title:Forces of Change
14: Thanks Page | Ms.Dunn Ms.Damon Ms.Sapp Ms.Moore Mohammad Ashour