Lecture 4 Water Humans and Civilization

Lecture 4 Water Humans and Civilization - Water, Humans,...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Water, Humans, and Civilization Must survive in low-oxygen environments Could not eat other organisms for food The First Organisms Two energy sources: Light and Chemical reactions Light: photoautotrophs Chemical reactions: chemoautotrophs Assemble complex carbon compounds from simple Carbon compounds (CO 2 ) using external energy. The First Organisms The First organisms: Chemoautotrophs (Fe and S) microtubes in pillow lavas containing residual carbon Evidence: Light: photoautotrophs Chemical reactions: chemoautotrophs Must survive in low-oxygen environments Could not eat other organisms for food The Early Organisms Photosynthesizers: photoautotrophs Blue-green algae/cyanobacteria- Removal of carbon dioxide- production of oxygen Earliest: Main effects: The Early Organisms Oldest macroscopic life: stromatolites Cyanobacteria colonies sediments Produced billions of tons of O 2 Stromatolites Oxygen O 2 combined with iron No immediate increase in atmospheric O 2 Colonization of land: Ozone Layer Screens harmful UV radiation Ozone Function: First land plants 480 mya Primates ~30 million years ago Pre-humans ~5-8 million years ago (hominids) Homo sapiens ~200,000 years ago Mammals ~65 million years ago Skipping Ahead Reptiles ~ 245 million years ago Kingdom:...
View Full Document

This note was uploaded on 07/31/2011 for the course SOS 2007 taught by Professor Dr.jamesbonczek during the Summer '07 term at University of Florida.

Page1 / 30

Lecture 4 Water Humans and Civilization - Water, Humans,...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online