History of the Universe

   

  Basic Information  

   

  Further Information  

   

  Other Hotu Pages  

   

  Questions  

   

  Edit  

Biological Environment > Colony of Algae

Earlier  1 Billion Years ago Later Plants Later

This site tells the story of the history of the universe. Click Earlier and Later to follow the story. Note: Many facts have been simplified to make them easier to understand.

 
Google
The next big step in evolution was when algae began to live together in colonies. They gained in several ways.
  • They were larger than any protozoan, so they could not be eaten so easily.
  • Their cells could specialize to do just one job. For example some cells, the reproductive cells, specialized in making new colonies. Cells which specialized did their job better than cells which didn't, so the colony gained.
  • Specialized cells in colonies could do new types of job which could not be done by single cells living alone. For example some cells specialized in swimming.
Colonies of algae probably first appeared around 1 billion years ago. The simplest ones had only a few cells forming a flat plate. More advanced ones formed solid balls. The most advanced forms had thousands of cells and formed hollow balls.
All sorts of algae evolved in lakes and on the shores of oceans. Today seaweed and many other forms of algae are still common. Nine out of every ten cells which use sunlight are algae or blue-green bacteria.
   
    Like this web site? Buy the book!

Earlier  1 Billion Years ago Later Plants Later

Biological Environment > Colony of Algae

   

  Basic Information  

   

  Further Information  

   

  Other Hotu Pages  

   

  Questions  

   

  Edit  

Search Now:
Amazon Logo

Copyright © 2007 Penny Press Ltd   Terms and Conditions of Use and Sales