BIOL 1202 Chapter : Day 1
Document Summary
Bacteria living in your colon or living within you in general: billions. Types of bacteria living in your body or the species are beneficial and cause no harm, prevent other pathogeneses to cause you any harm. Goal of a living thing is to reproduce. Life arose about 600 million years after earth was formed. Took so long because earth was cooling( earth was hot, had a lot of lava, probably not that much water) 1 species on planet 4 billion years ago - unicellular organism. Going from 1 species to 11 million species over 4 billion years: a change in population over time , which is evolution. eukaryotic , multicellular organisms, which humans are; we have trillions of cells. Bacteria on and in your body 500 trillion microbes. All living things on the planet are related, called family tree of life. About 200 thousand years ago, fist fossil record of humans , homosathian.