Tree of Life. Planet Earth is about 4.6 billion years old. Oldest known rocks are about 3.8 billion years old. Oldest fossils (prokaryotes) are about 3.5 billion years old. Tree of Life. All living organisms on this planet share a common ancestor.
PowerPoint Slideshow about 'Tree of Life' - arlo
An Image/Link below is provided (as is) to download presentation
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
There is a hierarchichal classification of life in which organisms are progressively nested within larger and larger categories as more distant relatives are included in the classification (we will explore classification shortly).
The highest level of classification is the Domain of which there are three.
The domains Bacteria and Archaea are both prokaryotes (they have no nucleus and the DNA is not arranged in chromosomes). Prokaryote derived from the Greek Pro meaning before and karyon meaning a kernel [i.e. a nucleus]
Includes most of the bacteria people are familiar with including disease-causing species (Salmonella; Vibriocholerae which causes cholera), nitrogen-fixing (Nitrosomonas) and parasites (Borreliaburgdorferi which causes Lyme disease).
The Archaea include many extremophiles, organisms that live in extreme environments.
Includes thermophiles which tolerate extreme heat (e.g. live in geysers and hot springs where temps may reach 90 degrees celsius) and halophiles (salt lovers, which live in very saline environments (e.g. Great Salt Lake, Dead Sea)