Transcript: The tree of life suggests that the first organisms on Earth were thermophiles, organisms that accustomed to and thrived in conditions of high temperature. The environments may have been hot springs or deep sea ocean vents. They came from two of the three branches of the tree of...

Transcript: In general, evolution proceeds from simple to more complex forms of life, but it’s not the unique and defining attribute of evolution. Simple organisms can be extremely well adapted. Anaerobic bacteria have survived on this planet for over three billion years. No large and complex...

Transcript: The existence and abundance of extremophiles on Earth has implications for the search for extraterrestrial life. Remember that the entire idea of a habitable zone is predicated on a range of distance from a star where water can be in a liquid form. Perhaps this is too limiting an...