
How Blood Evolved (Many Times)
Season 2 Episode 9 | 9m 56s
How Blood Evolved (Many Times)
Blood is one of the most revolutionary features in our evolutionary history. Over hundreds of millions of years, the way in which blood does its job has changed over and over again. As a result, we animals have our familiar red blood. But also blue blood. And purple, and green, and even white.
Problems playing video? | Closed Captioning Feedback
Problems playing video? | Closed Captioning Feedback

How Blood Evolved (Many Times)
Season 2 Episode 9 | 9m 56s
Blood is one of the most revolutionary features in our evolutionary history. Over hundreds of millions of years, the way in which blood does its job has changed over and over again. As a result, we animals have our familiar red blood. But also blue blood. And purple, and green, and even white.
Problems playing video? | Closed Captioning Feedback
How to Watch Eons
Eons is available to stream on pbs.org and the free PBS App, available on iPhone, Apple TV, Android TV, Android smartphones, Amazon Fire TV, Amazon Fire Tablet, Roku, Samsung Smart TV, and Vizio.

Welcome to Eons!
Join hosts Michelle Barboza-Ramirez, Kallie Moore, and Blake de Pastino as they take you on a journey through the history of life on Earth. From the dawn of life in the Archaean Eon through the Mesozoic Era — the so-called “Age of Dinosaurs” -- right up to the end of the most recent Ice Age.Providing Support for PBS.org
Learn Moreabout PBS online sponsorship- Science and Nature
A series about fails in history that have resulted in major discoveries and inventions.
Support for PBS provided by: