ELI5: Explain Like I'm 5

Branching order of bacterial phyla (Rappe and Giovanoni, 2003)

Okay kiddo, let's talk about bacterial phyla and how they are related to each other.

Think of all the different kinds of bacteria like different kinds of fruits on a tree. The tree represents the whole bacterial family, and the fruits are the different phyla (big groups) of bacteria.

Now, some of these fruits/phyla are closer to each other on the tree, meaning they are more closely related, and some are farther apart. Just like how some people in your family might look more alike than others because they are closer related.

Scientists like Rappe and Giovanoni wanted to figure out which phyla were most closely related to each other, so they made a big tree diagram (called a phylogenetic tree) to show this.

They studied different kinds of bacteria and compared their genetic information (like their DNA) to figure out who was related to who. And they put all this information together to make the tree diagram.

So imagine, the tree diagram shows you which phyla of bacteria came before others, and who are more closely related to each other. Just like how your family tree shows who your grandparents were, and who are your cousins.

Overall, this tree diagram helps scientists and us understand the evolutionary history of bacteria and how they are related to each other based on their genetic information.