The Tree of Life

Phylogenies are representations of relationships. They are a map of evolutionary history. Phylogenic trees can be used to show the similarities and differences between species. This can explain how closely a species is related to one another and why. For example, if a tiger is more closely related to a lion or a cheetah.

In phylogenies, there are different types of groups you can see in the tree. One type is called a monophyletic group. In this type of group, all the species share a common ancestor. This type of group is shown below

This group circled in orange represent a monophyletic group. This                 is because all six of the species come from the dot B. This dot represents a common ancestor they share. This one way to characterize and represent relationships. 

Another type of group that can be used to show different types of relationships is called a paraphyletic group. These types of groups also describe a group of species with a common ancestor, but not all the descendants are included. This could mean one or more species that came from that common ancestor is not included in the group. This is shown below

The circled orange group above is called a paraphyletic group. This is because all the species circled share a common ancestor, but it does not include autumn-bug and monsoon-bug which are also descendants. If these two species were inside the circle, we would call it a monophyletic group, but since they are not, we have to describe it as a paraphyletic group. 

Phylogenic tress are great ways to show and study relationships between species. You can learn what species share a common ancestor and which do not. They can show you the similarities and differences are between species to learn more about them.