#### Related to [[Evolution]]
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## How to read an evolution tree
- The **start** of the tree shows the oldest ancestor.
- Each **diverging branch represents a divergence in evolution**. This means that two populations of the same species developed differing traits over time. *(The diverging points are known as nodes).*
- At the end of the evolution tree will be a selection of spices all of which came from the ancestors at nodes that they are **directly connected to**. *(These are known as tips).*
>[!tip]
>- As the tree gets larger *(going down or across)* that generally symbolizes the passing of time.
>- You can think of the x or y axis as time.
>- Think of evolution trees **as those things that hang above cribs!** They can rotate about any node and still be the same.
>[!example]
>![[Pasted image 20230206110153.png]]
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## Who is more closely related?
- To figure out how closely related two different species are travel backwards in time until you find the **most recent common ancestor of those two animals**.
- **Whoever shares a *more recent* ancestor is more closely related.**
- If two species both share the same **most recent** common ancestor as another species then they are both *equally closely related.*
>[!quote]
>![[Pasted image 20230206111649.png|800]]
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## How to construct evolutionary trees
- Always construct an evolutionary tree from the varying/*living* spices on the left towards their common ancestor on the right.
- If a spices has a unique trait they must **branch from an intermediary common ancestor**.
- Next connect spices that have the same trait. The **fewer animals share a trait the more recent the development of that trait should be.**
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