[[G11 Pre-AP Biology]]
Species relatedness can be determined using a phylogenetic tree.
Phylogenetic trees are formed using evidence.
* Anatomical Evidence:
	* Studying structure and form.
	* Includes size shape and other physical features.
- Physiological Evidence:
	* Study of functions/processes, such as chemical and internal processes.
	* Example, guinea pig's insulin is closer to humans than mice.
- DNA Evidence:
	- Studying DNA sequence (bases) or amino acid sequence. DNA similarity positively correlates with relation.

In terms of evidence credibility for relatedness, DNA > physiological > anatomical.