The human gene for your muscle protein is different from monkey muscle protein in 4 places and different from a chicken's gene in 25 places.

What type of evidence is this?

The human gene for your muscle protein is different from monkey muscle protein in 4 places and different from a chicken's gene in  25 places.

This is molecular biology, and this shows a little bit about evolution because it shows human, monkey and chickens share a common ancestor.

Explanation:

The example shows some features about biology. Molecular biology is focused on all the components and elements of molecular cells. In this case, analysing muscle protein and genes is considering this type biology.

DNA is the origin of every living cell on earth and is unique for every species. The analysis of protein's DNA is a determination of how distant or close species are.

There are many other ways to relate evolution to the different animals, species or cells. You can use fossil record, anatomy, reproductive isolation, embriology, among many others.  

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added