Question

How might similarities and differences in genetic codes, or the proteins built as a result of these codes, be used to determine how closely related different species are?

Answer 1

Are you familiar with ribosomes and how they work? :-)

Answer 2

They are located inside a cell and make up proteins. Right?

Answer 3

Yep, and they do this by taking mRNA strand copies coming out from the DNA in the nucleus (or RNA, or just a mostly-unorganized glob of DNA with no nucleus like in some bacteria and archaea). Similar code sequences in the genome are shared from organisms with common ancestry. You have the DNA encoded from your parents (plus the mitochondria from your mother). In the same way you can do a paternal test and match up patterns, you can do that between species as well. Even to extinct species (either by a luckily preserved sample or logical inductive reasoning).

Answer 4

Like for example, you share about 90% of your DNA coding in common with plants, like a banana. :D

Answer 5

In truth there's very VERY light differences (percentage wise from total DNA you have) that makes you unique.

And even more than that, there's sections of your DNA which are "dormant"

Answer 6

Very SciFi-ish stuff there, but it's true, you have hidden sections in your genome that nobody quite knows what they do. Sometimes it's because they do something in other organisms, but in our physiology as humans the don't do anything because we don't have those organs, tissues, or cells that would make use of that information.

Answer 7

Anyways, the short answer is it's a matching game. If you can find protein markers that are the same across a group of people (or different species), then it means they share a common ancestry somewhere in the past. Sometimes very very long ago in the past (read: several million of years).

Answer 8

Am I making sense to you @belive_27?

Answer 9

Yes(: Thank you for everything this helped a lot(: