How are protein sequences used to provide evidence of common ancestry?

Answer 1

atgc strands adenine, guanine, thymine, cytosine, combinations are unique for individuals and are a part of the genepool brought teogether by set og genes from both parents, thus carrying in them a part of each, karyatyping is done to trace ancestry.

Answer 2

Let's put it in very simple terms: a protein sequence is nothing more than a sequence of amino acids. Each amino acid in the sequence is coded for by a codon (3 bases) in the RNA molecule. What scientists do is they take the sequence of amino acids and figure out what RNA molecule could have coded for it (this is not as easy as it sounds because there are several combinations of codons (again 3 consecutive bases in the RNA strand) that could code for the same amino acid, but then again, scientists have computers at their expense that make the job easier). Once they figure out the sequence of RNA, they can work their way backward and find the DNA sequence that must have coded for the RNA.

Remember the base pairing rules? If say you have amino acid x, and it is coded for by UAG, the corresponding DNA would be ATC.

Once they figure out the DNA composition, that's it. DNA is peculiar/specific to an individual (except in the case of twins) and so they can identify people with it, or compare it to other DNA and search for similarities that would suggest a relationship (i.e., between an individual and his ancestors).

Answer 3

Protein sequences from a diversity of organisms can be aligned (using a computer program) to generate a "phylogenetic tree." The relationship between the protein sequences can be visualized on the tree. Two organisms are thought to share a common ancestor if their protein sequences are highly "homologous" or share a high level if protein identity or have conserved amino acid resides in their protein sequences.

Answer 4

To answer you question in short: DNA mutations that cause variations in protein structures or function allow us to prove common ancestry. People who are closely related are more likely to share the same mutations than people who are not related. This is why people of the same races look more like each other than if you compare them to other races.

DNA is made up of bases A, G, T and C. These bases form a code that tells the cell how to string proteins together to form the functional units of our bodies. Every human being is unique. That means that we all have DNA codes that are slightly different. Our DNA codes will look very close to the codes of our parents and sisters and brothers because our DNA is inherited.

Here is an example: Imagine a little village where a family has a DNA code with a mutation in it. The mutation causes a protein to be made a lot more than it usually is. Let's pretend that this protein is used to make hair. So this family is very hairy. A child from this family moves to a country where people do not have a lot of hair. He starts a family with one of the natives of that country. Some of his children will inherit the mutation that causes hairy-ness. Those children will in turn pass that same mutation onto their children. If you have enough tissue samples from family members, you could trace that mutation back to the original ancestor.

DNA testing for ancestry is often done using mitochondrial DNA that allows us to trace our ancestors through our mothers.

FYI: Karyotyping is NOT used for tracing ancestry. Also, I wouldn't consider this simple.

Answer 5

Very simple, proteins are polymers of amino acids which get coded for by your DNA (genes). This code is universal among all organisms. For Example the sequence "AUG" (Adenine-Uracil-Guanine) always codes for Methainine (an amino acid), regardless of which organism we are talking about. This helps to prove a common ancestery among living things.

Answer 6

its simple they create a spectrometer on gel (complicated technique...) but with that they can compare the differences between 2 kind of DNA. Knowing how many differences between the 2 kinds..for example. Humans ans chimps have a 99,9% Dna similarityt...so only this 0,1% is what makes us different from a chimp...I think, and this isnt sure, that we have a 75% common gene sequence with plants...

Answer 7

a very generalized answer:

DNA is made up of protein sequences.