Question

Explain how DNA sequences can provide evidence of evolution

Answer 1

Well, part of the reason you can't find anything is that Creationists have been very busy posting deceitful and truly BAD information on the Internet. For example, typing "DNA evidence evolution", produces as the first two links, "All About Creation.org" and "Good News Magazine .org" ... the first of which is a page entitled "DNA Evidence for Evolution" but is exactly the *OPPOSITE* ... it is an attack on that evidence! (An attack using truly BAD science such as the infamously bogus "no new information" argument.) This is not providing information, this is outright *deceit*.

DNA provides *fantastic* evidence of evolution ... or more correctly, common ancestry between living species. It is even better evidence than fossils. In fact, if we had never discovered a single fossil, the evidence from DNA alone is a slam-dunk for evolution (common ancestry).

First, let's review what DNA is (as I don't know if you've learned this yet.) DNA is like the "alphabet" in which information is stored in cells. DNA is a really long molecule that is basically a chain of small molecules. These smaller molecules are called "bases" or "nucleotides", but the name doesn't matter that much ... you can think of them as "letters" in the alphabet. There are four letters ... A, G, C, and T (they stand for longer names, but calling them "letters" is fine for this discussion). So the special *sequence* of these letters is like the "spelling".

The first piece of evidence of common ancestry of *all* life forms is that the "spelling rules" are all the same for all life forms that we have ever discovered. First, life forms use "right-handed DNA" (that spirals to the right), even though "left-handed DNA" would work just as well. Second, there's no reason that GAC always means "leucine", never "tryptophan" ... but it does, for all organisms on the planet. The same "spelling rules" are strong evidence of common ancestry (because offspring cannot inherit different rules than their parents use).

Answer 2

The DNA sequences between two different animals, may indicate that both had a common ancestor that evolved until it gave rise to these two animals.

Step-by-step explanation:

There are totally different animals that have similar DNA sequences, this indicates that these animals are the result of the evolution of the same ancestor. For this reason, DNA sequences may be evidence of evolution.

Recent advances in Molecular Biology have made it possible to directly compare the genetic structure of different species, by comparing the nucleotide sequence of the DNA molecule. Other chemical compounds in living organisms have also been compared, especially proteins, such as gamma globulin, insulin, cytochrome C, hemoglobin and others. In general (albeit with many exceptions) the respective similarities of these biochemical systems align almost in the same way as similarities traditionally based on anatomical and other morphological characteristics. That is, animals that have many anatomical similarities usually also have very similar DNAs and proteins. This would be an expected fact, knowing that DNA is responsible for the production of proteins in a given organism and these, ultimately, will be responsible for their phenotypic characteristics.