sonofdad
Member
It doesn't prove it. Nothing will ever prove evolution.OK, I'll bite. How does DNA prove macro evolution?
This is science, math, the best we can do is draw logical conclusions from the available evidence.
We see DNA.
We see that every living thing that we know is made up of strings of DNA.
We see that the characteristics of an organism are determined by its DNA.
We see that there are vast similarities in the genetic code of different species that look or behave in similar ways. (for instance, a dog and a wolf or a human and a chimp)
We see that there are less similarities in the genetic code of different species that look and behave very differently (for instance, a koala and a sunflower)
(and remember, species are only classifications made up by people)
Sure, from these facts alone we could draw many different conclusions and vastly different theories. If DNA determines characteristics of organisms, then similar organisms will have similar DNA, regardless of how they came to be.
However, if we supplement this evidence with another little fact:
We see that DNA is not immutable at all, we see that it is constantly changing with every single generation. There is no apparent limit to how much the DNA of a population can change.
This leads us to the conclusion that species can change and become vastly different species given time. (we can even observe that to some extent)
If we apply uniformitarianism as well, we can theorize that species have been changing in similar ways in the past, all the way back to the first species of organisms.
Since there is so much similarity between all living things on earth, they are basically all made up of the same parts and all share some genetic code with other species, we can theorize that all originate from a single ancestral lineage, rather than multiple ones.
One of few things that could refute this would be if a mechanism that puts some kind of an upper limit on changes in DNA was demonstrated.