This article says man and gorilla are 98% identical on the genetic level.
There are several ways on how to measure genetic similartiy between species. You can't use the result of one way with a certain species and then compare that result to another way of a different species.
That's intellectually dishonest.
"Even if humans and gorillas actually were 98% genetically similar, why should that demonstrate common ancestry? We might reasonably ask the evolutionist why 98% similarity is considered powerful evidence for common ancestry, and at what point does the comparison cease to support common descent? What about 97% different? 95%? 90%? 80%? Is there an objective metric for falsification here?"
It demonstrate ancestry in the EXACT SAME WAY as paternity DNA tests demonstrate that your dad is your biological dad. Or your sister your actual sister.
Also, as has been mentioned countless times to you by now (I know, because i was one of them), it's not just about being similar. It's about the
pattern of the similarities, which Always (and I do mean ALWAYS) fits perfectly with the exact same phylogenetic tree. A hierarchy which is perfectly consistent with a family tree.
No matter which bone you trace, which gene, which genetic marker or even entire genomes... the exact same pattern emerges every single time.
And we know why... DNA is inherited by off spring with modification. These modifications accumulate and results in DNA strings that can be mapped in a hierarchical structure. Quite literally. You take a gene and you count which species have the gene. Those who have it are on the same branch, those who don't are on a different branch.
You can do this till you are blue in the face and you will be unable to find a single gene, marker or dna sequence which doesn't fit this tree like a glove.
We expect this in evolution theory. In fact, if a single species would break this tree, evolution as presently understood would be in tremendous problems (not to say falsified).
Creationists however... as a response to this FACT, all they can do is shrug their shoulders and say "that's how god made it", as if this god went through extra trouble to make it look AS IF everything evolved in truelly deceiving manner.
Wake up and smell the Obvious.
So just as a computer has a keyboard and a cell phone has a keyboard for texting, design in nature has many similarities too. It does not necessarily mean common ancestry.
The difference is that the similarties in life follow an extremely consistent pattern with NO EXCEPTIONS and which converge with plenty of independent research from completely unrelated fields like paleontology, geology, archeology, etc.
Genetic algorithms. It works.