About 50% to 60%.

And for Pete's sake, why do people misinterpret this in a childlike way to mean we are "50%-banana"? Why don't they do even the slightest bit of research to understand what this means?

That doesn't mean that there is or ever was something that *looks* like half-banana/half-human! Not all your DNA is what you *look* like. Most DNA is involved in production of proteins, enzymes for creating or breaking down sugars, for building cellular structures and processes, etc. etc.

Heck, the structure of the hemoglobin pigment (a protein) in animal blood has a lot of common code with the structure of the chlorophyll pigment in plants. That doesn't mean that we have some chlorophyll or plants have some hemoglobin. It means that the same basic molecule structure was basically readapted for two very different functions.

And it's not just the similarities, but the precise differences within those areas of similarity that points to ancestry. If there is a common sequence in the DNA of two organisms, but that sequence has a specific "typo" in location 123 .. then we can trace common relationships and branches by finding other organisms that have the same typo in the same location 123 of that same sequence.

And finally a lot of DNA has no function at all ... literally called "junk DNA." These are carryovers from common ancestors between the two organisms ... going right back to bits and pieces that are useful in even more elemental organisms.

It's this junk DNA that's really a tell-tale sign of common ancestry. Why else would there be common sequences of base-pairs in the DNA, that are present in both species, but serves no function in either species?