Best one sentence summation of how I feel, ever.

[finalgrunt]

dogs are descended from wolves

They do not. They have a common ancestor, and they branched at one point. For the same reason we can't say that Man descends from monkeys. We shared a common ancestor, branched over a very long period of time and evolved seperatly.

So the questions which remain to solve are:

- Do all species descend from the same unicellular ancestor? If so did other different kinds exist but did not survive our ancestor? How many times did life start and vanished before it stuck to the Earth?
- How such material were formed? This is still an ongoing research field, even though we're starting to have a better picture.

For the same reason people were unable (and in some cases still are) unable to explain how we can grow from a single cell with so much differentiation, it will take time to understand the mechanisms. And unlike living cells that we can study at will, we don't have any material to study for our origins. DNA don't survive well through time, and that's the reason why we may see one day Mammoths again, but dinosaurs not so much (until we can actually write DNA code and simulate its output, and then we can build something matching our imagination, which may come close but never will be the reality).