The “hierarchy” that Dawkins is referring to in the video is the tree of life that evolutionary biologists can generate.
You don’t have time to give a 30-minute answer outlining the different meanings of the word “evolution” and the evidence pro and con for each.
Neil Thomas, a professor and member of the British Rationalist Association, was a committed Darwinist and agnostic.
For my part, I think it’s better to approach the data without assumptions and to let the evidence speak for itself.
If lateral gene transfer is rampant throughout life, the universal tree of life becomes a matter of philosophical preference, not empirical demonstration.