Barrow's put-down of Dawkins.....on the mark or silly?
If his comments were serious, they are silly to the point of absurdity. Biologists most certainly
are scientists. They follow the scientific method and are responsible for a whole host of scientific knowledge, including modern medicine, genetics, agriculture, and a whole host of other fields.
Honestly, this sounds like a physicist making a bad joke, which is basically what your quote says ("Barrow laughed and said, “You have a problem with these ideas, Richard, because you’re not really a scientist. You’re a biologist.”). It sounds like he's just giving a fellow scientist a hard time.
As for the actual commentary on biology...it sounds more like he's going into the reasons he chose physics rather than biology because he wanted to understand the underlying forces of nature as opposed to "just" the outcomes. That doesn't mean biology is "not science," just that it's not Barrow's chosen field.
When you know you're going to wake up in three days, dying is not a sacrifice. It's a
painful inconvenience.