I mean, wouldn't you be kind of worried if science threatened some of your Buddhist beliefs? Especially that whole cycle of samsara, with birth and rebirth.
Actually, no. Samsara I don't think its really possible to refute: the concept is that this universe is filled with change and impermanence, which is fueled by an ever changing series of causal factors. I don't think any scientist would ever disagree with that.
Birth and rebirth I consider up for review myself, or at least many interpretations of them. Especially as they refer to the different realms.
As the dalai lama has said (even though he is not of my sect), if science finds something to be false then it is gone. Period.
Irrational Faith is considered a barrier to enlightenment, one of the worst in fact (belief in the efficacy of rules and rituals). This includes irrational faith in buddhist ideas(at least in my sect. But then again, their historical designation before the hinayana/mahayana split was the 'rationalists').