consistently = ?

It means that not only have they successfully manipulated the targeted genes, but they have done it repeatedly. It is significant because ite means that their successful manipulation is not an anomaly, but is evidence of their method being right, their method being justified by the repeated successes--the consistent successes.

Let me give you an analogy. If i am shooting a basketball (attempting to throw it through the rim and the net) and i can shoot the ball successfully from 30 feet away, that can be seen as evidence only of luck. But if i can do it repeatedly from 30 feet away, if i can do it consistently, then i have demonstrated that my technique, my method, is a sound one, a reliable method. (To reliably shoot a basketball, you want to hold the ball on the tips of your fingers, and not the palm of your hand--you'll have better control, and you'll be less likely to shoot too hard, causing the ball to bounde out of the rim--which, of course, has nothing to do with your question about English.)

Of course, everybody in the world is familiar with, and cares about, American sports.

Felt you hadn't demonstrated what an asshole you are recently? Basketball is a very familiar sport in China, wanker.

Excellent!
Thank you Set.

Invented by Canadian doctor, James Naismith.