For curiosity of the reader and myself. How are the genetic markers isolated in a way that it can without of a doubt explain an iceshelf collapse? I think an a

For curiosity of the reader and myself. How are the genetic markers isolated in a way that it can without of a doubt explain an iceshelf collapse? I think an article like this should go more in depth. I am just wondering because it doesn't explain the process. I also don't disagree with the worrisome amount of greenhouse emissions.