Saying “this is science” alone as an answer to the validity is really doing science a disfavor. Not only are these consumer grade tests, but there’s been a lot of evidence of the fallibility of DNA testing (particularly for crime scene analysis) in recent years, let alone the fact that everything they show is based on models that are constantly updated and effectively best guesses. I really wish they’d be more upfront but it’d probably be too big a challenge to sweeping in new customers.