Not just over/under estimating, but people intentionally ignoring instructions, answering absurdly for the lulz, or just misunderstanding and inverting their answers (percent not).
Your DNA sequence is generally pretty stable, but other characteristics do. Epigenetics is the field. Another example is methylation, which is basically like your cell putting a post-it note that says "don't use this" on a particular region. By looking at a bunch of different methylation sites an age can be estimated.
But in this case, it appears that the article is just mixing up "genetic testing was performed" and "the ages were determined" (separate statements from previous articles.)
Lemmy needs to distinguish itself with character-level voting. Somebody made a great post but unironically used an interrobang? Hit 'em right in the analytics.
Jeeeeeeffffrrreeeeyy... That kiiiiiills people!