Biology

For stuff like bacteria, they can engage in lateral gene transfer, where they swap genetic material with each other (almost sex, but not really), uptake and then express genertic material found in the environment (this is used in labs to get microbes to make proteins and stuff for us), and/or incorporate genetic material spread by viruses or other vectors into their genes.

Idk if any of the above mechanisms apply to the fly in the article, but there is also some gene-crossing that happens when we make sex cells. The "legs" of a chromosome can swap sections between them, leading to a gametes that would be different from the parent chromosome when recombined (this is one of the mechanisms for genetic variation between siblings). There are also mutations that happen naturally, which can be passed from parent to "clone"-child.