[junippor]

Fluff aside, here's the actual science:

> ( ... ) researchers from the Salk Institute and Kunming University of Science and Technology ( ... )

> In lab tests in culture, the team started with monkey blastocysts. Six days after fertilization they were injected with 25 human extended pluripotent stem (hEPS) cells, which contribute to the tissue as the embryo develops.

> And sure enough, when the researchers examined the batch of embryos 24 hours later, they detected human cells in 132 of them. After 10 days, there were 103 of these chimeric embryos remaining, but by day 19 only three still survived. After that, the embryos were terminated before they developed any further.

Saved you a click.

I'm guessing that the reason why this is called a chimera and not just a blob of cells from two different species is that the number of human cells increased from 25 to 132. But this seems like a very low bar to me...? I'm guessing that if you keep cells which you just extracted from a living organism and keep them in a comfortable bath, division might occur before they quickly die out.