Lights, Chimeras, Action?

Chimeras are not mythological creatures. Biologically speaking, they happen when the cells of one species are fused with those of another animal. The ethical debate seems to have been reignited with news that Professor Belmonte (US Salk Institute) has produced new chimeras by inserting induced human stem cells into Long-tailed macaque embryos (https://www.theguardian.com/science/2021/apr/15/human-cells-grown-monkey-embryos-reignite-ethics-debate). The human cells in Belmonte's human-macaque chimeras grew and multiplied. He hopes his studies will produce information on how the mixtures of cells communicate. Belmonte suggests this might facilitate effective chimera production, combining human cells with non-primate species. Chimera enthusiasts hope these entities will prove useful for growing 'human' organ transplants in other animals. Pigs and sheep are among the suggested possibilities. Belmonte's embryos were grown in Petri dishes and were destroyed 19 days after their production. People are concerned, however, that others might be tempted to let such human-ape chimera development go on much longer. This technology clearly opens a Pandora's box.