SCIENCE
The egg race: scientists vie to create synthetic human embryos
Process poses deep philosophical and ethical questions
A computer illustration of in vitro fertilisation
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At first, the cells had no specialism. In a dish in a lab each had the potential, in theory, to become many different human cell types. But the scientists who put them there had specific plans. The cells were bathed in chemical messages, and began to organise: clumping, dividing and forming a structure.
There, in the laboratory of a Cambridge scientist, they arranged themselves: to mimic a human embryo. It was an embryo, though, that had never seen an egg or sperm. These “model embryos” were not real embryos. They could never become a baby, but — in results announced this week — they were recognisably embryo-like.
Now, if the announcement is to be believed, they will be used to help us better understand early
