Trend Watch

Scientists Create a Human-Pig Chimera

Lookups for 'chimera' spiked after news that scientists had successfully combined the DNA of two disparate species

Lookups of chimera spiked on January 27, 2017, with the news that scientists had successfully combined the DNA of two disparate species into one viable embryo. The resulting embryo, called a chimera, lived to four weeks and represents a huge step toward the goal of growing replacement human organs in the lab.

The word chimera dates back to the 14th century, where it was used to refer to a fire-breathing she-monster from Greek mythology. Homer describes her in The Iliad as

... a thing of immortal make, not human, lion-fronted and snake behind, a goat in the middle, and snorting out the breath of the terrible flame of bright fire.
—translation from the Greek by Richmond Lattimore

She terrorized Lycia and was slain by the Greek hero Bellerophon and the Pegasus.

The fearsome creature lived on in people’s imaginations, and by the 16th century chimera was used to refer to any imaginary monster made of incongruous parts.

It seems an odd word for scientists to latch onto, but they did. In the early 20th century, botanists borrowed the word to refer to any plant that was made of two (or more) organisms from genetically distinct species, like grafted plants. Today’s scientific chimera refers to combining distinct genetic material in one organism, and is often used to refer to the insertion of human DNA into non-human cells or organisms (such as viruses).

Because chimera is borrowed into English from Greek, it retains a pronunciation that’s more in line with Greek conventions than English conventions: /kye-MIR-uh/. The Greek word that gave us chimera means “she-goat.”

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