Chinese scientists have cloned monkeys using the same process that created Dolly the sheep over 20 years ago.
The two long-tailed macaques born in December, named Zhong Zhong and Hua Hua, are the first primates to be cloned using somatic cell nuclear transfer, or SCNT.
The first primate ever cloned was a rhesus monkey named Tetra, in 1999, but a simpler cloning technique was used, known as embryo splitting.
SCNT has been used to clone 23 animal species, including cats, dogs, and rats.
Research published Wednesday detailed that 79 embryos were implanted into 21 surrogates, resulting in six pregnancies and two births.
The researchers hope to use genetically identical monkeys to advance studies of human diseases such as Alzheimer’s and Parkinson’s.