Serious attempts to create such a hybrid were made by Soviet biologist Ilya Ivanovich Ivanov in the 1920s,[1] and possibly by researchers in China in the 1960s, though neither succeeded.

[2] The possibility of hybrids between humans and other apes has been entertained since at least the medieval period; Saint Peter Damian (11th century) claimed to have been told of the offspring of a human woman who had mated with a non-human ape,[3] and so did Antonio Zucchelli, an Italian Franciscan capuchin friar who was a missionary in Africa from 1698 to 1702,[4] and Sir Edward Coke in "The Institutes of the Lawes of England".

Even hybridization between different families, as in the case of the sturddlefish,[a] is possible (albeit exceedingly rare) provided the parent species are genetically similar enough to one another.

[22] In the 1920s, Ivanov carried out a series of experiments, culminating in inseminating three female chimpanzees with human sperm, but he failed to achieve a pregnancy.

(For comparison with known cama statistics, in the case of male camel–female guanaco cross the probability that insemination would lead to pregnancy was approximately 1/6.

[23]) In 1929, he attempted to organize a set of experiments involving nonhuman ape sperm and human volunteers, but was delayed by the death of his last orangutan.

[26] Oliver's cranial morphology, ear shape, freckles, and baldness fall within the range of variability exhibited by the common chimpanzee.

According to this account, the experiment was cut short by the Cultural Revolution, with the responsible scientists sent off to farm labour and the three-months pregnant[29] chimpanzee dying from neglect.

Li Guong of the genetics research bureau at the Chinese Academy of Sciences was cited as confirming both the existence of the experiment prior to the Cultural Revolution and the plans to resume testing.

[30] In 2019, unconfirmed reports surfaced that a team of researchers led by Juan Carlos Izpisua Belmonte from the Salk Institute for Biological Studies in the U.S. successfully produced the first human-monkey chimera.