https://fee.org/articles/how-socialists-tried-to-breed-out-the-desire-for-freedom/?utm_source=zapier
I don't think creating chimp/human hybrids is unethical, provided the offspring are treated humanely after birth.
"Ivanov eventually received $10,000 from the Soviet Financial Commission and his project was approved by the Soviet Academy of Sciences. <...> Ivanov and his son traveled to French Guinea in Western Africa to carry out his artificial insemination experiments in March, 1926. <...> He only attempted to inseminate three female chimpanzees before being forced to abandon the project as useless. Desperate to make use of his limited funding, Ivanov then made the horrific decision to attempt the insemination of African women with chimpanzee sperm without their knowledge. He made a proposal to doctors at a local hospital about his experiment and was ready to proceed when the General Governor of French Guinea, Paul Poiret, rejected the plan."
"Ivanov eventually received $10,000 from the Soviet Financial Commission and his project was approved by the Soviet Academy of Sciences. <...> Ivanov and his son traveled to French Guinea in Western Africa to carry out his artificial insemination experiments in March, 1926. <...> He only attempted to inseminate three female chimpanzees before being forced to abandon the project as useless. Desperate to make use of his limited funding, Ivanov then made the horrific decision to attempt the insemination of African women with chimpanzee sperm without their knowledge. He made a proposal to doctors at a local hospital about his experiment and was ready to proceed when the General Governor of French Guinea, Paul Poiret, rejected the plan."