Scientists are combing human brain tissue with other animals.
The mice look ordinary at first glance, but the contents of their skulls are extraordinary: The cortex, or outer layer of the brain—vital for cognition, attention, and decision-making—is composed almost entirely of neurons grown from human stem cells. (Human neurons flourish in mouse brains, offering a new view of neurodevelopmental disorders | Science | AAAS.)
This tracks with Jesus’ warning (as recorded by Matthew) that the coming of the son of man will be in a time like the days of Noah. In the book of Genesis, the alien messengers are mentioned and Enoch describes the mingling of that race with humans in the antediluvian era. The book of Leviticus contains Torah instructions not to breed two different kinds of animals.