In an attempt to better understand the evolution of the human brain, researchers in China successfully transplanted a human gene for larger brain size into macaque monkeys. They used CRISPR technology to insert the human microcephalin gene into monkey embryos. Of the eleven monkey embryos that successfully received the gene, only five survived. The brain sizes did not increase, although they did take longer to develop, as in humans; the monkeys also performed significantly better on a memory test.
This type of experiment could not take place in the West because there are restrictions when working on intelligent animals due to ethical reasons. Western scientists in the article described how giving an ape more intelligence is cruel because it would be above all apes, but below all humans, giving it no meaningful existence.
Even though I love to see advancement in our understanding of human evolution, I believe that there is an ethical dilemma to altering the brain of an intelligent animal. There are other ways of furthering our knowledge of evolution, through archaeology, anthropology, and geology, to name a few.