I have a question about the following Qur’ānic verse:

Shall I point out to you something much worse than this (as judged) by the treatment it received from Allah? Those who incurred the curse of Allah and His wrath, those of whom He transformed into apes and swine, those who worshipped Evil; these are [many times] worse in rank and far more astray from the even Path. (5:63)

Which nation was turned into apes and swine and for what reasons?

If context of this verse is taken in consideration, it becomes evident that the addressees of this verse are the Jews of pre-Islamic times. It is not necessary that their bodies were turned into apes and swines; it could have been that their nature and behavior was transformed into that of these animals since they repeatedly denied Allah's revelations and persisted in their evil conduct.