Zaid Alsalami, Shaykh Dr Zaid Alsalami is an Iraqi born scholar, raised in Australia. He obtained a BA from Al-Mustafa University, Qom, and an MA from the Islamic College in London. He also obtained a PhD from... Answered 2 days ago
Bismihi ta'āla
This is interestingly a "new research", accommodating to today's popular trend.
Cannibalism is also common among animals, even their own babies. A lot of animals eat their own excrement, or self-mutilate, chewing off their own limbs. Some animals kill their partner, once mating season is finished.
A lot of animals are monogamous for life. There are animals that can change sex, or are two-sexed, and there are animals that don't need to mate to reproduce.
The point here is that the argument of comparing human behaviour to animals is a very weak argument, and does not justify anything.
And Allah knows best