Darwin’s theory and the flow of genetic information and how we evolves for example the primates this is an example of evolution. It is the progress of mankind and for creatures
I believe the inability to make saliva would affect digestion drastically. The first phase in the process of digestion comes with saliva - it breaks down some substances in your mouth, because it contains amylase which helps during this process. If it weren't for saliva, you probably wouldn't even be able to swallow food - and even if you did, it would be almost impossible to break it down in your body.
Through the umbilical vein.
