On the surface, tigers don't have a pair of wings suitable for flying.

Physically not suitable for gliding, so tigers can't fly.

The deep reason is that the characteristics of tigers are determined by genes and external environment, or

There are some genes suitable for flying in Xu's genes, but just look at the tigers now.

At least that gene is not expressed, if there is nothing suitable for flying.

Genes, not to mention whether tigers can fly;

Tigers have not made progress in the direction of flying because of natural selection.

So tigers can't fly.