The first suggests that laryngeal echolocation evolved twice in Chiroptera, once in the Yangochiroptera and once in the Horseshoe bats (Rhinolophidae).

A pet evolves twice during its lifetime.

This would make sense as syndactyly is so rare it is unlikely that it would evolve twice in two separate populations.

Since these species are not closely related to modern birds, either the alula evolved twice, or it did so more than 130 million years ago.

The first suggests laryngeal echolocation evolved twice in Chiroptera, once in Yangochiroptera and once in the rhinolophoids.

Animals that have guts are classified as either protostomes or deuterostomes, as the gut evolved twice, an example of convergent evolution.

As evidenced by the oviraptorosaurian cases, the pygostyle evolved at least twice, and rod-shaped pygostyles seem to have evolved several times, in association with shortening of the tail but not necessarily with a retractable fan of tail feathers.

But now we know that it's possible for intelligent life to evolve twice, and in very different ways.

This important adaptation evolved twice from ancestral turtles which did not have this ability.

The basic rationale is that, if a design is good enough to evolve once, the same design principle is good enough to evolve twice, from different starting points, in different parts of the animal kingdom.