Bat Bones and Intelligent Design

[Bill]

I think it will not be disputed when I say that all mammals have solid bones, and that all birds have hollow bones. This distinction is so clear cut, that if you came across the skeleton of an unknown critter, if it had hollow bones you would immediately know that it was a bird of some sort or other,

Birds need lightweight frames, and hollow bones trade off structural integrity for less weight to carry aloft. Mammals have no need to be so lightweight, and their solid bones give them the ability to withstand knocks and collisions that could easily kill a more fragile bird.

Without prior knowledge, one would expect the division between hollow and solid bones to be that all flying creatures would have hollow bones, and all ground based creatures would have solid bones. But this is not the case.

The mammalian order of Chiroptera (bats) all have solid bones, even though they spend almost all their waking hours airborne. Flightless birds, ostriches. emus and rheas have hollow bones, and suffer greatly from the consequences of having weaker skeletons than mammals.

This was a curious mistake for an Intelligent Designer to have made. Flying creatures need light bones, and flightless ones need solid ones.

Perhaps the ostrich has light bones in order to run quickly? That does not seem to answer the conundrum, for it is easily outpaced by the cheetah, which has solid bones.

Perhaps bats gain some advantage by having solid bones? If so, the presumed advantage is one still not observed by science. They cannot fly as high, or as for long, as their winged counterparts.

However, there is a simple explanation.

It all makes perfect sense if bats evolved from a mammalian line and inherited the traits of mammals, and if ostriches evolved within the class Aves, and now has all the characteristics of birds.

This is not in anyway a conclusive argument to prove the matter one way or the other, but it is another piece of evidence that needs to be weighed when considering the claim of those who propound an Intelligent Designer.