Gills, glands, and evolution - an inquiry

Factual Questions
1

Some Brits have decided that the parathyroid glands evolved from gills. Apparently, this is based on a few key facts: (1) fish have no parathyroid glands, (2) fish use gills to control their calcium level, (3) people use their parathyroid glands to do the same, (4) people have no gills, and (5) the parathyroid glands are in the neck area (where our gills would be, if we had them).

An astute friend pointed out that mammalian embryos have gill-like structures during their development.

So, if there were any evidence from embryology that some of the cells from these “gills” migrated to become the proto-parathyroid glands in the fetus, then that would add considerable weight to their hypothesis, would it not?

Does anyone know whether such a migration occurs?

:dubious:

2

Well, I guess it helps to read the whole article, not just skim it.

“They found both develop from the same type of tissue in the embryo, called the pharyngeal pouch endoderm.”

:smack:

Never mind.

3

For more information, you might Google “branchial arches”. There’s quite an interesting story of ontogeny recapitulating phylogeny there.