Ask A Scientist© Biology Archive

name         Shelley
age          20s

Question -   Is it true that some babies are born with some sort of
gills?  How and when do humans adapt from breathing inside to breathing
outside of the womb?
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Whoa!

You have received a great deal of false information.  First, babies are not
born with gills!  Get that out of your thinking!  Babies do not "breath"
for oxygen in the womb.  They do "practice breathing" using the amniotic
fluid of the womb, but it is not doing them any good otherwise.  All of the
embryo and fetal needs are received through the placenta.  The mother
provides everything that is needed.

As for the gills, there is a stage in the early human embryo development
whereby humans do show gill slits, but not functional gills.  Slits are not
gills!!  As a matter of fact, all vertebrates show these same gill slits.

Steve Sample
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At some point in development, all vertebrates have gill slits. However,
babies do not BREATHE in the womb. They get their oxygen and nutrients from
the mother through the placenta. The baby doesn't begin to "breathe" until
it is born.

Van Hoeck
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