Ask HN: Why/How Did We Evolve to Eat and Breathe Through the Same Passageway? - jelliclesfarm
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cimmanom
Part of it probably has to do with lungs originating as gills. Passage of
water across the gills was what was crucial for optimal oxygen intake, and
taking water in through the mouth facilitates that for fish. Getting food
stuck was probably less of an issue because if you had proper flow of water
it’d just get flushed right back out.

And the incremental nature of evolution favors the adaptation of similar but
suboptimal structures over the development of entirely new structures and
especially of new topologies (changes in what passages are connected to one
another or pass all the way through the body).

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jelliclesfarm
Thank you.

One more Q: Do fish and birds have gag reflexes as we do? Is gag reflex just a
mammalian thing.

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cimmanom
That I don’t know. Most birds have the ability to regurgitate food for their
young, but that’s not the same thing as a gag reflex. Maybe google or
Wikipedia have more info?

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jelliclesfarm
There seems to be whole slew of reflexes.

That’s what made me wonder..if we were to redesign human anatomy, what changes
would we have to make?

Eating and breathing through the same passageway seems to be an unfortunate
and fatal bad design.

Ditto with reproduction. The digestive system is pretty neat as is the
neurological and brain circuitry(as much as we understand it)

I just don’t get when we eat and breathe through the same tube..and give birth
so close to where we poop. Seems like bad design.

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cimmanom
What does “bad design” mean in the context of a system that wasn’t designed?

Evolution is a process that involves tiny random changes stabilizing at or
near local maxima. Where you end up is largely about where you started.

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jelliclesfarm
You are right in a way.

It’s just that sometimes I feel that if evolution can be tinkered with..or
improved upon, I could come up with a better design.

Purely theoretical, of course

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tropo
The lungs originate from the intestinal tract. Some fish would gulp air. This
got better and better... and hence became lungs. (FYI, the gills turned into
various features of the neck and lower face including ear bones and the jaw,
with some of this happening long before functional gills were lost)

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jelliclesfarm
Remarkable. Thanks!

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jryan49
DRY

