Kent Dunlap

And one of the things that's interesting is that the many features that the neck does, the many functions that the neck does, are sometimes competing with each other. So you can't optimize everything at once. Let me give you one example. Human speech is possible in part because we have a larynx, a voice box, which is situated relatively low in our throat compared to other animals.

And this position of the throat gives humans the capacity to make many, many different kinds of speech sounds. But on the other hand, this low position of the larynx also gives a lot of space above the vocal cords, above the voice box, which is susceptible to collapse. And a remarkably high number of people have sleep apnea, that is periods during their sleep when their breathing stops.

And this position of the throat gives humans the capacity to make many, many different kinds of speech sounds. But on the other hand, this low position of the larynx also gives a lot of space above the vocal cords, above the voice box, which is susceptible to collapse. And a remarkably high number of people have sleep apnea, that is periods during their sleep when their breathing stops.

And this position of the throat gives humans the capacity to make many, many different kinds of speech sounds. But on the other hand, this low position of the larynx also gives a lot of space above the vocal cords, above the voice box, which is susceptible to collapse. And a remarkably high number of people have sleep apnea, that is periods during their sleep when their breathing stops.

And we inherit this vulnerability to sleep apnea because we have this descended larynx leaving this space above the larynx that is so susceptible to collapse when we sleep.

And we inherit this vulnerability to sleep apnea because we have this descended larynx leaving this space above the larynx that is so susceptible to collapse when we sleep.

And we inherit this vulnerability to sleep apnea because we have this descended larynx leaving this space above the larynx that is so susceptible to collapse when we sleep.

It is remarkable and it even brings to the marvels of the respiratory system too because it's actually hard to suck a lot of air down a very long trachea, a very long windpipe. We know this is sort of true because we can't breathe out of very long snorkels. You may have noticed that all snorkels are relatively short. We don't dive 20 feet down underwater with a snorkel.

It is remarkable and it even brings to the marvels of the respiratory system too because it's actually hard to suck a lot of air down a very long trachea, a very long windpipe. We know this is sort of true because we can't breathe out of very long snorkels. You may have noticed that all snorkels are relatively short. We don't dive 20 feet down underwater with a snorkel.

It is remarkable and it even brings to the marvels of the respiratory system too because it's actually hard to suck a lot of air down a very long trachea, a very long windpipe. We know this is sort of true because we can't breathe out of very long snorkels. You may have noticed that all snorkels are relatively short. We don't dive 20 feet down underwater with a snorkel.

and that's because it's really hard to pull enough fresh air down that long pipe to get to our lungs. So this has been a big question about how very long-necked animals can pull in enough air down through that very long trachea.

and that's because it's really hard to pull enough fresh air down that long pipe to get to our lungs. So this has been a big question about how very long-necked animals can pull in enough air down through that very long trachea.

and that's because it's really hard to pull enough fresh air down that long pipe to get to our lungs. So this has been a big question about how very long-necked animals can pull in enough air down through that very long trachea.

Thank you very much, Mike. It's been a pleasure.

Thank you very much, Mike. It's been a pleasure.

Thank you very much, Mike. It's been a pleasure.