Question of the day

GeoffCapes

GeoffCapes

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Having just caught up on this I read on the plane back from Rome in a food section that Scallops have hundreds of eyes.
That's gotta be in with a shout.
 
JonW

JonW

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GeoffCapes said:
Having just caught up on this I read on the plane back from Rome in a food section that Scallops have hundreds of eyes.
That's gotta be in with a shout.
Click to expand...

Well done Mark! Scallops can have over 100 eyes, with each eye having a lens, an optic nerve, and a retina!
 
Slowly

Slowly

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JonW said:
Well done Mark! Scallops can have over 100 eyes, with each eye having a lens, an optic nerve, and a retina!
Click to expand...

Seems an unnecessary duplication (or centuplication perhaps!) of effort when the brain they feed with data is not going to have the processing power to deal with more than a very simple image. Still, evolution rather than a planned organism is just that, so weird anomalies abound. The recurrent laryngeal nerve is a good example. Both take an indirect route from the skull base to the larynx, with the left going right down into the chest to loop under the aortic arch before climbing back up into the neck, rendering it inconveniently susceptible to trauma during thyroid surgery or to being affected by disease in the upper medial part of the left lung. In the giraffe it is the same, so it travels ~15 feet further than it needs to to get to the larynx....
 
Navcorr

Navcorr

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Slowly said:
Seems an unnecessary duplication .... Still, evolution rather than a planned organism is just that, so weird anomalies abound.
Some kind of defence mechanism/strategy perhaps? If not with "improved" vision more the appearance of it.
The recurrent laryngeal nerve is a good example.... In the giraffe it is the same, so it travels ~15 feet further than it needs to to get to the larynx....
Interesting this indirect path has occurred across species. Does this nerve & routing exist in all mammals?
Click to expand...

The recurrent laryngeal nerve - what a fantastic question that would've been.
 
Slowly

Slowly

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Re indirect path - yes I think so, because as we've evolved from simple symmetrical segmented creatures (like worms) and, in the case of the aorta, as that structure has moved down into the chest, it dragged the L recurrent laryngeal with it. The giraffe is the most striking example because it has evolved such a long neck. Embryology often shows you evolution sped up billionfold as the embryo develops - the early embryo human is pretty symmetrical and has rudimentary gill slits separating branchial arches which then become things like the ear, jaw, larynx... and so on. Not infrequently bits get left behind and may appear later as e.g. pits in front of and slightly below the ear, often with rudimentary auricles, branchial cleft cysts a little beneath the angle of jaw, thyroid in the tongue or between it and its normal location below the larynx, and there are other reminders of our heritage like... well, I'll leave that for a potential question of the day.

If anyone is interested in evolution then a great and accessible book is "The greatest show on earth" by Richard Dawkins, marred only by his banging on about how misguided people are if they believe in religion -vs- evolution. He is as evangelical on that as any creationist, which seems unnecessary as I doubt that people who genuinely believe that the world was created in 7 days would be reading his books.

https://en.wikipedia.org/wiki/Recurrent_laryngeal_nerve
 
GeoffCapes

GeoffCapes

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14,000
You can find out all of this but finding a cure for poxy hay fever would appear to be impossible!
If I'm not up to my eyeballs in anti-histamines I'm sneezing constantly! :(
 
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