Dolphins

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Dr Jekyll

Original Poster:

23,820 posts

268 months

Monday 21st July 2014
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Why are dolphins smart? To be more specific, what evolutionary advantage did smart dolphins have over thick ones and why did this not apply to fish?

Hackney

7,022 posts

215 months

Monday 21st July 2014
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Something to do with being mammals perhaps?

Shaolin

2,955 posts

196 months

Monday 21st July 2014
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Dolphins use many types of fishing behaviour which are co-operative and require complex communications. They think up the behaviours and then work together, this all seems conducive to evolving intelligence as a survival technique. Similar to man in some ways as not the biggest, fiercest, fastest or best armed animal, but able to out think both predators and prey.

otolith

59,153 posts

211 months

Monday 21st July 2014
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A few things spring to mind - cetaceans are evolved from terrestrial animals, so they have at times been subject to different selection pressures than fish. They are also large, long-lived social animals with extended care of offspring. There are fish which care for their offspring, but even they tend to invest less in their brood than mammals do.

All of the examples of unusually intelligent animals I can think of are homeotherms ("warm blooded" animals which maintain a constant core temperature). Reptile, amphibian and fish brains are less complex than those of mammals and birds. Perhaps a variable body temperature is inimical to evolving a large and complex brain. Perhaps you just can't run an efficient brain at room temperature. A big brain is an expensive thing to run - but perhaps it is less of a cost to an animal with a much higher metabolic rate to begin with.

Shaolin

2,955 posts

196 months

Monday 21st July 2014
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There is a limit to brain size if you come out of an egg, so mammals already have an advantage in that regard.

anonymous-user

61 months

Monday 21st July 2014
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I watched a program on YouTube where the US navy have tought dolphins to carry tools, patrol harbours, plant mines, and incredibly shoot enemy divers using a weird gun type arrangement that fitted on their snout.

Dr Jekyll

Original Poster:

23,820 posts

268 months

Monday 21st July 2014
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Shaolin said:
There is a limit to brain size if you come out of an egg, so mammals already have an advantage in that regard.
Generally yes, but crows and magpies have relatively as big a brain as chimps and dolphins.

Simpo Two

87,122 posts

272 months

Monday 21st July 2014
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Dr Jekyll said:
Why are dolphins smart? To be more specific, what evolutionary advantage did smart dolphins have over thick ones and why did this not apply to fish?
Communication perhaps?

Perhaps if the apes had developed speech things might have been rather different - but even the smartest chimp can't say words, they just don't have that part of the brain.

uk_vette

3,336 posts

211 months

Monday 21st July 2014
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Dolphins have two brains.

When they sleep, they shut down one brain, leaving them half awake, in case any predators.

Vette

Shaolin

2,955 posts

196 months

Monday 21st July 2014
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uk_vette said:
Dolphins have two brains.

When they sleep, they shut down one brain, leaving them half awake, in case any predators.

Vette
One with two sides (like all mammals). The resting half at a time is interesting though. Birds can do it to some degree too while migrating, go on autopilot and keep flapping while having a snooze.

otolith

59,153 posts

211 months

Monday 21st July 2014
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I've had co-workers like that...

Hooli

32,278 posts

207 months

Tuesday 22nd July 2014
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otolith said:
I've had co-workers like that...
Lucky you, most my co-workers only seem to have the sleeping half of their brains.

otolith

59,153 posts

211 months

Tuesday 22nd July 2014
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Mine had half in sleep mode and half in flapping mode.

Gandahar

9,600 posts

135 months

Thursday 24th July 2014
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Dr Jekyll said:
Why are dolphins smart? To be more specific, what evolutionary advantage did smart dolphins have over thick ones and why did this not apply to fish?
How smart is it though?

What about an octopus? Which is a cephalopod rather than fish
or mammal.

What is the ratio of brain power of a dolphin compared to an octopus?

And why are both smarter than people who bought SUV's when a nice sensible estate car would have suited them better?