The place for everything else

(1) I would guess a bull African elephant for land, and maybe a sperm whale for sea.

(2) I know there are a few animals with greater brain/body ratios than humans, but I'm not sure which animal has the greatest. Maybe an ant?

I agree with the answers to (1). Good if recollection, impressive if guessed from scratch!

The contenders for (2) are small mammals, with some mice and shrews having a ratio of over 10%. A good source suggests that mice win, rather than shrews as I thought earlier, but obviously it depends on the species and I think the answer has some uncertainty.

A remarkable demonstration of a specific type of intelligence in chimps is this video from a Nature article.

[Interestingly in Douglas Adams' The Hitchhiker's Guide to the Galaxy, man was the third most intelligent species on Earth, with dolphins second and mice first]

Such were common lunch questions in grade school. Sorry, I didn't know we were limited to just mammals for (2). I've heard that mice have a higher ratio than humans but I thought dolphins had a ratio just below humans.

hi

Hi back to you :)

How big is a roch? Or did you mean the mythical bird known as a "roc"?  Anyhow, I was honored by your guess for (2) even if lions brains are not very big compared to their bodies (1/550 according to this source).

strangequark, the question was not limited to mammals, but most other classes of animals have tiny brains. Even birds don't really compete. If I recall, insects typically have tens of thousands of neurons in their brains, which is really, really tiny, even in comparison to body size. Most "lower" (i.e. very old) classes of animal tend to have very small brains. Eg sharks, reptiles, snakes. Birds are an interesting class, as they exhibit a lot of intelligent behaviour, but mostly have quite small brains. Their brains may be more efficient than ours (as in some ways their metabolisms are) due to a long development mostly under the weight constraints of flight.

Oh, and yes, the ratio for dolphins is lower than humans, because their bodies are quite large. Just shows you can't rely on comedy science fiction as a source of data.

Yes. And they would have to protect us from their airborne fishing nets, as they gathered in a catch of buffalo.

ok, another very interesting question. A bit of preamble first.

Humans live unusually long compared to most animals (but not as long as some), but this comparison is greatly distorted by the fact that some animals live faster than others. For example, giant turtles live pretty slowly. To be quantitative, animals have widely varying specific metabolic rates, which is the amount of energy used per unit mass, per unit time. The product of the specific metabolic rate and the lifespan of an animal gives a good indication of how long it lives allowing for the speed at which it lives. For example, if a mouse has a specific metabolic rate 14 times that of a human and lives 3 years, then you could say it effectively lives for 42 years. [Incidentally, doggy years are substantially less than 7 human years, even for small dogs]

The question is which animal has the longest corrected lifespan (i.e. product of lifespan and specific metabolic rate)?

It's my fault for not explaining well enough if you don't understand the question. Each animal burns a roughly fixed amount of energy per kilogram per day (we humans need perhaps 30 kiloCalories of food energy per kg of body mass, for example). We are looking at the comparison of the product of this and the lifetime for different animals, which essentially says how much they live (the product of how long they live and how fast they live).

In general, cold-blooded animals have much lower specific metabolic rates than warm-blooded animals. This is actually obvious, since most of the energy from metabolism is wasted as heat (c. 75%) and if an animal produced as much heat per kilogram as a warm-blooded animal, it would be warm. The definition of cold-blooded is not being able to keep the core temperature high when outside temperatures get low. In fish, tropical fish have 6 times higher SMRs than polar fish, and this direction is a general one. Therefore sturgeon, being cold water fish, aren't going to feature - they just live long and slow.

As a hint, I am aware of one mammal that lives about 3 times as much as humans by this comparison, but I am not sure it is the winner. I am aware of another non-mammal which gives a number close enough to not be sure which wins.

I know that birds and bats have high metabolic rates and often have a strong lifespan in terms of years as well but I can't think of any specific one that is the best. Birds generally live longer than mammals of equal size, and trade offs between energy expenditure and longevity have not been found (the embryo growth is different). In general long living birds have a higher metabolic rate than shorter living birds, making the final effect in this scenario a bit greater I think.

Would anyone here happen to know of any links to articles trying to mathematically disprove the possible extraction of real-world probabilities derived from the Schrodinger equation alone (that is, a many worlds scenario)?

Bats, good idea, didn't think of those. They are rather like flying mice, and flying creatures generally have high metabolic rates. For one thing the breeze helps them avoid overheating. Interesting (and surprising) point about long lived birds having higher metabolic rates - I've never heard this, but my favourite is small, high matabolic rate and lives long.

I have occasionally pondered many worlds calculations, and have been sufficiently bewildered to have never looked at a paper on it. Do bear in mind Schroedinger's equation is a similar rough approximation to Newtonian physics. The truth lies in relativistic quantum field theory.

I have not taken an official position in regards to quantum mechanical interpretations but I do not like the MWI. I wish to know more about GRW but I am also trying to explore MWI more.

Hmm they don't exactly have a nervous system, the earliest that do have such are the notochords on chordates (I think), and waterbears are far more primitive than that.

Water bears? You tell me - never even heard of them! strangequark, I assume he was suggesting them for the "corrected longevity" question. I suppose some asexual creatures that are considered immortal would win, really, but that seems like cheating.

I'm surprised that you've never heard of water bears (perhaps there is a different colloquial name in England?), but that's fine...although when we talk about asexual creatures being immortal we don't really mean that the individual organisms are immortal, it's more of a misnomer. Water bears can survive for a long time in stasis (50 years or more I think), but this would be cheating because their metabolism is turned off during that period.

That's quite fine, Kobe! It is true that I don't know the exact lifespan of water bears.

water bears seem to be a good example of the need for the correction. They effectively hibernate (the reason for their name?), which slows down their metabolism almost to a stop. This is allowed for when correcting the lifespan. Otherwise the winner would simply be anything that can survive freezing to absolute zero, with it being kept there for a very long time.

The question was mainly aimed at large complex creatures. Asexual creatures' cell lines are essentially immortal in the sense of maximum lifetime, although they do have a finite average lifetime (as they divide, but don't expand infinitely). But it makes sense for any creature where the lifetime of an individual has a clear starting point.

If you look at paragraph 2 of this paper you will find data which can be used to derive estimates of specific metabolic rates for fish. The front page of this paper is where I found the fact that tropical fish have 6 times higher metabolic rates as well - shame I can't read the rest of it, but not bad anyway!

Comparing, the textbook resting VO2 for humans is 3.5 ml/kg/min = 210 ml/kg/hour = 0.3 g/kg/h = 0.0094 moles/kg/h

By comparison, the formula for fish says a 7.5kg Koi (such as 215 year old example ) would have a specific metabolic rate of 0.0029 moles/kg/h. So if it had been a similar size most of its life (reasonable assumption), its age would be corrected to 215*0.0029/0.0094 = 66 human years.

So Koi do compete with humans, but they are a long way short of creatures that beat humans by about 3 to 1 (the mole rat and some long-lived small birds are the best examples I have found)

[I'm impressed by the picture of young Kobe looking at water bears through his microscope! Did they move fast when magnified?]

It's interesting to see the biologist side of you, Kobe: it's nice!