Is one intelligent species the norm for a planet?

[Mighty mouse]

I wander what the probabilities of two or more intelligent species developing on a planet are?

Leaving aside the question of animal intelligence I guess that I find it odd that other animals have not gone on to evolve like us. Any biologists out there?

[Curt Chiarelli]

On our world man may be the dominant life form, but hardly the only intelligent one. Man is not separate from the rest of the animal kingdom (as the Victorians promulgated), he is a part of its continuum.

Therefore the cetaceans, with their sophisticated means of communicating across vast expanses of ocean would be an excellent candidate to join the club. Likewise, simians have shown a capacity for language and regularly implement tools in their acquistion of food. They too would be considered intelligent.

Essentially, if you analyse it, the only reason why man has become the technological creature he has is because of opposable thumbs (courtesy of an erect spinal column), vocal chords capable of speech and an enlarged braincase whose rapid, cross-generational development was stimulated when the species altered its diet from roots, plants and tubers toward animal protein.

That other species would be divergent in their evolution is a function of their unique morphology. Also, we need to consider the fact that man would not tolerate any close competitors for their food source. In all likelihood, he would kill off any species whose resourcefulness threatened his own.

Bear in mind that man's is only one kind of intelligence. It would be a mistake to dismiss the other varieties forund in other species in the animal kingdom.

[Rane Longfox]

Considering that theres only one inhabited planet we know of... yes, it's very much the norm!

[pyan]

But it must be remembered that H.sapiens being the only "intelligent" species on the planet is a very recent, geologically speaking, occurrence. Up to about 30,000 years ago, we shared Earth with H. neanderthalis, and before that, there were many other varients of Man all existing in pockets around the world. In fact, there is evidence that neanderthalis was, in fact, more intelligent than sapiens, just not as good at killing each other.

[Parson]

Originally Posted by pyanfaruk

In fact, there is evidence that neanderthalis was, in fact, more intelligent than sapiens, just not as good at killing each other.

That must be a minority opinion! I've never heard or read anything like that. As far as I can tell the large majority opinion is that neanderthalis was less adapatable as far as creating tools and techniques to meet changing climatic and social changes. Secondly, there is little to no representative art or progression in tool making. All of which together would be a pretty fair estimation of the level of intelligence.

As to the original question we would need to understand what level of intelligence/development is needed to be considered an "intelligent species." If one means present human development or its rough equal, the logical answer would be 1, given something like humanity use of natural resources. But earlier deveopment (see pyanfaruk's post) no obvious limiting number presents itself. If we can project a future development where science has mostly solved the limited natural resource barrier, we could well have multiple "intelligent species" with technical ability.

[Milk]

Ive read in many places that the neanderthals did actually have larger brains, which might mean greater intelligence, but I really doubt it. I would think its more the greater density of nerve clusters in the brains that carries the intelligence not the size of the brain itself. Then people float around the ole "we use ten percent of our brains part" well Im gonna guess that some of that extra brain we apparently dont use is spare brain..to be used in case of injury. Parts of the brain have been known to take over for other parts. Im not saying this always happens in an injury, just that it is possible.
So neanderthals having had larger brains might be atributed to them having had the ability to survive greater head trauma over being smarter.




Like those railway spikes going through brain tissue, but the person survives.

In any case there is a lot of controversy still over whether neanderthals were assimilated (interbred) into sapien sapien or if we killed them off, or simply that when the ice ages ended, our branch was better adapted to the hotter climate.


Probably all three.
Heres an example.. infant mortality rate was probably enormous back then. A homo sap group kills off most members of a neanderthal group because of competition for resources that were dwindling because the ice age was receeding.. but they see value in adopting the neanderthal children since their own babies die so often. Those neanderthal children grow up within the sapian tribe and interbreed with them. Repeat and rinse. Killing, interbreeding and a receeding ice age.

I do think that as a species there is a sense of being lonely, which might be why so many people make up stories about meeting elves or aliens or sasquatches. And why Science Fiction and Fantasy is so popular.

[Urien]

The point being I guess that there were two intelligent species on this planet at one time. By most consideration neanderthals were not as intelligent as us, but very much smarter than the other animals.

Also were the neanderthals a different species to us or just a variation on the theme? There are many different types of finches, but they're all finches.

[chrispenycate]

The traditional definition of "species" involves reproductive capability. If two members of different groups can produce fertile offspring, they are considered part of the same species even if their appearances differ. The various families of hominids might or might not have been species, or subspecies. It's fairly obvious that the remaining hominids are cross-fertile, thus only one species remains that took that particular rout to sapience. The others might have been bred in, or massacred, or hung around until recently masquerading as elves; they're not around now.
What one uses as a yardstick to define the intelligence of other species will change the results; IQ tests don't even work across cultural barriers, let alone species. If we had an intelligent octopus, or an intelligent fungus, how would we ever find a concept base to transfer information and, before all, recognise that the possibility of communication.
Finally, can we put a sharp limit line---intelligence; nine tenths of humanity are above this standard baseline, therefore we define humans as intelligent and chimpanzees, who might only have one individual in a thousand above it, they are non-sentient.
Still, if they are not in direct competition for resources, at least until they've developed a sophisticated social morality, I see no reason why several species can't develope intelligence as a survival characteristic; after all, most other ecological niches got filled by the local version of the global model: maybe a marsupial in Australia, a placental mammal in Eurasia, a lizard or a flightless bird somewhere else; Pehaps it's our tendency to travel which allowed us to wipe out all potential competitors before they became dangerous.

[pyan]

Originally Posted by Milk

Ive read in many places that the neanderthals did actually have larger brains, which might mean greater intelligence, but I really doubt it.

This is what I must have read. Sorry, Parson, my memory ain't what it used to be!
I do remember, though, and can reference that the HH.neanderthalis/sapiens interbreeding theory is unlikely.

BBC NEWS | Science/Nature | Blow to Neanderthal breeding theory

Neanderthal DNA Shows No Interbreeding With Human - Health and Medical Information produced by doctors - MedicineNet.com

[Parson]

Finally, can we put a sharp limit line---intelligence; nine tenths of humanity are above this standard baseline, therefore we define humans as intelligent and chimpanzees, who might only have one individual in a thousand above it, they are non-sentient.

I had never thought of that before.

Last night I was watching my 15 mo. old grandson solve the problem of getting into the rocking chair, by righting the foot stool and shoving it over the chair so that he could use it as a step and climb into the chair. I remember thinking how I could see him progressing in intelligence, but I would guess that at least some chimps could solve that problem as well, and a few highly trained chimps seem to have very rudimentary communication ability with humans. So.... is a two year old human intelligent and a high end chimp not?

[Milk]

Ive always been curious about Giant Squid being contenders for the 2nd major sentient lifeform on Earth.

Octopi and Squid are amazingly intelligent. They use tools, and solve all kinds of problems in labs. That ole "such and such animal has the equivalent intellect of a 3-year old child" thing was put on them like it was with Parrots and a number of other animals in varius articles Ive read---which is a statement used on animals Ive never understood anyhow.

Okay granted they are some of the smartest beings in the oceans, the least is known about Giant Squid.. With the least being known about them this gives more leway for some extreme facts concerning their intellect.

So maybe they could be much smarter then we know of. They have the largest eyes of any animal (their eyes are actually a lot like human eyes but as big as dinner plates which is really weird), and senses and the brain are tied closely together.

[Urien]

I remember the old texts "Book of Arion: Third Artec of Atlantis." The Atlanteans wrote once of a long ago war with the Parrotsquids of Mu.

... "And lo 'twas as though assailed by a many tentacled army of three year olds, even now my mind is haunted by their battle cry 'polly want a cracker.'"

[Delvo]

Neanderthal brains were bigger because it apparently takes a bigger brain to handle a bigger body; what determines intelligence is how the species's brain size relates to its total mass. Different methods to try to calculate a number for this have been proposed, from straight ratios to ratios with exponents invovled to simply subtracting the body-operating parts of the brain and comparing sizes of the leftover "extra" (roughly, comparing cerebram but leaving the medullae and cerebella out of it). The latter is meant to compensate for problems with a ratio-based approach, such as the shrew, which has a higher ratio than humans but isn't very intelligent because it doesn't even have an ounce of brain in all, nevermind in the cerebrum alone. Elephants, meanwhile, could have several "extra" pounds of cerebral tissue above what's needed to operate their bodies, and the difference wouldn't make much of a dent in their brain/body ratio.

* * *

I'd expect it to be rare for a planet to have two independent developments of intelligent, technological species, just because I consider it unlikely for even one to develop, and if you square "unlikely" you get "even less likely".

Earth has had large vertebrates on land for hundreds of millions of years. It's even had large, warm-blooded ones on it for over two hundred million. Some people would say that "large, warm-blooded, and terrestrial" is too restrictive a set of minimum requirements for intelligence and intelligence could arise in other kinds of lineages than that, but even by that limiting standard, it still took a ponderously long time for us to come along; expanding the "minimum standard" would only mean it was even more noteworthy how long this planet took to produce an intelligent species despite abundant opportunity.

Why? Because there's nothing that compels it to happen, no reason why it should be expected as an axiom, no reason why animals can't just go merrily along their worlds' histories without it. The fact that it happened eventually in our case involved a series of unlikely coincidences that could very well not repeat themselves on other planets

What you could get is more than one related species of a limited group, such as Earth's homonids, with some level of intelligence and technologicality (yes, I did just make that up). But that would still really only mean it happened once and just split afterward and they're all really just variations on a theme, and the resulting species would probably be similar enough to each other to compete with each other until only one is left anyway (as it happened on Earth).

[ray gower]

The only logical answer is ultimately there can only ever be one 'Intelligent' species on a planet.

Two intelligent species evolving would inevitably create competition for resources. As resources dwindle or become more desirable then argument and warfare result, which ultimately is why Neanderthal Man lost out. He was hunted out by more hostile forces

[Curt Chiarelli]

Originally Posted by Milk

Ive always been curious about Giant Squid being contenders for the 2nd major sentient lifeform on Earth.

Octopi and Squid are amazingly intelligent. They use tools, and solve all kinds of problems in labs. That ole "such and such animal has the equivalent intellect of a 3-year old child" thing was put on them like it was with Parrots and a number of other animals in varius articles Ive read---which is a statement used on animals Ive never understood anyhow.

Okay granted they are some of the smartest beings in the oceans, the least is known about Giant Squid.. With the least being known about them this gives more leway for some extreme facts concerning their intellect.

So maybe they could be much smarter then we know of. They have the largest eyes of any animal (their eyes are actually a lot like human eyes but as big as dinner plates which is really weird), and senses and the brain are tied closely together.

Yes, as far back as I can remember I've had a fascination with Architeuthis dux, ever since I saw one give good Captain Nemo a run for his money in Walt Disney's adaptation of 20,000 Leagues Under the Sea.

I've always maintained that after our species destroys itself through global warming and Reno, Nevada becomes beachfront property once again, the dominant lifeform on this planet will become the giant, sapient cuttlefish - not, as it is usually (and jokingly) assumed, the cockroach. I can tell you right now, if one of those critters breaks into a submerged National Guard armoury mankind's not going to be the only extinct species on this planet - it's going to be the Sperm Whale, too.

Who knows what they're up to down there in the black, briny depths? Making little baby squids to swell their ranks . . . . slowly and surely plotting their vengeance . . . . the occasional game of backgammon to relieve the tension . . . . and waiting, biding their time with infinte patience for their day of reckoning . . . .