Problem solving and intelligenceEdit
Life adapts to different environments, so all what is hospitable to one lifeform may be inhospitable to another. Most documentaries about life in extreme environments focus on microbes, but there is more complex cases, including vent communities, deep abyss fish tolerating extreme pressures, mammals coping well with the radiation in Chernobyl, among others.
When the environment changes, howewer, it is not really hospitable to anyone. It is when the environment changes that evolution favors the ability to solve problems, and thus intelligence. There is archaeological evidence that the proto-human brain evolved during back-and-forth climate change. The most likely reason why other animals did not evolve intelligence is that their physical ability to manipulate their environment was very limited.
Apes only have their hands free a limited part of the time due to their mode of locomotion, and elephants only have one trunk (try MAKING, not just using, tools with only one hand, and discover how difficult it is). If the being cannot physically solve problems, then intelligence lacks practical survival value and are not selected by evolution.
Howewer, the fact that elephants have a humanlike number of neurons suggest that they may be intelligent anyway (and, by extension, that one hand is enough even for aliens to evolve intelligence). Their lack of complex culture may be due to the fact that their ancestors were spread across the world prior to becoming intelligent simultaneously in multiple places, making it impossible for them to avoid competition with each other. Proto-humans could, according to this theory, avoid competition because they became intelligent in one place (Africa) and spread out from there roughly 2 million years ago, (and of course it was important that they did not compete for the same food as the elephants). To test this theory, experiments analogous to the faliure cause investigation tests the chimpanzees failed should be adapted for elephants. If elephants pass the test, it means, in a cosmic sense, that one hand is enough to evolve intelligence (as long as it is free).
Other theories debunkedEdit
The theory of social intelligence cannot explain WHY some animals have relationships while others merely herd together. The most likely reason is that beings with minimal intelligence are easy to predict and behaviorally generalize about, while smarter beings invent new behaviors and thus need individual-to-individual relationships to be able to predict each others behavior. Intelligence provides a gradient of how complex the personalities are, so more intelligence makes each realtionship more complex (of course debunking Dunbaresque numerical relationship counting) But that means that intelligence is the cause of relationships and not the effect, so intelligence cannot evolve specifically for social purposes. Robin Dunbars Machiavellian intelligence hypothesis also makes the additional error of assuming that neural networks follow a causality between brain capacity and intelligence indefinitely, which they do not.
Sexual selection are extremely limited because it relies on one sex being pickier than the other for the eliminating selection process, and thus can only evolve gender characteristics, not traits common to both sexes. This is supported by the fact that in most species, males have to impress females, while in seahorses, where the males gestate, it is the reverse, and hermaphrodites such as snails lack mate-impressing ornaments and behaviors altogether. If the trait is only selected by sexual selection, or if natural selection exaggerates a trait that in a small degree is favored by natural selection but the exaggeration is a survival disadvantage, evolution will solve the contradiction by adding receptors for sexual hormones to the trait, making it vestigial in the picky sex that does not need to impress, and that evolution goes faster the greater the survival disadvantage of the exaggerated trait is. Unless NATURAL selection favors intelligence, a energy-hungry sapient brain and the behaviors that makes no biological sense which inevitably results from the instrumentality and versatility of intelligence are BIG survival disadvantages. If the picky sex should choose to select for intelligence, it would soon find itself unable to distinguish between the different levels of superior intelligence in the opposite sex due to its own inferior intellect.
This means that environments where intelligence evolves are not the most hospitable to anyone, and therefore the pessimist scenario about cosmic conquest of natives, based on the assumption that the worlds where intelligent life evolves is the most hospitable worlds in the Universe, is nonsense.