To go from 136 million in 1871 to zero in 1900 (the year the last passenger pigeon was shot in the wild) would have taken a phenomenal killing effort. At that size of population the reproduction rate must have been getting on for 100 million new birds a year, and every bird killed must simply created a better chance that next year's young would survive, because they would be competing for food with a smaller flock.

Granted, the nesting areas were relatively small and therefore subject to easy destruction, but two (related) factors should also be taken into account: disease and invasive species (which could well have brought diseases with them.)

Although introduced to late to be the culprit with respect to passenger pigeons, the common starling is an example of the massive effect invasive species can have on local ecologies. Furthermore, the massive changes to the prairie eco-system as the result of farming must have had an effect as well.

So while hunting and wanton destruction of nesting habitat obviously didn't help, it's interesting to ask, "Could the passenger pigeon have survived even without deliberate attempts to kill it?" The answer is not obviously "yes" (nor is it obviously "no", which is why the question is interesting.)

In this context it is worth remembering that the exclusion zone around the worst civil nuclear disaster in human history is far, far better for the local wildlife that simply having a thriving human population in the area: http://www.slate.com/articles/... (the article incorrectly states that observations of wildlife diversity around Chernobyl depend on the assumption that radiation isn't as bad for animals as humans, but this has causality backward: it is simply a matter of empirical fact, backed up by systematic observations carefully ignored by critics, that wildlife diversity in the exclusion zone is as high as that in protected nature reserve.)

But you're also concluding that if the machine does it as well as the human it is "really" a human intelligence, but if a man does it as well as a woman he is not "really" a man.

The basic premise of the test is, "If two unlike things behave alike in one case, we say they are the same; in the other case, we say they are different."

The premise of the test violates its conclusion.

Absolutely none of which is relevant to ride-share arrangements, but was relevant before a ubiquitous network allowed people arriving at airports to pre-arrange with a party on the receiving end, who has been vetted by an honest broker (Uber et al).

The ability to personally connect with the person picking you up makes rideshare services more like a buddy picking you up and you paying for gas than a traditional, anonymous taxi service.

tl;dr: Irrelevant rules are irrelevant.

None of those species developed the kind of representational, specifically human intelligence that builds spaceships and discovers universal gravitation. They "could have", of course, but as a poster up this thread has pointed out, we have left the hand-wavey philosophy behind and are now using the only way of knowing: the discipline of testing ideas by systematic observation, controlled experiment and Bayesian inference... this discipline is called "science".

We know of exactly one species that developed specifically human intelligence: us. There are tool-users all over the place. Tool-use is found in bonobos and birds. There are language-users of a kind as well: it would be astonishing if humans were so good at language if it wasn't an elaboration of capabilities that existed in our ancestors.

But what we do--specifically human intelligence, not the intelligence of beings who chipped flints into useful shapes or use sticks to capture ants or whose various articulations communicate a variety of important states--what we alone do is unique to us, and we are even beginning to understand why that is the case.

Obviously specifically human intelligence did not evolve to write sonnets or build spaceships, so it could not have been selected for due to its enormous problem-solving scope. Our brain uses 10% of our body's energy budget, which is a ridiculous burden, and it wasn't evolved against the possibility that one day it would be useful in the development of the political state. It was developed because it got us laid. Proto-human males and females were more likely to mate with partners who could entertain them, and being modestly bright themselves they found brighter partners more entertaining (this also explains why both males and females have the same intelligence, because both minds had to be engaged in the process for it to work.)

Quite accidentally, that resulted in our specifically human intelligence, which is not the intelligence of tool-using birds or communicative pack hunters, but the only kind of intelligence that builds spaceships and discovers mathematical laws describing reality (which is the only kind of intelligence the Drake Equation is concerned with.)

So all the actual evidence we have tells us that specifically human intelligence--not the intelligence of dolphins or whales--evolved:

a) by accident, as an epiphenomenon of sexual selection

and

b) exactly once.

Given the former, the latter is not surprising.

This is quite unlike every other complex characteristic of species. Eyes have evolved independently dozens of times (different types of eye use different biochemistry). Wings, likewise. Ditto fins. And so on.

So it is not at all implausible that the probability of developing specifically human intelligence of the kind required for a species to be detectable at stellar distances--a kind that is not found in any other species on Earth--is extremely improbable, even though life itself is extremely probable. And that is my personal bet, as we go out and explore other worlds: we will find life everywhere, and the specifically human intelligence that took us to the stars in the first place... no where.

[I've had this argument before, and am not under any illusions as to the ability of people who believe intelligence must be common to bring up imaginary "counter arguments", but what we can or cannot imagine has no bearing on what is real, only reality does.]

Not even close, because our conclusion about other humans is based on a huge amount of non-verbal communication and experience, starting from the moment we are born. AI researchers (and researchers into "intelligence" generally) conveniently forget that the vast majority of intelligent behaviour is non-verbal, and we rely on that when we are inferring from verbal behaviour that there is intelligence present.

Simply put: without non-verbal intelligent behaviour we would not even know that other humans are intelligent. Likewise, we know that dogs are intelligent even though they are non-verbal (I'm using an unrestrictive notion of "intelligent" here, quite deliberately in contrast to the restrictive use that is common--although thankfully not universal--in the AI community.)

With regard to the Turing test as a measure of "intelligence", consider it's original form: http://psych.utoronto.ca/users...

Turing started by considering a situation where a woman and a man are trying to convince a judge which one of them is male, using only a teletype console as a means of communication. He then considered replacing the woman with a computer.

Think about that for a second. Concluding, "If a computer can convince a judge it is the human more than 50% of the time we can say that it is 'really' intelligent" implies "If a woman can convince a judge she is male more than 50% of the time we can say she is 'really' a dude."

The absurdity of the latter conclusion should give us pause in putting too much weight on the former.

There's no real point in arguing with a gun nut, but I'll do so anyway.

You point out that the US has more guns per person. But the US also has (plausibly) seen a considerable drop in the number of people who own guns in the past 30 years: http://www.pewresearch.org/fac...

So triumphal ballyhooing about "proof" (never a good sign in someone who pretends to be arguing the data, which only ever increase or decrease plausibility) is a bit premature. It is at least as plausible that some types of violent crime have decreased because fewer people can lay their hands on a deadly weapon in a moment of anger or confusion.

When making a statistical argument (but I repeat myself) it is always important to dig into the sub-structure of the data. In this case, the distribution of gun ownership. In other cases, the kind of gun owned may be important: there is some evidence that the prevalence of handguns specifically are associated with homicides. Canada, for example, has comparable long-gun ownership to the US--and they are used for the same primary purpose here as they are there, which is to commit suicide--but far fewer handguns and a far lower gun-murder rate.

I'm just guessing here based on nothing but a few decades of involvement in the scientific community, but I'd say it's pretty likely that a) the scientists in question have thought of your objection already and b) they have quantified the relative contributions from increased grain size vs increased dark pollutants.

What would be incredibly stupid is assuming that people who study this stuff professionally can be out-thought by a random Internet commenter who has just encountered the question for the first time.

But just in case, let me ask you: what is the quantitative relationship between grain size and reflectivity of snow? Please respond with a graph or formula. You must have access to this information to judge the relative importance of grain size vs pollutant cover, and it would be a positive contribution to this discussion to share it.

"Todayâ(TM)s strict evolutionists are unhappy about Darwinâ(TM)s views, for even today he would be unable to provide a satisfactory explanation"

Pretty much everything he says about evolution is wrong, and this is utterly wrong, particularly with regard to the "transition fossils" question it seems to be referring to. There are plenty of transition fossils. It's simply not an issue any more.

Darwinian theory predicted that there would be transition fossils. In Darwin's day transition fossils had not been found. Today they have, in abundance. To claim otherwise is to divorce yourself from simple, ordinary truth.

Furthermore, the invoke God as the "simplest explanation" for the diversity of life is to claim that somehow God, who is by definition incomprehensible according to Scripture, is somehow "simpler" than a process that necessarily follows from the chemistry of carbon compounds and the laws of probability as we currently understand them: http://www.amazon.com/Darwins-...

Because of the degree of randomness in evolution by variation and natural selection, there are very few limits imposed by the incremental nature of the process. Random steps can take a locally deleterious feature a long way "up hill" in terms of fitness before it gets lost entirely from the population, and that process may well carry it over into a new local minimum that was deeper than the one it drifted out of.

That said, there are quite likely strong constraints on facial morphology that put limits on armouring. The human face is extremely important as a communications device, and remember: selection is driven by the differential probability of getting laid and creating successful offspring (where "successful" means... "getting laid and...")

So for example, blood flow in the face is a very important communications tool. There is reason to believe that the whole point of human's red/green colour acuity is so that we are maximally sensitive to variations in blood flow in each others' skins, particularly in the face. So variations that substantially reduced that already-subtle signalling channel would plausibly reduce the chance of those individuals getting laid.

Likewise, facial flexibility and mobility are important aspects of communication between humans (and likely proto-humans), and so on. Because we are by nature social primates, the effective communication goes beyond simple mate competition, too: the ability to form viable troops, work together cooperatively, etc, all will affect the individual's reproductive fitness, particularly when kin-selection is factored in (my genes will go on if my siblings and cousins are successful at mating, even if I am not, so my contributions to their success matters in the evolutionary process.) [Of course, there are also completely kooky speculative ideas about group selection, which are fun to play with: http://www.amazon.com/Darwins-...

Prediction is hard, especially with regard to the future.

Anyone posting on /. ought to be well aware of the long, long history of technical prognostications of exactly the kind you are posting here that turned out to be utterly, absolutely wrong.

I won't fault any of your numbers, but failure to acknowledge the role of serendipity in the history of science and technology is just a statement of your own ignorance, not a convincing argument. This is why public funding for things like fusion power is important: because the most corporate funding is based on a greedy algorithm. It simply heads toward the deepest local minimum. The history of science and technology--to say nothing of optimization theory--tells us that such an approach will miss a lot of interesting and important stuff.

And yes, this is a recipe for throwing away a lot of public money on things that a) won't work and b) can reasonably be expected to not work. Someone has to take those risks, though, if we are ever to get the benefits of the odd thing that does work, regardless of "proofs" to the contrary. The arguments against the viability of fusion, while significant, are not at the level of strength that suggests we shut the whole enterprise down quite yet.

Not quite. Because fusion reactors will contain mostly light elements, the waste produced will be almost all relatively short-lived (decades or years or less, not centuries). This is a huge benefit over fission, which necessarily creates a great deal of long-lived waste simply by virtue of neutron irradiation of heavy elements.

I do agree that fission (today) and fusion (in the future) are far better alternatives to base-load coal than anything else going, and get frustrated no end with self-proclaimed "environmentalists" who will do anything--absolutely anything--to stave off climate change except admit they were wrong about the risk-reward proposition on nuclear back in the '70's.

Science is the discipline of publicly testing ideas by systematic observation, controlled experiment, and Bayesian inference. The last one is important, because Bayesian inference never "proves" or "disproves" anything in the Cartesian (or Poperian) sense of those terms. It instead increases or decreases the plausibility of propositions.

At best, "proof" and "disproof" are convenience terms that mean "overwhelmingly plausible with no alternative that has remotely similar plausibility" and "hugely implausible regardless of alternatives."

The asymmetry that Popper pointed out still exists on the Bayesian view: an extremely plausible idea may turn out to be in competition with unknown alternative ideas (think Newtonian gravity vs General Relativity) that are incrementally more plausible. Newtonian gravity (in its modified form) is still fairly plausible (although I don't think anyone really accepts it is better than GR), unlike, say, phlogiston theory, which is utterly implausible.

This is important because it means we don't have to accept the "most plausible" idea as "true"--the Bayesian standard of plausibility is absolute, not relative. It just never reaches a value of 1.0, only 1 - epsilon (or conversely epsilon for a maximally implausible idea.)

Bayesianism is compatible with "I don't know" as an answer when all current ideas have very low plausibility, and with "This is good enough for going on with" when one idea alone has high absolute plausibility, and "Could be this or that" when two or more ideas have similarly high plausibilities.

Not exactly. One thing missing from the popular discussions of this question is why we believe that isotope ratios necessarily vary across all larger bodies in the solar system.

It is true that measurements on meteorites show different ratios from what we see on Earth, but no particular conclusion can be drawn from that. It certainly does not follow from "None of the people I measure are the same height" that "No two people anywhere are the same height", so it would be bizarre in the extreme to go from a sample of fairly odd, mostly non-planetary, space rocks to a sweeping generalization about what is necessarily the case across the whole solar system. There may be some theoretical reason for believing this to be the case, but I've never seen it mentioned in any of the articles on this subject.

Furthermore, Theia has a very, very special property: its orbit intersected that of Earth's almost instantly after its formation. This is not the case with meteors, which have been wandering the solar system for more than four billion years, and therefore likely formed in very distant regions. Theia almost by necessity formed in a similar orbit to that of Earth. We know this, because only a body that formed in a similar orbit would likely find itself in a collision with Earth almost immediately after formation.

None of this "proves" or "disproves" anything, mind, because we're talking about knowledge here, not faith. Knowledge is by its nature uncertain, and the quest for certainty is simply an error pursued by pre-scientific peoples (philosophers), no different from the alchemical pursuit of transmutation of base metals into gold, or attempts to build perpetual motion machines, or attempts to trisect angles with nothing but straight-edge and compass.

Which raises the burning question: why is anyone reporting user feelings rather than actual data to /.? It's the 21st century... surely by now everyone on here knows that how people feel and what is actually going on are almost completely decoupled.

Some people "feel" that wifi is interfering with their qi, even though the data show that no such effect occurs (that is, no one is able to tell if wifi signals are turned on based on such feelings.)

Ten years ago a surgeon I know worked on a study of post-operative pain in people with knee implants to see if different implants made a difference to patient outcome. While there were some objective measures (range of motion, etc) that showed a correlation with a suspect implant, simply asking patients about pain revealed only one thing: how much they liked their surgeon.

Psychology literature is full of things like this: it is an uncontroversial fact that what we feel is a lousy indicator of anything except our own internal state. Feelings are facts. They are just facts about us. While sometimes facts about us are important, they are a terrible gauge of anything else. Reporting feelings as if they were relevant to the actual edge a player has is exactly like saying, "My brother and my cousin--both big into gaming--use PC-style controls with their Xbox because the are both six feet tall, so they say this gives them an edge over users of the Xbox controller". "Being six feet tall" is a fact about them, just like "feeling it gives them an edge" is a fact about them. It is not a fact about the rest of the world (that is, their actual performance).

I'm being long-winded and pedantic about this (because hey, this is /.) but the parent was such a nice example of this extremely common failure mode in human thinking (confusing facts about ourselves with facts about the rest of reality) that it was too good an opportunity to pass up. That's how I feel about it, anyway...

That statement is false. Quantum mechanics deals explicitly with "identical particles", which are particles that are literally indistinguishable from each other, but are not the same particle. This is an empirically demonstrable violation of the principle of "identity of indiscernibles", which states that if two things are indiscernible any means whatsoever, even in principle, they are the same thing. Even though we have known this principle to be false for almost a century, philosophers still take it seriously for some reason.

There is a relatively simple proof that atoms of the same kind are indiscernible. The heat capacity of solids is a measure of how much the temperature goes up as you add energy to a block of material. The temperature is just the average energy per vibrational mode of the crystal lattice. The number of vibrational modes is intimately linked to the number of distinguisable particles in the crystal. N distinguishable particles have a different number of modes than N indistinguishable particles, so crystals will have a different heat capacity depending on which situation actually obtains.

This can be seen by considering a pair of distinguishable coiins vs a pair of indistinguishable coins. If we have two coins that are distinguished by the labels A and B, we have four ways of arranging them by which face is showing (H for heads, T for tails): AH/BH, AT/BH, AH/BH, AT/BT. If they are not distinguishable we only have three states: H/H, H/T, T/T because there is no way to distinguish AT/BH from AH/BT when we remove the labels.

So by a simple macroscopic measurements like the heat capacity of crystalline solids we can prove positively and directly by experiment that atoms of the same kind are in fact indistinguishable, and that the principle of the identity of indiscernibles is false. It is not false "for quantum particles" but false, absolutely--it just happens that quantum particles are the only case we know of where different particles are genuinely indiscernible from each other. But there is no limited domain of application to this result, and philosopher's attempts to treat it as somehow restrictive to the quantum domain are simply misguided (it turns out that the identity of indiscernibles being false makes nonsense of a bunch of other things philosophers want badly to believe, not least of which is how utterly useless the human imagination is in deciding what is and is not true of the world.)