Cognitive biologists from Emory have recently issued an impressive survey of the anatomical and behavioral evidence for intelligence among dolphins and whales (and maybe porpoises?). You can link to it from the title, and should read it, but before I go much futher down this thread, let me give you the upshot:
I added the following language:
"Dolphins exhibit a range of behavior consistent with higher order consciousness, including knowledge of syntax, vocal imitation, and complex social grouping. Moreover, the physiological evidence is similarly consistent with a capacity to perform high order cognitive thinking. For an impressive survey of the cognitive biological literature, consult http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1868071 .
In most cases, it is entirely appropriate for policy makers to consider animals as resources. In the case of dolphins, it may not be sufficient to conserve them as a population; a strong ethical argument can be made from scientific sources that they have a moral entitlement to protection as individuals."
to cyber pro-dolphin petitions and letter writing campaigns, which you can link to in subsequent posts (sorry for the techological putzery, still working on the embedding link task, my own capacity for higher order thinking may be in question).
Marino and company have indeed produced an impressive survey of quite varied evidence -- anatomical, experimentally driven behavior in captivity, and behavioral evidence in the wild-- that cetaceans are capable of some form of higher order cognition. A number of environmental thinkers have produced persuasive arguments about the immorality of extinction, and a moral duty owed to the elements of the environment generally. If you go for them, you have embraced an argument for protection of the population generally, an argument for making sure that their overall numbers do not approach zero, and that they are allowed to flourish as beings in an environment that we do not have a right to manipulate without limit. Personally, I don't really go for them -- extinction produces sadness and a sense of waste, and there are strong utilitarian/human centered reasons to be against wastefullness -- but this is not the same as the kind of moral duty we owe to other humans.
A moral duty to consider the consequences of our actions (or inactions) on other people, however, must come from somewhere, and in my mind the answer is a nervous system. We do not know exactly what produces consciousness, but it sure seems to have an awful lot to do with the neurons that can send information into complex processing centers. I dont eat animals or participate in their death or torture, but neither do I regard them as the moral equivalent of human beings, because of the limited order of consciousness they exhibit. Once a certain level of self-awareness has been reached, however, killing becomes a profound act, the extinguishment of an independent perceptual universe, an event the object of killing can fear and contemplate, and with which we can and should empathize. Feeling creates a right not to suffer; feeling with greater acuity creates a stronger right not to suffer; thinking, at least thinking about the self, creates a right not to be killed.
There is an alternative viewpoint, associated with abortion opponents, opponents of euthanasia, and opponents of animal rights, that locates the source of moral value in humanity. Respectfully, this position is simply not intuitive, and confounds a descriptive account of human behavior with a set of normative principles. I know that individualized experience is good because I experience it, and I like it, and want it, and can feel, implicitly and directly, its identity with value. While individualized experience has great overlap with humanity, humanity is neither a necessary nor a sufficient condition for experience, particularly the experience of self-hood. Dead bodies have no experience, and while there are good reasons, perhaps spiritual reasons, to treat them respectfully, I suspect few of us would have much difficulty choosing between allowing harm to come to a live and a dead human. Moreover, treatment of humanity as valuable in itself -- independent of its capacity for consciousness -- is either without logical support or dependent on larger principles that are problematic in themselves. That is to say, either the notion that humanity is the reference of value is completely empty, or it leads more generally to the conclusion that we should treat humans well because they are like us. We have seen where likeness to self goes when it is treated as the source of value, indeed we have exhibited an ugly propensity to label virtually group we (and by we I mean "Europe" but probably also humanity generally) wish to abuse as not quite human.
Now, if you agree with me that all creatures that exhibit sufficiently complex patterns of neural activity as to achieve a threshold of self-awareness are worthy of moral weight, you should really consider the case for elevating cetaceans (dolphins and whales, and maybe porpoises) above this threshold.
Marino points to:
Experimental Behavior Evidence, including:
1. They exhibit mimicry, both vocal, which is useful for complicated patterns of social organization, and bodily.
2. They exhibit not just semantic understanding (the capacity to associate a sound with a meaning) but also, I shit you not, syntactical understanding. I actually have read the Herman studies that Marino cites, and they exactly what Marino says they do. The sound for ball followed by word for hoop can, to a dolphin mean something different than sound for hoop followed by sound for ball (bring the ball to the hoop vs. bring the hoop to the ball).
3. Their semantic skills extend to events as well as objects.
4. They can identify themselves in a mirror, a skill previously seen only in some primates and elephants.
5. Unlike most other mammals, they can understand the significance of pointing and gaze, specifically that it refers not merely to a direction but to an object.
6. Dolphins can themselves point, either by echolocation or, if trained, by orienting a portion of their body.
7. Dolphins can understand, in abstract terms, the difference between repetition and non-repetition of a behavior, independently of the behavior itself.
8. Dolphins can even relate their knowledge about certain conditions, using pitch if trained to do so, in terms of their certainty about it, certainly a behavior that practically screams self-awareness if ever there was one.
Behavioral evidence in the wild:
1.Dolphins exhibit culture, both linguistic and behavioral, and can spontaneously learn the culture of another grouping. Some of this is directly related to food gathering, but other is simply the spontaneous use of the body for play and social relationships, without a direct relationship to safety or sustenance.
2. Like their human counterparts, especially those on the right (/snark, /hypocrisy), they can express group loyalty, and can form alliances between groupings.
3. A variety of non-vocal communicative acts accompany vocal exchange, including flipper touching, flipper orientation and gesturing, and something called "teeth raking." (I would love to see those off the coast of Sicily, surely they must be among the most gestural).
4. Most suggestively, the significance of the sequence of auditory emissions is retained in the wild and, Marino points, auditory emissions evolve over time. Surely a species exhibiting vocal behavior this similar to human language in the wild cannot be totally lacking in self-awareness.
5. Dolphins can teach each other foraging behavior.
6. Dolphins can use tools e.g. sponges to scrape crevices of the ocean.
1. Their brain size is comparable (bigger in fact) than every other candidate for higher order thinking, in both absolute and relative terms with respect to the overall mass of the body, and it evolved at a time when environmental pressures would have predicted a reduction in brain size in the absence of some ecological advantage.
2. The architecture of the brain is segmented to a degree comparable with that of other higher order primates.
3. Those aspects of the brain responsible for "attention, judgment, intuition, and social awareness" in primates are expansive in the cetacean brain, albeit in different regions.
4. The particular cells (large layer V spindle neurons) thought to be responsible for neural networking and complex awareness are expansive in the cetacean brain.
This shit, in short, adds up.