A Sentient Alien Species, if they exist, will likely look humanoid

At this time I will present my case. I will reserve rebuttals for round three.MY CASESentience implies, "the ability to feel, perceive, or experience subjectively." [1] What this means is that a sentient being is not merely rational, but emotional. In its common, colloquial usage, however, sentience oftentimes also encompasses an ability for higher order cognition.Let's consider the resolution. We are asked whether alien, sentient lifeforms will resemble humans. To answer this question, we need look no father than our own planet: Earth. There are many bizarre lifeforms on Earth that have come close to obtaining sentience. I will argue that the existence of such animals on Earth means that sentience could evolve in non-humanoid aliens elsewhere, because the evidence suggest that the qualities necessary for sentience: higher order cognition, the ability to feel, and the ability to experience subjectively (i.e. rudimentary emotions), are found in animals here on Earth already.I will talk about several animal groups in particular: Cephalopods, Porpoises, and Proboscids. I will show, through a variety of means, that animals in these groups exhibit higher order cognitive powers and/or emotion, which should be sufficient to make my point. Before I begin this analysis though, let's set some standard for the two criteria I intend to meet: (1) higher order cognition, and (2) emotion.Higher order thinking implies problem-solving in a creative or analytical fashion. If I am told or shown that I can break the shell of a coconut with a hammer, that is not higher order thinking, because it require no ingenuity on my part. However, if I deduce that hitting something hard against it might break it open, leading me to grab a hammer, I have engaged in higher order thinking. Perhaps we can summarize this to say that higher order cognition is the ability to think or problem-solve creatively.Emotion is a fairly clear concept, but to avoid any ambiguity, we can say that emotion is a psychophysiological phenomenon whereby someone experiencing it enters a specific mental state associated with each emotion (e.g. an empathetic mental state) and undergoes a physiological response (e.g. the release of adrenaline). CephalopodsCephalopods are an order of animals primarily composed of octopi, squid, and cuttlefish. Cephalopods have successfully undergone classical conditioning regimens, meaning that through a process of inducing pain or pleasure, scientists have been able to reinforce or disincentivize certain behaviors. [2] More importantly, however, Cephalopods have been reported to engage in observational learning and have a great spatial learning capacity. [2, 3] Why are Cephalopods so awesomely smart? One explanation is their encephalization quotient (EQ). The EQ "measures the size of a creature's brain against the size of the rest of its body, and compares this ratio to that of other species of roughly the same size." [4] Octopi have the highest EQ of all invertebrates. [2]Cephalopods are also noted tool users. Some octopi have been observed using coconut shells as tools--as shields from predators or as shelter for them on the sea floor. This type of behavior is highly complex and "involves picking up and carrying a tool to use later on." [2 - See Image] This seemingly creative use of tools to achieve various objects illustrates, in my opinion, higher order cognition. "Tool use has long been considered an indicator of rational thought because it involves complex cognitive processes, such as planning, problem-solving, and manipulating an environment." [5] Ultimately, Cephalopods are amazing little animals. Consider, "These creatures can navigate mazes, open jars, and modify their homes using found objects." [5] I believe I have demonstrated that at least some cephalopods meet the definition of higher order cognition I set out earlier.PorpoisesPorpoises, in a colloquial sense, refers broadly to all dolphins, whales, and porpoises. They are an eclectic, lovable, and enigmatic group of animals, whose intelligence, as determined by their EQ, is rivaled only by our own. In other words, they are probably the smartest non-human animals, surpassing even primates. Notice that dolphins lack the bipedality Pro argues is so key--as aquatic animals, they have no need for feet anyway. Let me start with perhaps the most amazing piece of evidence in favor of dolphin intelligence: they have a language. While this language is not comparable to human language, it does show evidence of a sono-pictorial communication system amongst a dolphin species that is, nonetheless, highly developed. [6] Moreover, a research "team was able to teach the dolphins simple and complex sentences involving nouns and verbs, revealing that dolphins comprehend elements of human language, as well as having a complex visual language of their own." [7]Dolphins are fantastic observational learners, are self-aware, are highly social, have demonstrated numerical continuity, have shown awareness of the future, have participated in cross-species participation, and--importantly--have "demonstrated the ability to produce creative responses." [8] The full creativity-inducing experiment can be read about here [8], but it is important to note that the "experiment was repeated with humans, and it took the volunteers about the same length of time [as the dolphins] to figure out what was being asked of them. After an initial period of frustration or anger, the humans realised they were being rewarded for novel behavior. In dolphins this realisation produced excitement and more and more novel behaviors--in humans it mostly just produced relief." [8]Dolphins have also bee shown to use tools [8], which, as noted earlier, is another hallmark of creativity. Thus, dolphins also seem to meet the standard of higher order cognition I set.ProboscidsProboscids are, very simply, Elephants. Perhaps one of my favorite animals out there, they are truly remarkable beasts. They can experience emotions in an almost human-like way. "Studies show that structures in the elephant brain are strikingly similar to those in humans. MRI scans of an elephant's brain suggest a large hippocampus, the component in the mammalian brain linked to memory and an important part of its limbic system, which is involved in processing emotions. The elephant brain has also been shown to possess an abundance of the specialized neurons known as spindle cells [which dolphins also have], which are thought to be associated with self-awareness, empathy, and social awareness in humans. Elephants have even passed the mirror test of self-recognition, something only humans, and some great apes and dolphins, had been known to do." [9] Experts have even concluded that, like humans, elephants can suffer from psychological disorders such as PTSD. [9] Elephants even mourn their dead and even display altruistic activities. [10]Besides having human-like emotions, elephants are highly intelligent, about on par with the porpoises. [11]The first conclusion we can draw from these three examples is that non-humanoid animals can develop high-level cognitive and emotional capabilities, and so there is no reason to believe that non-humanoid aliens could not develop such capabilities, and perhaps even develop them beyond those of the species I mentioned.I think also we can negate the topic in an entirely separate way. Let's consider the infinite potential for life--there are many diverse landscape throughout the universe, from nebulas in space to worlds caked in ice, where life could evolve. Life will adapt in such a way that it is best suited for the environment it lives in; not all such environments will lend themselves to humanoid shapes. What leads to intelligence, most experts seem to agree, is predation. [4] Hunters become smart in order to better hunt down and track prey. Prey sometimes becomes smarter to avoid predators, but usually evolves other mechanisms instead. But, nevertheless, as prey becomes more challenging to capture, predators become smarter and smarter. Therefore, I would conclude that in any environment or ecosystem where animals are capable of neurological or neurologic-like functions, and where predation takes place, sentience and, perhaps even, civilization is possible.And finally, the universe is a big place [12]--there are just so many possibilities out there, how can we reasonably assert that a sentient alien will likely take on one specific set of traits? That assumption in itself seems statistically unsupportable. Thus, I rest my case and turn things over to Pro.SOURCES1 - http://en.wikipedia.org...2 - http://en.wikipedia.org...3 - http://www.pbs.org...4 - http://dinosaurs.about.com...5 - http://academic.reed.edu...6 - http://wakeup-world.com...7 - http://www.speakdolphin.com...8 - http://en.wikipedia.org...9 - http://ngm.nationalgeographic.com...10 - http://video.nationalgeographic.com...11 - http://en.wikipedia.org...12 - http://www.space.com...