What type of biological life will more than likely be found on other planets?

Hi, Jar. I don't know. At first glance, I would have to say that it doesn't seem like they could. But, from my understanding of the evidence, they very well might have.Hominins (Homo heidelbergensis and Homo antecessor) are known from Europe from around a million years ago, which is at least half a million years before use of fire became very widespread.And, I have no idea whatsoever when clothing was invented, but, if Wikipedia's article on clothing is to be believed, clothing is very likely less than half a million years old.So, neither of these seems particularly strongly tied to either the first wave of hominin expansion (ca. 1.5 million years ago) or the recent wave of Homo sapiens expansion (ca. 50,000-100,000 years ago).

Hi, Catholic Scientist. Echinoderms reverted to radial symmetry: the larvae are still bilateral, but the right side is absorbed back into the animal, and the left side develops into the radial animal we know (starfish, sea urchin, etc).

Hi, Jar. No, I don't. But, you didn't say "humans" or "Siberia": you said "hominids" and "Ice Age areas." The only hominin I know of from Siberia is the Denisova hominin from around 40,000 years ago, which is well after the invention of both fire and clothing. So, yes, I agree with you that humans were probably able to reach Siberia largely because of fire and clothing.But, as I already pointed out, hominins apparently expanded into other areas (even cold areas, like Europe) long before they had clothing or control of fire. That tells me that fire and clothing are not the only drivers of hominin expansion. Fire and clothing certainly don't explain how hominins expanded into tropical Asia, Australasia or Central America.Remember, my argument is that the key to human expansion is the ability to invent new technology and new tactics to meet new challenges in new environments. So, in some cases, like Siberia, clothing and fire were the key to success in their new home; in other cases, new tool-making techniques were the key (e.g. Clovis); in other cases, it was discovery of new types of food (e.g. fish on the sea coast, fruit in the jungle, horses on the steppes, etc.); in yet other cases, it was rafts or canoes (e.g. Indonesia).Humans were successful in so many different environments because we could change our technology and our lifestyle to match whatever environment we expanded to. We could do that because we are intelligent.

Hi, Jar.It seems to me that, if you're not in total control of the flow of discussion, then we can't get anywhere. I'm perfectly happy letting you dictate the conversation, but, like Catholic Scientist said, it's kind of frustrating for me. To me, it doesn't seem like this is particularly complicated, but you keep getting lost at every step.Look at this: I don't understand where this comment is coming from.My point was pretty simple:

1. Humans expanded into both cold regions and tropical regions.
2. Humans developed some technologies to help them survive on the cold steppes.
3. Humans developed other technologies to help them survive in tropical rainforests.

So, we were able to develop two different tool sets for two different environments.Are you with me so far?Edited by Blue Jay, : "list" code

Hi, Jar. And, the frustrations continue to mount. I understand that you have a point that you really want to get across, but, in order to get there, you have just kind of deflected all the counter-arguments I have been making. I thought the whole point of a slow-walk process was to isolate the point of disagreement and deal with it.Now, how about a substantive response to my counter-argument? Intelligence makes it possible for us to invent new technologies to deal with new challenges in new environments. That's how humans have adapted to every environment on the planet. I'm sorry: I don't buy this. I'll grant that cephalopods are very intelligent, but there's no evidence that their cognitive abilities are comparable to ours.But, I'm perfectly willing to grant that technological development is also strongly limited by the environment, and that land is a better habitat for technology than sea. But, I'm not sure what the point is: even on land, only the one species with the highest intelligence was able to develop technology. So, clearly, intelligence is the real limiting factor here.

Hi, Jar.I think it's almost time to wind this down a bit. I'm getting too personal, so I need to back off. This post is sort of a summary post, then I'll stop pushing this specific vein of discussion. Let me restate my position:My position is that human success cannot be chalked up to a single factor. There is no "magical tool" that we have that explains all of our success. There is no specific anatomical adaptation that explains all of our success. We succeeded in different environments for different reasons.So, regional success can be chalked up to specific inventions and innovations, like clothing, fire, stone tools, hunting tactics, discovery of new food sources, etc. But, global success cannot be explained by specific inventions. Rather, global success is explained by the underlying process of repeatedly and flexibly adapting to the challenges of each new environment with new inventions and innovations. I attribute this adaptability to human intelligence.That is my position. I agree. And we can only speculate as to why other apparently intelligent animals did not develop the sophisticated tool sets humans developed.Does a marine environment preclude technological development?
Does a short lifespan preclude technological development?
Does an arboreal lifestyle preclude technological development?
Does an herbivorous lifestyle preclude technological development?
Does the lack of hands preclude technological development?I don't know. As a long-time science fiction writer and world-builder, I have always enjoyed speculating on these things. But, that's all it is: speculation.The best option is to infer from our one example (us) what may or may not have been influential in our tremendous, global success, and extrapolate that. And, by my reading, the evidence does not seem to show that human expansion across the globe was due to a small handful of key inventions. If you have evidence that says otherwise, please share it, because I would be most interested in learning what technological developments unlocked the secret for global success, and speculating about non-intelligent creatures that could duplicate our success by just happening to "evolve" those technologies.

Hi, Straggler. There's certainly a lot of complexity to consider.First off, the flexibility afforded by intelligence makes it most useful to animals with a variable ecology: animals that eat many different things, that have to deal with many different dangers, etc.But, most tools used by apes are for functions related to obtaining meat. So, tool-making, for us, seemed to start as a predatory strategy.But, maybe this is because ape anatomy isn't particularly well-suited to predation, so we had to invent tools in order to facilitate our carnivory.But, intelligent predators wouldn't need tools to facilitate their carnivory, because they're already adapted to that.
So, would they only invent technology if they wanted to obtain plant foods?
Of course, what tools do you need to pick fruit? Maybe intelligent predators wouldn't need tools at all.So, maybe omnivores with "aspirations" to become predators are the only type of technology-wielded intelligences we'll see?

Hi, Jar. Then, I apologize for misunderstanding you. And, you're right: our ideas don't differ so much in substance as they do in degree.-----I'd like to discuss a couple other points here: I'm not comfortable with this notion. The absence of something is more difficult to study than the presence of something. It's certainly possible to hypothesize about why, e.g., octopus didn't invent tools, but it's difficult to test the hypotheses. The way I see it, you came up with about four or five hypotheses:

1. No fire under water
2. Short lifespan
3. Low level of socialization
4. No guidance during childhood
5. Some combination of the above factors

How do we test these? Give octopus access to fire, lengthen their lifespan, force them to socialize, and see if they start making tools?People didn't come up with these hypotheses by observing octopus and determining why they don't make tools: they came up with them by comparing octopus to humans, and extrapolating. So, it's still the insights from the "success" of humans, and not insights from the "failure" of octopus, that is driving the hypothesis.As a further illustration of this, take the elephant. As you mentioned, the elephant lives on land, has a long lifespan, a prehensile limb, a complex social life and extensive parental care. Clearly, giving all these attributes to an intelligent animal isn't enough to generate tool-making behavior.So, this means your list may not include all the relevant factors. Do they have to eat meat? Do they have to weigh less than a ton? Do they have to have significant predators? Do the limbs have to have a rigid skeleton?I don't know. It's easier to look for positive evidence (e.g. correlations between specific characteristics of humans and their successful geographic expansion) than it is to look for negative evidence (which we couldn't identify in the absence of positive evidence, any way).

Hi, Jar. We can't know this: it's just a hypothesis. Let's look at octopus again. They don't live very long: usually just a few months, or, in some species, a few years. But, they don't need a few months to learn new tricks: they can figure out screw-top jars in a matter of minutes. Clearly they have enough time to learn the trick of tool use, so is lifespan really an issue?Also, some people have suggested that octopus are capable of observational learning (i.e. learning by copying other octopus). If true, then tool-using behaviors could feasibly be transmitted in the absence of a pervasive social system.Your concept of "need" is a very interesting idea, though, and one that I think is probably highly important. It could be argued that octopus already have a multi-tool for a body --- with a beak, a drilling tongue, venom, prehensile tentacles, ink, chromatophores, a water squirter, and suckers --- and so any tools they could make may not provide any useful advantages to them.Humans, on the other hand, do not have a particularly impressive suite of biological adaptations: without our tools, we'd probably be an easy target for most predators, and we'd have trouble killing food or competing with monkeys for fruit. Maybe that's why we developed tools: because we are pretty pathetic without them?