** Arik Kershenbaum Episode link: [https://www.preposterousuniverse.com/podcast/2022/03/14/188-arik-kershenbaum-on-what-aliens-will-be-like/](https://www.preposterousuniverse.com/podcast/2022/03/14/188-arik-kershenbaum-on-what-aliens-will-be-like/)  Essential characteristics for alien life. It's very reasonable to assume that ALIENS will have the following: 1. **Heritable information** (thorough DNA or similar molecules) 2. **Predation** 3. Land --> Moving (on a solid surface) --> Limbs / jointed appendiges (legs) -> Levers (when moving on a solid surface)  4. **Bilateral symmetry** 5. **Language** (ability to communicate an infinite number of abstract concepts & to support advanced mathematical thinking) - Fish fly - min 11 in the podcast. the only difference is buoyancy, they don't fall and get squished on the ground like birds - A world without predation - min 19… pre-Cambrian and post-cambrian.  - Our intelligence evolved because of language. Language evolved as a byproduct of complex social interactions. Min 30 / 32. See also Yuval Harari that language evolved for gossip.  - Animals are not trying to be human, they don't evolve to become more human. Animals have communication systems that suit them. They don't need language. They would only evolve a language if they had a need for it. Also, "dolphins don't need to use a hammer, that's why they didn't evolve an opposable thumb." - Fish live in the water. Humans live in the air. - Animals do appear to have a "linguistic ability". Alex the parrot, cats, etc. They don't do that in the wild, they don't use that ability for language. All communication evolved from the senses, from sensory systems. Which in their turn evolved based on environmental constraints. Communication is a secondary purpose, a secondary function of sensory systems evolved to fulfill a primary function that responds to an evolutionary need.  We can speak because we can hear, not the other way around. We evolved ears to hear when we switched our living medium from water to air.   - Min 40 aline animals. Back to the original definition based on characteristics. Animals are "heterotrophs". They have to get out and get food, they can't produce food themselves.  - Essential characteristics for alien life. There are physics based reasons for the specific solutions that life has found. Other constraints are based on evolutionary interactions, not physics. For example walking on twos and arms and hands doesn't seem fundamental, it's contextual.  Natural selection will drive complexity on other words. It's easy. You only need some variation that is heritable and some sort of differential fitness, some configurations that are more efficient  than others and it just goes. Animals have a time constraint, whereas plants don't, they work on a different time scale. So it's likely we'll see intelligent animals more than intelligent plants with roots. Min 1h - all communication evolved from the senses, from sensing. We speak because we can hear, it's not the other way around. We didn't evolve ears to speak. That is why there is no telepathy. We will not see telepathy as a means of communication. Because it is not needed. We don't evolve **