I am confused with the topic of ‘what should be the behaviour of Human species towards others species’. If i want to analysis this by evolution - its all looks like continuum of species from bacteria to plants and animals including human beings itself. I am a human being so i should protect and help to grow my species. But what concern me after that is our behaviour towards others species. If we hold a logic on feelings of pains (physically and mentally) by other species. Then we have put our logic on neuroscience and upcoming research shown that even lower order species like plants and cockroach can have some neuro-feedback loops , so they can feels pain etc.
Now we just trapped,we can’t do photosynthesis so we have to kill some species for our food-need and protection.
If the arguments come into play just on methods of killing and eating, like stun and block their pain feelings loops and then we can kill them.Then i can’t differentiate between stunning and killing a chicken or a man or a monkey etc. Now on behalf of evolution we can’t draw a line killings of which species is bad or good.We can exclude the human species by the argument of Intra-species. But is a killing of a monkey/chimpanzee is as valid as a killing of chicken or a killing of bacteria ?
I think i have explained the argument and confusion clearly. Maybe i am lacking with more knowledge on this topic. So i will welcome all the comments and suggestions on this.
I think common sense actually helps here, best not to discard it, we are emotional beings, so emotional well-being is important for us, and we are advanced enough to have empathy, which expands first to our fellow humans (usually) and or our immediate loved ones (sometimes, this is a pet), and then life forms we are less and less familiar or fond of. Also, the more advanced the emotional-system of a life-form, the greater the possible suffering of that life form. For example, apes, which includes humans, can feel suffering and loss when they lose a family member or loved one; so even if you could ‘nullify’ the pain for killing that loved one, you still cause reverberating suffering throughout the family or community, therefore it’s no good. What drives us to be civil, when we can afford to be, is we are looking out for own asses, if we start killing a bunch of cute cuddly teddy bears, who is to say the mob won’t come for our children next? So, if we can afford to be civil, humanity tends to strive to not kill cute things that look like us or make us feel good or even just shares some human trait - like pain receptors, because we don’t want to live in a world where things that look cute or make us feel good suffer or don’t get a chance to be happy, because that puts us closer and closer to ‘unhappy world to live in’.
As for what is a humane food source, it’s irrelevant to my mind, eventually we will engineer our food to be superior to anything nature provides, it’s just a matter of time. The amount of time that we will have to remain part of the food-chain cycle (even though we are at the top) is relatively limited. And more importantly I think it’s sensible in the short term if those are the riches food sources available to us for now, since life-forms best chance of proliferating beyond earth and its constrained time period and beyond unforeseen global catastrophe is relying on currently evolving intelligent lifeforms and sustaining them in the hopes they stop just carrying seeds in their poop to the next island, but all the way to the next planet - these intelligent creatures typically require rich nutrient sources like animal food or sheer abundance of ripe fruit to evolve big brains.