# Life

*Life is the greatest miracle of our Universe.*

The definition of *life* depends on context and particular field of study and is typically very broad and fuzzy, but generally speaking it's a form of very complex behavior similar to that of humans, often characterized by attributes such as reproduction, thinking, emotion, reacting to stimuli, growing, communication, consciousness, self preservation instincts etc. This separates matter to living (animals, humans, plants, ...) and non-living (rocks, water, ...), we say something is either alive of dead. It's hard to isolate an exact set of attributes identifying life because whenever we think of an attribute as a necessity for life, we can subsequently break the definition by imagining something without said attribute that would still be perceived as living: for example should we naturally assume reproduction a necessary attribute of life, we can immediately think of a sterile individual incapable of reproduction who is nonetheless still quite clearly a living being. Therefore we tend to classify life by fuzzy clustering, in terms of "closeness" to what we typically expect a living being to look like (and this closeness, i.e. distance, may give rise to a spectrum, implying some things may be "more alive" than others, as in "humans are more alive than viruses"), and this in turn comes with borderline cases where we remain unsure, such as artificial intelligence. Some have alternatively defined life as **that which resists entropy**, i.e. systems that maintain their own ordered structure in spite of natural laws constantly working towards everything "turning to dust", and that would be an excellent definition wasn't it for the fact that some just can't find it satisfactory: for example most religions or biologists can't accept it as even robots are hereby classified as living beings. Biologists may define life as carbon-based matter exhibiting certain biological processes. Religions often connect life with "soul", a supernatural essence present in humans, animals and perhaps even plants. For the purposes of our wiki we will define life as that which **by its behavior, especially showing experience of pleasure and suffering, is similar to us, humans**. For us life is the greatest miracle in our Universe and we choose to make it our goal to support it, make it thrive and be happy.

Life and circumstances of life, such as its origin, mechanisms, "purpose" and abundance in the Universe still belong among the most profound mysteries to be solved. After thousands of years science still have more questions than answers -- sometimes we lack even remote guesses. Earth is so far the only place in Universe known to ever have hosted life -- despite best efforts we never came across a compelling evidence or even a hint of alien life anywhere besides our home planet. But it's still possible that life is all around us, just staying hidden -- does an ant crawling on human's shoe realize he's touching a giant living being? Origin of life itself remains fundamentally unanswered as well. Some believe it may have been brought to Earth from different parts of the Universe, e.g. by comets -- the so called *panspermia* theory. Most prevalent is however the theory that life arose itself by chance from non-living matter, which we call *abiogenesis*. But, again, we don't really have a clue about how likely it is for life to randomly come to be on its own, scientists never satisfyingly replicated such process in their laboratories, although we at least have a few parts of the puzzle here -- for example an experiment in 1953 showed that in conditions similar to those on early Earth some building blocks of proteins will form from inorganic matter after just one week. But still too many unknown variables remain, such as how likely it is for these "right conditions" to appear on a planet in the first place. Computer science and math aid in answering the questions mainly by experiments with cellular automata (see also artificial life), many of which show that ordered, self replicating and self organizing structures can possibly arise from random configurations. In 2020 computers were used to design xenobots -- tiny biological robots that are capable of performing various tasks, including self healing and self replication, and so many already call them synthetic living organisms. Of course there are also cases of potential non-organic life created by humans, best example of which are artificial neural networks, colloquially called "AI", that show human-like behavior and are constantly improving; worthy of mention is also the work of Theo Jansen who has since 1990s been creating astonishingly beautiful, purely mechanical "creatures" called strandbeest that walk just by the power of wind and which he's been constantly improving towards more animal-like behavior, for example to be able to store energy and sense and avoid water. In the book *Selfish Gene* the author Richard Dawkins argues that (at least somehow complex) life is merely a side effect of evolution of GENES, the smallest "units of evolution" -- according to the presented theory genes appeared by chance in the primordial soup as simple chemical structures capable of self-replication and then simply by the process of natural selection kept developing more and more sophisticated means of perpetuating themselves in competition with other genes, and then what we know as life (our bodies, animals, plants, viruses etc.) are merely "survival machines" built by the genes for this purpose. Religions on the other hand are typically built upon a belief that life was created by god or another kind of supernatural entity. Most of what we know from scientific point of view can probably be summed up like this: life is based on the the chemical element carbon, it probably needs water in liquid state, in its most primitive form it appeared on Earth nearly 4 billion years ago and then continued to slowly change over time according to Darwin's laws of evolution and natural selection and the genetic information of living organisms is carried (mostly) by the DNA molecule.

All known biological life is based on the chemical element carbon for its ability to form complex organic molecules. There's a debate (and a lot of sci-fi novels) on whether another element could serve as a basis for (biological) life, mainly for example silicon, but there are no known examples yet. Genetic information in living organisms is carried by the DNA molecule present in their cells, except for some viruses that instead use RNA, which is a little simpler.

TODO

It is currently better to be dead than alive. LRS is trying to change this but it will fail.

{ My current experience as a living being is that life is worse than death -- life in itself could be good but the environment doesn't allow this, it would be very good to have life in an environment that allowed for happiness of life, I would call that a paradise. Now I already also know it's impossible to make such environment but the only good thing to do is still strive for it, even knowing one will fail, doing anything else is just worse. So I will try to achieve this, then I will fail and die and I will be in peace. ~drummyfish }

Life is a constant change for the worse.

The end goal of a life form is to free itself from the slavery of competition -- achieving this is the goal of our less retarded society.

## On Human Life

In the animal kingdom humans have been gifted an extraordinarily long life span and relatively high intelligence and capacity for learning. And so this all culminates in individuals who at the end of their days has gone through profound development of personality and carry with them a treasure of valuable experience and knowledge, most of which unfortunately ends up taken to the grave and lost forever. So let's try to collect some of what the old usually have to say about life. It is however worth noting that one of first such common observations is pessimistic on this matter, stating that life experience cannot be passed on, in part owing to the young never listening and thinking they "know better", and by this they doom themselves to learn the same lessons over and over the hard way, by repeating the mistakes of their parents.

Life of a typical homo sapiens monkey is complex and simple at the same time, both wonderful and miserable, and still every one's journey through life is unique in countless ways, so hardly anything about life can be stated with absolute generality except perhaps that death is a certainty. Depending on when and where one is born there's a certain "expected path" for an average society member from which everyone diverges to some degree, and these divergences are potentially the best way to describe someone's life. In the first world the traditional path starts with carefree childhood, continues through the "education" system towards work, family and eventual retirement -- possible divergences include being an orphan, getting home schooled, attending military service, traveling, being too poor or rich, homeless, single and childless, disabled, gay etc. It's also funny to notice how patterns in our Universe repeat and that human body can be imagined as something akin to a downscaled society, maybe a country, a kingdom or fortress, a colony of united cells and microorganisms with their own working class, neural highways, military (the immune system) and government (the brain), which as a whole matures over time in its own internal culture (personality, morals, education, ...), who interacts with other similar "city states" in friendly and non-friendly ways, who see periods of growth and prosperity as well as tragedies and downfalls, and eventually passes the three grand stages of rise, peak and fall before eventual turning to dust only to get replaced by something new.

Every human begins as a single cell formed (most commonly) after sex that results in successful fertilization of a female egg with the fastest sperm of her male partner. The cell subsequently keeps dividing and slowly forms a baby human who after 4 weeks is about 5 mm long, after 7 weeks has more or less complete limbs and eyes and is finally born after 9 months on average. For the majority of people life is most beautiful close to its beginning, when as children we are taken care of, enjoy unconditional love of our parents, attention of our whole family, leisure time and games with no responsibility, and when we haven't yet seen enough of the world to know how truly horrible it is -- at this point it appears the world is 100% purely good. At the time we aren't annoyed by sexual desire, thought of war, disease or death, competition or prejudice, we are just constantly perplexed by ever present wonders of the world we just began to explore. At around 1 year of age we start to use language. We get told fairy tales about how good wins over evil and we have no reason not to believe them. It's an interesting fact that adult humans practically never remember anything before their 3 years of age -- this is called *childhood amnesia* and is most likely related to the development of brain. Children pass through various funny development stages, for example they create imaginary friends and once they learn to ask "why?", they'll keep spamming the question until learning some kind of new annoying phrase (albeit some never stop asking "why?" and those usually become scientists). Even around the age of early elementary school life is still just a tutorial, everything is very simple, for example if someone is 1 year older, it's pretty clear he's better at EVERYTHING than you are -- every new month of life brings huge discoveries and so we still measure our age in fractions of years. These earliest years are crucial for the development of our core values and basis of our personality, the mind is tabula rasa, we see adults as flawless, perfect individuals and mimic their behavior, we never question anything stated by an adult or even admit they could ever be wrong. In adulthood we remember these times with fond memories which later on manifest as nostalgia -- people experience nostalgia towards times of youth even if objectively they lived in difficult times such as those of war, because the world seen through eyes of a child always looks beautiful, exciting and interesting, there's always something new and unknown and intricate evil (hiding in politics etc.) cannot be comprehended yet. In those years we live in the moment and don't care about the future, we are closer to blissfully ignorant animals. Memories of those times are like photographs of good old times and keep us going on through later stages of life when we find ourselves on the verge of suicide. Even though memory is selective and most people admit they only remember the good, the emotion connected to the memories is real. Still there are numerous people unfortunate enough to be born to very bad conditions and denied even this one brief, truly happy moment of life, and then we can hardly blame them for often growing up knowing nothing but evil.

Soon after the 10th year one hits the beginning of puberty. That's when the body starts to mature sexually and there appears strong sexual desire of fucking the opposite sex (disregarding any legally established age limits). Soon the kid starts to masturbate furiously and thinks of nothing but sex. Females experience their first menstruation, meaning they can now get pregnant. There's also a lot of hormonal change and emotion, boys start to compete for females, females play hard to get and both sexes want to rebel against parents, teachers and authorities in general, which is why a lot of the young lean towards revolutionary "(pseudo)leftist" ideologies. Most people also search for their "identity", go through phases, mimic various celebrities and closely follow latest trends and fashion. Teenage years are infamous as the life's "cringe phase", maybe because it's when a child that's silly in a cute way gradually shapeshifts into the stupidest kind of adult, one who just discovered abstract thinking and experiences some very minor life hardships and suddenly begins to see how "deep" pop music lyrics are and how profoundly intellectual it is to set a quote by someone famous as a desktop wallpaper. Many say that love in teenage years feels the best: it's the first time, people get first innocent kisses and lose virginity, but it's rare for any teenage relationship to last long. Around the age of 18 people in most countries become legally adult.

The 21st year of life has been found by various questionnaires to generally feel most ideal and it's not hard to see why: the body is physically at the peak, full of energy, as well as the mind that's still full of illusions and motivation and the social life is generally quite enjoyable as well -- some live the university life full of partying and others start to earn their first big money, while not yet being encumbered by too much responsibility, namely that of own family. It's also at this age that the world will soon belong to "your" generation as the older one is losing its influence and slowly fading towards retirement.

Joyful as life may seem now however, it's not to last long. Aging further slowly shatters all child illusions and naivity. It started slowly when we got torn away from the mother's breast and assigned simple duties with simple punishments (no TV unless you wipe your own ass!), then we got the mandatory share of bullying at school and discovered our shortcomings in comparison to classmates, and met that one or two asshole teachers -- in retrospect one realizes all teachers were actually assholes and parents weren't saints either, we see we've been lied to and abused even by those we considered friends, but we can still forgive, we now think world is maybe 20 to 30 percent evil. First and second job teach us that any business is a genuine dictatorship cult and everyone's on to kill and rape you. Somewhere between the age of 20 to 40 the realization strikes that the whole world is actually devoid of any good people, that one's a complete slave, a robot, that all struggle is meaningless and resistance is futile. We realize the world is 100% evil. But it's too late -- the great trap has fallen. To this people tend to react in one of two ways. Some immediately adapt the egoistic mindset of self interest and start playing the capitalist game full on, immediately dooming themselves and further strengthening this very dystopia. Others are psychologically unable to bear the thought of complete absence of good and so they descend to a state of denial known as optimism by which they'll refuse to let go of a certain few selected illusions to which they'll stick for the rest of their lives like a drowning man clutching on to a straw -- usually this is some sort of meaningless shallow phrase such as "social justice", "democracy", "patriotism" or "fairness". Neither of the two ways is good.

Life becomes more unbearable every new day, and not just for the aforementioned realizations and the fact that older people get treated more and more like cattle. Physically the body peaks around the age of 25 and the health starts to deteriorate, mental abilities decline, body starts to replace muscle with fat and it's storing it as if expecting a nuclear winter, balding appears and the few remaining hair starts to turn gray, joint and back pain soon joins in, constant stress takes its toll, suddenly there's depression, burnout and insomnia, memory starts to fail as do all our senses. Women lose all charm with pregnancy and after first birth never regain their previous beauty, their tits get saggy and faces full of wrinkles. After the age of 30 you find yourself on a downhill ride -- slow at first but irreversible nonetheless. A new generation is elbowing forward and soon its disgusting shit will flood the world and they're already beginning to call you an old man. At this point you're still strong but feel it won't last forever and you're under immense stress, paying the rent, mortgage, children's education, healthcare, and soon you'll be paying off the kindness of your parents as they once cared for you with love because they're going to need you to care for them as they get old. Midlife crisis may come creeping in any moment. Friends leave and the only close people who might have ever truly loved you, your relatives, start to die: first grandparents, then parents, and suddenly you're alone in the whole world, the only thing left is your memories of childhood. The more fortunate will have families of their own, although "fortunate" may be an unfortunate term -- marriages hardly ever work out, even small imperfections of two individuals living together get amplified by the shared decades and sooner or later turn to hatred, one either ends up cheating and lying or being cheated on, or sexually frustrated anyway; then arguments appear, the man starts to drink and beat his wife, the wife turns cold and files for a divorce, children suffer and perhaps start doing drugs, switching genders or even killing themselves. The same story repeats over and over.

Very fortunate are those who have siblings, because sibling are a family that will always be there, that will never divorce you or leave like your friends do. As a child having siblings sucks because you have to share all your toys, but as an adult having siblings is a blessing.

Part of aging is an interesting effect that seemingly makes time fly by faster the older we get -- a year to a 30 year old feels like a month to a child, and to a 60 year old a year is but a fleeting blink of an eye before death. This can be seen both as negative or positive, depending on whether we dwell on life or not.

After 40 years of age one gets lazier and lazier but simultaneously calmer, seeking peace and getting more avoidant of change, many people become *politically conservative* and more "rightist", desiring order rather than revolution, even for the price of less freedom. It becomes more difficult to learn anything new and there is little reason to, a man at this age has typically found his place in life a long time ago and is now completely comfortable where he stands, only wishing to not be disturbed. A common observation that many share is also that at a certain age you realize you're doing the same things that you hated about your parents and that you swore to never do. Many praise the age of 50 as the true "comfiest" age, but they're usually old boomers who at their time were retiring with amassed wealth and big happy family. The truth is this is when health problems start to become a true burden and you feel becoming ACTUALLY old, not able to keep up anymore with the young no matter how hard you'd try. Around this age women will also go through menopause, their menstruation will disappear along with the ability to get pregnant. The age of 60 is when you're undeniably old, it's when you start to look back at your life and try to put things in order because your time may come literally any moment, when you no longer expect to get cured of diseases but rather guess how long it'll be before they kill you, and you rather focus on helping your children and grandchildren than yourself (provided you actually have some and that you're not extremely retarded to remain selfish even at this age). A funny observation is that some of those who married at young age and still remain together after all these years now start to resemble each other, as if they're becoming one and the same.

With age all pleasure starts to slip away -- how quickly depends on things such as your intelligence and personality -- hobbies and fun activities give ever less enjoyment, there appears the feeling of "having seen it all", unbearable exhaustion, being fed up and desensitized, everything's predictable, fake, cheap and plain wrong, people keep repeating the same stupid shit over and over and you can do little more than watch them run head against the wall and fuck everything up time and time again. Giving advice is in vain and quickly shows to be naive, no one will listen. Entertainment and consumption stop bringing pleasure, video games seize to be fun anymore because you've played thousands already, movies are shit as well,all the same tropes and tricks over and over, everything's a ripoffs and it also goes for music and any other kind of art and the sunsets suddenly look crappy too and food tastes bitter and orgasms somehow stop working as well -- in fact it takes progressively more perversion and you find yourself asking if it's even worth the effort to jerk off. A kid is happiest with a Tamagotchi or Pikachu plush and can't wait to be adult to buy more and more toys but an adult who can have hundred of Tamagotchis and literally catch them all just wants to kill himself. Suddenly you realize you're clutching on to any tiny joy there might be, and usually you'll find it in stupidest things, like walking your dog or cleaning the henhouse and at very old age you're just happy when you take a good shit. For the luckiest who achieved to have their own children they become the whole meaning of their life, most parents will tell you becoming a parent changes your life, but nowadays many more people remain childless and even children will grow up one day and you'll still be left to rely on the small things to get you through every week. In this, a little paradoxically maybe, you discover a sort of minimalist philosophy -- you realize hoarding things or money or medals or even friends is not happiness. Happiness lies hidden in something more intricate, in relatively few things that actually matter, especially in making good, selfless choices -- it is easy to lie to others and mask egoism for selflessness but one can never lie to himself. Most events in life are beyond our control and only the stupid pity themselves for being unlucky. The wise think instead of the decisions that are theirs: you cannot be loved, everyone in the world will hate you, but you can still choose to love, no one can take this choice away from you, and choosing love is the only correct life path. Thus the misery of aging also leads towards salvation, and part of it is also becoming less and less afraid of death. In fact the stupid never reach this realization, most people probably stay psychologically stuck right after the infantile stage or puberty, consuming endlessly and only buying progressively more expensive toys until they perish screaming that they haven't had enough yet, but a wise man naturally grows to see life is in fact endless suffering and after doing one's part, it may be a relief to leave. After all, the wisest philosophies, such as Buddhism, teach exactly this. It's not to say a healthy man will seek voluntary death, but he won't dwell on life for any cost -- dying in one's teens is a tragedy, but a man at the age 40 is ready to die if there is a good reason, he won't make a big deal of it, and an old man awaits death with open arms, maybe only wishing for it to be quick and painless -- that is if he's still conscious enough. Old age sucks on one hand, you live in an overwhelmingly foreign world of new technology you don't understand and new cultural values conflicting those you held for your whole life, but on the other hand you can always choose the "half full glass" view, for instance to paraphrase some ancient writer: a young man hopes to live a long life but may not be so lucky to accomplish this, the old man already has. No one expects anything from you anymore, you're not supposed to work, which capitalists hate but normal people love and so if it wasn't for the piling health issues, many would even find the old age retirement enjoyable. Like it's been said: a child has health and time but no money, an adult has health and money but no time and the old man has money and time but no health. Nearing the end of life (especially unnaturally prolonged one) sometimes symbolically completes the circle by the return to a child-like state, when the mind is largely gone, the body weak and fragile again, and the man is left to fully depend on others, and maybe these are the fortunate ones who no longer think too much and who are taken care of and rid of all responsibilities. Yet the luckiest of these people have their own children taking care of them and maybe a faithful life partner still by the side to complete the life journey together, but this kind of ending is nowadays only seen in the movies. When asked what they'd do differently if they had a second chance at life, people on the deathbed often say they regret having spent too much time at work and not enough time with their family, about pretending and trying to appeal to others instead of following their own way and being too hesitant, leaving for later what they truly wanted to do, living for the future rather than for the moment, usually the regret is about what they have NOT done. The stupidest of men are scared of death, they are those who want to live forever and never advance beyond the egoistic stages.

## Classification/Taxonomy

Biological life encountered in real life is classified by scientists using so called *taxonomy* into a tree of groups that narrow down to individual species and even further (subspecies, races etc.). Naturally this is a gargantuan task and there is mess, constant evolution, merging and divisions, disagreements, controversies over where to place something, how to call stuff and so forth, but let's not get preoccupied with this, we can comfortably leave that to miserable academics. This section simplifies all this shit to something like a grand overview of how it works on the average.

The tree shown below consists of the levels (categories, classes, ...) whose names are indicated at the top. Note that there in fact exist more/different categories as well, this is just what we chose here. Ordering is not necessarily alphabetic. Obviously the tree is INCOMPLETE as well, including only some of the most notable things. Extinct things are marked with `+`.

```
all
| life
| | domain/empire
| | | kingdom
| | | | phylum/division
| | | | | class
| | | | | | order
| | | | | | | family
| | | | | | | | genus
| | | | | | | | | species
| | | | | | | | | | subspecies/race/breed/...
| | | | | | | | | | | ...
V V V V V V V V V V V

vitae (life)
| acytota (non-cellular): no cells
| | viroid
| | virus: infectious, only replicates in bodies of other organisms
|   | riboviria
|     | orthornavirae
|     | | pisuviricota
|     |   | pisoniviricetes
|     |     | nidovirales
|     |       | coronaviridae
|     |         | betacoronavirus
|     |           | betacoronavirus pandemicum
|     |             | SARS‑CoV‑2 (the covid virus)
|     | pararnavirae
|       | atverviricota
|         | 	revtraviricetes
|           | ortervirales
|             | retroviridae
|               | lentivirus
|                 | HIV (gay virus)
| cytota (cellular): consists of cells
  | prokaryota: no nucleus in cells, usually single cell only
  | | archaea: similar to bacteria but with some special properties
  | | apicomplexa
  | | | conoidasida
  | |   | eucoccidiorida
  | |     | sarcocystidae
  | |       | toxoplasma (the cat parasite)
  | | bacteria
  |   | pseudomonadati
  |     | pseudomonadota
  |       | gammaproteobacteria
  |         | enterobacterales
  |         | | enterobacteriaceae
  |         | | | salmonella
  |         | | yersiniaceae
  |         |   | yersinia
  |         |     | yersinia pestis (the black death bacteria)
  |         | vibrionales
  |           | vibrionaceae
  |             | vibrio
  |               | vibrio cholerae (the cholera bacteria)
  | eukaryota: have nucleus in cells
    | protozoa: single celled
    | chromista: more complex criteria, controversial
    | plantae (plants): (almost) don't move, mostly use photosynthesis
    | | tracheophyta/magnoliophyta
    |   | magnoliopsida
    |     | asterales
    |     | | asteraceae
    |     |   | helianthus
    |     |     | helianthus annuus (common sunflower)
    |     | fagales
    |     | | fagaceae
    |     |   | quercus (oak)
    |     | rosales
    |     | | cannabaceae
    |     | | | cannabis
    |     | | rosaceae
    |     |   | fragaria
    |     |   | | fragaria ananassa (garden strawberry)
    |     |   | malus (apple)
    |     |   | | malus domestica (domestic apple)
    |     |   | pyrus (pear)
    |     | solanales
    |       | solanaceae
    |         | solanum
    |           | solanum tuberosum (potato)
    | funghi: (almost) don't move, no photosynthesis, chitin in cell walls
    | | agaricomycetes
    |   | agaricales
    |     | amanitaceae
    |       | amanita
    |         | amanita muscaria
    | animalia (animals): move, breath oxygen, eat organic food
      | annelida
      | | clitellata
      |   | opisthopora (earthworm)
      | arthropoda
      | | arachnida: 8 legs
      | | | araneae (spider)
      | | | | pholcidae (daddy longlegs spider)
      | | | ixodida (tick)
      | | insecta (insects)
      |   | coleoptera
      |   | | coccinellidae (ladybug)
      |   | diptera
      |   | | culicidae (mosquito)
      |   | | muscidae
      |   |   | musca
      |   |     | musca domestica (house fly)
      |   | hymenoptera
      |   | | aculeata
      |   | | | formicidae (ant)
      |   | | apidae
      |   |   | apis (honey bee)
      |   | siphonaptera (flea)
      | echinodermata
      | | asteroidea (sea star)
      | mollusca
      | | cephalopoda
      |   | octopoda
      |     | octopodidae
      |       | octopus
      |         | octopus vulgaris (common octopus)
      | chordata: various features, e.g. a "true" tail
        | actinopterygii ("typical" fish)
        | | cypriniformes
        |   | cyprinidae
        |     | cyprinus
        |       | cyprinus carpio (common carp)
        | aves (birds): have feathers, beaks, lay eggs, often fly
        | | accipitriformes
        | | | accipitridae (hawks)
        | |   | haliaeetus
        | |     | haliaeetus leucocephalus (bald eagle)
        | | anseriformes
        | | | anatidae
        | |   | anas
        | |     | anas platyrhynchos (wild duck, mallard)
        | |       | anas platyrhynchos domesticus (domestic duck)
        | | apodiformes
        | | | trochilidae (hummingbird)
        | | columbiformes
        | | | columbidae
        | |   | columba
        | |   | | columba livia (feral pigeon)
        | |   | raphus
        | |     | raphus cucullatus (dodo) +
        | | galliformes
        | | | phasianidae
        | |   | gallus
        | |     | gallus gallus
        | |       | gallus gallus domesticus (chicken)
        | | passeriformes
        | | | passeridae
        | |   | passer
        | |     | passer domesticus (house sparrow)
        | | sphenisciformes
        | | | spheniscidae
        | |   | aptenodytes
        | |     | aptenodytes forsteri (emperor penguin)
        | | struthioniformes
        |   | struthionidae
        |     | struthio
        |       | struthio camelus (common ostrich)
        | amphibia
        | | anura
        |   | bufonidae
        |     | bufo
        |       | bufo bufo (common toad)
        | chondrichthyes
        | | lamniformes
        |   | lamnidae
        |     | carcharodon (shark)
        |       | carcharodon carcharias (great white shark)
        | reptilia (reptiles):
        | | crocodilia
        | | | alligatoridae
        | | | | alligator
        | | | crocodylidae
        | |   | crocodylus (crocodile)
        | |     | crocodylus acutus (american crocodile)
        | | ornithischia
        | | | ceratopsidae
        | | | | triceratops
        | | saurischia
        | | | diplodocidae
        | | | | brontosaurus
        | | | dromaeosauridae
        | | | | velociraptor
        | | | tyrannosauridae
        | |   | tyrannosaurus
        | |     | tyrannosaurus rex +
        | | squamata
        | | | boidae
        | | | | eunectes (anaconda)
        | | | elapidae
        | |   | ophiophagus
        | |     | ophiophagus hannah (king cobra)
        | | testudines
        |   | cheloniidae
        |   | | chelonia
        |   |   | chelonia mydas (green sea turtle)
        |   | testudinidae
        |     | chelonoidis
        |     | | chelonoidis niger (Galapagos giant tortoise)
        | mammalia (mammals): feed young with milk glands, have hair
          | artiodactyla: mostly herbivore, five toes (mostly hooves), walk on 3rd and 4th
          | | balaenopteridae
          | | |	balaenoptera
          | | | | balaenoptera musculus (blue whale)
          | | bovidae: have horns
          | | | bison
          | | | | bison bonasus (European bison)
          | | | bos
          | | | | bos taurus (cattle, cow)
          | | | capra (goat)
          | | | | capra hircus (domestic goat)
          | | | connochaetes (wildebeest, gnu)
          | | | ovis (sheep)
          | | | | ovis aries (domestic sheep)
          | | camelidae
          | | | lama
          | | | camelus (camel)
          | |   | camelus bactrianus
          | |   | camelus dromedarius (one-humped camel)
          | |   | camelus ferus
          | | delphinidae (ocean dolphin)
          | | | orcinus
          | |   | orcinus orca (orca, killer whale)
          | | hippopotamidae
          | | | hippopotamus
          | |   | hippopotamus amphibius (river hippopotamus)
          | | giraffidae
          | | | giraffa (giraffe)
          | | suidae
          |   | sus
          |     | sus domesticus (pig)
          | carnivora (carnivores): specialize in eating meat
          | | canidae: usually social, co-operative hunters, big tail
          | | | canis
          | | | | canis familiaris (dog)
          | | | | | German shepherd
          | | | | | chihuahua
          | | | | | golden retriever
          | | | | | bulldog
          | | | | | ...
          | | | | canis lupus (gray wolf)
          | | | | canis rufus (red wolf)
          | | | vulpes (fox)
          | |   | vulpes vulpes (red fox)
          | | felidae (cat): retractive claws, mostly solitary predators
          | | | acinonyx
          | | | | acinonyx jubatus (cheetah)
          | | | felis
          | | | | felis catus (domestic cat)
          | | | | | Siamese
          | | | | | Sphynx
          | | | | | ragdoll
          | | | | | ...
          | | | | felis silvestris (European wildcat)
          | | | lynx
          | | | machairodontinae (sabertoothed cat)
          | | | panthera (big cat)
          | | | | panthera leo (lion)
          | | | | | panthera leo leo
          | | | | | | Asiatic lion
          | | | | | | Barbary lion +
          | | | | | panthera leo melanochaita
          | | | | panthera onca (jaguar)
          | | | | panthera pardus (pardus)
          | | | | panthera tigris (tiger)
          | | |   | panthera tigris tigris
          | | |   | | Bengal tiger
          | | |   | | Siberian tiger
          | | |   | panthera tigris sondaica
          | | |     | Sumatran tiger
          | | | puma
          | |   | puma concolor (cougar)
          | | herpestidae
          | | | suricata (meerkat)
          | | mustelidae
          | | | lutra
          | |   | lutra lutra (Eurasian otter)
          | | ursidae
          |   | ailuropoda
          |   | | ailuropoda melanoleuca (giant panda)
          |   | ursus (bear)
          |     | ursus arctos (brown bear)
          |     | | ursus arctos horribilis (grizzly bear)
          |     | ursus maritimus (polar bear)
          | chiroptera
          | | vespertilionidae
          |   | corynorhinus (big-eared bat)
          | diprotodontia
          | | macropodidae
          |   | osphranter
          |     | osphranter rufus (red kangaroo)
          | eulipotyphla
          | | erinaceidae (hedgehog)
          | lagomorpha
          | | leporidae
          |   | oryctolagus
          |     | oryctolagus cuniculus (european rabbit)
          | monotremata: only mammals laying eggs
          | | ornithorhynchidae
          |   | ornithorhynchus (platypus)
          | perissodactyla
          | | equidae
          | | | equus (horse)
          | |   | equus ferus
          | |   | | equus ferus aballus (domesticated horse)
          | |   | equus quagga (plains zebra)
          | | rhinocerotidae
          |   | ceratotherium
          |   | | ceratotherium simum (white rhinoceros)
          |   | diceros
          |     | diceros bicornis (black rhinoceros)
          | pilosa
          | | bradypodidae
          | | | bradypus
          | |   | bradypus variegatus (brown-throated sloth)
          | | megatheriidae
          | | | megatherium (giant ground sloth)
          | | myrmecophagidae
          |   | myrmecophaga tridactyla (giant anteater)
          | primates: 5 fingers with nails, social, big brain, good sight
          | | cercopithecidae
          | | | papio (baboon)
          | | lemuridae
          | | | lemur
          | | hominidae (great apes): big, no tail, thumb in opposition
          |   | gorilla
          |   | | gorilla beringei
          |   | | | gorilla beringei beringei (mountain g.)
          |   | | | gorilla beringei graueri (eastern lowland g.)
          |   | | gorilla gorilla
          |   |   | gorilla gorilla diehli (cross river g.)
          |   |   | gorilla gorilla gorilla (western lowland g.)
          |   | homo (human): intelligent, use tools, language etc.
          |   | | homo erectus +
          |   | | homo habilis +
          |   | | homo neanderthalensis +
          |   | | homo sapiens (modern human)
          |   |   | caucasian (white)
          |   |   | negro (black)
          |   |   | jew: big nose, loves money
          |   |   | ...
          |   | pan
          |   | | pan paniscus (bonobo)
          |   | | pan troglodytes (chimpanzee)
          |   |   | pan troglodytes troglodytes
          |   |   | ...
          |   | pongo (orangutan)
          |   | | pongo pygmaeus
          |   | | pongo abelii
          |   | | pongo tapanuliensis
          |   | gigantopithecus +
          |     | gigantopithecus blacki
          | proboscidea
          | | elephantidae
          |   | loxodonta (elephant)
          |   | | loxodonta africana (African bush elephant)
          |   | | loxodonta cyclotis (African forest elephant)
          |   | | elephas maximus (Asian elephant)
          |   | mammuthus
          |     | mammuthus primigenius (woolly mammoth) +
          | rodentia
            | castoridae
            | | castor (beaver)
            | cricetidae
            | | cricetus
            |   | cricetus cricetus (European hamster)
            | muridae
            | | mus
            | | | mus musculus (house mouse)
            | | rattus (rat)
            | sciuridae
              | sciurus
                | sciurus vulgaris (red squirrel)
```

## See Also

- game of life
- anthropic principle
- consciousness
- AI
- death