Looking at HumansChances are... you're a human. Whether you're a boy or a girl, man or a woman, you are still human. It doesn't matter what you look like, or what you believe... you're still a part of the human species. You are of the species Homo sapiens! That's what a scientist would call you anyway. But what makes you a Homo sapiens? Why are you different from a dog? Or a cat?
How Are Humans Labeled?Cats, dogs, and now you. Below is the exact name a scientist would use to describe you. If an alien came from outer space, and wanted to understand about every living thing on Earth, they would use these labels. You could put a big sign on your dog with his description and you could wear one that described you. Your sign would read...
ANIMALIA - CHORDATA - MAMMALIA - PRIMATA - HOMINIDAE - HOMO - SAPIENS
Why Do Scientists Think You Are Human?We don't care what people say about you, we know that you are human. But then again, we're scientists. So let's start with the biggest grouping. You live in the KINGDOM - ANIMALIA. If you remember, there are four Kingdoms. You are made up of many, many cells (multicellular) and all those cells have a nucleus with a membrane. You don't have any chlorophyll. If you did, you would be a plant.
Next is the Phylum. You are PHYLUM - CHORDATA. So when you were a fetus (in the womb before you were born) you had something called a notochord. That's a rod made out of cartilage. As you developed, that cartilage turned into a spinal cord made out of bones. That's what scientists call vertebrae. Those magic vertebrae put you in the SUBPHYLUM - VERTEBRATA.
Feel your hand. Hopefully it's warm, not cold like a snake. Having warm blood makes you special. Look in the mirror. Do you have any feathers? Do you have teeth? If you had feathers and no teeth scientists would toss you in with the birds. One last thing, if you are an adult woman you should have the ability to nurse your babies. That's called breast feeding (or suckling). Most mammals do that for their babies. Now you're falling into the CLASS - MAMMALIA.
Okay, you're a mammal. That's still a long way from being human. As far as we know, you're some blind mole that lives out in the desert. Do you lay eggs? No. Do you have a pouch? No. You, assuming you are an adult female, have babies that start their life in something called a placenta. That's the lining for the womb where the baby (or fetus) grows until it is born. That magic placenta puts you in the SUBCLASS - EUTHERIA.
Now for the easy stuff. You should have five fingers and five toes on each hand and foot. One of those fingers should be a thumb. You have flat fingernails on those fingers and toes. You have a collarbone (that's the one between your neck and your shoulders). You are officially in the ORDER - PRIMATA (that's where the primates and monkeys are). Your eyes are in the front of your head. Not on the sides like a dolphin or some other monkeys. SUBORDER - ANTHROPOIDEA.
Almost there. Tail? Nope. Do you walk on two legs? Yup. Your spinal cord and vertebrae are also "S" shaped (that's important). That puts you in the FAMILY - HOMINIDAE.
You are in the GENUS - HOMO. There was another genus, which is now extinct called Australopithecus. Very close to you, but not quite human.
And finally, you are SPECIES - SAPIENS. There used to be a species Homo erectus. They are now extinct. That's it. All those names tell scientists huge amounts about you, your physiology, your genetics, and they way you develop into being an adult.
Tracing Genetic Ancestry (London Nat. Hist. Museum Video)
Encyclopedia.com (Homo sapiens):