We may not always look it , but humans are repurposed reptiles . consider it or not , but all of these trait chew over your inner lounge lizard .
1. Our Yolk Sacs
When we ’re embryos , a souvenir of our testis - position past hangs in the uterus with us — a egg yolk sac . Just like razzing and reptile eggs , this pouch supply embryo with nutrients . Yolk sacs developed about 300 million years ago when the first amphibious vehicle moved onto farming . Along with the amniotic Sauk , it keep their eggs from drying out .
2. Resilient Skin
It may not look like it , but our skin develop thanks to a reptilian battle with the constituent . 300 million year ago , reptilian evolve a new kind of hide to cover with the dry melodic line on land : a watertight barrier of utter skin cells , which rest atop a layer of fresh , living cadre . We inherit that same layering system .
3. The Hair On Our Heads (And Elsewhere)
dismal mammals , but reptiles beat you to the punch and grew hairsbreadth first . Animals like thrinaxodon — a burrowing reptilian that subsist 245 million days ago — evolved whiskers to feel around in the wickedness . Within 20 million years , animals bring hairy and hairier , and the first mammalian appeared .
4. Ears and Sense of Hearing
Three pearl in our middle ear help magnify good . Amazingly , two of those bones are part of a reptile ’s jaw . The dodo record indicate that over 200 million old age ago , those two mandible start move back back into ancient reptilian ’ heads . Hadrocodium , a little shiner - like puppet that descended from reptile some 190 million year ago , was one of the first critter to inherit the special three - deboned ear .
5. Big Brains
As late reptiles and early mammals developed beard and a better horse sense of auditory modality , their mental capacity had to action more data . Because of this , their encephalon take up to grow .
6. Our Teeth
Most modern reptiles have long , sharp , pin - shape chompers ( think crocodile ) . They do n’t have cuspid — those are purely found in mammal . But it was n’t always that way . The heel - like lizard gorgonopsid was one of the first ancient reptiles to ostentate long , saber - toothed canines . By the time the shrew - alike tritheldonts appeared 230 million long time ago , reptiles were chewing on works and developing molar - corresponding teeth . Teeth became more complex , setting the stage for humans — and tooth doctor .
7. The Genes That Make Us Us
Of course , we do n’t inherit reptilian teeth , skin , and bones directly . We but inherit the genes that make them potential . One gene has a lot to do with all of these transformation — EDA . EDA control how many teeth you have , what those teeth attend like , how haired you are , and how soft and sweaty your skin is . It ’s believed that mutant to EDA in ancient reptiles assist us inherit our body ’s current design .
Want to learn more about our reptilian past times ? melody in to Your interior Pisces tonight at 10 pm Eastern/9 postmortem Central on PBS ’s Think Wednesday lineup .
