That someone once said "everything that's to be invented has already been invented." It's a bullshit quote.
In that same segment, he says that cars and planes were invented in the 1900s. While the Wright brothers' invention flew for the first time in 1903, around 1850 there were already gliders in working condition. Automobiles go back to the 1700s.
This is a technicality, but that doesn't make it less wrong. Ricky says "dinosaurs and humans did not coexist". Scientifically speaking, all current birds are dinosaurs. All current birds belong to the clade dinosauria, which are descendants from what people usually think of when they hear "dinosaur" (Brachiosaurus, Apatosaurus, Iguanodon, Triceratops, etc.) So not only humans did coexist with dinosaurs, but we still do.
That chimps/monkeys/apes don't have opposable thumbs. Loads of creatures have them, including monkeys: tarsiers, capuchins, baboons, orangutans, some marsupials, the bambiraptor, and even some frogs.
His so-called definition of determinism... "it's--- it's, you know... it's not whether you can choose, but whether you can choose your choice... it's got to do with brain states..."
This claim: "There's nothing as expressive as the English language". Just a soundbite: no evidence, no discussion, no reasoning... nothing.
There's also his claim that English has at least twice as many words as the second biggest language... for which -again- there is no evidence. It's even nearly impossible to calculate how many words there are in a language alone. If you want to find out more about this, here's an article.
I think it was when Karl was discussing cutting a worm near its neck to make two worms, that Ricky wanted to sound smart and avoid using the word "worm", so instead he named the different types of worm there are (platyhelminthes, nematodes, I can't remember if he mentioned another one), basically just trying to guess what was the correct one. Just fucking say "worm".
When they're discussing whether a 50 lb tiger would beat a 50 lb tarantula, Ricky says that arthropods have a critical mass and that they can't grow any bigger than that. That's scientifically pretty dumb, because of how evolution works. Let's go about it in very basic terms and say a type of spider has a recorded record lenght of 5 cm. This spider could breed 10 little spiders with genes saying "grow up to 6 cm" and 10 little spiders with genes saying "grow up to 5 cm". 5 of the "grow up to 6"-spiders die because their body couldn't obtain enough oxygen to feed its cells, and 4 die from other causes. If one makes it to 6, she could breed another 10 with the "grow up to 5" and 10 with "grow up to 6". We're all products of genetic mutations, every spider and their sizes is a product of a genetic mutation. I can say "humans can't survive with 4 arms", but that's bullshit. If someone is born with 4 arms and their organs can manage the load, he will survive, it's as simple as that. And if he reproduces, maybe more 4-armed people will appear, and maybe not. We cannot know for sure.
There are just too many to mention.