usually, in biology we use monophyletic groupings, like all descendants of rodents will always be rodents.
however, those terms “lizard/fish” are not monophyletic, because otherwise all vertebrates would be fish. those are paraphyletic (group includes some descendants of a common ancestors).
there are already polyphyletic, where we have descendants of multiple sources, ie, Herbivores would be polyphyletic.
Do birds have more brain myelination than reptiles? How do the compare to mammals?
Transitivity Rex
All dinosaurs are birdsAll birds are dinosaurs
Birds are reptiles in the same sense that people are fish.
The correct sense, yes.
Am I a hagfish?
No, your a sexy terrapin
This meme had strong Clint’s repiles vibes until it was etymologically wrong in the third row
In evolutionary taxonomy, reptiles are gathered together under the class Reptilia (/rɛpˈtɪliə/rep-TIL-ee-ə), which corresponds to common usage. Modern cladistic taxonomyregards that group as paraphyletic, since genetic and paleontological evidence has determined that crocodilians are more closely related to birds (class Aves), members of Dinosauria, than to other living reptiles, and thus birds are nested among reptiles from a phylogenetic perspective. Many cladistic systems therefore redefine Reptilia as a clade (monophyletic group) including birds, though the precise definition of this clade varies between authors.
I kinda know what some of those words mean.
Can I get a picture?
Which is especially weird if you’ve ever held a bird in your hands and looked at its feet up close: birds are scaly!
Any particular words you don’t know? Probably the most likely ones are para- and monophyletic. For a taxon (scientific grouping) to be a valid clade, it needs to be monophyletic, meaning it contains the most recent common ancestor of the group’s other members and all known descendants of that common ancestor. Paraphyletic, by contrast, means not all the descendants are in there. For example, imagine if the mammals just randomly excluded the bears – that would be paraphyletic, because the bears also share a common ancestor with the other mammals.
So a monophyletic group of your family tree might include your grandmother, all her children, and all their children’s children, etc. A paraphyletic one might exclude Gertrude and her kids because she got drunk and stole and wrecked the LeBaron and we fucking know she did it and we don’t talk to her after that.
That was a brilliant explanation, thank you.
para- and mono-phyletic were indeed the problem words. I can tell they are related to phylum but “phylum” doesn’t mean much to me except to know that it’s a word for some grouping of species.
The other part where I was snagged is the significance of cladistics and the new/old classification methods. I knew both terms as “words for groups of species and hadn’t dug further.
Between the family tree example and the diagram — got it, thanks to you and your sibling reply.
humans are also reptiles!
and fish
And worms
This is why I love science memes - daily new information presented in an enjoyable format that I know I can one hundred percent trust because science.
birds are fish
