i can’t even begin to understand cladistics and i don’t understand how they play a role in taxonomy at all. don’t cladistics and taxonomy contradict each other? (not trying to disprove cladistics i’m just so so confused)
In: Biology
Cladistics is akin to building a family tree for organisms, grouping them based on shared traits. It classifies living things by evolutionary links rather than just physical traits. In taxonomy, this method organizes species by their evolutionary past, offering a more precise and dynamic system compared to older methods. Instead of conflicting, cladistics enriches taxonomy by revealing deeper insights into species relationships over time.
Genetic clades are the consequence of divergent evolution, i.e. once genomes differ, they never evolve to be identical again. The evolutionary branches never grow back together.
Morphology (physical body characteristics) CAN converge, to an extent, even though the genetics differ. Environmental pressures can “force” similar adaptations.
(Everything that I type is going to be a pale imitation of the amazing explanations from Clint of the YouTube channel [Clint’s Reptiles](https://youtu.be/xb_pvKbtWd8?si=VkT8aeDdvBH3px-M). If anything that I say is confusing/piques your interest, check out the video I linked, and then fall down the rabbit hole of [phylogenetics](https://youtube.com/playlist?list=PLgtE7_5uJ2p6W4LcTly6oTGA27qSCKO2m&si=XAqiCIIklHWTysJa))
Taxonomy is literally just the name we give to the process of building a classification system, it doesn’t just have to be animals. For example, a taxonomy of musical instruments might include classifications like string instruments, wind instruments, and percussion instruments.
In animal taxonomy, we are trying to build a system to classify the wild diversity that we see in nature, and we can do that based on a couple things. In cladistics, organisms are grouped together based on similar traits, not necessarily shared ancestry. So to pick an example from Clint, you might look at a falcon and a hawk and see they both have hooked beaks, talons, etc. and conclude that they are more closely related than the falcon is to a vulture, or the hawk is to a parrot. You could make a clade, or group, called “raptors” to describe all birds with those traits.
If you keep doing this, eventually you can classify all organisms by their shared traits, and voila you have a taxonomy.
But looks can be deceiving, and phylogeny is a classification system that tries to overcome that fact. Phylogenetics is a classification that is concerned only with shared ancestry. A clade in phylogenetics is an organism and *all* of its common ancestors, regardless of how weird and unrelated they may look.
That’s why if geckos are reptiles, and crocodiles are reptiles, then birds are also reptiles, because they are more closely related to crocodiles than either birds or crocodilians are to geckos. Same is true of snakes being lizards, butterflies being crustaceans, and termites being cockroaches.
Phylogenetics is often more useful than cladistics as a taxonomic system because our silly human eyes can trick us, things that look like each other aren’t always closely related, and things that are don’t always look like it.
TL;DR: Taxonomy=general term for a classification system. Cladistics is a classification system that groups organisms by shared traits. Phylogenetics is a classification system that groups organisms by shared ancestry. A phylogenetic taxonomy will sometimes contradict a cladistic one because organisms can evolve along completely separate paths and exist today with very similar appearances, while actually not being closely related.
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