A female pig is known as a sow, a female bear is known as a sow. A male pig is known as a boar, a male bear is known as a boar. These two animals aren’t closely related. Why do they have the same names? I presume they once believed they were closely related.
The group names for pigs is drift, drove, team or sounder. The group names for bears is sleuth or sloth. Why are they different from each other if they were thought to be closely related?
Just because the same name is used doesn’t imply that people thought they were closely related. Young goats and young humans are both called “kids”. Female deer and female rats are called “does”. Group names are different; a large number of them are just made up for fun and aren’t really used seriously by anyone.
A male dolphin is called a bull; a female dolphin is called a cow; and a baby dolphin is called a calf. Maybe dolphins were once thought to be related to bovines?
However, a group of bovines is called a herd or a drove, while a group of dolphins is called a pod. Why are these names different if dolphins were once thought to be related to bovines?
This is a good question, and I don’t know why people are being jerks about it.
Just checking the OED. “Sow” for “pig” goes back to Indo-European. “Sow” for “bear” is only attested in the OED from 1976. “Boar” for “pig” goes back to common Germanic; “boar” for “bear” is not mentioned at all as a specific term, but the forms are similar and it looks like they’re occasionally confused from the Middle English period. “Sloth,” on the other hand, is more traditional: it goes back to 1452.
So, as an educated guess, I would say that once the “boar” was applied to “bear” in error, “sow” naturally followed to go with it by analogy.
The bull / cow / calf thing is a more straightforward analogy, applied to many other very large animals.
If by “plural noun” you mean group name (e.g. pride of lions, pod of whales), understand that group names are essentially a practical joke played by the Victorians on the English language.
They are the 19th century equivalent of modern lolcats; cutesy memorable terms invented as the great Age of Exploration and exotic species discovery was in full swing.
If that were true, how do you explain the multiple fifteenth-century attestations of “sloth” as a group name for bears?
I don’t disagree that the profusion of these names is somewhat artificial, but only somewhat (as the names describe different group behaviours), and it’s late medieval, not Victorian.
Note also that we have different names for a variety of animals when they are alive, versus when they are served at dinner. Many English names for living animals trace back to Germanic origins; many English names for animals-as-food trace back to French original (and further back to Latin).