…the Mbabaram word for “dog” was in fact dúg, pronounced almost identically to the Australian English word…
To expand on this, in linguistics, when you notice a similarity between two words, there are three main possibilities.
- Common ancestry. The English word “house” and the German word “Haus” are obviously similar, and this is because they both descend from Proto-West-Germanic, with the source word being something like hūs around 1700 years ago or so.
- Borrowing. The English word “chef” is a direct loan from French “chef”. It’s pretty common for the borrowed word to specialize its meaning somewhat. French “chef” merely means “boss”, while English “chef” specifically means “boss of a kitchen” (who’s probably from France because no one wants to eat English cooking).
- Pure coincidence. This dog example is the classic one, but it really does happen, and not exactly infrequently. There are only so many sounds in human language, and across all languages, you’re bound to get some random collisions. There is the special case where both words originate from a phenomenon like onomatopoeia or infant language ability (think mama, papa, etc).
The first two are fun because they’re evidence of some kind of historical connection, which can sometimes stretch back further than the historical record. Sanskrit in India having a lot of similarities to Greek and Latin is the classical example there (and controversial if you’re a Hindu nationalist). Coincidence can be disappointing when you think you’ve discovered some exciting historical connection, but the dangerous bias that has to be kept in mind is that generally, if you’re looking for something, you will find it.
You forgot universals, words that wind up with a common derivation in a lot of languages. For example, “Mama” is a common word for mother in completely unrelated languages, because it’s derived from babies frequently making mmm sounds first.
Also animal names derived from the sounds said animals make IIRC Crow is an example of this
I kinda touched on that under coincidence, which is admittedly stretching it a bit, but I also think “universals” is a bit of an overly strong name for the phenomenon.
But it is true that there are some underlying elements of human biology and psychology that can cause some interesting effects as well, though I think people have a tendency to exaggerate them.
https://en.m.wikipedia.org/wiki/Bouba/kiki_effect
This is a pretty classic example of it.
How? Dingos aren’t dogs, so how did they have a word for a species that they hadn’t seen before colonisation?
Dog.