Consider that "spanish" and "italian" are officially separate languages, while the US and Scotland both officially speak "english". The terminology won't help you predict which pair has an easier time communicating. It's political.
The fact that they are capable of producing fertile offspring ?
No idea the academic answer though.
Even with a full genome, or a full skeleton is it even possible? Surely the only way we currently have to determine mating compatibility is to have live subjects to mate/extract gametes from and means to incubate the zygote [and care for it to adulthood].
I'm not certain, but that doesn't sound right to me.
I'm pretty sure Americans and Scots have a far easier time communicating than someone who only speaks Italian and someone who only speaks Spanish.
(Assuming Scottish accents that are reasonably mainstream, not an extreme outlier.)
If I'm wrong, I'd like to be enlightened.
That said, it tends to be as much a vocabulary problem as the accent itself. Lot's of colloquialisms to learn.
Not so fast. Even if you limit yourself to a vocabulary made of the most common 10000 words, you still need a lot more practice to differentiate between nouns that have a gender in Italian and another in Spanish, irregular verbs, idioms, etc.
Understanding a language is one thing. Speaking and writing it is a whole new level.
The objects referred to by nouns aren't inherently gendered, gender is a feature of grammar (sex is a feature of some classes of objects, and fairly recently the grammatical term was adopted as a euphemism for sex by people afraid of the word "sex", and even more recently, inspired by that use, as a name of a social construct associated with, but distinct from, biological sex.)
But grammatical genders, while in some languages they have some correlation to sex distinctions, have no necessary relation to them, as gender distinctions may be on other axes entirely.
So the whole statement seems based on not understanding what "gender" is at all.
Your parent was just saying gender is unnecessary, and you did not answer anything to disprove that, or to prove that they were once needed.
For instance (speaking of Latin), why is Lapis (stone) masculine but Saxum (stone) neuter?
The Romans could have chosen to place all new words on the 2nd declension neuter (the simplest) but instead it (Classical Latin) created 3 more 3rd declension variants on top of the existing ones! And it was more productive, in this 3rd declension, in assigning masculine and feminine rather than neutral, which the 3rd declension also supported!
So what is the reason for that?
Gender isn't senseless, it's a checksum strategy for information. It's not even about sex, lots of grammars have genders that have nothing to do with male/female. The point of gender is agreement: if you're talking about something female, all verbs, adjectives, and adverbs in the sentence have to agree, or the listener gets a syntax error. The syntax error helps the listener figure out that they missed something, or that the transmission was garbled. https://www.reddit.com/r/linguistics/comments/3i1695/eli5_wh...
If you get rid of gender, as English mostly has, you end up forced to adopt different constraints that seem equally arbitrary and wasteful, like strict word order and lots of prepositions. https://www.reddit.com/r/linguistics/comments/3i1695/eli5_wh...
Very excellent comment demonstrating the point about English and word order - in Russian, you can say three words that mean "the dog saw the rabbit" in every possible order, and it's still a valid sentence that means the same thing, because Russian doesn't depend on word order. If it was English, "the dog saw the rabbit", "saw the rabbit the dog", "saw the dog the rabbit", "the rabbit the dog saw", and "the dog the rabbit saw" would all mean exactly the same thing, unambiguously, because the gender of "dog" would have to match the gender of "saw". https://www.reddit.com/r/linguistics/comments/1kdxsc/are_the...
For example, Finnish is utterly genderless, but it has more declension cases for nouns than Latin had. And so, Finnish affords itself the ability to have free word order and checksum benefits while doing entirely away with the concept of gender.
So I reject your explanation on the basis that it is clear to me that the declension of nouns into cases is what is responsible for the checksum and word order benefits, and not whether a language has grammatical gender.
That's consistent with simply making a tradeoff. So a Roman could say:
I don't understand why the Finns created more declension cases when they could have just used gender.
Languages aren't generally products of design.
Indeed, the differences between long-separated human populations are such that even non-racist scientists acknowledge subspecies..
http://dienekes.blogspot.sk/2009/09/is-homo-sapiens-polytypi...
And those types of events happen a lot.
It went down to estimated 1500 worldwide. That is plenty.
Note that last common ancestor of the most differing human ethnics is something like 180-200k years ago.
Furthermore, with the advent of denser living and agriculture, evolution sped up quite a lot.
The New York Intellectuals, who were connected to the Frankfurt School, who got the baton from Psychoanalysis.
Read The Culture Of Critique by Kevin Macdonald and you will have precisely your answer.