Wikipedia says that monoculture is growing a single crop over wide regions. This provides advantages since the farmers can concentrate on developing techniques to maximize yields for only one crop. So they can develop machines that can efficiently harvest one type of fruit or grain. And crops can be developed that are specifically designed to do well in a specific area.
But monoculture has its disadvantages too. It makes large regions more susceptible to diseases. Think of things like the Irish Potato Blight. Or you could think about the “forests” that are planted after areas are clear cut. They are never quite the same as a naturally developing forest.
And we can use this as a metaphor or allegory for culture. Most of us are pretty immersed in the huge monoculture of the United States where we speak English and watch network TV. Certain songs are selected and spread everywhere. People go in the millions to see movies that have been designed to appeal to specific groups of people.
English has acted as an invasive weed and worked to eliminate many other languages that were spoken. But if you go to Google and run a search for “concepts not in English” you will find many lists of words in other languages that have to be described with many words in English. And now we do more to try to preserve languages. There are people in the Tehachapi area working to preserve and learn the local Kawaiisu language.
But a language evolves to solve problems for people in a specific location. And knowing the words that were used in the past will provide information on things that were important to the speakers of that language. If we lose a word we lose a connection to that place and time.
But, English isn't some dead language, it is still evolving. Just check out all the lists that come out letting us know what some of the best new words of the year are or were. Words are still coming into existence to deal with the world we have now.
And we are still bringing in new words from other languages. Most of us around where are familiar with many words in Spanish, and will use them when we need to. So perhaps we're not yet living in a complete monoculture.
And the Internet is going to help. Instead of having to deal with the “culture” that is provided to us, we can go out and find the music that we like, and there are shows out there that you've never heard of that you'd find funnier than anything on TV. And if you have to learn a new language to discover that? Well, that might not be a bad thing.