Thanks Snitchcat so much, that is really great info there.
The mixing languages thing is interesting. I learned some French and a little Arabic through classroom/academic style learning, and have never been much good at languages. I often find that when speaking one of these languages, words from the other language slip in. I'm not confident at speaking French because I never got the hang of the grammar though I can understand it well because I recognise lots of words. In Arabic I can only really do small talk and order food from restaurants sort of thing although the Arabic that I can speak I'm more confident at. Most of the problems I have with language learning seem to be due to limitations of classroom/academic learning, such as trying to memorise grammar and failing. I have been watching French you tube videos in an attempt to acquire some grammar.
Keep in mind that language, such as it was, in the time you describe was extremely limited. Forget adverbs and pronouns, you get simple word like food, water, shelter, cold, hot, danger and so on. Nobody really has a clue but it's estimated that language of the time might have consisted of a hundred words or so beyond proper names.
Jeff
This was widely believed in the past but one of my main motivations for writing prehistoric fiction (other than my general obsession with palaeoanthropology and evolutionary biology) is to correct a lot of these common misconceptions.
In case anyone else is as fascinated by this whole topic as I am, here's further info:
The level of language described above is less than the level of language that Kanzi the Bonobo and Koko the Gorilla (RIP) are/were capable of, albeit they don't/didn't "speak" it because non-human great apes don't have a human's vocal apparatus. Kanzi uses a lexicon (board with symbols that represent words) and Koko used signs from American Sign Language. Both have/had a vocab of 500+ words and can make simple sentences (e.g. "give me banana"). They can/could understand some basic sentence grammar too. For example, Kanzi understands sentences like "go into the garden and get me the ball" because it's command 1 + command 2, but couldn't understand "go and get me the ball from the garden" because one command is embedded in the other.
Kanzi and Koko both learned language from humans. How much language bonobos use in the wild isn't known but one recent study I remember reading about found about 15 different context dependent vocalisation (i.e. 15 words).
From an evolutionary point of view, if two other species of great apes (humans being a species of great ape) can attain this level of language in a single lifetime of exposure to human language, this would represent the baseline that humans started with before we evolved any specific adaptations for vocal language. As soon as humans or human ancestors started using language to communicate in ways that go beyond how other great apes currently communicate in the wild, they would've attained a Kanzi/Koko level very rapidly. Then, as random mutations result in characteristics that make individuals better at language occur, they'll be selected for and eventually become fixed in the population. And over enough time, the language capacity and complexity increases.
Modern cognition in
Homo sapiens evolved around 70-100,000 years ago, long before my story's set. By that I'm talking about things like art, music, evidence of symbolic thought, ability to track lunar cycles and tides (e.g. for gathering shellfish at low spring tide), emerging rapid development of complex technology that started then and continues to the present day. It's likely they also had storytelling and a rich oral tradition, but evidence of this doesn't fossilise.
There are modern human adaptations for spoken language which evolved significantly earlier than this and Neandertals had these adaptations, suggesting that they could have been present in the common ancestor. (Things can evolve separately but where they are so similar this tends to be due to the common ancestor having it.) The date range for when the last common ancestor of the two species (before/not counting interbreeding) is 600,000- 1 million years ago.
Adaptations for complex speech shared between Neandertals and
Homo sapiens people include:
1. Identical hyoid bones. The modern human hyoid bone is very different to that of other great apes and is specifically adapted for enabling the vocal chords to make modern speech sounds. This is why Kanzi and Koko can't/couldn't make the right sounds for human speech. Kanzi makes some weird noises (weird for bonobos) when communicating with humans - analysis of these noises confirm he's trying to imitate human speech, i.e. what human speech sounds come out like when put through a bonobo's vocal apparatus. There's a Neandertal skeleton that was found with an intact hyoid bone - it is so similar to modern human hyoid bones that the only reason they knew it was Neandertal is because it was found as part of a Neandertal skeleton.
2. Same FOXP2 genes in Neandertals and modern humans - this gene is very important for complex speech. Modern people who due to random mutations get a damaged copy of this gene have severe handicaps when it comes to speech and language. However this is not the only gene involved in speech/language.
3. The size of the spinal chord where the nerves for breath/diaphragm control (needed to speak in long sentences as opposed to the short sharp noises that most animals make) - as measured by the size of the space on the inside of the vertebrae at this part of the chest. Non-human great apes have a narrow space. The Narikotome boy, who lived 1.6 million years ago and is these days considered to be
Homo ergaster, an early species of human (previously classified as
Homo erectus), had a narrow gap here, like non-human great apes. Neandertals had a big gap, same as modern humans. This means they had sufficient breath/diaphragm control to speak in long, complex sentences. This doesn't mean the Narikotome boy couldn't speak, just that his speech would've been limited to short sentences/vocalisations. There are no surviving hyoid bones from his species so we can't see if this was like modern humans, other great apes, or somewhere in between. Shame, because we could learn so much from it. Maybe one might get discovered one day.
For these things to be selected for, humans would already need to be using language enough so that having them would give a selective advantage. They would've had a need to communicate in complex sentences - and already be speaking in as long sentences as they can manage. So it's possible that humans have been speaking in complex sentences with grammar for more than a million years.
Was their complex language as complex as modern language? There's no way to tell. But grammar rules are very flexible and vary massively between different modern languages. Sign languages evolve where people can't use spoken languages and new they quickly develop enough grammar and vocab to express the ideas that people want to express. More complex thinking would lead to more complex language - and human evolution has involved a steady increase in brain size and cognitive ability over a period of just over 2 million years. For the purposes of writing my story, using English to represent long dead languages, if my characters can conceive of an idea, they'd be able to express it in their own language.
If sign languages preceded spoken language or supplemented early spoken languages, the date when complex grammar evolved could be even earlier, for example if Narikotome boy's people used signing to express more complex ideas than they could through speech alone.
One thing I find really interesting is that in Clan of the Cave Bear, which was written by Jean Auel in 1980 therefore based on a 1970's level of scientific knowledge (it was very well researched for its time) is that she gave the Neandertals a sign language. It was thought in the 70s that Neandertals lacked any adaptations for complex language so she had them making simple vocalisations but using sign language. Basically, it's impossible to conceive that they had the level of technology they had without being able to communicate complex ideas with each other. And since the 70s we've learned that Neandertals had far more and better technology that what was known back then.
Examples of Neandertal technology include tanning hides for clothing and textiles, twisting/plaiting fibres together to make string/cord, using birch tar as glue for composite tools, e.g. hafting flint blades to make knives, spears, etc - to get the tar from birch you need higher temperatures that are possible with ordinary wood fires, which means they had the ability to make some kind of basic furnace. We don't yet know how they did this, but we know they had the birch tar as traces of it have been found on some of their tools. The first composite tools (using more than 1 material to make a tool) were done by Homo heidelbergensis - hafting a stone blade on a wooden spear.
Neandertals made tools that required gathering materials from different locations and being very precise about which materials they selected. Their flintknapping techniques required the ability to visualise the finished tool inside the rock before you start making it. They co-operatively hunted animals much larger than themselves, including mammoths and bears (although sometimes bears ate Neandertals, seems to have been a bit of competition regarding who the apex predator was) - one of the ways they hunted bears was to attack female bears when they had just given birth, when still vulnerable before they recovered enough to go "mama bear" on anyone who threatens their cubs. There's emerging evidence of Neandertal art and symbolic thought, and a disputed artefact that's thought by some to have been a flute. They cooked meat and vegetables. They buried their dead, possibly with flowers or grave goods - they may have believed in an afterlife, though no-one can say for sure what they believed as beliefs don't fossilise. They nursed people with broken bones back to health and may have used simple herbal medicine.
Also, it's not plausible that human language went from sub-bonobo level to modern human level in just 40,000 years and if it had, it wouldn't be found in all modern populations. Evolution is a slow process. Homo sapiens people from 40,000 years ago are basically the same as us. There were already
Homo sapiens people in Australia at this time and they would've crossed significant amount of sea to get there. Evolution doesn't stop but it's very slow and all that's evolved since then are superficial ethnic differences. Neandertals were different, being a different species, but still very closely related and as I've shown there's a lot of evidence to suggest they had complex language.