As per western model of human evolution, modern humans are more advanced than our ancestors thousands and millions years ago. Then how could our ancestors could have built up such a massive literature of Vedas, Puranas, Upanishads with knowledge of everything if they are considered to be primitive by western models of evolution?
Darwin's theory of evolution states that there is a physical chain of birth from amoeba to man, meaning your great^great^^100-grandfather was a single cell organism.
Whereas padma purana mentions there are 8.4 million 'species' :
jalaja nava-laksani sthavara laksa-vimsati krmayo rudra-sankhyakah
paksinam dasa-laksanam trimsal-laksani pasavah catur-laksani manusah
900,000 species of aquatics 2,000,000 species of plants 1,100,000 species of insects/worms/reptiles 1,000,000 species of birds 3,000,000 species of animals 400,000 species of humans
Note - this definition of species is different from modern one that implies reproducible offspring.
We believe that each soul migrates through one of these 84 lakh bodies, until it reaches human form when it can either obtain mukti, or fall back in samsara (either in higher worlds from satya-svarga-loka or in lower worlds from atala-patala-loka).
There are 3 types of knowledge :
- facts perceived by senses (pratyaksha)
- inferences based on previous facts perceived by brain (anumana)
- knowledge gained from shastras/vedas (shabdam)
In our own experience, we know that the first two are fallible and prone to error. Whereas shabdam has never been wrong so far and will never be because it is apaurusheya (not created by anyone).
In modern theory of evolution, there are 2 knowledge types - facts & inferences :
- facts - DNA resemblance between apes & humans, gene mutation, fossil records
- inference - amoeba's great^n-grandon son had features of fish, whose great^n-grandson had features of ape, whose great^n-grandson is now human
The facts cannot be argued, but the inference can. I can make another inference that the atma/soul migrates from one lower form to another in each birth, just like a student going from 1st grade to 12th. The curriculum (DNA) is very close between 1st grade (amoeba) & 2nd grade (fish), or 11th grade(ape) and 12th (human), otherwise students cannot understand the new syllabus easily. Within each grade, there are many subjects and specialties that students can adapt to (gene mutation) to based on their environment (natural selection) and the best students get the highest marks, while others are demoted to lower grade (survival of fittest).
It is common knowledge that science deals with physical matters, while religion deals with spirituality. So most inferences that western theories make are centered around the body, because science only accepts first 2 types of knowledge (senses and intuition) while eastern theories are centered around soul, so they accept the 3rd type of knowledge (vedas).
In short, Darwin came pretty close to figuring out the spiritual theory of evolution. He himself mentions in the landmark Origin of Species book that his works are speculative in nature. But atheists nowadays have used him as the mascot to push their agendas.
Firstly, Darwinian evolution occurs at a scale of millions of years, whereas the Vedas, Puranas, etc. are dated within the last 5000 years. There is no suggestion of any significant evolutionary transformation in humans in the last 5 millennia. However, this is also the answer to your question-- Darwinian evolution is at a larger timescale than the knowledge of our ancestors.
Secondly, it is surely a stretch to claim that this literature had a
knowledge of everything. The texts you speak of describe rituals, philosophy and practices that were enlightened when they were first conceived, but can hardly be said to be accurate in the 21st century.
I hope you do not mean to treat mythology as history, and claim that a
vanar sena can be legitimately fitted into our past as @Amit Saxena suggests.