All organisms are constantly evolving. What they evolve to or what trait or characteristic they will develop in the future is uncertain and hard to predict in most cases. However, according to Darwin, in short-term evolution, we can predict that organisms lower in fitness will eventually eliminated out and those with higher fitness will be the majority of the population so you can probably predict the frequency of the alleles.
Again, it's hard to predict evolution because the process is random & sophisticated. Remember there are 5 main forces that drive evolution: Mutation, Migration, Genetic Drift, Non-random Mating, and Natural Selection.
Although this is not my area of expertise, it would seem that the trend of evolution is toward survival vs. non-existence.
Since this is not my area of expertise, I searched Google under the key words "'modern evolution theory'" to get these possible sources:
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In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.
I hope this helps. Thanks for asking.