Biology Prove that evolution is constant (Provide at least two arguments to support your position)

[BillTre]

Wouldn't " ongoing" here be more accurate than " constant "?

because it can vary?

 

[Rive]

The word 'constant' indeed does not goes well for a spinning dice...

 

[Laroxe]

I think we have to go back to the original question and consider what is meant by the word evolution in biology. We are usually talking about genetic changes in a population over time and there are in fact a number of things that influence these changes. In fact very few of these things can be considered constant, yes changes occur in the genome's, but these changes usually copy errors, that occur at critical points in the organisms development, must be compatible with continued development and life, most aren't. The critical periods are important as the changes must be in germinal cells to be properly incorporated and become heritable. However for these changes to effect a whole population, they have to provide some sort of fitness advantage, these advantages are usually dependent on the environment at the time, these are the selective forces that most evolutionary changes act upon. I suspect that this complexity is what Rive is refering to as a spinning dice.
Its probably a mistake to talk about evolution as the ability to adapt, really this need to be clarified, its adaption in a particular environment. Bill mentioned the role of extinction, there needs to be some sort of ecological gap that can be filled or taken over for changes to become more common. In fact most genetic changes occur much earlier in organisms, and tend to be concentrated in specific parts of the genome, selection only occurs when a change becomes relevant.
Just for interest, in the messy genetics of the HIV virus its considered that there are already viruses in the wild that are resistant to every HIV drug, and in fact resistant to every drug that will ever be developed in future. There are also humans that carry a heritable gene variant, that occured as a copy error at some point in history, that has been identified as preventing HIV infection. Exposure wasn't necessary.
https://www.imperial.ac.uk/news/246635/genetic-variant-linked-lower-levels-hiv/