Hi all
First, my apologies to those whose interest in evolutionary theory is slight. It happens to be one of my chief interests. I spent quite a bit of time trying to find a neat summary of the difference between short term and long term adaptation. They are related, of course, but not exactly the same. And short term does not accurately predict long term.

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One must realize that we are concerned with three time scales at different levels. The first level is the life cycle of the individuals in the population. During this life cycle the various evolutionary and genetic mechanisms act, e.g., viability selection acts on the population and recombination occurs. This is an individual time scale that is of no direct concern while studying evolutionary processes, but it is essential in setting up the evolutionary dynamics. 

At a higher level we are concerned with the changes in the population from one generation to the next due to selection, recombination and inheritance. This process occurs on the so-called ‘short- term’ evolutionary time scale . On this time scale evolution can be studied and it is the topic of the classical population-genetic approach. 

On the third level, one studies the changes in the population from one equilibrium on the short-term scale to another due to invasions of mutant alleles. On this level each time step is an evolutionary process. Thus, this leads to a higher-order evolutionary process, driven by a sequence of invading mutations, which was named ‘street-car model’ by Hammerstein (1996). We refer to this time scale, which is considered in adaptive dynamics, as the ‘long-term’ evolutionary time scale. While each time step on the short-term scale is an individual’s life cycle, each time unit on the long-term scale consists of (infinitely) many such life cycles. Summarizing, the classical population-genetic and the adaptive-dynamics approach are typically concerned with different time scales. 

Schneider (2006). Long-term evolution of polygenic traits under frequency-dependent intraspecific competition

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Contrary to an implicit working assumption dating back to Fisher (1930), and tacitly adopted without examination by mainstream students of qualitative evolution, the laws governing long-term evolution cannot possibly be extrapolated from results obtained for the short-term process: the two processes are qualitatively different from one another. One difference between short-term and long-term evolution, which is the subject of the present article, concerns the tendency of a multilocus genetic system in the long-term process, but not in the short-term, to approach a phenotypic optimum under the operation of frequency-independent selection and an _evolutionary stable strategy_ (when it exists) under frequency-dependent selection. 

Eshel (1998). Long-term evolution, short-term evolution, and population genetic theory.

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