The answer is no, high biological fitness in one environment doesn’t have to be high in another environment.
Biological fitness is a term used in evolutionary biology and it is the quantitative representation of how a genotype (or phenotype) is successful (reproductively) in a certain environment. Fitness depends on environment so it changes if the environment changes. The fitness of a genotype is manifested through its phenotype, which is affected by the environment.
It should be an explanation on what you wanna learn about in the experiment, it should be based on prior knowledge, it is also different from a prediction
