International Journal of Molecular Ecology and Conservation 2024, Vol.14, No.1, 18-26 http://ecoevopublisher.com/index.php/ijmec 21 Figure 2 Models to predict adaptability (Jerison et al., 2017) Note: Each point represents the average fitness change of four populations descended from the same founder after 500 generations of evolution in the (A–C) OT environment or (D–F) HT environment (Lines show the predictions of different models) For example, there is a hemoglobin variant (sickle cell variant) that is resistant to malaria in populations located in Africa. In areas where malaria is prevalent, individuals carrying this variant have higher survival and reproduction rates due to their stronger resistance to malaria, resulting in a higher frequency of this variant in the population (Olukorede et al., 2022). This is an example of how natural selection can increase population adaptability to certain genetic variations in specific environments. 3.3 The impact of environmental stress on genetic adaptability Environmental pressure is the main driving force behind genetic adaptive evolution. When environmental conditions change, the original biological adaptability may no longer adapt to the new environment. At this time, genetic variations that can increase biological adaptation to the new environment will be favored by natural selection (Guzella et al., 2017). Environmental pressure can refer to changes in the ecological environment, such as climate change and changes in food sources; It can also be changes in biological factors, such as the spread of diseases, the emergence of predators or competitors. These environmental pressures prompt organisms to continuously adapt, thereby driving the evolution of genetic adaptability. Climate change is a typical example of environmental stress. As global temperatures rise, many species have to adapt to warmer climate conditions. Roth et al. (2014) found that due to climate warming, some species in low altitude areas have shifted towards adapting to warm conditions and have correspondingly moved up to a certain altitude. However, as altitude increases, the rate of change in butterfly communities slows down, while bird communities transition towards species that adapt to warmth at all altitudes. This indicates that there are differences in the response of different species to climate change. Chen et al. (2011) demonstrated through meta-analysis that species are changing their distribution at an increasingly rapid rate in response to climate change. The migration rates of these species towards higher altitudes and latitudes are 11 meters and 16900 meters per decade, respectively, which are approximately two to three times higher than previously reported rates. The distance of species migration is related to the level of temperature change, indicating that the range of species depends on multiple internal and external factors. Genetic adaptability is one of the core mechanisms of biological evolution, which enables organisms to survive in constantly changing environments. Genetic variation provides the raw materials for adaptive evolution, while natural selection determines which variations can be preserved, and environmental pressure is the main driving force behind this evolutionary process. Understanding this process is not only crucial for revealing the formation
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