What is climate change's potential impact on genetic diversity within species?

Climate change plays a significant role in shaping genetic diversity within species, primarily through mechanisms like habitat loss and altered selective pressures. As climates change, many species face shifts in their habitats, resulting in fragmentation and loss of these critical environments. This can lead to reduced populations and a decline in genetic variability, as smaller populations tend to have less genetic diversity due to inbreeding and a decrease in the effective population size.

Additionally, climate change introduces new selective pressures—such as changes in temperature, food availability, and competition with invasive species—that can further drive certain traits to become more or less favorable. Species that cannot adapt to these rapid changes may face extinction or severely decreased populations, thus further minimizing genetic diversity within those species.

While mutations do happen, they often do not sufficiently counterbalance the losses in genetic diversity resulting from the negative impacts of climate change. Similarly, gene flow can occur, but if populations are isolated due to habitat fragmentation, such movement becomes restricted. Therefore, the assertion that climate change can significantly reduce genetic diversity through habitat loss and changing selective pressures accurately reflects the broader ecological and genetic dynamics affected by this global phenomenon.