Climate Change Impact on Animal Nervous Systems

Climate change, driven by human activities, is reshaping the Earth's habitats, leading to rising temperatures, fluctuating precipitation and seasons, and ocean acidification. This transformation presents new, often challenging conditions for animal species. But how exactly do animals adapt to these extreme environments?

The key to understanding this lies in examining the role of animal's nervous systems, which act as the pivot for their response to climate change. As a biologist and neuroscientist, my research revolves around two primary areas: understanding animal responses to extreme temperatures and exploring the forces that shape the animal nervous system, particularly the brain. This crossroads of interests has ignited a journey into the realm of climate effects on the nervous system and potential animal responses to swiftly changing habitats.

Nervous system functions, namely sensory sensing, mental processing, and behavior direction, are vital. They enable animals to traverse their environments, ensuring their survival and reproduction. However, climate change may detrimentally impact these functions. For example, temperature changes can modify the energy balance of ecosystems, affecting the sensory experiences of animals. The sensory realm of animals - from sight and taste to smell and touch - faces a significant challenge due to climate change.

Animals, including mammals, sense temperature through specialized receptor proteins in their nervous systems. These proteins, which discern between moderate and extreme temperatures, guide animals to suitable habitats and may be pivotal to their temperature change adaptation. Climate change, however, disturbs the environmental signals animals depend on for habitat selection, foraging, and mate choice.

Take mosquitoes as an example, these creatures use temperature gradients to navigate their environment, and temperature changes are shifting their host-seeking behaviors, leading to shifts in disease transmission. More mosquitoes are now favoring humans as their preferred hosts due to climate change.

Moreover, climate change's impact on chemical signals used by animals for communication or competition can be particularly intricate since these chemical compounds are highly susceptible to temperature. Researchers have noted how extreme temperatures can modify individual neurons at genetic and structural levels, and even the overall brain organization.

In marine settings, climate-induced alterations in water chemistry, such as ocean acidification, can disrupt the cognitive performance and sensory abilities of animals like odor detection in coral reef fish and sharks. Animals may react to such climatic adversities by migrating to different locations, which, in turn, might expose them to new environmental stimuli.

For instance, fish in warming seas have sought cooler, deeper waters with significantly different light intensity and color range than their visual systems are used to. Species migrating to new habitats, times of day, or seasons will encounter new challenges, including different food plants, prey animals, competitors, predators, and pathogens.

Though animal brains are incredibly adaptable, capable of substantial changes even in adulthood, studies reveal strong environmental effects on brain evolution. The nervous systems of animals evolve to adapt to each species' sensory environments. This indicates that new climatic regimes will eventually reshape nervous systems through forced evolution. As the range of sensory stimuli and seasonal signals change, natural selection may favor those with new sensory or cognitive abilities.

Some parts of the nervous system are limited by genetic adaptations, while others are more malleable and responsive to environmental conditions. A deeper understanding of how animal nervous systems adapt to swiftly changing environments can provide insights into how all species will be affected by climate change.