Climate change is a bitter truth, and it is happening faster than we can wrap our minds around it. With the rapidly changing climatic conditions, are the immune systems of different species of fauna evolving fast enough to tackle new disease risks that the change brings? Maybe not, claims a new study.
A study in birds by researchers at the Lund University in Sweden suggests that climate change may leave certain species of birds vulnerable to diseases that they are not built to handle. This is because their immune systems have not evolved enough to catch up with new diseases that climate changes expose them to. According to the study, this finding could be applicable to other animals as well.
"Evolution may not be able to "keep up" with climate change. There is a risk that many animals simply will not be able to cope with changes in the number and type of pathogens that they will be exposed to," said Emily O'Connor, co-author of the study, in a statement.
Finding the link between climate change and evolution of immune system
Around 37 different species of birds habituating diverse climatic regions were studied by O'Connor's team. The genetic diversity in the immune system of every species of these birds was examined. That is because this diversity impacts the effectiveness of their immune systems in combating the diseases that they are susceptible to in the climatic regions they live in.
In addition to genetic data, scientists also analysed climatic data such as precipitation and temperature in different areas. The meteorological data for a period of 116 years (ie) 1901 to 2017, was studied in order to establish the link between the evolution of the immune system and climatic change.
Climate dictates genetic diversity of the immune system
Using the above-mentioned methodology, the scientists effectively demonstrated that the diversity that a species has in the genes of its immune system is linked to the climate that it lives in. It was found that that species which did not move from the tropical and rainfall-rich areas where they have dwelled their whole life, showed the most variety in their immune system genes. According to the authors, it is this high diversity that aids these species in dealing with more pathogens.
The study also found that migratory birds that breed in temperate climates after spending winters in tropical areas had immune systems similar to birds native to Europe. This genetic similarity could be attributed to their relocation that helps them avoid diseases, the researchers say.
Applicable to other animals as well
The results of the study suggest that the immune systems of numerous species of birds have been customised by evolution to fight diseases specific to the climate and environment that they live in.
Drastic climate change may leave not just birds but also other animals with such customised immune systems at risk. O'Connor avers that the result could be applicable to other animals also, as the immune system genes that were analysed are characteristic of all vertebrates.
For example, if wetter and warmer tropical climate descends upon temperate northern Europe, diseases that existed in tropical climates will start appearing in this climatic region. Different kinds of animals may be presented with new challenges brought on by new diseases.
