Roosevelt Institute | Cornell University

Watching Evolution in Real Time: Is Climate Change Already Impacting Evolutionary Paths?

By Danielle RaginPublished October 5, 2015

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Some people still claim that global warming is a fallacy. However, whether or not you choose to believe it is from climate change, the world is changing. Melting ice, rising sea levels, and habitat loss are all pushing species to the brink, forcing many to adapt or perish.
By Danielle Ragin, 10/5/2015

Melting ice, rising sea levels, habitat loss, erratic temperatures—The Earth is changing and it is already pushing certain species to adapt or perish  Recent studies are finding evidence of species that species are changing their behaviors, migration patterns, and possibly even evolving to cope with their changing environments.
 
In September, Aarhus University published a study which found that tropical mountain plant species have been dramatically migrating upslope for the past 210 years in what is believed to be a reaction to climate change.  Plants appear to be gradually migrating to higher altitudes where temperatures are cooler and more suitable for survival.
 
Migration patterns are so critical for the survival of pink salmon that it is actually built into their DNA.  However, a study on Alaskan salmon recently found that there are genetic changes in salmon populations telling more fish to migrate approximately two weeks earlier than they did 40 years ago.  Scientists believe that these genetically-induced early migrations help fish battle the increasing temperatures of the local waters.
 
The appearance of tawny owls and European larger banded snails also appears to be changing because of shifting climates.  For what is thought to be for better camouflage, the hereditary coloration of tawny owls typically corresponds with climate.  Tawny owls in warmer environments tend to be dark with brown dominating their coat, while those in colder regions tend to be pale with grey dominating their coat.  Historically, pale owls have dominated Finland due to its snowy climate; however, the proportions of this genetically determined trait has significantly changed.   With Finland's climate getting warmer and less snow falling, the presence of pale owls has decreased and dark owls have become much more prevalent.
 
European larger banded snails, whose shell coloration is also genetic, are displaying a similar reaction to their changing environment.  Snails with light colored shells have been shown to have a lower body temperature than those with dark colored shells in a given environment.  Increasing temperatures are causing the light shelled snails to become much more popular in the Netherlands, even in shady forest environments where dark shelled snails usually flourish.
 
Several plant and animal species appear to be exhibiting physical and behavioral changes in response to global warming.  However, plants and animals are not the only ones who are starting to feel the effects of our changing world.  Humans, including those who populate the Pacific nation of Tuvalu, are starting to see the disastrous impacts the changing climate can cause.  Rising sea levels are already flooding main roads, damaging croplands, and leaving areas partially underwater on the small islands of Tuvalu. The government and scientists both predict all of the 11,800 people who live in Tuvalu will be displaced by rising sea levels within the next 50 years and they are not alone.  Many other island nations such as Kiribati, the Maldives, Palau, the Cook Islands, and Fiji, to name a few, are all feeling the stress of what is to come as the effects of global warming become more intense.
 
Global warming is coming and will only get worse without change.  But even if we were to stop emitting all greenhouse gases at this very moment, past emissions would continue to warm the atmosphere for at least 40 more years.  Many species are being pushed to the brink.  Pink salmon, tawny owls and larger banded snails are some of the species trying to cope with their changing environments.  However, many scientists believe that even if a species is already starting to adapt or evolve, it may not be fast enough to combat the pace of climate change.