Acclimation vs. Adaptation

by Savannah Volkoff

Three weeks ago, I made a cross-country move from San Francisco, California to Durham, North Carolina, to participate in an internship here at Duke University’s Superfund Research Center in the Research Translation core. Weeks up to the move, my roommate and I spent hours preparing for “The Tar Heel State” by watching movie renditions of Nicholas Sparks’ books, which are all set in North Carolina; so, Durham’s greenery and undeveloped space were not surprising to me, despite coming from a concrete jungle like San Francisco.

Savannah (far left) in San Francisco

Despite the Hollywood preparation, the move has been a dramatic change, to say the least. My San Franciscan life, stereotypically complete with running after buses and bundling up to endure foggy afternoons in June, has been swapped with bicycle transportation, huge insects, and humidity. On my way to school in San Francisco, my walk to the bus stop featured rows of houses, tangled telephone wires, and a Golden Gate Bridge backdrop. Now, my quick bike ride to Duke features the sounds of birds chirping and running creeks, amongst never ending greenery of climbing ivy, hanging lichen, and towering trees. My environment has been completely transformed.

Much like my environment, the environment of the Fundulus heteroclitus or “mummichog” in Virginia’s Elizabeth Riverhas also been significantly altered. In the last century the Elizabeth River has been a dumping site for various industries, including some which used creosote to coat wood products. Creosote contains toxic mixtures of PAHs (polycyclic aromatic hydrocarbons) which can have carcinogenic, if not fatalistic, effects on organisms.

David Ownby from the Virginia Institute of Marine Sciences is one of the leading authors on a paper entitled “Fish (Fundulus heteroclitus) populations with different exposure histories differ in tolerance of creosote-contaminated sediments” (2002). This paper focuses on the mechanisms driving the Fundulus’ ability to survive within a heavily polluted environment.

Ownby provides definitions for two words driving his research: acclimation and adaptation. He defines “adaptation” as the genetic process by which a population changes to accommodate environmental factors; and “acclimation” as the physiological changes an individual makes to minimize the effects of stressors (Ownby, 2002). Research conducted by Ownby, as well as Duke University’s Di Giulio and Meyer labs, show that mummichogs from certain areas of the Elizabeth River have the ability to survive in an environment with high levels of toxicity. The question he poses is whether this is because of the mummichog’s ability to acclimate or adapt to its environment.

In this particular paper, Ownby determines that mummichogs sampled from river areas of heightened toxicity were more resistant to deformities than mummichogs from less toxic river areas. Furthermore, the mummichog’s tolerance to varying levels of PAH toxicity in the Elizabeth River is heritable as shown by embryo tolerance to PAH-contaminated sediment. From this research, Ownby concluded that mummichogs have adapted to their environment.

Since arriving at Duke, I have spent a significant amount of time reading research papers about the mummichog situation and I can’t help but draw parallels between my move and the mummichog’s altered environment. Not only have I moved from the West Coast to the East Coast, but even more overwhelming, I’ve moved from the Northwest Coast to the Southeast Coast. Perhaps this summer will be a test of my ability to, like the mummichog, either acclimate or adapt to this new environment. Maybe I’ll just learn to act like a “Durhamite” for a few months, or maybe Durham will find its way into my heart and become a part of me; providing me with stories and memories to pass down to the generations.