Extinction

Dealing with extinction is difficult. All this was written because of my despair over the extinction of the frogs at El Valle, yet most of the writing dances around the actual issue. As the second trip approached, my dread at seeing Rio Maria without frogs increased. As a scientist the response is often to study the problem. Take for example cancer researchers that start a career because someone close to them is affected. Describing the science is like working harder to avoid thinking about the death of a loved one, it is ducking the fact that the frogs will never been seen in nature by people again.

The harsh reality, to me, is that most people do not care much about extinction of other species. In my introduction to biology course I ask a class of 80 students about this issue. I describe a local species that is going extinct, a small fish that is spiny and non-descript (the Topeka Shiner). I ask the class to raise their hand if they think the fish should be saved. Most of the class puts their hand up. Then I tell them to leave their hand up if saving the fish would be worth it if it required some personal expense to them. Over half the people in the class put their hand down.

A man has a business that removes gravel from some of the streams where Topeka Shiners still remain. He argues, in public hearings, that he is strongly against listing the species as endangered. He thinks that his right to make a living one particular way is greater than the right of that species to exist. He asks the crowded room, “what is more important, people or fish?” Many in the room nod in agreement with his arguments.

How willing are people to actually pay to save species? Is the life of a single person more important than the existence of an entire species? Is there a monetary value to a species? In a recent paper I wrote with my students we attempted to answer this question. The US requires recovery plans to be filed when species are listed as endangered. The average recovery cost was $732,000 per year. Some species cost much more to replace. Tens of millions of dollars have been spent on recovery of the black footed ferret. Total costs of recovery for the California Condor are in excess of $35 million over the last half century. Clearly some species are thought to be very valuable. However, putting a monetary value on species is dangerous. This sets up a situation where somebody could simply pay to be allowed to do an activity that threatens or causes extinction of a species.

Evolution is slow and mutation is random so that once a species has gone extinct, there is essentially zero probability it will ever return. The potential exception to this in the future is the technology for sequencing and synthesizing DNA is growing so rapidly that we might be able to completely recreate a species if the sequence of its entire genome is known. Scientists have already done this for bacteria. It is possible because bacteria have very simple genomes. It is not completely impossible that a complete genome could be synthesized and inserted into an egg of a similar species, allowing for recreation of an entire species. That is not possible for most species now, and probably for decades it will not be possible. For now, extinction is forever.

Current rates of extinction are thousands of times greater than rates of evolution of new species. It has taken 3.5 billion years for life to reach its current level of complexity. Over half the existing species are predicted to be gone in most of our lifetimes. Extinction is one of the major global environmental trends occurring during our lifetimes. We are living in unusual times where one species, us, can influence the entire planet. For the majority of species, we are a disaster. The reasons for this global trend and others are described more fully in my book, “Humanity’s Footprint”.

The fate of most species is to go extinct. As a scientist, I know that 99% of all species that ever existed on earth do not exist now. That fact does not make me feel better about humans destroying over half of all species on earth now.

In Douglas Adams’s science fiction novel “Hitchhiker’s Guide to the Galaxy” the planet Earth is destroyed to make way for an intergalactic bypass. The lead character escapes right before the destruction. He laments the loss of his entire planet but nobody from other planets seems to care much. The lack of interest by most people in extinction is similar; people who care about the plants and animals of the earth and are educated as to what is actually happening to them have a difficult time conveying the urgency of saving species. So many issues are deemed more important by most people, that preserving species ends up very low on the list.

I have dedicated my entire scientific career to studying ecology because I have always been fascinated by the natural world. I am a tree hugger. It is deeply saddening, both intellectually and emotionally, to know these losses are occurring.

It is curious to think about why people grieve. When a close loved one is lost, the feeling is physical. It is such intense emotion that it sweeps all else away. Yet, we know that people are dying all the time around the world, of hunger, disease, violence, and it has almost no emotional effect on most people. I think grief has deep evolutionary roots and leads to people protecting those who are related to them. That is why grief is so physical.

Little evolutionary advantage has existed for our species to protecting other species from extinction, just as there has been little evolutionary advantage to protect people we do not know well. Grief over loss of other species is intellectually driven emotion. Still, it is grief.

Utilitarian arguments for conserving diversity are good ones; species are the glue that holds ecosystems together. The next cure for cancer or some other disease may be found in an exotic organism or in the mold that grows in the dirt under your feet. Still, someday we could cure cancer some other way or find replacement species to keep ecosystems working in ways that provide benefits to humans. The ability to engineer ecological systems to perform functions for humanity does not, in my mind, make the extinctions acceptable.

The nitty gritty of science between trips

Now that Matt had secured funding for a second research trip, we had a lot of preparation to do. One of the most pressing issues was the need to analyze the results from the first experiment. This work required analysis of thousands of samples. Many hours of work to be done included the tedious processing, grinding and weighing of samples. Samples needed to be submitted for analysis and when the results were received, the data entered. Once the data were entered, we need to use the computer models I had created to calculate the results. Given the fact that I am not the world’s best modeler, the calculations were time consuming and required a good bit of data manipulation. The results of this complex modeling would tell us the flux rates of nitrogen through the ecosystem before the tadpoles were extinct.

We needed to finish this modeling and analysis in order to be able to conduct the second large experiment correctly. A romantic picture of field biologists who spend all their time tramping about exotic locales is not accurate for many of us. The reality is that we spend more hours behind computer screens than we do outdoors. The further along the career of an academic, the more time spent writing and administering. A horrible fate, being a department head or, God forbid, a dean, will suck the life out of a research career and eliminate research trips to the field for serious science.

Understanding how nitrogen moves through ecosystems provides one avenue to understanding the way the stream works to support the life that is found there, and how it influences the rivers and oceans downstream. Many scientists had originally considered streams as gutters that simply transport everything that enters them downstream. The research that I have been involved with disputes that view. The science demonstrates that it does matter what happens in the stream with respect to what moves downstream. This understanding has assumed great importance in the US because nitrogen transported out of the Mississippi River into the Gulf of Mexico is causing major environmental problems.

This nitrogen pollution that originates in runoff from cropland moves through the streams and fertilizes the waters of the Gulf. The fertilizer stimulates growth of the microscopic plants that live in the surface waters where there is light. These microscopic algae photosynthesize, grow, and eventually die and sink to deeper, darker waters. When they reach this area, the bacteria that live there decompose the sunken microscopic corpses, and in the process use up the oxygen that is dissolved in the water. Most animals absolutely require abundant dissolved oxygen to survive. Fishes can swim away from the low-oxygen water, but the invertebrates that serve as food to the fishes do not swim so well will die in the low oxygen waters. The pollution is thought to cause substantial economic damage.

Stream ecologists such as myself, Bob Hall and a group of others have determined that what happens in the small streams determines how much of the nitrogen makes it down into the Gulf of Mexico. We, therefore, need to account for how much nitrogen is held back in each stream. This is part of the reason that the methods we were using in Panama were developed.

The second reason is that the way the nitrogen is used in the system alters the ability of different animals to exist in the food webs found in the streams. Thus, nitrogen allows us to characterize properties of the stream relevant to conservation of stream organisms. This conservation has the goal of maintaining the biotic integrity of the stream. Again, the methods developed in general would be useful in the specific case of the Panama streams.

I wrote a computer model to analyze the data. Matt and Bob checked it, and Piet started running it on the data we had. He had lots of questions about the model, and some of them were related to errors he found. After hours of re-programming and discussions with Piet and Matt about how to use the model, Piet was finally able to get some results. A true picture of the importance of the tadpoles in the stream began emerging. Piet’s work with the modeling confirmed that the tadpoles were central to how the ecosystem of Rio Maria functioned. The open question was what would happen once the frogs were gone.

Now Matt had funding and the group’s preparations needed to begin for our next trip to El Valle and Rio Maria. Matt made the arrangements to fly, ordered materials, and Edgardo started working on local arrangements. Matt needed to find some new students to replace the ones who had graduated. The ball was rolling toward the next trip.

An inkling of a problem

This is a travelogue, a research log, and most of all an extinction log. It describes two research trips to gauge the effects of loss of frogs caused by a fungal disease that is sweeping through Central America. The story is one of extinction, and how people who study these animals respond to the loss. The story is a wake for lost diversity; we will never see these many species of frogs again in the wild. The blog also places the loss in the cultural context of Panama and the ecological context of the rain forest

In 1977, I visited the Costa Rican cloud forest preserve, Monteverde. The small park headquarters had an aquarium that contained a Golden Toad. I did not know at the time that this species was doomed to extinction. The animal was a beautiful, brilliant neon orange frog (Bufo periglenes), about 2 inches long. A staff person at the headquarters mentioned that this species had only been found in this one small area of this cool, wet, and high-altitude forest. He said that very few had been seen recently and we would be very lucky if we saw some in the wild. I had this in the back of my mind as we left to explore the cloud forest, but our main objective was to see the extravagantly colored Resplendent Quetazal, a bird with a two foot long bright green tail. I saw screaming monkeys, I was chased by a giant cat weasel (Jaguarondi). I never saw the frog in the wild.

In 1989 the last Golden Toad was seen, none have been reported since then. The news gradually filtered out through the scientific community that the toad was extinct, but the exact cause was not understood. Monteverde is a pristine cloud forest at the top of a mountain range; it was not developed, and should not have had much human influence. Yet, this extinction was to become emblematic; loss of this species was for many the beginning of general scientific awareness of a global trend of amphibian extinction. The extinction of the Golden Toad bewildered and saddened me, and came to mind when reading the articles that started surfacing in the 1990’s about amphibian extinctions elsewhere in the world. Little did I know that my experience with frog extinction would become very real in future years.