Tuesday, 29 January 2013

IGERT Course Wrap Up

As the IGERT course comes to a close I get to think back about all the cool stuff we have been able to do.  We got to learn about different aspects of the research taking place at STRI, some of which I had not been exposed to before (e.g. the Agua Salud Project).
 Dr. Jeff Hall describing the interesting research being done in the Agua Salud site

We learned how many of the ecological principles we learned about during lectures are applied to everyday problems.  For example, this subsistence farmer in the picture below unknowingly described principles underlying interspecific competition and pathogen ecology when he talked about the issues facing his crops.

 We learned how new techniques are applied to old problems.  For example Dr. Greg Gilbert demonstrated his new toy which allows him to "see" inside a tree to determine the proportion of wood affected by fungi.
Dr. Gilbert showing off his new toy (thanks to Alex Tran for the picture)

We saw truly beautiful spots in La Fortuna that must be protected from mining and hydroelectric projects.

We also found some awesome seascapes in Bocas del Toro...

...and  just as important we were able to interact and share among a great group of people

After all that fun hiking and swimming, one thing is for sure... these boots are NOT meant for walkin' (...anymore).

Thursday, 24 January 2013

Evolution of life history traits of marine sister species across the Isthmus of Panama

    The rise of the Isthmus of Panama created the conditions with which to test hypotheses considering the causes and consequences of adaptive radiation and speciation of terrestrial, freshwater and marine species. The rise of the isthmus first led to an important paleozoogeographic event called the “Great American Interchange” characterized by the migration of terrestrial and freshwater fauna between South American and North American ecozones. In addition, the Isthmus of Panama isolated reproductive populations of marine species across taxa that allowed the speciation and adaptive radiation of geminate, or sister, species on either side of the isthmus to different biotic and abiotic conditions in the western Atlantic and eastern Pacific environments.

     The evolution of Atlantic and Pacific sister species has also been the subject of decades worth of research that has measured rates of evolutionary change on the molecular level by calibrating the molecular clock with the geologic data on the dates of the rise of the isthmus of Panama, which is thought to have occurred about 3.5 million years ago, although this hypothesis is now contested, as an alternative, but not conclusive, date of approximately 18-20 million years has been proposed for the rise of the isthmus. Nevertheless, the rise of the isthmus has permitted one of the most important and extensively studied natural experiments in evolution, a natural experiment that now allows scientists to test specific predictions considering the ecological and evolutionary dynamics that have allowed species to adapt to the biotic and abiotic conditions in different environments.

     Adaptation to different environment conditions can impose differential selection pressures on reproductively isolated populations. Therefore, we should predict that physiological and behavioral traits should confer adaptive value to the different conditions found in the coastal marine environments of Panama. We have recently tested the effects of adaptive radiation to different environmental conditions of the Pacific and Atlantic Oceans on the strategies of larval development in two geminate species of coastal mud snails (Potamididae) across the Isthmus of Panama, Cerithideopsis californica on the Pacific coast and C. pliculosa on the Atlantic. Differences in the productivity of western Atlantic and eastern Pacific coastal environments in this region allowed us to predict that in an environment of relatively low productivity (the Atlantic), natural selection will favor the evolution of larval developmental strategies that allow it to survive in these environments of low productivity through increased maternal investment and reduced larval duration in development.

     This pattern of larval development is consistent with models of life-history evolution in which increased maternal investment is selected for in low-productivity environments. In this case, we observed larger size and reduced planktonic duration of larvae in the Atlantic than in a relatively highly productive environment (the Pacific).  While geminate sister species pairs across taxa that inhabit the Pacific and Atlantic coasts of Panama are excellent systems with with to study adaptive radiation to different environments, this pair of snail species is an especially important system with chih to study the drivers of life-history evolution because both species have an exceptionally broad biogeographical distribution, spanning over 30 degrees latitude on both the Atlantic and Pacific coasts. Both of these species are found in habitats with different abiotic and biotic conditions, such as food availability, salinity and temperature that change with increasing latitude that can thus impose differential selection on larval and adult snails that can drive the evolution of important life-history traits, as was observed in the study considering larval developmental strategies across the Atlantic and Pacific coasts of Panama. Testing whether differences in life history traits of Atlantic and Pacific snails across their latitudinal range is an evolutionary or plastic response to different environments, however, is a whole different story. Write on!

Paper can be found here.  http://mollus.oxfordjournals.org/content/77/3/255.short
Email me at victor.frankel@mail.mcgill.ca for a copy of the PDF.

Sunday, 20 January 2013

A History Lesson with Dr. Richard Cooke


If I had to list my three favorite talks from this course, Richard Cooke’s presentation would undoubtedly be in that group.  On Saturday Dr. Cooke took us on a trip back in time: first to the initial migrations of humans to America, then to the rapid spread of these early Native Americans throughout the continent, and lastly to the establishment of communities in Panama and their subsequent decline after the arrival of Europeans. 

Though I have lived in Panama for most of my life, the picture that Dr. Cooke painted during his presentation came as a surprise to me in many ways.  I was interested in the connection that many native groups had to the sea.  The presence of remains of marine animals in archeological sites, such as tiger sharks and dolphins, show that these early groups were experienced seafarers.  This is a stark contrast to my previous view of native groups as sedentary agricultural societies.  I was also impressed by the fact that native groups in the Caribbean of Panama harvested monk seals, a species which is no longer found there.

Aside from those interesting facts Dr. Cooke’s presentation illustrated how human communities can alter ecosystems.  Sediment cores suggest that forests in central Panama declined quickly after the arrival of these first human groups.  Prior to human settlement central Panama was covered in dry forests.  The cores suggest that once humans established the forest receded rapidly, and signs of secondary forest and charcoal appeared.  Interestingly, the same cores show that after the arrival of Europeans forests reappeared, suggesting that native groups were abandoning their communities.

I find it both interesting and sad that in Panama, where 83% of the population shares native lineages, this history is ignored and is not discussed in schools.  This lack of attention to the history of native groups is surely at the heart of the social issues facing modern day native communities in this country.


Indigenous Peoples of Panama

by Divya Sharma

The last week has involved many lectures, a field trip to Agua Salud, an evening excursion to a pond (replete with fish and capped with a waterfall), a trip to the mall, lunch at the beach, dinner at a tapas bar, a walk up a lighthouse, and a performance by Rubén Blades at the Panama Jazz Festival.

I think we’re settling in nicely.

Yesterday, as Alex mentioned, Richard Cooke gave us our first anthropology talk about the isthmus as a bridge for the migration of early colonists from the strait of Beringia down to the tip of Chile. I found this talk particularly interesting, since my research will consist of working with the Indigenous Peoples of Panama on land use management, as part of the larger project of reducing emissions from deforestation and forest degradation (REDD+). The general idea of REDD+ is that more developed countries pay for reforestation in less developed countries, in order to offset carbon emissions and minimise global warming and climate change. Part of the mandate of REDD+ is the explicit inclusion and participation of local groups in the planning and implementation of reforestation programmes. Nevertheless, much of the adversity facing the project stems from its potential negative impacts on indigenous groups, such as a decrease in autonomy and loss of traditional practices. Alex has already mentioned some of the trials facing indigenous groups in Panama today, but here is some more information about the different tribes on the isthmus.

The three main indigenous groups are the Ngobe-Bugle (population of ~250 000), the Kuna (~50 000) and the Choco or Embera-Wounan (~8000) (MRGI 2008). Panama largely consists of a mestizo population of indigenous, Chinese, African and Spanish origins. According to Richard Cooke, approximately 83% of Panamanians cluster into native pan-American lineages, providing evidence for population continuity (i.e. Panamanians are descended directly from original colonists who arrived in the Americas around 10kya). Various microhabitats across the isthmus enabled the trade of specialised products from the Caribbean to the Pacific. When towns began to form, territories were divided into chiefdoms spreading from the coast to the cordillera.

Currently, five out of seven indigenous groups have officially recognised semi-autonomous territories, or comarcas. The Kuna, who inhabit the San Blas Islands, have the most political power of the three groups, and secured their comarca after a violent uprising against the Panamanian government in 1925. According to Richard Cooke, it is possible that the Kuna were present along the Caribbean coast at the time of the arrival of the Spanish in the 15th century. The Ngobe-Bugle lack the political clout that the Kuna maintain, given that they live in small communities in the rainforest and are not as widely organised. The Choco live in the Darien province near Colombia, and also lack the political influence of the Kuna. Colombian refugees and mestizo squatters entering their area have resulted in ongoing conflicts (MRGI 2008).

Panama’s strong indigenous traditions have demanded that current REDD+ efforts focus on reconciling the social, political and economic needs of the country’s indigenous culture with the necessity of taking active steps to offset global climate change. While this balance of interests poses a challenge, it is an essential consideration of any environmental endeavour.   

MRGI (Minority Rights Group International), World Directory of Minorities and Indigenous Peoples - Panama : Overview, December 2008, available at: http://www.unhcr.org/refworld/docid/4954ce3823.html [accessed 21 January 2013]

Low tide at Veracruz beach

Dilapidated lighthouse in Gamboa


View of the Canal from the lighthouse

 Walking along the one-lane bridge in Gamboa

A Voyage Through Time

by Alex Tran

Kuna Yala.

In this post I'll give you a little peek into the time traveling that our NEO course has offered us. I won't go in any particular order. Let's start with the future.

Welcome to Winterland. 

Every day, before our guest speakers start their lectures, the students all go through a round of introductions.

"Hi I'm Alex from McGill, I'm interested in the evolution of signals in electric fish."
"Hi I'm Kelsey from Illinois, I'm interested in using ancient dog DNA to study the movement of ancient human civilizations."
"Hi I'm Peter from Arizona State, I'm interested in ant behaviour, specifically in the Cecropia - Azteca Ant mutualism."
"Hi I'm Larissa from Panama, I'm interested in insect vectors of diseases."


Then, came the turn of our speaker: "Hi I'm Klaus, I'm a gardener." Klaus Winter is a STRI scientist looking at the effects of climate change on plants. He effectively uses greenhouses as time machines, pumping in high CO2 levels that reflect the predicted levels of CO2 in the next decades. Together, these little greenhouses scattered across the STRI station form what is known as Winterland. 

Klaus winter and students.

An inflatable pillow.

In the long run, Klaus is hoping to increase the scale of his greenhouses and see how a diverse community of trees responds to the anticipated environmental conditions. Although this weird thing might look somewhat like a time machine, it's a small greenhouse made of ETFE (ethylene tetrafluoroethylene). According to Klaus, these "inflatable pillows" show promise as the building materials for the future larger greenhouses. Compared to glass, it is lighter, more flexible, more cost-efficient, and has better optical and thermal properties. It's also self-cleaning, which is always a big plus. With rapidly increasing amounts of CO2, forests as they are may change completely, affecting not only the trees themselves but all biodiversity that inhabits them. What Klaus does now allows us to peek into the future.

Now let's go to the past.

Church in Natá, the 2nd oldest city in Panamá.

What better way is there to travel back in time than listening to a lecture by an archeologist? We had the pleasure of having Richard Cooke present to us a historical perspective of the isthmus, a first non-biology class. Just like detectives arriving on a crime scene, archeologists arrive in the present to look for hints of a story in the past. Dr. Cooke pulled up images a stone wall of this place called La Cueva de los Vampiros. To me, it really looked like just a stone wall. But with the right eyes and tools, you can read a story from the past. By looking at the soil chemistry, the types of deposit, the radioisotopes and the tools used on the rock, archeologists can reconstruct certain events that happened along with their timeline. Amazing.

I also never realized how tiny pieces of information could provide so much insight. The discovery of similar mastodon tusk spears in different areas proposes a path used by ancient human civilizations. Manatee-tooth carvings found on the Pacific side of the isthmus suggest exchanges between the Atlantic and Pacific coasts since manatees were inexistent in the latter. Others pieces of the puzzle, however, are more difficult to interpret. Dr. Cooke explains that when it comes art, one may get hints of religious beliefs or social structure, but in the end it's often still just a guess. One enigmatic image recurring in pre-colombian art forms in the isthmus was this anthropomorphic crocodile feathered with stingray tails. Interestingly, it was not only found in artifacts associated with the rich, such as golden earrings, helmets and plates, but also in artifacts that the poorest treasured, in the form of iguana dung. Whether this represented an almighty clan, a symbol power, or a revered deity, we may never know. 

And now, back to the present.

Erin, Peter and Buttons in Galeta.

These relics are small glimpses into the past, and many were forever lost after the arrival of the conquistadores which resulted in the wiping out entire civilizations in the 1500s. As Dr. Cooke noted, the current indigenous groups - the Ngobe, the Kuna and the Emberá - are living relics representing a very long-lived lineage. 

Unfortunately, still today, these indigenous groups must fight to defend their land and culture. Canadian corporations are overseeing the development of destructive colossal mining projects in Ngöbe territory. The ongoing losses of mangrove ecosystems are resulting in an increasing number of floods, threatening the homes of the Kuna. The neglect of the Darién province from the Panamanian government effectively causes poor health problems and low income opportunities to persist for the Emberá. Today, indigenous groups all over the world are links to the past, but they may not persist in the future unless a change of attitude comes along.

Ngöbe children performing the Jegi.

Performance during a historical reenactment of the Kuna revolution in Ukkupseni.

In an ideal world I would have a picture of the Emberá, but I have yet to see them. Soon, though.

Thanks for reading!

Thursday, 17 January 2013

The Agua Salud Project

Today we visited the Agua Salud Project near the Panama Canal basin.  The Agua Salud project is spearheaded by Dr. Jeff Hall who gave us a daylong tour of the site.  One of the goals of this project is to study the ecosystem services provided by various types of land use strategies.  Within this theme one central question is whether tropical soils act as sponges, storing water during the wet season and releasing it during the dry season.  Although this idea has long been accepted almost to the point of dogma, Dr. Hall has decided to take a closer look.  He has hypothesized that forested land may be a more effective sponge than deforested land.  To test this hypothesis his group has been studying the hydrology of plots with different land use characteristics, including secondary forest, teak monocultures, and selvo-pastoral sites.  

The gang at the Agua Salud site

Teak monoculture

One key application of this research is determining how land use affects water supply to the Panama Canal basin.  Although one may think that folks at the Panama Canal are concerned about the prospect of having too little water, in reality a greater concern is having too much water.  In 2010, for example, unprecedented rains caused the Panama Canal to close because water overflow from the Gatun Dam generated currents that posed a threat to ship traffic.  Therefore, understanding how land use affects water runoff into the Canal basin is critical for the functioning of this waterway.  

 A great view of the Panama Canal from the Agua Salud site

Although I found that aspect of this project to be most interesting, the Agua Salud site is also used for a range of other projects including research on forest succession and studies focusing on reforestation using native tree species.  The really cool thing about the site is that Dr. Hall encourages other people to come and do research there (as long as it doesn't mess up any long term goals of the project).

 We also saw this cool mantis... according to one of our bug experts this one is a female, so guys, watch out for your heads!

Ecology Meets Agriculture

This weekend, on our way back from the Galeta Marine Lab, we took a side trip across the Gatun Locks to a polyculture farm where they grow plantains and rice, as well as corn. What's special about this farm is their understanding of the life histories of plantains and rice and how they use it to minimize their pesticide use while increasing crop yield.

Ships waiting to leave the canal for the Caribbean

Walking to the plantation

Step 1: In the dry season, plant plantains.

Ready for planting

Step 2: Wait until the plantains are about a foot tall, then burn the field! Although this may sound crazy, the fire won’t damage the seeds under the ground, and when the plantains grow back they will have significantly less pathogens.

Step 3: Wait a bit, then plant the rice.

This staggering allows the plantains, which would naturally be outcompeted by rice, to grow large enough that they aren’t outcompeted. As well, the plantain leaves provide a shade canopy over the rice plants during the short dry spell around May [veranico?] which would cause considerable damage to unshaded rice plants. The biodiversity in the polyculture, especially since it is bordered by and occasionally interspersed with natural forest, also helps to reduce pathogen loads of each crop.

Thus, by simply understanding the life histories, yield is increased without harmful chemicals.

In the plantation learning its secrets

The view from the cornfield

Additionally: by rotating crops, and including legumes and other nitrogen fixers between rotations, the soil retains nutrients with minimal chemical fertilizers (such as in monoculture).

Harvested rice

The rice produced is primarily for the owner and workers, and sold to community members; but a proportion (~30%) is sold in a market. The rice seed gathered each year is also used primarily by the farm for the following year, but often sold to friends and other community members.

And in the nearby town of Achiote (where we stopped for lunch), we took the time to visit a coffee museum and try out the traditional method of processing coffee beans!

Coffee tree

Removing the husks
Coffee beans drying