Barbequed clams on the menu for ancient Puerto Ricans

By: Thomas Schmitt Attorney on November 27, 2019 / comment : 0 Americas, Archaeology, Puerto Rico, South America

Scientists have reconstructed the cooking techniques of the early inhabitants of Puerto Rico by analysing the remains of clams.

Photographs of all shells analyzed in this study [Credit: Cardiff University]

Led by Philip Staudigel, who conducted the analysis as a graduate student at the University of Miami Rosenstiel School and is now a postdoctoral researcher at Cardiff University, the team has used new chemical analysis techniques to identify the exact cooking temperatures at which clams were cooked over 2500 years ago.

With cooking temperatures getting up to around 200oC according to the new analysis, the team believe the early Puerto Ricans were partial to a barbeque rather than boiling their food as a soup.

The study, which also involved academics from the University of Miami and Valencia College, has been published today in the journal Science Advances.

Whilst the results throw new light on the cultural practices of the first communities to arrive on the island of Puerto Rico, they also provide at least circumstantial evidence that ceramic pottery technology was not widespread during this period of history - it's likely that this would be the only way in which the clams could have been boiled.

Lead author of the study Dr Philip Staudigel, currently at Cardiff University's School of Earth and Ocean Sciences, said: "Much of peoples' identity draws upon on where they came from, one of the most profound expressions of this is in cooking. We learn to cook from our parents, who learned from their parents.

Measuring in excavation unit at CRNWR_P13 [Credit: Carlos Mora]

"In many parts of the world, written records extend back thousands of years, which often includes recipes. This is not the case in the Caribbean, as there were no written texts, except for petroglyphs. By learning more about how ancient Puerto Rican natives cooked their meals, we can relate to these long-gone peoples through their food."

In their study, the team analysed over 20kg of fossilised clam shells at the University of Miami's Rosenstiel School of Marine and Atmospheric Sciences Stable Isotope Lab, which were collected from an archaeological site in Cabo Rojo, Puerto Rico.

The pre-Arawak population of Puerto Rico were the first inhabitants of the island, arriving sometime before 3000 BC, and came from Central and/or South America. They existed primarily from fishing, hunting, and gathering near the mangrove swamps and coastal areas where they had settled.

The fossilised shells, dating back to around 700 BC, were cleaned and turned into a powder, which was then analysed to determine its mineralogy, as well as the abundance of specific chemical bonds in the sample.

When certain minerals are heated, the bonds between atoms in the mineral can rearrange themselves, which can then be measured in the lab. The amount of rearrangement is proportional to the temperature the mineral is heated.

Sample reacting with phosphoric acid, releasing CO2 gas which will then be analyzed using mass spectrometry [Credit: Philip Staudigel]

This technique, known as clumped isotope geochemistry, is often used to determine the temperature an organism formed at but in this instance was used to reconstruct the temperature at which the clams were cooked.

The abundance of bonds in the powdered fossils was then compared to clams which were cooked at known temperatures, as well as uncooked modern clams collected from a nearby beach.

Results showed that that the majority of clams were heated to temperatures greater than 100°C - the boiling point of water - but no greater than 200°C. The results also revealed a disparity between the cooking temperature of different clams, which the researchers believe could be associated with a grilling technique in which the clams are heated from below, meaning the ones at the bottom were heated more than the ones at the top.

"The clams from the archaeological site appeared to be most similar to clams which had been barbequed," continued Dr Staudigel.

"Ancient Puerto Ricans didn't use cookbooks, at least none that lasted to the present day. The only way we have of knowing how our ancestors cooked is to study what they left behind. Here, we demonstrated that a relatively new technique can be used to learn what temperature they cooked at, which is one important detail of the cooking process."

Source: Cardiff University [November 27, 2019]

Pre-Columbian stone figures with 'mysterios markings' point to 'lost civilisation' in Puerto Rico

By: Thomas Schmitt Attorney on July 18, 2019 / comment : 0 Americas, Archaeology, Puerto Rico, South America

A puzzling cache of stone figures covered in mysterious symbols could be the first evidence of a "lost civilisation".

The mystery carvings could hold the key to a lost civilisation [Credit: University of Haifa]

The bizarre figurines were first discovered in the 19th century by a local monk who claimed he was led to the "secret stash" by a dying woman who lived in a hut in the Puerto Rican mountains.

It was previously believed the figurines may have been created as a hoax by the monk, however archaeologists at Israel’s University of Haifa have recently discredited this theory.

Using microscopic testing, they have been able to confirm the statuettes were carved in the later 14th or early 15th century.

“To date, we have not found any similar carved stone art objects from this region of America, and this is why many researchers assumed that they must be fake," researcher Dr Iris Groman-Yaroslavsky said.

Reniel Rodríguez Ramos examining some of the Puerto Rican figurines at Haifa University [Credit: University of Haifa]

"However, the microscopic tests we performed show beyond any doubt that the stones were carved around 600 years ago."

According to the research, the stones were "unequivocally carved in ancient times".

"Under the microscope, we can see the erosion of the stones and the brown-grey patina that is typically found when items have been buried or exposed to the ravages of nature for extensive periods," he explained.

"The items are made from a mineral that was originally a greenish black, but the erosion covers the engravings across the entire item, and there is no evidence of any modern manipulation that would have exposed the natural surface of the mineral.

El Yunque view from Yokahu Tower on a clear day, mountain forests of Puerto Rico [Credit: WikiCommons]

"The processing marks on the items show that special chiselling tools were used, and all the items appear to share a unique style."

Researchers also found the objects had previously been coated in red paint and gold - a fact supporting evidence the stones were produced locally, as gold and ochre mines can both be found in Puerto Rico.

While the discovery still puzzles researchers, they will continue to investigate "the existence of a previously unknown pre-Columbian civilisation waiting to be uncovered".

Author: Matt Dunn | Source: 9News [July 18, 2019]

Climate warming experiment finds unexpected results

By: Thomas Schmitt Attorney on January 04, 2019 / comment : 0 Climate Change, Environment, Natural Heritage, Puerto Rico

Tropical forests store about a third of Earth's carbon and about two-thirds of its above-ground biomass. Most climate change models predict that as the world warms, all of that biomass will decompose more quickly, which would send a lot more carbon dioxide into the atmosphere. But new research presented at the American Geophysical Union's 2018 Fall Meeting contradicts that theory.

Dried leaf samples are bagged and numbered before being returned to study sites in Puerto Rico’s El Yunque National Forest. Heaters warmed experimental plots to four degrees higher than the ambient temperature of the tropical forest [Credit: Stephanie Roe]

Stephanie Roe, an ecology Ph.D. student at the University of Virginia, measured the rate of decomposition in artificially warmed plots of forest in Puerto Rico. She found biomass in the warmed plots broke down more slowly than samples from a control site that wasn't warmed.

Her results indicate that as the climate warms, forest litter could pile up on the ground, instead of breaking down into the soil. Less decomposition means less carbon dioxide released back into the atmosphere. But it also means less carbon taken up by the soil, where it's needed to fuel microbial processes that help plants grow.

"These results could have significant implications on the carbon cycle in a warmer future," Roe said.

Roe said there are few empirical studies of how tropical forests will respond to climate change. She set out to address this gap in June of 2017, when she and her research team travelled to El Yunque National Forest in Puerto Rico. They landed at a site called TRACE—the Tropical Responses to Altered Climate Experiment.

TRACE is the first-ever long-term warming experiment conducted in a tropical forest. It was established by the US Forest Service in 2016 for research like Roe's. The site consists of three hexagonal plots of land enclosed by a ring of infrared heaters raised four meters above the ground, and three more plots enclosed by fake heaters that are used as the "control" forest.

Roe collected leaves from the plots, dried them out in the lab, and then returned them to the plots randomly. In addition to the native plants, she also included black and green tea, and popsicle sticks to represent woody biomass, to see how different materials would respond to the warming.

The heaters were programmed to continuously heat the plots to four degrees higher than the ambient temperature of the forest. The experiment was supposed to run for a full year, but at the beginning of October, Hurricane Maria swept across the island, destroying the TRACE sites.

Roe was back in Virginia when the storm struck. She had collected samples from the first few months of the experiment, and they were already showing signs of significant decomposition, so she decided to go ahead with the analysis based on what she had. And the results were not what she thought they would be.

"We would expect that microbes tend to work faster, like their metabolisms increase, with warmer temperatures," Roe said. "So we would expect to see an increase of activity of microbes and other decomposers to decompose the litter."

But instead of seeing faster rates of decomposition, Roe observed the warming produced a drying effect in the plots, which slowed decomposition. "What we found is actually it went the other way because moisture was impacted so much," Roe said. Moisture in the litter from the treatment sites was reduced by an average of 38 percent.

Roe pointed out that the increase in frequency and severity of storms in the region could amplify this effect. Hurricane Maria reduced significant portions of the tree canopy in El Yunque, allowing a lot more sunlight to reach the forest floor that can dry up the litter.

The results Roe shared are preliminary and not yet published. Her next project is to do further analysis of the nutrients in the litter and of the microbial communities to see if there are other factors that could explain the unexpected slowdown in decomposition.

Author: Emily Pontecorvo | Source: American Geophysical Union [January 04, 2019]

Two degrees decimated Puerto Rico's insect populations

By: Thomas Schmitt Attorney on October 15, 2018 / comment : 0 Climate Change, Ecosystems, Environment, Natural Heritage, Puerto Rico, Wildlife

While temperatures in the tropical forests of northeastern Puerto Rico have climbed two degrees Celsius since the mid-1970s, the biomass of arthropods—invertebrate animals such as insects, millipedes, and sowbugs—has declined by as much as 60-fold, according to new findings published in the Proceedings of the National Academy of Sciences.

Credit: RPI

The finding supports the recent United Nations Intergovernmental Panel on Climate Change warnings of severe environmental threats given a 2.0 degree Celsius elevation in global temperature. Like some other tropical locations, the study area in the Luquillo rainforest has already reached or exceeded a 2.0 degree Celsius rise in average temperature, and the study finds that the consequences are potentially catastrophic.

"Our results suggest that the effects of climate warming in tropical forests may be even greater than anticipated" said Brad Lister lead author of the study and a faculty member in the Department of Biological Sciences at Rensselaer Polytechnic Institute. "The insect populations in the Luquillo forest are crashing, and once that begins the animals that eat the insects have insufficient food, which results in decreased reproduction and survivorship and consequent declines in abundance."

"Climate Driven Declines in Arthropod Abundance Restructure a Rainforest Food Web" is based on data collected between 1976 and 2013 by the authors and the Luquillo Long Term Ecological Research program at three mid-elevation habitats in Puerto Rico's protected Luquillo rainforest. During this time, mean maximum temperatures have risen by 2.0 degrees Celsius.

Major findings include:

- Sticky traps used to sample arthropods on the ground and in the forest canopy were indicative of a collapse in forest arthropods, with biomass catch rates falling up to 60-fold between 1976 and 2013.

- The biomass of arthropods collected by ground-level sweep netting also declined as much as eight-fold from 1976 to 2013.

- As arthropods declined, simultaneous decreases occurred in Luquillo's insectivorous lizards, frogs, and birds.

- The authors also compared estimates of arthropod abundance they made in the 1980s in the Chamela-Cuixmala Biosphere Reserve in western Mexico with estimates from 2014. Over this time period mean temperature increased 2.4 Celsius and arthropod biomass declined eightfold.

Cold blooded animals living in tropical climates are particularly vulnerable to climate warming since that they are adapted to relatively stable year-round temperatures. Given their analyses of the data, which included new techniques to assess causality, the authors conclude that climate warming is the major driver of reductions in arthropod abundance in the Luquillo forest. These reductions have precipitated a major bottom-up trophic cascade and consequent collapse of the forest food web.

Given that tropical forests harbor two thirds of the Earth's species, these results have profound implications for the future stability and biodiversity of rainforest ecosystems, as well as conservation efforts aimed at mitigating the effects of climate forcing.

Andres Garcia, of the Universidad Nacional Autònoma de Mèxico, was co-author on the study which was funded by the National Science Foundation.

Research into the effects of climate change is an exciting aspect of The New Polytechnic, an emerging paradigm for teaching, learning, and research at Rensselaer. The foundation for this vision is the recognition that global challenges and opportunities are so great they cannot be adequately addressed by even the most talented person working alone. The New Polytechnic is transformative in the global impact of research, in its innovative pedagogy, and in the lives of students at Rensselaer.

Source: Rensselaer Polytechnic Institute [October 15, 2018]

Puerto Ricans, Spaniards restore fort that defended San Juan

By: Thomas Schmitt Attorney on September 15, 2018 / comment : 0 Archaeology, Caribbean islands, Heritage, Puerto Rico, Spain

Puerto Ricans and Spaniards have joined forces to continue with the restoration of San Geronimo de Boqueron Fort, the island's smallest fortification but considered the most important; it was rebuilt in the 18th century and defended the capital city of San Juan for hundreds of years.

Credit: David Diaz/GoogleMaps

Architect Juan Vera of the Council of Nautical Archaeology at the Puerto Rico Institute of Culture, along with another Puerto Rican, Ismael Rodriguez, and the Spaniards Rafael Gomez Aguilar and Manuel Minero, are in charge of the restoration.

In an interview with EFE, Vera said that 2007 saw the start of the cleaning and reconstruction work of what he considered "the altar of Puerto Ricanism" because of the events that occurred there, particularly the British invasion of 1797.

Gomez, for his part, told EFE that working on restoring the fortress - which he has done for five hours every Friday for at least the past four months - makes him the "happiest guy in the world," because he feels "privileged" working on a fort used by the Spanish army as a military defense post.

Credit: Wandy Arroyo/GoogleMaps

Gomez, 39, said it was Minero who invited him to join the cleaning crew at the small fort, a structure that he "hadn't the slightest idea" what it was until he got there the first time and found it "sad, poor and full of trash," but today it's very different.

Diego Menendez, governor of the island between 1582 and 1593, fortified the simple construction at Boqueron Point and installed artillery there to protect the second entrance to San Juan Bay.

The original construction defended San Juan from British attacks by Sir Francis Drake in 1595 and Sir George Clifford in 1598.

Credit: Wandy Arroyo/GoogleMaps

The small fort was later rebuilt when a soldier of Irish origin, Alejandro O'Reilly, came to the island in the mid-18th century to reorganize the army and improve the defensive structures.

Later on in the century when England lost the 13 colonies that became the United States, it decided to concentrate on the conquering the Caribbean.

Its ambition reached the point of offering to return Gibraltar to Spain in exchange for Puerto Rico, but the Spanish government refused to accept the offer "because of the geographical importance" of the Caribbean island, Vera said.

Credit: GoogleMaps

England, for its part, was not satisfied with the Spanish government's decision and sent a large invasion force to Puerto Rico led by Ralph Abercromby, with more than 14,500 troops against 6,411 in the local military.

The fort had five cannons on the second floor, and the height of the structure meant a cannonball could be fired at such an angle that it would ricochet off the water, hit an enemy boat at the waterline and sink it.

"If we had lost the battle of 1797, it would have been a different story," Vera said.

Source: EFE [September 15, 2018]

Elusive venomous mammal joins the genome club

By: Thomas Schmitt Attorney on March 16, 2018 / comment : 0 Biology, Evolution, Genetics, Puerto Rico

An article published in the open-access journal GigaScience presents a draft genome of a small shrew-like animal, the venomous Hispaniolan solenodon (Solenodon paradoxus). This species is unusual not only because it is one of the very few venomous mammals, it is also the sole remaining branch of mammals that split from other insectivores at the time of the dinosaurs. The genome sequencing and analysis of this endangered animal was carried out by an international team lead by Dr. Taras K. Oleksyk from the University of Puerto Rico at Mayagüez. The availability of the solenodon genome sequence allowed the researchers to answer several evolutionary questions, particularly whether the solenodon species indeed survived the meteor impact that laid waste to the dinosaurs.

Hispaniolan solenodon (Solenodon paradoxus) is one of the only extant venomous mammals. Its species separated from other insectivores at the time of the dinosaurs [Credit: Eladio Fernandez, Caribbean Nature Photography]

As one of the only extant mammals that are venomous, the Solenodon's venomous saliva flows from modified salivary glands through grooves on their sharp incisors ("solenodon" derives from the Greek for "grooved tooth"). They also have several other primitive and very unusual characteristics for a mammal: very large claws, a flexible snout with a ball-and-socket joint, and oddly positioned teats, which are on their rear. While the mammalian tree of life has been heavily researched, this is the most distantly related branch to be added to the 'genome club'. It has particular importance and implications for conservation because morphometric studies have suggested that southern and northern Hispaniolan solenodons may be subspecies rather than separate species.

Solenodon is not just genetically but also geographically isolated. Highly endangered, they remain only in a few remote corners of the Caribbean islands of Cuba and Hispaniola. Its nocturnal lifestyle makes it even more elusive and therefore less studied. Thus, it was crucial for the researchers to work with local experts at the Instituto Tecnológico de Santo Domingo and Universidad Autónoma de Santo Domingo and with local guides who helped them track and ambush passing solenodons at night.

One of the lead authors, Dr Juan Carlos Martinez-Cruzado, noted that "local resources are absolutely necessary for this kind of work; only they truly know their animal's behavior." He added, "this project may open doors to many others to come, and we always assumed this to be one of many projects that will help research, education and conservation efforts in the Dominican Republic."

For this project, there was more than just the challenge of obtaining the organisms for blood samples, the solenodon genome proved particularly difficult to sequence. Carrying out genomics research in remote parts of the Caribbean provided a challenge, particularly in transporting high quality DNA to the lab. Due to the constraints of poor quality DNA as well as a limited budget, the commercial lab used to carry out the sequencing turned out a very low coverage per individual.

Having already ventured into the jungle, the researchers embraced this new challenge by coming up with novel approaches to assemble the genome. First, the researchers reasoned that because the species has existed for tens of millions of years in isolation, it was extremely inbred and had a very homozygous genome. This lead to a potential work-around, because the five collected sets of genomic data could be pooled to increase the coverage. Despite initial doubts, this worked better than expected especially when that strategy was combined with using a string graph approach rather than the more standard de Brujn graph assembly method. String graphs incorporate more of the sequencing data than de Brujn graphs. Based on the results here, this new technique provides a low budget alternative for genome assembly, particularly in the highly homozygous genomes of endangered species.

The first author of the paper, Kirill Grigorev elaborates: "For me, perhaps the most interesting part of this research was the challenge of delivering a de novo genome assembly that was suitable for comparative genomics, using an amount of sequencing data much smaller than in other similar projects."

After carrying out their assembly, the researchers had data of sufficient quality for answering many scientific questions on solenodon evolution. With regard to conservation plans, the data supports that there was a subspecies split within the Hispaniolan solenodon at least 300,000 years ago, meaning the northern and southern populations should be treated as two separate conservation units and may therefore need independent breeding strategies.

These data also shed light on the initial speciation event for this branch, and showed that solenodons likely diverged from other extant mammals 73.6 million years ago. Dr. Oleksyk said: "We have confirmed the early speciation date for Solenodons, weighing on the ongoing debate on whether the solenodons have indeed survived the demise of dinosaurs after the asteroid impact in the Caribbean."

Source: GigaScience [March 16, 2018]