Tag Archives: South America

America’s first human inhabitants

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This video from the USA is called America’s National Treasures: Prehistoric American Indians.

From the Universidad de Barcelona in Spain:

Towards the origin of America’s first settlers

17 April 2013 Universidad de Barcelona

The most supported traditional hypothesis points out that the earliest well-established human culture in the North American continent were the Clovis, a population of hunters who arrived about 13,000 years before present from North-East Asia through the Bering Strait, and scattered over the continent. A new genetic study of South American natives, published on the journal PLOS Genetics, provides scientific evidence to reformulate the traditional model and define new theories of human settlement of the Americas. Professor Daniel Turbón, from the Department of Animal Biology of the University of Barcelona, is one of the authors of this international research, led by Lutz Roewer (Charité – University Medicine, Berlin). Eduardo Arroyo-Pardo and Ana Maria López Parra (Complutense University of Madrid) also sign the paper.

Which was the earliest well-established culture in America?

This new research is based on the analysis of male Y-chromosomal genetic markers in about one thousand individuals, representing 50 tribal South American native populations. According to the authors, the extant genetic structure of South America native populations is largely decoupled from the continent-wide linguistic and geographic relationships. This finding evidences that the initial human settlement of the Americas was not a single migration process —regardless of whether it took place through the Bering Strait—, but rapid peopling, followed by long periods of isolation in small tribal groups.

Profesor Daniel Turbón, expert on molecular and forensic anthropology and the origin and evolution of hominids, states that “Probably, America is one of the most recent examples of human settlement of a large continent. For scientists, it constitutes an excellent laboratory to compare the methodological tools used on genetic and population studies. Even if it has been widely held, the hypothesis of a single migration movement to explain the origin of America’s settlers is a reductionist view which is more and more questioned”.

Studies of Y-chromosomal markers

Authors analyse the genetic variation of every male individual by means of a series of Y-chromosomal genetic markers: to be exact, 919 subjects (91 % of the total) were typed for the 16 most common single nucleotide polymorphisms (SNP) in South America, and for the 17 short tandem repeat (STR) most widely used in forensic anthropology. The analysis of polymorphisms enabled to determine each individual’s geographical origin and to compare these data with other populations from North and Central America.

The research presents also a powerful international database on forensic genetics based on relevant collective studies (with native atomized small populations) developed by the international co-authors. The experts Francesc Bert and Alfons Corellas, both authors of doctoral theses supervised by Professor Daniel Turbón, also represent UB’s participation in the research.

“Nowadays, science is strongly atomized”, affirms Turbón. “On the one hand, many published researches are based on small population samples and use few genetic markers. That prevents us to observe the global scene. On the other hand, there are some macro genetic studies that show a wider scene, but it is difficult to compare them due to methodological reasons. Studies with biological samples are also carried out; samples come from hospitals located at large population centres with a high hybridization level. Native communities, which usually live in a more isolated way, are becoming scarcer”.

Native communities in danger of extinction

The paper published in PLOS Genetics identifies also a lineage which has not been described to date in North and Central American populations: C-M217 (C3*) haplotype, which occur at high frequency in Asia. Moreover, experts detected a Polynesian lineage in Peru.

The international scientific community faces the exciting challenge of discovering the origin of America’s first settlers. This new publication shapes some alternatives to the hypothesis of a single migration movement —which denies any trans-Pacific migration with remarkable effects on population’s genetics— as a model to describe America’s population origin.

“In the future, it would be essential to find an archaeological site which has a continuous archaeological sequence. Furthermore, it would be necessary to develop a complete genetic study of native populations as their danger of extinction is increasing day by day”, concludes Professor Turbón.

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Amphibian mothers feed young with their skins, new discovery

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Young Microcaecilia dermatophaga caecilians eating their mother's skin, photo: Emma Sherratt et al., PLoS ONE

From PLOS ONE:

A New Species of Skin-Feeding Caecilian and the First Report of Reproductive Mode in Microcaecilia (Amphibia: Gymnophiona: Siphonopidae)

Mark Wilkinson, Emma Sherratt, Fausto Starace, David J. Gower

Abstract

A new species of siphonopid caecilian, Microcaecilia dermatophaga sp. nov., is described based on nine specimens from French Guiana. The new species is the first new caecilian to be described from French Guiana for more than 150 years. It differs from all other Microcaecilia in having fewer secondary annular grooves and/or in lacking a transverse groove on the dorsum of the first collar. Observations of oviparity and of extended parental care in M. dermatophaga are the first reproductive mode data for any species of the genus. Microcaecilia dermatophaga is the third species, and represents the third genus, for which there has been direct observation of young animals feeding on the skin of their attending mother. The species is named for this maternal dermatophagy, which is hypothesised to be characteristic of the Siphonopidae.

Introduction

Kupfer et al. [1] discovered a novel form of extended parental care in the oviparous African herpelid caecilian Boulengerula taitanus in which altricial hatchlings feed upon the modified and lipid-rich outer layer of the skin of their attending mothers using a specialised deciduous juvenile dentition.

Subsequently, Wilkinson et al. [2] reported the putatively homologous behaviour and associated morphological and physiological features of maternal dermatophagy in a second species of caecilian, the Neotropical siphonopid Siphonops annulatus. Because these two species of skin-feeding caecilians are not particularly closely related and represent lineages that have been separated for more than 100 million years, Wilkinson et al. [2] suggested that skin feeding was a relatively ancient trait and predicted that it would prove to be more widespread among caecilians.

The Neotropical siphonopid genus Microcaecilia Taylor, 1968 includes eight previously described nominal species of relatively small caecilians with heavily ossified, stegokrotaphic skulls, and small eyes that are covered with bone [3] which suggest they are dedicated burrowers. Very little is known of their biology and there are no previous reports of the reproductive biology of any Microcaecilia. Here we describe a new species of Microcaecilia from French Guiana. Observations of reproduction in captivity reveal that this is a third caecilian species known from direct observation to practice maternal dermatophagy. The species is identified as a member of the Siphonopidae on the basis of being an oviparous caecilian with imperforate stapes and no inner mandibular teeth, and as a Microcaecilia on the basis of having eyes under bone, tentacular apertures closer to the eyes than the nares, and no diastemata between the vomerine and palatine teeth [4].

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Lizards endangered by climate change

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This video says about itself:

Shining Tree Iguana (Liolaemus nitidus)

* Family: Iguanidae,

* Genus: Liolaemus,

* Species: L. nitidus,

* Phylum: Chordata,

* Class: Reptilia,

* Order: Squamata,

* Type: Reptile,

* Diet: omnivorous

* Average life span in the wild: no data,

* Size: no data,

* Weight: no data,

** Liolaemus nitidus is a species of lizard in the Iguanidae family. It is endemic to Chile.

From Wildlife Extra:

Some lizards particularly vulnerable to climate change

Lizards facing mass extinction

March 2013. Climate change could see dozens of lizard species becoming extinct within the next 50 years, according to new research. The often one-directional evolutionary adaptation of certain lizard species’ reproductive modes could see multiple extinctions as the global temperature increases.

Viviparous lizards at risk

Globally it has been observed that lizards with viviparous reproduction (retention of embryos within the mother’s body) are being threatened by changing weather patterns. The new study suggests that the evolution of this mode of reproduction, which is thought to be a key successful adaptation, could, in fact, be the species’ downfall under global warming.

Dr Daniel Pincheira-Donoso, from the School of Life Sciences at the University of Lincoln (UK), is the lead author of the paper detailing these amazing predictions, published in the scientific journal Global Ecology and Biogeography.

Researchers, including academics from the University of Exeter, investigated the hypothesis that historical invasions of cold climates by Liolaemus lizards – one of the most diverse groups of vertebrates on earth – have only been possible due to their evolution to viviparity (live birth) from oviparity (laying eggs). Remarkably, once these species evolve viviparity, the process is mostly irreversible and they remain restricted to such cold climates.

Viviparous lizards are facing extinction in the next few decades.

By analysing this evolutionary transition in the lizards’ reproductive modes and projecting the future impact of climate change, the scientists discovered that increasing temperatures in the species’ historically cold habitats would result in their areas of distribution being significantly reduced. As a consequence, if global warming continues at the same rate, viviparous lizards are facing extinction in the next few decades.

Dr Daniel Pincheira-Donoso is one of the few people in the world who works on the ecology and evolution of these lizard species. He said: “Lizards’ reproduction is largely linked to climatic temperatures and viviparous species are usually found in cold environments. When reptiles initially moved to colder areas they needed to evolve emergency measures to succeed in these harsh places, and we believe viviparity is one of these key measures. However, this transition is mostly one-directional and unlikely to be reversed. Rapid changes in the environment’s temperature would demand rapid re-adaptations to secure the species’ survival. Through the research we found that over the next 50 years nearly half of the area where these species occur may disappear, causing multiple extinctions due to climate change.”

Overall the conclusion is that although viviparity allowed lizards in the past to invade and adapt to live in cold environments, and was therefore a key trait for evolutionary success, it will now ultimately lead to multiple events of extinction.

Dr Pincheira-Donoso said: “These lizards are one of the most diverse groups of animals, and are able to adapt to remarkably diverse conditions. Unfortunately, a reduction in cold environments will reduce their areas of existence, which means that their successful evolutionary history may turn into a double-edged sword of adaptation. Their extinctions would be an atrocious loss to biodiversity.”

Climate change must not be underestimated

Dr Dave Hodgson, from the University of Exeter, said: “Climate change must not be underestimated as a threat to modern patterns of biodiversity. Our work shows that lizard species which birth live young instead of laying eggs are restricted to cold climates in South America: high in the Andes or towards the South Pole. As the climate warms, we predict that these special lizard species will be forced to move upwards and towards the pole, with an increased risk of extinction.”

The work formed part of Dr Pincheira-Donoso’s post-doctoral work, which was funded by the Leverhulme Trust.

The paper ‘The evolution of viviparity opens opportunities for a lizard radiation but drives it into a climatic cul-de-sac’ is published in the latest issue of the peer-reviewed journal Global Ecology and Biogeography.

Dr Pincheira-Donoso will continue his research at the University of Lincoln by developing projects to investigate the ecology of evolutionary adaptations and its interactions with human-induced climate change.

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Monkeys ride capybara, photo

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Friends in Low Places Supervliegzus 2010/Getty Images

Popular Science writes about this photo:

Megapixels: Monkeys Take A Ride On The World’s Largest Rodent

Wheeeeeeee!

By Susan E. Matthews

Posted 03.15.2013 at 3:30 pm

In the rainforests of South America, squirrel monkeys and capybaras would never meet. While squirrel monkeys live in trees up to 60 feet high, capybaras—the world’s largest rodents—dwell along river banks.

But at the Beekse Bergen Safari Park in the Netherlands, the two species have shared an enclosure for eight years now, and they seem to be friends. The monkeys ride and groom the capybaras. They even eat and play together. Interspecies relationships are more frequent between captive animals, says behavioral ecologist Marc Bekoff. Because keepers feed them, they can spend time getting to know their enclosure mates instead of foraging for food. In 2005, a similar arrangement at a zoo in Japan went sour when a capybara mauled a monkey to death. But Bekoff says that, for the most part, zoos are safe environments for odd relationships.

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Operation Condor trial in Argentina

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This video is called Investigating Operation Condor – 52 minute documentary – trailer.

By Bill Van Auken from the USA:

Operation Condor trial begins in Argentina

7 March 2013

A trial that opened Tuesday in Buenos Aires is the first to consider the totality of crimes carried out under Operation Condor, a coordinated campaign by various US-backed Latin American dictatorships in the 1970s and 1980s to hunt down, torture and murder tens of thousands of opponents of those regimes.

Condor was prosecuted in the name of a crusade against “terrorism.” Its methods in many ways prefigured the systematic and continuing crimes carried out by the US government decades later with its use of “extraordinary rendition,” torture and “targeted killings.”

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Suriname conservation, video

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This video says about itself:

Jan 8, 2013

In the latest “Where on Earth is Russ?” video report,​ Conservation International President Russ Mittermeier takes you into the Central Suriname Nature Reserve—an area CI helped to establish that is now designated as a UNESCO World Heritage Site for its pristine tropical rainforest.

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Good South American tapir news

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This video is called Mammals of the World: Lowland Tapir.

From Wildlife Extra:

Huge population of tapir discovered on Peru – Bolivian border

Paradise found for Latin America’s largest land mammal – WCS documents at least 14,500 lowland tapirs thriving in Peru and Bolivia‘s Madidi-Tambopata Landscape

January 2012. Wildlife Conservation Society (WCS) scientists have documented a thriving population of lowland tapirs – the strange forest and grassland-dwelling herbivore with the trunk-like snout – living in a network of remote national parks spanning the Peru-Bolivia border.

Camera traps

Using a combination of camera traps, along with interviews with park guards and subsistence hunters, WCS estimates at least 14,500 lowland tapirs in the region. The population bridges five connected national parks in northwest Bolivia and southeastern Peru. The study brings together 12 years of research on lowland tapirs in the region. Together with WCS studies on jaguars, the results underscore the importance of this protected area complex for the conservation of Latin America’s most charismatic terrestrial wildlife species.

Madidi-Tambopata

“The Madidi-Tambopata landscape is estimated to hold a population of at least 14,500 lowland tapirs making it one of the most important strongholds for lowland tapir conservation in the continent,” said the study’s lead author Robert Wallace. “These results underline the fundamental importance of protected areas for the conservation of larger species of wildlife threatened by hunting and habitat loss.”

Largest terrestrial mammal in South America – Threatened by habitat loss and hunting

The lowland tapir is the largest terrestrial mammal in South America, weighing up to 300 kg (661 pounds). Its unusual prehensile proboscis or snout is used to reach leaves and fruit. Tapirs are found throughout tropical forests and grasslands in South America. However, they are threatened by habitat loss and especially unsustainable hunting due to their large size, low reproductive rate (1 birth every 2-3 years), and ease of detection at mineral licks in the rainforest. Lowland tapirs are considered Vulnerable by the IUCN.

WCS collected and systematized 1,255 lowland tapir distribution records in the region. These records came from research observations and camera trap photographs as well as interviews with park guards of Madidi, Pilón Lajas and Apolobamba National Parks in Bolivia, and Bahuaja Sonene and Tambopata National Parks in neighboring Peru, and subsistence hunters from 19 Takana and Tsimane’ communities.

Camera trap data revealed that lowland tapir abundance was higher at sites under protection than sites outside protected areas. At one site sampled over time, the Tuichi River, camera trapping has revealed that lowland tapir populations have been recovering following the creation of Madidi National Park in 1995. Prior to the creation of the park, loggers had hunted heavily in this area.

Madidi National Park

Madidi National Park contains 11 percent of the world’s birds, more than 200 species of mammals, 300 types of fish, and 12,000 plant varieties. The 19,000 square-kilometre (7,335 square mile) park is known for its array of altitudinal gradients and habitats from lowland tropical forests of the Amazon to snow-capped peaks of the High Andes.

Working with government partners in Bolivia and Peru, the Greater Madidi-Tambopata Landscape Conservation Program aims to develop local capacity to conserve the landscape and mitigate a variety of threats to biodiversity and wildlife including lowland tapirs, including road construction, logging, unsustainable natural resource use, and agricultural expansion.

Julie Kunen, WCS Director of Latin America and Caribbean Programs said: “WCS commends our government and indigenous partners for their commitment to the Madidi-Tambopata Landscape. Their dedication is clearly paying off with well-managed protected areas and more wildlife.”

WCS’s conservation research in the Madidi-Tambopata Landscape has been made possible by the Gordon and Betty Moore Foundation, The John D. and Catherine T. MacArthur Foundation, the blue moon fund, USAID, the Beneficia Foundation, the Disney Worldwide Conservation Fund, Woodland Park Zoo, and other generous supporters.

The WCS findings were described in the December issue of the journal Integrative Zoology. Authors include Robert Wallace, Guido Ayala, and Maria Viscara of WCS’s Greater Madidi-Tambopata Landscape Program.

February 2013. The Critically Endangered subspecies of Colombian Tapir has been rediscovered in the Paujil Nature Reserve after being considered extinct in the Magdalena Valley rainforests of central Colombia. Camera trap photos and fresh tracks of this rare creature from the Paujil Reserve demonstrate that the purchase and active protection of the last remnant of rainforest in the Magdalena Valley can make a real difference to saving species on the edge of extinction: here.

Malaysia may be home to more Asian tapirs than thought: here.

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Strange fossil mammal discovery

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From Discovery News:

Scrappy Mammal Survived Dinosaur Extinction

Jennifer Viegas
Analysis by Jennifer Viegas
Mon Nov 19, 2012 02:55 PM ET

Necrolestes patagonensis, Reconstruction by Jorge Gonzalez, Copyright Guillermo W. Rugier

A scrappy family of mammals with unusual, mismatched features moved underground and, like living in a perpetual bomb shelter, managed to survive the mass extinction event 65 million years ago that wiped out the world’s non-avian dinosaurs. We know this thanks to new research on the fossil mammal Necrolestes patagonensis, whose name translates to “grave robber,” referring to its burrowing and underground lifestyle. The animal, described in the latest Proceedings of the National Academy of Sciences, had an upturned snout, a sturdy body structure, and short, wide legs.

It lived 16 million years ago, long after the dinosaur demise. But it was found to be related to another fossil mammal, Cronopio, which belonged to the Meridiolestida, a little-known group of extinct mammals from the Late Cretaceous and early Paleocene (100–60 million years ago) of South America.

Cronopio and Necrolestes share a number of features in common, including the fact that they are the only known mammals to have single-rooted molars. Most mammals have double-rooted molars.

The animals were so odd and puzzling, at least to modern eyes, that they mystified scientists for years.

“Necrolestes is one of those animals in the textbooks that would appear with a picture and a footnote, and the footnote would say ‘we don’t know what it is,’” co-author John Wible of the Carnegie Museum of Natural History said in a press release.

For a long time it was thought that “grave robber” was a marsupial. Further analysis, however, found that Necrolestes actually belonged in a completely unexpected branch of the evolutionary tree believed to have died out 45 million years earlier than the time of Necrolestes.

This is an example of the Lazarus effect, in which a group of organisms is found to have survived far longer than originally thought. (“Lazarus” comes from the Bible story about how Jesus raised a man from the dead.)

“It’s the supreme Lazarus effect,” said Wible. “How in the world did this animal survive so long without anyone knowing about it?”

A good example of the Lazarus effect is the ginkgo tree, thought to be extinct until it was rediscovered growing in China in the 17th century.

The researchers believe that Necrolestes’s supreme burrowing adaptations are exactly what enabled it to survive for 45 million years longer than its relatives.

“There’s no other mammal in the Tertiary of South America that even approaches its ability to dig, tunnel, and live in the ground,” explained Wible. “It must have been on the edges, in an ecological niche that allowed it to survive.”

See also here.

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