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Why the Assassin Bug More Than Lives Up to Its Name

Smithsonian Magazine
The assassin bug's deadly proboscis is both sword and siphon. It uses its sharp nose to pierce and inject toxins into its victims

Myth and Reason on the Mexican Border

Smithsonian Magazine
The renowned travel writer journeys the length of the U.S.-Mexico border to get a firsthand look at life along the blurry 2,000-mile line

Textile Waste Comes in Many Forms

Cooper-Hewitt, National Design Museum
Luisa Cevese using yarn waste. Courtesy of Reidizioni.What defines pre-consumer textile waste?

Kudos Affiliates! June 2018

Smithsonian Affiliates

Congratulations to these Affiliates on their recent accomplishments! Do you have a kudos to share? Please send potential kudos to Aaron Glavas, GlavasC@si.edu. Funding Conner Prairie (Fishers, Indiana) announced a partnership with Ritz Charles to invest approximately $3 million to renovate and expand Eli Lilly’s historic Chinese House. Support for the project includes a $500,000 pledge […]

The post Kudos Affiliates! June 2018 appeared first on Smithsonian Affiliations.

Oldest Stone Tools Outside Africa Unearthed in China

Smithsonian Magazine

Throughout the 20th century, the widely accepted story of humanity’s migration from Africa began with a human ancestor called Homo erectus, a relatively big-brained, tall species of hominin that began to venture all across Asia more than a million years ago. But in recent decades, new evidence has begun to punch holes in that timeline. Now, reports Carl Zimmer at The New York Times, new stone tools unearthed in China indicate someone made it 8,000 miles from Africa to east Asia as far back as 2.12 million years ago, and that someone probably wasn’t Homo erectus.

Zimmer reports that back in 1964, researchers found the skull of a Homo erectus in the Lantian area of the Shaanxi province, which at the time they placed at around 1.15 million years. When researchers revisited the Lantian site in the early 2000s, however, they determined that the layer the skull came from was older—about 1.63 million years old. They also noticed what appeared to be stone tools embedded 200 feet up in a cliff face.

That observation led to 13 years of painstaking excavations. During that time, the team found that various human ancestors occupied the site in Shangchen’s southern Chinese Loess Plateau between 1.26 and 2.12 million years ago. According to their study, published in the journal Nature, the researchers uncovered 80 stone artifacts found in 11 layers of soil deposited when the climate was warm and wet. They also uncovered 16 artifacts in six layers that date to a time when the climate conditions were colder and drier.

Most importantly, they were able to date the layers of soil using a technique called paleomagnetism by looking at certain minerals which align with the Earth’s magnetic field, which occasionally flip flops. The oldest artifacts were found in a layer sandwiched between rock formed 2.14 million years ago and 1.85 million years ago. Based on their position, the researchers estimate six of the tools are 2.12 million years old, making them the oldest stone tools found outside Africa.

The finding doesn’t necessarily indicate that it was Homo erectus which made it to China faster than previously thought. It’s believed Homo erectus hadn’t even evolved by this point, so the artifacts could suggest that a whole other species of hominins expanded east to Asia.

“The implications of all this are large,” Michael Petraglia, a paleoanthropologist at the Max Planck Institute not involved in the study, tells Zimmer. “We must re-evaluate our understanding of human prehistory in Eurasia.”

So if it wasn’t Homo erectus, who was living in China so long ago? A trove of fossils unearthed in Dmanisi, Georgia, which was the previous oldest hominin site outside of Africa, may shed some light. It included stone tools and, more importantly, part of a skull from a relatively small-brained, short hominin. It’s possible that this species or one like it expanded across Eurasia first.

Then again, perhaps we don't have the dates for Homo erectus nailed yet. “It is entirely possible that Homo erectus occupied China at this time, but given the age of the site, and the possibility that artifacts may be found at even earlier ages, another member of the genus Homo may be occupying Asia, such as a Homo habilis-like ancestor,” Petraglia tells Michael Greshko at National Geographic.

Rick Potts, the head of the Smithsonian Institution’s Human Origins Program, agrees, telling Zimmer that he believes that some Homo erectus-like fossils older than 2.1 million years old may still be found in Africa, making it plausible that a larger human-like hominin made the artifacts found in Lantian.

Just because this species made it out of Africa, however, doesn’t mean that they are somehow the ancestor of modern humans. There were likely many species or populations of hominins that left Africa, only to die out somewhere in their journey across the globe. “Some populations got all the way over to eastern Asia, but we have to imagine that these were small, sort of hunting-and-gathering populations,” Petraglia tells Robinson Meyer at the Atlantic. “And while they may have mated across East Asia, it doesn’t mean they survived for a long period of time. Some populations might have become isolated, and some might have become extinct.”

Some might have even gone on to develop into other species, like the Indonesian Homo floresiensis (dubbed the “hobbits” by the media) who may have evolved much earlier than first thought, according to recent research.

It’s unlikely this will be the only discovery about early humans to come out of China. While most paleoanthropologists have spent most of their time and resources searching for hominins in Africa, an increase in fieldwork in China and the rest of Asia is sure to dig up a few more surprises about our increasingly complex human family tree.

Coral Reefs Need Fewer Rats and More Bird Poo

Smithsonian Magazine

Coral reefs are facing many threats, including agricultural runoff, coastal development, overfishing and rising sea temperatures. But one threat has more or less flown under the radar: Some reefs lack enough bird poop. Ed Yong at The Atlantic reports that a new study in the journal Nature shows that reefs around islands where seabird populations are thriving—and defecating—clearly fare much better than those where bird populations have been wiped out.

The study was made possible by an accidental experiment. The Chagos Archipelago is an isolated group of 60 or so largely uninhabitated islands in the middle of the Indian Ocean. During the eighteenth and nineteenth centuries, sailors stopping in the area brought with them black rats, which colonized about two thirds of the islands, decimating seabird populations. The other islands are rat free and contain huge colonies of seabirds. In the 1960s, the few Chaggosians in the archipelago were relocated to make way for an American military base on Diego Garcia, the largest of the atolls. So for over 40 years, the rats have been allowed to roam free without human interference and the islands with birds have also been left to nature.

That’s why the Chagos are a perfect place to study the impact of rats—which have infested 90 percent of the globe’s island groups—on bird populations. The team examined six rat-infested islands and six rat-free islands, finding the ecological harm of the rodents extends into the soil and hundreds of feet out to sea, even impacting coral reefs.

The biggest difference, of course, is that the rat-free islands are full of birds—bird density was 760 times higher. “Islands with no rats are noisy, their skies are full of birds, and they absolutely stink of guano,” lead author Nick Graham from Lancaster University tells Yong. “But if you step foot on an island with rats, the skies are empty, it’s quiet, and it doesn’t smell. The difference is unbelievable.”

All those birds, incuding boobies, frigatebirds, noddies, shearwaters and terns, poop. Their guano adds the nutrient nitrogen to the islands, leading to big changes in the ecosystem. According to a press release, not only does that nitrogen make its way into the soil, plants and shrubs on the island, the team found it also leaches into the sea where it spurs the growth of algae and sponges. In fact, there were 50 percent more fish in the reefs around the birdy islands versus the ratty islands. Those fish contained more nitrogen and grew larger. And algae grazing, in which species like parrot fish nibble away algae and dead coral from the reefs stimulating new coral growth, happened 3.2 times as often around the birdy banks. “It was mind-boggling to see just how strong the differences are, across the board, for everything we looked at,” Graham tells Yong.

While the fact that rats have decimated entire ecosystems is sobering, it’s also good news in a way. While stopping pollution and climate change are monumental tasks, eradicating rats is low-hanging fruit—humans are pretty good at pest control and Yong reports rats have been eliminated from 580 islands globally so far, with projects getting even more ambitious. In fact, just last May, South Georgia Island near Antarctica, which has been plagued by rats for centuries, finished a $13 million, decade-long rat eradication, the largest ever conducted. It was officially declared rodent-free and its endangered native birds and other wildlife now have a fighting chance. New Zealand, home to tons of rare endemic species being gobbled up by rats, cats, weasels and other invasive species, is undertaking a monumental campaign to eradicate non-native mammals by 2050. Even the Chagos Islands themselves have seen some success. Last year, the Chagos Conservation Trust announced that rats had been exterminated from Ile Vache Marine, an important bird habitat.

The study shows that rat eradication projects are even more important than previously thought. “These results show how conservation can sometimes be a bloody business, where doing right by the ecosystem means there is a time to kill,” co-author Aaron MacNeil of Dalhousie University says in the press release. “For these invasive rats, that time is now."

Graham tells Victoria Gill at the BBC that rat eradication could also help mitigate the impacts of climate change, since healthier reefs are more resilient and can probably recover faster from warm-water bleaching events. And the Chagos need all the help they can get. A bleaching event in 2015 and 2016 damaged or killed 85 percent of the corals in the archipelago, which may never fully recover.

Fresh Plaid

Cooper-Hewitt, National Design Museum
Textile, 2014, USA, designed by Wallace Sewell, manufactured by Designtex, twill and satin weave wool, Gift of Designtex Group, 2016-14-8New York-based textile design firm Designtex collaborated with Harriet Wallace-Jones and Emma Sewell of the British textile studio Wallace Sewell to create series of wool upholstery fabrics showcasing the duo’s signature sophisticated color work. Wallace Sewell is well-known for their colorful woven home and fashion accessories, but had not previously designed for the built environment....

Diagonal Plaid

Cooper-Hewitt, National Design Museum
Textile, 1930–31, USA, designed by Donald Deskey (American, 1894–1989), screen printed linen, Museum purchase through bequest of Ida C. McNeil in memory of Lincoln C. McNeil and Catherine McNeil, 1989-86-1Industrial designer Donald Deskey, along with his contemporaries, Norman Bel Geddes and Gilbert Rohde, adapted austere European Modernism to be palatable for the American taste. Deskey introduced novel ideas with the use of new materials such as Bakelite, aluminum, Permatex, and rayon. He was sensitive to budget constraints of the 1930s consumer, an offered a...

Off His Rocker: Prince Rupert and the Mezzotint

Cooper-Hewitt, National Design Museum
Proudly displaying his royal, albeit long-embattled standing, Prince Rupert of the Rhine (1619-1682) placed a crown on his initials in the top right corner of his 1662 mezzotint, Head of the Executioner. Besides his impressive lineage, the Prince is also credited with revolutionizing the mezzotint printing process. Mezzotint is a printing method in which the...

Fascinating Rhythms: Music of the Jazz Age

Cooper-Hewitt, National Design Museum
James Stalzman of the Manhattan School of Music discusses the musical pieces he paired with particular objects from The Jazz Age: American Style in the 1920s.

Façade, Remembered

Cooper-Hewitt, National Design Museum
The ephemeral Midtown Manhattan edifice of the American Folk Art Museum, once described as a “handsome flake of metallic crystal glinting on West 53rd Street,” lives on thanks to sketches like this one, donated by Tod Williams Billie Tsien Architects (TWBTA) to Cooper Hewitt shortly after the building was completed in late 2001. Unveiled “at...

Historical land use and stand age effects on forest soil properties in the Mid-Atlantic US

Smithsonian Libraries
The conversion of agriculture lands to forest has been occurring in parts of North America for decades. The legacy of management activity during this transition is reflected in soil physical and chemical properties years after abandonment. This study was conducted at the Smithsonian Environmental Research Center, Maryland, USA, to determine land-use history and forest age effects on soil nutrients, carbon, pH, and bulk density. Soils in young and old successional forests and forests with no evidence of historical disturbance were sampled. The young forest stands were abandoned from agriculture 50-70 years ago and the old forest stands had been abandoned from agriculture or grazing 120-150 years ago. The oldest forest stands had no recorded history of disturbance even though it is likely they were at least disturbed by tree removal or grazing of animals in the colonial era. Young forest soils had higher concentrations of Mg, Ca, NO3 and a higher pH than old, which may be an age effect. The old forest soils that had been abandoned from agriculture and grazing had higher bulk density and lower C content than undisturbed stands indicating a land-use effect. In the stands that were formally agriculture there was evidence of erosion, indicated by a Bt horizon closer to the surface. The most evident difference between stands of different land-use history was the absence of a well-developed O horizon, which we attribute to the presence of earthworms. Land-use legacy set the forest ecosystem in a different trajectory of soil evolution.

Lampridae, opahs

Smithsonian Libraries

Niche construction and optimal foraging theory in Neotropical agricultural origins: A re-evaluation in consideration of the empirical evidence

Smithsonian Libraries
The various theoretical approaches advanced over the past 50 years to explain the origins of agriculture have prompted much discussion and debate. Most recently, controversy has arisen concerning the utility of two Darwinian approaches; namely, cultural niche construction (CNC) and human behavioral ecology-derived optimal foraging theory (OFT). Recent papers advocate for the primacy of cultural niche construction, calling for optimal foraging approaches to be all but disregarded in the quest to explain how and why foragers became farmers (Smith, 2015, 2016; Zeder, 2015, 2016). In particular, it is claimed that archaeological, paleo-environmental, and paleontological evidence from the Neotropics of northern South America fail to meet predictions derived from OFT theory, while predictions said to be derived from CNC-based approaches are supported (Smith, 2015, 2016; Zeder, 2015). However, a number of misreadings of the northern South America evidence are made in those discussions, while some pertinent literature is not considered. In this paper we discuss these misreadings and provide a clear re-articulation of the original data and interpretations, finding support for OFT predictions. Our re-evaluations of OFT and CNC further suggest they can, in fact, be complimentary explanatory approaches.

Stratigraphic and Earth System approaches to defining the Anthropocene

Smithsonian Libraries
Stratigraphy provides insights into the evolution and dynamics of the Earth System over its long history. With recent developments in Earth System science, changes in Earth System dynamics can now be observed directly and projected into the near future. An integration of the two approaches provides powerful insights into the nature and significance of contemporary changes to Earth. From both perspectives, the Earth has been pushed out of the Holocene Epoch by human activities, with the mid-20th century a strong candidate for the start date of the Anthropocene, the proposed new epoch in Earth history. Here we explore two contrasting scenarios for the future of the Anthropocene, recognizing that the Earth System has already undergone a substantial transition away from the Holocene state. A rapid shift of societies toward the UN Sustainable Development Goals could stabilize the Earth System in a state with more intense interglacial conditions than in the late Quaternary climate regime and with little further biospheric change. In contrast, a continuation of the present Anthropocene trajectory of growing human pressures will likely lead to biotic impoverishment and a much warmer climate with a significant loss of polar ice.

Can community structure track sea-level rise? Stress and competitive controls in tidal wetlands

Smithsonian Libraries
Climate change impacts, such as accelerated sea-level rise, will affect stress gradients, yet impacts on competition/stress tolerance trade-offs and shifts in distributions are unclear. Ecosystems with strong stress gradients, such as estuaries, allow for space-for-time substitutions of stress factors and can give insight into future climate-related shifts in both resource and nonresource stresses. We tested the stress gradient hypothesis and examined the effect of increased inundation stress and biotic interactions on growth and survival of two congeneric wetland sedges, Schoenoplectus acutus and Schoenoplectus americanus. We simulated sea-level rise across existing marsh elevations and those not currently found to reflect potential future sea-level rise conditions in two tidal wetlands differing in salinity. Plants were grown individually and together at five tidal elevations, the lowest simulating an 80-cm increase in sea level, and harvested to assess differences in biomass after one growing season. Inundation time, salinity, sulfides, and redox potential were measured concurrently. As predicted, increasing inundation reduced biomass of the species commonly found at higher marsh elevations, with little effect on the species found along channel margins. The presence of neighbors reduced total biomass of both species, particularly at the highest elevation; facilitation did not occur at any elevation. Contrary to predictions, we documented the competitive superiority of the stress tolerator under increased inundation, which was not predicted by the stress gradient hypothesis. Multifactor manipulation experiments addressing plant response to accelerated climate change are integral to creating a more realistic, valuable, and needed assessment of potential ecosystem response. Our results point to the important and unpredicted synergies between physical stressors, which are predicted to increase in intensity with climate change, and competitive forces on biomass as stresses increase.

Liana effects on biomass dynamics strengthen during secondary forest succession

Smithsonian Libraries
Secondary forests are important carbon sinks, but their biomass dynamics vary markedly within and across landscapes. The biotic and abiotic drivers of this variation are still not well understood. We tested the effects of soil resource availability and competition by lianas on the biomass dynamics of young secondary tropical forests in Panama and assessed the extent to which liana effects were mediated by soil resource availability. Over a five year period, growth, mortality, and recruitment of woody plants of >=1 cm diameter were monitored in 84 plots in 3-30 y-old secondary forests across the Agua Salud site in central Panama. Biomass dynamics and the effects of lianas and soil resources were examined using (generalized) linear mixed-effect models and a model averaging approach. There was strong spatial and temporal variation in liana biomass within and across the plots. The relative biomass of lianas had a strong negative effect on overall tree growth, growth of understory trees decreased with soil fertility and dry season soil water content, and the effect of lianas on tree mortality varied with soil fertility. Tree recruitment was not associated with any of the predictor variables. Our model indicates that tree biomass growth across our landscape was reduced with 22% due to competition with lianas, and that the effect of lianas increased during succession, from 19% after five years to 32% after 30 years. The projected liana-induced growth reduction after 60 years was 47%, which was consistent with data from a nearby site. Our study shows that the observed liana proliferation across tropical forests may reduce the sequestration and storage of carbon in young secondary forests, with important implications for the carbon balance of tropical forest landscapes and consequently for global climate change. Our study highlights the need to incorporate lianas and soil variables in research on the biomass dynamics of secondary forest across tropical landscapes, and the need for well-replicated longitudinal studies to cover landscape-level variability in the relevant abiotic and biotic components. This article is protected by copyright. All rights reserved.
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