Museum of Natural History
Museum of Natural History
News Article | May 19, 2017
The Garden of the Ediacaran was a period in the ancient past when Earth's shallow seas were populated with a bewildering variety of enigmatic, soft-bodied creatures. Scientists have pictured it as a tranquil, almost idyllic interlude that lasted from 635 to 540 million years ago. But a new interdisciplinary study suggests that the organisms living at the time may have been much more dynamic than experts have thought. Scientists have found It extremely difficult to fit these Precambrian species into the tree of life. That is because they lived in a time before organisms developed the ability to make shells or bones. As a result, they didn't leave much fossil evidence of their existence behind, and even less evidence that they moved around. So, experts have generally concluded that virtually all of the Ediacarans--with the possible exception of a few organisms similar to jellyfish that floated about--were stationary and lived out their adult lives fixed in one place on the sea floor. The new findings concern one of the most enigmatic of the Ediacaran genera, a penny-sized organism called Parvancorina, which ischaracterized by a series of ridges on its back that form the shape of a tiny anchor. By analyzing the way in which water flows around Parvancorina's body, an international team of researchers has concluded that these ancient creatures must have been mobile: specifically, they must have had the ability to orient themselves to face into the current flowing around them. That would make them the oldest species known to possess this capability, which scientists call rheotaxis. "Our analysis shows that the amount of drag produced with the current flowing from front to back is substantially less than that flowing from side to side," said Simon Darroch, assistant professor of earth and environmental sciences at Vanderbilt University, who headed the study. "In the strong currents characteristic of shallow ocean environments, that means Parvancorina would have benefited greatly from adjusting its position to face the direction of the flow." The analysis, which used a technique borrowed from engineering called computational fluid dynamics (CFD), also showed that when Parvancorina faced into the current, its shape created eddy currents that were directed to several specific locations on its body. "This would be very beneficial to Parvancorina if it was a suspension feeder as we suspect because it would have concentrated the suspended organic material making it easier to consume," Darroch said. Details of the analysis are described in a paper titled "Inference of facultative mobility in the enigmatic Ediacaran organism Parvancorina" published online May 17 by the Royal Society journal Biology Letters. These conclusions are reinforced by an independent study performed by a team of Australian researchers published March 30 in the journal Scientific Reports. Analyzing an Ediacaran site in South Australia, they found that the Parvancorina fossils were preferentially aligned in the direction of the prevailing current and determined that this alignment was not passive but represented a rheotactic response at some point in the organism's life history. This is only the second time that CFD has been applied to study Ediacarans. In 2015, the same team of researchers applied this technique to analyze flow patterns around an organism called Tribrachidium heraldicum. This is a disk-shaped organism characterized by three spiraling ridges on its back. In this case, their analysis supported the conclusion that it was the oldest known suspension feeder, dating back to 555 million years. "We decided to stop trying to figure out where these species fit in the tree of life and to try to determine how they were shaped by evolutionary forces," said Darroch. "We wanted to understand how their weird architectures affected how they ate, reproduced and moved. Because they lived in a shallow sea environment, strong currents must have played a major role in their evolution. So computational fluid dynamics is the perfect tool for addressing this question." According to team member Imran Rahman, research fellow at the Oxford University Museum of Natural History, CFD has been used to analyze the design and optimize the performance of a wide variety of structures and machines, ranging from nuclear reactors to aircraft, but it is only in the last few years that they have begun applying it to study the fossil record: "CFD has the potential to transform our understanding of how ancient organisms fed and moved, so I would anticipate that many more paleontologists will start making use of the method in coming years." "When you sit back and think about it, we are virtually recreating ancient oceans, and populating them with digital representations of long extinct organisms that have defied our understanding for over 50 years in order to gain insight on how they lived their day to day lives," added co-author Marc Laflamme, assistant professor of earth science at the University of Toronto Mississauga. "This kind of work would not have been feasible even a decade ago, and I believe it represents the direction that modern paleontology is forging." "The fact that we have now established that one Ediacaran species could move around suggests that our picture of this period may be fundamentally wrong," said Darroch. "There may have been a lot more movement going on than we thought and we intend to apply this technique to other Ediacaran fossils to determine if that was the case." Vanderbilt graduate student Brandt Gibson and Rachel Racicot at the Natural History Museum of Los Angeles County also contributed to the study. The research was supported by National Science Foundation grants DEB 1331980 and PLR 134175 and by National Science and Engineering Research Council of Canada grant RGPIN 435402.
News Article | May 19, 2017
The Garden of the Ediacaran was a period in the ancient past when Earth's shallow seas were populated with a bewildering variety of enigmatic, soft-bodied creatures. Scientists have pictured it as a tranquil, almost idyllic interlude that lasted from 635 to 540 million years ago. But a new interdisciplinary study suggests that the organisms living at the time may have been much more dynamic than experts have thought. Scientists have found It extremely difficult to fit these Precambrian species into the tree of life. That is because they lived in a time before organisms developed the ability to make shells or bones. As a result, they didn't leave much fossil evidence of their existence behind, and even less evidence that they moved around. So, experts have generally concluded that virtually all of the Ediacarans -- with the possible exception of a few organisms similar to jellyfish that floated about -- were stationary and lived out their adult lives fixed in one place on the sea floor. The new findings concern one of the most enigmatic of the Ediacaran genera, a penny-sized organism called Parvancorina, which is characterized by a series of ridges on its back that form the shape of a tiny anchor. By analyzing the way in which water flows around Parvancorina's body, an international team of researchers has concluded that these ancient creatures must have been mobile: specifically, they must have had the ability to orient themselves to face into the current flowing around them. That would make them the oldest species known to possess this capability, which scientists call rheotaxis. "Our analysis shows that the amount of drag produced with the current flowing from front to back is substantially less than that flowing from side to side," said Simon Darroch, assistant professor of earth and environmental sciences at Vanderbilt University, who headed the study. "In the strong currents characteristic of shallow ocean environments, that means Parvancorina would have benefited greatly from adjusting its position to face the direction of the flow." The analysis, which used a technique borrowed from engineering called computational fluid dynamics (CFD), also showed that when Parvancorina faced into the current, its shape created eddy currents that were directed to several specific locations on its body. "This would be very beneficial to Parvancorina if it was a suspension feeder as we suspect because it would have concentrated the suspended organic material making it easier to consume," Darroch said. Details of the analysis are described in a paper titled "Inference of facultative mobility in the enigmatic Ediacaran organism Parvancorina" published online May 17 by the Royal Society journal Biology Letters. These conclusions are reinforced by an independent study performed by a team of Australian researchers publishedMarch30 in the journal Scientific Reports. Analyzing an Ediacaran site in South Australia, they found that the Parvancorina fossils were preferentially aligned in the direction of the prevailing current and determined that this alignment was not passive but represented a rheotactic response at some point in the organism's life history. This is only the second time that CFD has been applied to study Ediacarans. In 2015, the same team of researchers applied this technique to analyze flow patterns around an organism called Tribrachidium heraldicum. This is a disk-shaped organism characterized by three spiraling ridges on its back. In this case, their analysis supported the conclusion that it was the oldest known suspension feeder, dating back to 555 million years. "We decided to stop trying to figure out where these species fit in the tree of life and to try to determine how they were shaped by evolutionary forces," said Darroch. "We wanted to understand how their weird architectures affected how they ate, reproduced and moved. Because they lived in a shallow sea environment, strong currents must have played a major role in their evolution. So computational fluid dynamics is the perfect tool for addressing this question." According to team member Imran Rahman, research fellow at the Oxford University Museum of Natural History, CFD has been used to analyze the design and optimize the performance of a wide variety of structures and machines, ranging from nuclear reactors to aircraft, but it is only in the last few years that they have begun applying it to study the fossil record: "CFD has the potential to transform our understanding of how ancient organisms fed and moved, so I would anticipate that many more paleontologists will start making use of the method in coming years." "When you sit back and think about it, we are virtually recreating ancient oceans, and populating them with digital representations of long extinct organisms that have defied our understanding for over 50 years in order to gain insight on how they lived their day to day lives," added co-author Marc Laflamme, assistant professor of earth science at the University of Toronto Mississauga. "This kind of work would not have been feasible even a decade ago, and I believe it represents the direction that modern paleontology is forging." "The fact that we have now established that one Ediacaran species could move around suggests that our picture of this period may be fundamentally wrong," said Darroch. "There may have been a lot more movement going on than we thought and we intend to apply this technique to other Ediacaran fossils to determine if that was the case."
News Article | May 11, 2017
In the pitch dark, the beam of a head torch illuminates hundreds of bats encircling a silhouetted figure in front of us. It’s Jose, telling us he’s spotted the species we have travelled thousands of miles to a remote underground cave in western Cuba to find – the Cuban greater funnel-eared bat. We move deeper into the cave, treading carefully. Dozens of Cuban boas – some of them 3 meters long – lie strewn across the lunar-like floor. Giant crabs, centipedes and tarantulas scuttle back into their burrows. The wildlife down here is well fed – some of it feasting on guano and unfortunate newborn bats that lose their grip. There are 13 species of bat in this cave – but the greater funnel-eared bat (Natalus primus) is special. Seen only as fossils, the species was thought to be extinct. In 1992, it came back from the dead. Two Cuban scientists stumbled on an apparently sizeable population of the species in a remote cave in western Cuba, nicknamed Cueva la Barca (“the boat cave”). The cave is a crucial habitat as it provides the humid and hot conditions – 40°C in the deepest chamber – that some bat species seem to require for breeding. It might just be the most important cave for bat conservation in the Caribbean. Our hearts race as we spot our first N. primus. Several dozen individuals fly up and down the sinuous cave walls. Its leisurely, aerobatic flight pattern suggests the species makes its living in a very different way from the other bats in this cave. It may be adapted to forage in the dense, tangled understorey of the surrounding forest. N. primus is evolutionarily unique. The species is a top priority species for ZSL’s EDGE of Existence programme. The Natalid family of bats have been evolving in isolation from other bats for around 50 million years, so they represent a disproportionately large share of mammalian evolutionary history. We emerge into the dappled shade of the forest, relishing the deep breaths we can take for the first time all morning. Jose Manuel de la Cruz – a bat expert based at the Pinar del Río Museum of Natural History and our local guide – tells us that he’s worried about how few N. primus we saw. Perhaps fewer than 400. The species desperately needs a long-term monitoring project, but resources for conservation are scarce in Cuba. Trucks rumble past in the distance and Jose tells us foresters are sizing up the area for logging. When N. primus was discovered alive and well, the boundaries of the nearby Guanahacabibes National Park were extended to encompass Cueva la Barca, but only just. The cave lies a mere 250 metres inside the boundary. Presumably, our bat forages outside the park, but we don’t really know. Very little is known about the species. To find out where N. primus goes each night, we deploy dozens of sound traps in the forest – acoustic versions of camera traps, tuned to listen for and record the ultrasonic call of the species. Carolina Soto Navarro, one of the EDGE scientists on the expedition, says the goal is to “find out how the different bat species in this forest partition their use of the habitat, and exactly how far they go from Cueva la Barca”. But the forest doesn’t make it easy. Its floor is covered in dientes de perro (“dog’s teeth”) – the dagger-sharp remains of coral reefs from a bygone era. It tears chunks out of the soles of our boots as we walk gingerly across it. “How many other bat caves remain undiscovered amongst this coral?” Carolina wonders. Cuba is a forgotten trove of biodiversity. Decades of diplomatic tension between the US and Cuba have done little to change this. Our hope is that through continued work with our Cuban colleagues, we can help preserve its treasures and finally unravel the mystery of N. primus.
News Article | May 9, 2017
Fun fact: Australia's custom officials are known for procedures teetering on the absurdly overzealous, thanks to the continent's unique natural environment. But those procedures are under investigation, after officials destroyed "irreplaceable" rare flowering plants sent from France. "They were the first type specimens collected of a species," Michelle Waycott, chair at the Council of Heads of Australasian Herbaria, told ABC News. "That would be the equivalent of material collected in the Flinders expedition, going and then destroying those. So literally irreplaceable collections and of high historic and scientific value." D'oh! These border officials have absolutely zero chill. SEE ALSO: This company is creating a fusion reactor, which is how stars produce energy The plant samples from the Museum of Natural History in Paris dated back to the mid-1800s. It was intended for the Queensland Herbarium, but was destroyed due to paperwork issues in March. In a statement via email, the Department of Agriculture acknowledged "the intrinsic value of the specimens," and conceded that its destruction was "premature." Once the plants were detained, the Queensland Herbarium sent correspondence to an incorrect email address. Ugh. When their information was eventually received, it was not sufficient, and the plants were destroyed in line with policy. RIP, rare flowering plants. A "comprehensive review of this incident" will be undertaken by the department to prevent a similar situation from occurring again. "This is a deeply regrettable occurrence, but it does highlight the importance of the shared responsibility of Australia's biosecurity system, and the need for adherence to import conditions," according to the statement. In a similar incident, New Zealand's Landcare Research Allan Herbarium loaned lichen samples collected in the 1930s to the Australian National Herbarium last year. The loan was to see if lichen found in both countries were similar, but the sample was destroyed by border officials in Sydney. The incident prompted the Allan Herbarium from stopping further samples being sent to Australia until assurances of its safe arrival are made in writing. The department said it was "unaware of this incident," however it is "investigating it as a matter of priority."
News Article | March 1, 2017
Humans: The greatest contributor to diversity of minerals since oxygen; Officially recognized minerals, formed by nature: More than 5,000; Formed due to human activity: 208 Human industry and ingenuity has done more to diversify and distribute minerals on Earth than any development since the rise of oxygen over 2.2 billion years ago, experts say in a paper published today. The work bolsters the scientific argument to officially designate a new geological time interval distinguished by the pervasive impact of human activities: the Anthropocene Epoch. In the paper, published by American Mineralogist, a team led by Robert Hazen of the Carnegie Institution for Science identifies for the first time a group of 208 mineral species that originated either principally or exclusively due to human activities. That's almost 4% of the roughly 5,200 minerals officially recognized by the International Mineralogical Association (IMA). Most of the recognized minerals attributed to human activities originated through mining -- in ore dumps, through the weathering of slag, formed in tunnel walls, mine water or timbers, or through mine fires. Six were found on the walls of smelters; three formed in a geothermal piping system. Some minerals formed due to human actions can also occur naturally. Three in that category were discovered on corroded lead artifacts aboard a Tunisian shipwreck, two on bronze artifacts in Egypt, and two on tin artifacts in Canada. Four were discovered at prehistoric sacrificial burning sites in the Austrian mountains. According to the paper, the first great 'punctuation event' in the history of Earth's mineral diversity occurred more than 2 billion years ago when the increase of oxygen in the atmosphere -- 'the Great Oxidation' -- gave rise to as many as two-thirds of the more than 5,200 mineral species officially recognized today. Says Dr. Hazen, who co-wrote the paper with Edward Grew of the University of Maine, and Marcus Origlieri and Robert Downs of the University of Arizona: "Mineral evolution has continued throughout Earth's history. It has taken 4.5 billion years for combinations of elements to meet naturally on Earth at a specific location, depth and temperature, and to form into the more than 5,200 minerals officially recognized today. The majority of these have arisen since the Great Oxidation event 2 billion years ago. " "Within that collection of 5,200 are 208 minerals produced directly or indirectly by human activities, mostly since the mid-1700s, and we believe that others continue to be formed at that same relatively blazing pace. To imagine 250 years relative to 2 billion years, that's the difference between the blink of an eye (one third of a second) and one month." "Simply put, we live in an era of unparalleled inorganic compound diversification," says Dr. Hazen. "Indeed, if the Great Oxidation eons ago was a 'punctuation event' in Earth's history, the rapid and extensive geological impact of the Anthropocene is an exclamation mark." A mineral species is defined as a naturally occurring crystalline compound that has a unique combination chemical composition and crystal structure. As of February, 2017, the IMA had approved 5,208 species (see rruff.info/ima for a complete list). The authors of the recent paper argue that with so many minerals and mineral-like compounds owing their origin to human activities, "a more comprehensive understanding and analysis of the mineralogical nature of the Anthropocene Epoch is warranted." Humanity has had a major impact on diversity and distribution in the mineral world in three principal ways, according to the paper: 1 a) Manufacturing synthetic "mineral-like" compounds, and b) causing minerals to form as an unintentional byproduct of human activity a) Directly creating synthetic mineral-like compounds such as YAG (yttrium aluminum garnet) crystals used in lasers, silicon "chips" for semi-conductors, carbide grits for abrasives, and various specialty metals and alloys for magnets, machine parts, and tools. Other examples include bricks, earthenware, porcelain, glass and limestone-based Portland cement -- the world's most common form of cement, used in concrete, mortar, stucco and grout -- a combination of calcium silicates, calcium sulfates, and other compounds b) Indirectly contributing to the formation of new minerals through mining, with new compounds appearing on mine walls or in mine dumps, for example. Of special interest are minerals found associated with ancient lead-zinc mining localities, including some possibly dating from the Bronze Age, and others from as far back as 300 AD.? In addition to creating new compounds, human activities such as mining and the transport of stone blocks, rocks, sediments, and minerals from their original location to help build roads, bridges, waterways, monuments, kitchen counters, and other human infrastructure, rivals in scale nature's redistribution such as via glaciers. Mining operations, meanwhile, have stripped the near-surface environment of ores and fossil fuels, leaving large open pits, tunnel complexes, and, in the case of strip mining, sheared off mountaintops. Diamonds, rubies, emeralds, sapphires, and a host of semi-precious stones, accompanied by concentrations of gold, silver, and platinum, are found in shops and households in every corner of the globe. Collections of fine mineral specimens juxtapose mineral species that would not occur naturally in combination. From modest beginner collector sets of more common minerals to the world's greatest museums, these collections, if buried in the stratigraphic record and subsequently unearthed in the distant future, "would reveal unambiguously the passion of humans for the beauty and wonder of the mineral kingdom," the paper says. Says Dr. Downs: "Given humanity's pervasive influences on the environment, there must be hundreds of as yet unrecognized 'minerals' in old mines, smelters, abandoned buildings, and other sites. Meanwhile, new suites of compounds may now be forming in, for example, solid waste dumps where old batteries, electronics, appliances, and other high-tech discards are exposed to weathering and alteration." Adds Dr. Origlieri: "In the sediment layers left behind from our age, future mineralogists will find plentiful building materials such as bricks, cinder blocks, and cement, metal alloys such as steel, titanium, and aluminum, along with many lethal radioactive byproducts of the nuclear age. They might also marvel at some beautiful manufactured gemstones, like cubic zirconia, moissanite, synthetic rubies, and many others." Says Dr. Grew: "These minerals and mineral-like compounds will be preserved in the geological record as a distinctive, globally-distributed horizon of crystalline novelty--a persistent marker that marks our age as different from all that came before." Calclacite, described by a Belgium-based scientist in 1959, and which originated in an old oak storage cabinet for mineral specimens at the Royal Museum of Natural History, Brussels, is an officially recognized mineral that wouldn't qualify today; in 1998 the IMA decided to disallow any substance "made by Man." Other recognized anthropogenic minerals in this category include several slag-related minerals as well as a pair from Russia, niobocarbide and tantalcarbide, which some experts believe may have been a hoax -- "a laboratory product ... deliberately passed off as a natural material" in the early 1900s. Though unlikely to pass scrutiny today, says Dr. Grew, previously recognized minerals such as these, rather than being invalidated, have been allowed to remain in the IMA catalog. The IMA did agree to recognize a mineral in cases "in which human intervention in the creation of a substance is less direct." The origin of up to 29 forms of carbon: humanity Of the 208 human-mediated minerals identified by the Deep Carbon Observatory researchers, 29 contain carbon. Origins and forms, along with movements and quantities, are four themes of the DCO (deepcarbon.net). Dr. Hazen is the DCO's Executive Director. Now we know that as many as 29 carbon minerals originated with human activities, of which 14 have no recorded natural occurrences. It is fair, therefore, to consider the 14 as the youngest carbon mineral species. Among the 14, candidates for the very youngest include a dozen minerals related to uranium mines. The mineral andersonite, for example, is found in the tunnels of certain abandoned uranium mines in the American Southwest. At places along the tunnel walls, sandstone becomes saturated with water that contains elements that form a beautiful crust of yellow, orange and green crystals. Prized for its bright green fluorescent glow under a black light, a good sample of andersonite will fetch up to $500 from a collector. Another notable carbon-bearing mineral is tinnunculite, determined to be a product of hot gases reacting with the excrement of the Eurasian kestrel (Falco tinnunculus) at a burning coal mine in Kopeisk, Chelyabinsk, Russia. It was subsequently discovered also on Russia's Mt. Rasvumchorr -- an entirely natural occurrence. Tinnunculite is one of eight new minerals identified as part of the Deep Carbon Observatory's Carbon Mineral Challenge, launched in 2015 to track down an estimated 145 carbon-bearing minerals yet to be formally recognized. The IMA recognized tinnunculite as a mineral in 2015. Inadvertently produced or human-mediated minerals, occurring or suspected to occur in nature Although yet to be confirmed by the International Union of Geological Sciences, there is growing advocacy for formal recognition of the "Anthropocene Epoch," the successor of the Holocene Epoch, which began some 11,500 years ago when the most recent ice age glaciers began to retreat. Epochs are normally separated by significant changes in the rock layers to which they correspond. A 35-member Working Group on the Anthropocene (WGA) recommended formal designation of the epoch Anthropocene to the International Geological Congress on 29 August 2016. It may be several years before a final decision is reached.? Robert Hazen is Senior Staff Scientist at the Carnegie Institution of Washington, DC, and Executive Director of the Deep Carbon Observatory Edward Grew is a Research Professor, Earth and Climate Sciences, University of Maine Marcus Origlieri is a Research Associate, University of Arizona Robert Downs is a Professor of Geosciences specializing in mineralogy and crystallography, University of Arizona
News Article | February 22, 2017
BOSTON--(BUSINESS WIRE)--Beginning March 1, the Harvard Museum of Natural History, located on the historic Harvard University campus, will join the Boston CityPASS® program. For 20 years, CityPASS ticket booklets have allowed travelers to visit a destination’s top attractions while saving nearly half off combined admission prices. Each 2017 Boston CityPASS booklet includes prepaid, discounted admission to the New England Aquarium, Museum of Science, Skywalk Observatory at the Prudential Center, and a choice between either a Boston Harbor Cruise or the Harvard Museum of Natural History. Blurring the line between science and art, two stunning collections at the Harvard Museum of Natural History are must-sees. The impressive Glass Flowers collection, which was started in 1886 by father and son artists Leopold and Rudolf Blaschka and took more than five decades to complete, features 2,000 dazzling, intricate and botanically precise glass flowers. Years before they were commissioned by Harvard University to create the Glass Flowers, the Blaschkas meticulously shaped glass into lifelike models of marine and terrestrial animals. Sixty of their oceanic creations—delicate jellyfish and anemones, octopus, tentacled squid and bizarre-looking sea slugs captured in glass—are now part of a permanent display titled Sea Creatures in Glass. Once you’ve been dazzled by the glass collections, explore the museum’s 15 remaining galleries and 9,000 additional specimens. See thousands of rare minerals and gemstones, hundreds of mammals and birds, and the new Marine Life gallery. The exhibits document the earth’s evolution from the days of dinosaurs to such modern challenges as climate change and species extinction. As of March 1, the start of the program year, each 2017 Boston CityPASS ticket booklet will save travelers 45 percent off combined admission to the included attractions. Boston CityPASS prices (as of March 1): $56 for adults (a value of $102); $44 for children, age 3-11 (value $78). Ticket booklets can be purchased online at CityPASS.com or at any of the participating attractions. They are valid for nine consecutive days, beginning with the first day of use. Celebrating its 20th anniversary in 2017, CityPASS has been making vacations easier, happier and more affordable for two decades. CityPASS booklets, which save travelers up to 50 percent off admission to a destination’s top attractions and allow visitors to bypass some main-entrance ticket lines, have a 98 percent customer recommendation rating. CityPASS booklets are available for New York City, Southern California, Atlanta, Boston, Chicago, Dallas, Houston, Philadelphia, San Francisco, Seattle, Tampa Bay and Toronto. Visit CityPASS.com to learn more. Prices and programs subject to change. CityPASS® is a registered trademark of City Pass, Inc., and the exclusive property of City Pass, Inc.
News Article | February 22, 2017
This May 5, 2011, photo provided by University of Colorado Boulder Museum of Natural History adjunct curator of anthropology Larry Benson shows the Pueblo del Arroyo archaeological site at Chaco Culture National Historical Park in northwestern New Mexico. —More than a century ago, archeologists working in New Mexico’s Chaco Canyon unearthed a hidden crypt containing the remains of 14 people: members of an elite, judging by the jewelry with which they were buried, roughly 1,000 years ago. The crypt was at the center of Pueblo Bonito, the ruins of a 650-room labyrinth. It was also at the center of a debate: Did the Chaco society operate with a strict hierarchy – and not governed communally, the way some Native American tribes are today? Now, researchers say an analysis of DNA extracted from the crypt’s remains, combined with radiocarbon dating techniques, offers new revelations. In a study published this week in the journal Nature Communications, the team writes that nine of the people buried in the Pueblo Bonito crypt were members of a dynasty extending over about 300 years and were related through their mothers. In other words, Chaco leadership was inherited through their mothers. Their discovery of a matrilineal elite could shift researchers’ theories about the nature of power in Chaco society. "For the first time, we're saying that one kinship group controlled Pueblo Bonito for more than 300 years," Steve Plog, a University of Virginia anthropologist and one of the study's co-authors, told Penn State’s news service. "This is the best evidence of a social hierarchy in the ancient Southwest." The first of the 14 to be buried, the team writes, was a man in his 40s who died from a blow to the head, after which he was interred with thousands of turquoise and shell beads and artifacts acquired from as far away as the Pacific Ocean and the Gulf of California – making it the “richest burial known in the American Southwest”. "It has been clear for some time that these were venerated individuals, based on the exceptional treatment they received in the afterlife – most Chacoans were buried outside of the settlement and never with such high quantities of exotic goods," Adam Watson, a postdoctoral fellow in the American Museum of Natural History's anthropology division, told Penn State’s news service. "But previously one could only speculate about the exact nature of their relationship to one another." Using DNA from mitochondria, sub-cellular structures that inherit DNA through the mother alone, the scientists concluded that the other eight people whose DNA they tested shared a maternal ancestor with him, according to Scientific American. That technique is an innovative one. And in providing evidence for the hereditary nature of power among the Chacoans, it also achieves a notoriously difficult feat, as National Geographic notes: finding evidence of hereditary leadership in societies that did not have writing systems. "If these results hold up, I think it's a game changer," American Museum of Natural History archaeologist David Thomas, who was not involved in the study, told the magazine. But it has also raised questions about whether the researchers should have gotten the permission of tribes that consider the Chacoans their ancestors, including the Navajo, Hopi, Zuni, and Acoma. The Native American Graves Protection Act of 1990 requires that researchers using federal funding return human remains found on federal or tribal lands to Native American groups who can prove a direct cultural connection with them. In a statement cited by Scientific American, however, the paper’s authors wrote that the ancestral link to “specific modern communities based on existing data” was impossible to establish due to the “cultural complexity of the region.” “I am dismayed that there was not an effort to engage contemporary tribal leaders prior to undertaking and publishing this study,” Rebecca Tsosie, a Native American professor at the University of Arizona who specializes in federal Indian law, told the magazine. The research, she added, constitutes a “prime example” of “a study by cultural outsiders to dictate the truth of the history and structure of governance of the cultural insiders, Pueblo Indian nations.”
Krist M.,Museum of Natural History |
Krist M.,Palacky University
Biological Reviews | Year: 2011
Parents affect offspring fitness by propagule size and quality, selection of oviposition site, quality of incubation, feeding of dependent young, and their defence against predators and parasites. Despite many case studies on each of these topics, this knowledge has not been rigorously integrated into individual parental care traits for any taxon. Consequently, we lack a comprehensive, quantitative assessment of how parental care modifies offspring phenotypes. This meta-analysis of 283 studies with 1805 correlations between egg size and offspring quality in birds is intended to fill this gap. The large sample size enabled testing of how the magnitude of the relationship between egg size and offspring quality depends on a number of variables. Egg size was positively related to nearly all studied offspring traits across all stages of the offspring life cycle. Not surprisingly, the relationship was strongest at hatching but persisted until the post-fledging stage. Morphological traits were the most closely related to egg size but significant relationships were also found with hatching success, chick survival, and growth rate. Non-significant effect sizes were found for egg fertility, chick immunity, behaviour, and life-history or sexual traits. Effect size did not depend on whether chicks were raised by their natural parents or were cross-fostered to other territories. Effect size did not depend on species-specific traits such as developmental mode, clutch size, and relative size of the egg, but was larger if tested in captive compared to wild populations and between rather than within broods. In sum, published studies support the view that egg size affects juvenile survival. There are very few studies that tested the relationship between egg size and the fecundity component of offspring fitness, and no studies on offspring survival as adults or on global fitness. More data are also needed for the relationships between egg size and offspring behavioural and physiological traits. It remains to be established whether the relationship between egg size and offspring performance depends on the quality of the offspring environment. Positive effect sizes found in this study are likely to be driven by a causal effect of egg size on offspring quality. However, more studies that control for potential confounding effects of parental post-hatching care, genes, and egg composition are needed to establish firmly this causal link. © 2010 The Author. Biological Reviews © 2010 Cambridge Philosophical Society.
News Article | February 27, 2017
A newly discovered trove of 16 engraved and otherwise modified limestone blocks, created 38,000 years ago, confirms the ancient origins of the pointillist techniques later adopted by 19th and 20th century artists such as Georges Seurat, Vincent Van Gogh, Camille Pissarro, and Roy Lichtenstein. “We’re quite familiar with the techniques of these modern artists,” observes New York University anthropologist Randall White, who led the excavation in France’s Vézère Valley. “But now we can confirm this form of image-making was already being practiced by Europe’s earliest human culture, the Aurignacian.” Pointillism, a painting technique in which small dots are used to create the illusion of a larger image, was developed in the 1880s. However, archaeologists have now found evidence of this technique thousands of years earlier—dating back more than 35,000 years. The findings appear in the journal Quaternary International. Major discoveries by White and his colleagues—which include images of mammoths and horses—confirm that a form of pointillism was used by the Aurignacian, the earliest modern human culture in Europe. These add weight to previous isolated discoveries, such as a rhinoceros, from the Grotte Chauvet in France, formed by the application of dozens of dots, first painted on the palm of the hand, and then transferred to the cave wall. Earlier this year, White’s team reported the uncovering of a 38,000-year-old pointillist image of an aurochs or wild cow—a finding that marks some of the earliest known graphic imagery found in Western Eurasia and offers insights into the nature of modern humans during this period. Now, in short order they have found another pointillist image—this time of a woolly mammoth—in a rock shelter of the same period known as Abri Cellier located near the previous find-site of Abri Blanchard. Abri Cellier has long been on archeologists’ short-list of major art-bearing sites attributed to the European Aurignacian. Excavations in 1927 yielded 15 engraved and/or pierced limestone blocks that have served as a key point of reference for the study of Aurignacian art in the region. In 2014, White and his colleagues returned to Cellier, seeking intact deposits that would allow a better understanding of the archaeological sequence at the site and its relationship to other Aurignacian sites. They had their fingers crossed that the new excavation might yield new engraved images in context, but nothing prepared them for the discovery of the 16 stone blocks detailed in the Quaternary International article. One of these, broken in half prehistorically, was found in place with a radiocarbon date of 38,000 years ago. Remarkably, the remaining 15 blocks, including the pointillist mammoth, one of three mammoth figures recognized during the new work at Cellier, had been left on-site by the 1927 excavators. As many of the engraved traces are rudimentary and thus difficult to interpret, the original excavators set them aside just in case they might have something inscribed on them. The new article presents evidence that the 38,000 year date for the newly excavated engraving also applies to the new trove and to the other blocks found in 1927 and now housed in the French National Prehistory Museum. Over the past decade, with these and other discoveries, White and his team have increased our known sample of the earliest graphic arts in southwestern France by 40 percent. The team includes researchers from the University of Arizona, the University of Toronto, the University of Toulouse, Paris’ Museum of Natural History, and the University of Oxford.
News Article | March 1, 2017
Since their discovery in 2010, the extinct ice age humans called Denisovans have been known only from bits of DNA, taken from a sliver of bone in the Denisova Cave in Siberia, Russia. Now, two partial skulls from eastern China are emerging as prime candidates for showing what these shadowy people may have looked like. In a paper published this week in , a Chinese-U.S. team presents 105,000- to 125,000-year-old fossils they call “archaic Homo.” They note that the bones could be a new type of human or an eastern variant of Neandertals. But although the team avoids the word, “everyone else would wonder whether these might be Denisovans,” which are close cousins to Neandertals, says paleoanthropologist Chris Stringer of the Natural History Museum in London. The new skulls “definitely” fit what you’d expect from a Denisovan, adds paleoanthropologist María Martinón-Torres of the University College London—“something with an Asian flavor but closely related to Neandertals.” But because the investigators have not extracted DNA from the skulls, “the possibility remains a speculation.” Back in December 2007, archaeologist Zhan-Yang Li of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing was wrapping up his field season in the town of Lingjing, near the city of Xuchang in the Henan province in China (about 4000 kilometers from the Denisova Cave), when he spotted some beautiful quartz stone tools eroding out of the sediments. He extended the field season for two more days to extract them. On the very last morning, his team discovered a yellow piece of rounded skull cap protruding from the muddy floor of the pit, in the same layer where he had found the tools. The team went back for another six seasons and managed to find 45 more fossils that fit together into two partial crania. The skulls lack faces and jaws. But they include enough undistorted pieces for the team to note a close resemblance to Neandertals. One cranium has a huge brain volume of 1800 cubic centimeters—on the upper end for both Neandertals and moderns—plus a Neandertal-like hollow in a bone on the back of its skull. Both crania have prominent brow ridges and inner ear bones that resemble those of Neandertals but are distinct from our own species, Homo sapiens. However, the crania also differ from the western Neandertals of Europe and the Middle East. They have thinner brow ridges and less robust skull bones, similar to early modern humans and some other Asian fossils. “They are not Neandertals in the full sense,” says co-author Erik Trinkaus, a paleoanthropologist at Washington University in St. Louis in Missouri. Nor are the new fossils late-occurring representatives of other archaic humans such as H. erectus or H. heidelbergensis, two species that were ancestral to Neandertals and modern humans. The skulls are too lightly built and their brains are too big, according to the paper. The skulls do share traits with some other fossils in east Asia dating from 600,000 to 100,000 years ago that also defy easy classification, says paleoanthropologist Rick Potts of the Smithsonian National Museum of Natural History in Washington, D.C. Those features include a broad cranial base where the skull sits atop the spinal column and a low, flat plateau along the top of the skull. The Lingjing crania also resemble another archaic early human skull that dates to 100,000 years ago from Xujiayao in China’s Nihewan Basin 850 kilometers to the north, according to co-author Xiu-Jie Wu, a paleoanthropologist at IVPP. Wu thinks those fossils and the new skulls “are a kind of unknown or new archaic human that survived on in East Asia to 100,000 years ago.” Based on similarities to some other Asian fossils, she and her colleagues think the new crania represent regional members of a population in eastern Asia who passed local traits down through the generations in what the researchers call regional continuity. At the same time, resemblances to both Neandertals and modern humans suggest that these archaic Asians mixed at least at low levels with other archaic people. To other experts, the Denisovans fit that description: They are roughly dated to approximately 100,000 to 50,000 years ago, and their DNA shows that after hundreds of thousands of years of isolation, they mixed both with Neandertals and early modern humans. “This is exactly what the DNA tells us when one tries to make sense of the Denisova discoveries,” says paleoanthropologist Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “These Chinese fossils are in the right place at the right time, with the right features.” But Wu and Trinkaus say they can’t put fossils in a group defined only by DNA. “I have no idea what a Denisovan is,” Trinkaus says. “Neither does anybody else. It’s a DNA sequence.” The only way to truly identify a Denisovan is with DNA. IVPP paleogeneticist Qiaomei Fu says she tried to extract DNA from three pieces of the Xuchang fossils but without success. Regardless of the new skulls’ precise identity, “China is rewriting the story of human evolution,” Martinón-Torres says. “I find this tremendously exciting!”