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This Gross-looking Worm Gives Clues About Humans' Ability to Breathe and Talk

Smithsonian Magazine

When most people think about human evolution, they look to our closest cousins the apes. But dial the evolutionary clock back just a bit more (by perhaps a few hundreds of thousands of years) and you’ll find the point where humans diverged from a more wormy cousin: acorn worms. 

Acorn worms are humans’ closest invertebrate relatives. The last common ancestor between our two lineages lived about 570 million years ago.​ These worms are a group of invertebrates that burrow in the ocean floor. They get their name from their front end, which is an acorn-shaped, muscular proboscis they use to burrow. Many species of the worm filter seawater through gill slits to catch floating bits of food. 

Their appearance may seem far removed from people, but the same genes that give rise to those gill slits are involved in shaping the human pharynx, the passageway leading to the esophagus and larynx that gives us the ability to chew, swallow and speak, writes Robert Sanders in a press release.

Now, new research from a team of international researchers shows that humans share about 70 percent of their genome with acorn worms, according to a new study published in the journal Nature.  "It’s an ugly beast," says an author of the paper John Gerhart, of the graduate school at the University of California, Berkeley. But that doesn’t make the creatures any less important.

The researchers decoded the DNA of two species of acorn worms to investigate the roots of the vertebrate family tree. They teased out the shared genes comparing the DNA of the Atlantic acorn worm Saccoglossus kowaleskii and a tropical Pacific acorn worm Ptychodera flava with other animals. 

Similarities actually extend beyond the critter's genes to an anatomical quirk seen early in development: Humans and other terrestrial creatures briefly sport vestigial pharyngeal gill slits as embryos. The gene cluster involved in this act is shared by all "deuterostomes" (a large group of animals that includes vertebrates as well as some invertebrates such as sea stars and yes, acorn worms). 

If having such a homely cousin is unappealing, take comfort in the fact that 30 percent of the human genome isn’t shared with acorn worms. We likely have more genetic similarities with those whose evolutionary lineage diverged from ours more recently: attractive creatures like the blobfish, the naked mole rat and the probosics monkey.

'Staggering' Damage to Florida’s Everglades Remains in the Wake of Hurricane Irma

Smithsonian Magazine

In September of last year, as Hurricane Irma tore through the southern United States, fierce winds battered the Florida’s Everglades National Park. As Megan Gannon reports for Live Science, NASA scientists recently conducted an aerial survey of the Everglades to assess the impact of the storm—and found massive damage to the region's mangrove forests.

The research team was able to get a particularly good sense of forest casualties because in April of last year, several months before the storm hit, NASA surveyed the area using an airborne instrument called G-LiHT, which stands for Goddard’s Lidar, Hyperspectral and Thermal Imager. This device maps terrestrial ecosystems using thermal measurements, imaging spectroscopy and a remote sensing technique known as LiDAR. By sending out up to 500,000 laser pulses per second, LiDAR can create detailed 3-D maps of dense forested areas from far above the ground.

As NASA explains on its website, the goal of the 2017 project was to find out how freshwater ecosystems—like the marshes of the Everglades—are transitioning to saltwater ecosystems due to rising sea levels and coastal erosion. By comparing images from this dataset to information gleaned from the most recent aerial survey, researchers were able to assess how the Everglades changed after Irma.

The team returned to the area in December of this year, flying the same path across 500 square miles of wetlands and supplementing that information with 3D scans taken from the ground by local agencies. Researchers discovered that 60 percent of the area’s mangrove forests were severely damaged. Heavy winds had sliced off the limbs of trees and torn them out of the ground, creating gaps across 40 percent of the forest canopy in the surveyed area. The average height of the canopy dropped between three to five feet due to fallen trees and branches.

“It’s staggering how much was lost,” Lola Fatoyinbo, a remote sensing scientist at NASA’s Goddard Space Flight Center, said in the agency’s statement. “The question is, which areas will regrow and which areas won’t.”

The team plans to compare datasets from before and after the storm to see if areas that were under stress prior to Irma recover as quickly as ones that were not. As Maddie Stone explains in Earther, it is important to track the health of this ecosystem because the Everglades act as a buffer that protects residents of south Florida from storms and rising sea levels. “If the Glades are being weakened and lost by natural disasters, development and climate change,” Stone writes, “that’s bad news for the nearly seven million people living nearby.”

NASA researchers are now heading to Puerto Rico to conduct G-LiHT flights over areas that were hit hard by both Irma and Hurricane Maria last year.

“It’s a good way to document which areas were more susceptible to events like Hurricane Maria,” Bruce Cook, G-LiHT lead scientist at NASA Goddard. “And also it’s a way to start tracking recovery as well. A lot of people are interested in the recovery, and what we might be talking about in terms of reestablishing the forests in the future, and whether it will require human intervention.”

Lloyd-Creak Dip Circle

National Museum of American History
The key feature of this circle is a second needle to measure the relative intensity of the field. Humphrey Lloyd, a professor of natural philosophy at Trinity College, Dublin, introduced the design in the 1840s. E. W. Creak, a Captain in the Royal Navy who served as Superintendent of the Compass Department of the Admiralty, improved the design around 1900, and the Admiralty paid for its development and tests. It soon replaced the Fox-style dip circles that had been in use since the 1830s. This example is marked "Dover, Charlton Kent. Circle 168" and "C.&G.S. No. 35." The vertical circle is inside the box and viewed by opposite microscopes on the outside. This circle is silvered, graduated to 30 minutes, and read by opposite verniers to single minutes; and there is a curved thermometer along its top edge. The axle holding the needle rests in jeweled holes. The horizontal circle is silvered, graduated to 30 minutes, and read by vernier to single minutes. There are two level vials on the base.

The U.S. Coast and Geodetic Survey modified this instrument in 1906, making it more useful at areas within 30 or 40 degrees of the magnetic equator. The original deflection distance of 7.3 cm was replaced with two deflection distances of 7.9 and 9.4 cm. by placing an aluminum case on the frame between the reading microscopes. A small telescope was added in front of the instrument, and an auxiliary needle, used to determine magnetic declination, on top. This instrument sailed on the Galilee, a ship owned by the Carnegie Institution of Washington, in 1905-1907 and was later used in Canada, Greenland, and Newfoundland. It came to the Smithsonian in 1959. Ref: "The Lloyd-Creak Dip Circle for Observations at Sea," Terrestrial Magnetism 6 (1901): 119-21. L. A. Bauer, "Results of Magnetic Observations," Report of the. . . Coast and Geodetic Survey (1903-04), App. 3. D. Hazard, Directions for Magnetic Measurements (Washington, D.C., 1911), pp. 97-99.

Joslin 10-inch Celestial Globe

National Museum of American History
The cartouche reads: “JOSLIN’S / Ten-Inch / CELESTIAL GLOBE / CONTAINING / all the Stars to the fifth Magnitude, inclusive. / From the Maps of the Stars, Published by the Society / for the Diffusion of Useful Knowledge. / Drawn and Engraved by W. B. Annin / BOSTON -- GILMAN JOSLIN.” This globe is supported on Joslin’s “full wood stand” with four short wooden legs, a wooden horizon circle and a brass meridian. Gilman Joslin (1804-about 1886) worked for Josiah Loring in Boston before issuing a globe under his own name in 1839. At mid-century, Joslin’s manufactory employed three men and two women, and boasted a 3-horsepower steam engine. The women probably pasted the paper gores onto the globe balls. William B. Annin, the artist who drew and engraved for this celestial globe, also worked for Loring. Ref: Gilman Joslin & Son, Joslin’s Terrestrial and Celestial Globes (Boston, 1885), p. 41. D. J. Warner, “The Geography of Heaven and Earth,” Rittenhouse 2 (1988): 100-103.

Sir Sandford Fleming's Pocketwatch

National Museum of American History
This watch belonged to Sir Sandford Fleming, chief engineer of the Canadian Pacific Railway. About 1880, Fleming devised a plan for worldwide time zones and had a complicated watch made to reflect both zoned time and local time.

The maker of Fleming's watch is the London firm of Nicole, Nielsen & Co. Successor to a business founded by Swiss immigrants Adolphe Nicole and Jules Capt in the late 1830s, the firm made high-quality timepieces. Fleming ordered the watch through retailer E. White, also of London.

Fleming's first notions about time reform emerged on a trip to Ireland in 1876, when he missed a train because he misread a timetable. His initial plan concentrated on replacing the two twelve-hour designations of the day, A.M. and P.M., with a twenty-four hour system. Almost immediately, though, he expanded his ideas about time reform to propose a system he called variously "Terrestrial Time," "Cosmopolitan Time," and "Cosmic Time"-a division of the globe into twenty-four zones, each one hour apart and identified by letters of the alphabet.

As the 1880s began there was no binding international agreement about how to keep time for the world. Traditionally, each country used its own capital city or main observatory for measuring time and designating lines of longitude on national maps. After publication of the British Nautical Almanac began in 1767, many nations came to use Greenwich time for navigation and some scientific observations. Local mean time served for all other activities.

Added emphasis on Greenwich had come from North America when the railroads there voluntarily adopted a standard zoned time in 1883. In that system, the zones were based on meridians counted west from Greenwich, England, at zero degree of longitude.

Fleming was not the first or only proponent of world standard time. Quirico Filopanti, an Italian mathematics and engineering professor, for example, published a scheme based on twenty-four zones counted from Rome as prime meridian in 1858.

Organized international support emerged slowly for fixing a common prime meridian. Not until October 1884 did diplomats and technical specialists gather to act on scientific proposals. The International Meridian Conference, held in Washington, DC, recommended that the nations of the world establish a prime meridian at Greenwich, count longitude east and west from the prime meridian up to 180 degrees in each direction, and adopt a universal day beginning at Greenwich at midnight. Although the International Meridian Conference had no authority to enforce its suggestions, the meeting resulted in the gradual worldwide adoption of a time-zone based system with Greenwich as zero degrees.

The military and some civilian science, aviation and navigation efforts still use alphabet identifiers for time zones. The time of day in Zone Z is known as "Zulu Time." The zone is governed by the zero degree of longitude that runs through Greenwich.

Scientific Foundations for an IUCN Red List of Ecosystems

Smithsonian Libraries
An understanding of risks to biodiversity is needed for planning action to slow current rates of decline and secure ecosystem services for future human use. Although the IUCN Red List criteria provide an effective assessment protocol for species, a standard global assessment of risks to higher levels of biodiversity is currently limited. In 2008, IUCN initiated development of risk assessment criteria to support a global Red List of ecosystems. We present a new conceptual model for ecosystem risk assessment founded on a synthesis of relevant ecological theories. To support the model, we review key elements of ecosystem definition and introduce the concept of ecosystem collapse, an analogue of species extinction. The model identifies four distributional and functional symptoms of ecosystem risk as a basis for assessment criteria: A) rates of decline in ecosystem distribution; B) restricted distributions with continuing declines or threats; C) rates of environmental (abiotic) degradation; and D) rates of disruption to biotic processes. A fifth criterion, E) quantitative estimates of the risk of ecosystem collapse, enables integrated assessment of multiple processes and provides a conceptual anchor for the other criteria. We present the theoretical rationale for the construction and interpretation of each criterion. The assessment protocol and threat categories mirror those of the IUCN Red List of species. A trial of the protocol on terrestrial, subterranean, freshwater and marine ecosystems from around the world shows that its concepts are workable and its outcomes are robust, that required data are available, and that results are consistent with assessments carried out by local experts and authorities. The new protocol provides a consistent, practical and theoretically grounded framework for establishing a systematic Red List of the world’s ecosystems. This will complement the Red List of species and strengthen global capacity to report on and monitor the status of biodiversity

Conr. Gesneri Tigurini, medicinae et philosophiae professoris in Schola Tigurina, Historiae animalium liber II : qui est De quadrupedibus ouiparis

Smithsonian Libraries
Title page vignette ("De crocodilo terrestri, aegyptiaco vel arabico") also appears on page 23.

Pages 22 and 78 are misnumbered 25 and 87, respectively.

Includes indexes.

Signatures: *⁴ A-K⁶.

Leaf *4 (pages [7]-[8], 1st group) is blank.

Wellisch, H. Conrad Gessner, 24.2

Also available online.

SCNHRB and SCDIRB have one copy each.

SCNHRB copy 39088016899387 is imperfect: the blank leaf *4 (pages [7]-[8], 1st group) is wanting.

SCNHRB copy has bookseller's printed label on front paste-down endpaper: Aus C.E. Haessler's Magazin wohlfeiler gebundener Bücher. Hamburg. Neuenwall 142.

SCNHRB copy is stamped on title page.: National Zoological Park; overstamped: Cancelled; written in ink: 486.

SCNHRB copy is stamped on verso of title page: Ludwig K. Schmarda; Smithsonian National Zoological Park Institution [overstamped] Cancelled; Smithsonian Institution National Museum, Aug 23 1944, accession number [in red written over in black pencil] 326592.

SCNHRB copy has an old gilt-tooled, tree-stained full leather binding with raised bands, marbled endpapers, and all edges gilt. Housed in a modern linen-covered box with printed brown paper spine label (the date "1602" was printed on the spine label in error).

SCNHRB copy is bound with: Gessner, C. Historia animalium. Liber V, qui est De serpentium natura. Tiguri : In officina Froschouiana, MDLXXXVII [1587] -- Gessner, C. Nomenclator aquatilium animantium. Heidelbergae : E Typographeio Iohannis Lancelloti : Impensis Andreae Cambieri, anno MDCVI [1606].

SCDIRB copy 39088016899429 has ownership inscription of Count Joannes Josephus Inzaghi on t.p. dated 1692; binding stamped with initials I.F.D.E and date 1599 on front cover.

SCDIRB copy has bookplate: Burndy Library ... gift of Bern Dibner.

SCDIRB copy has a contemporary binding of blind-tooled full alum-tawed pigskin over wooden boards, stamped on the front and back with allegorical female figures; raised bands; metal clasps; and blue edges. Housed in a modern archival paperboard portfolio with reddish-brown paste-paper spine.

SCDIRB copy is bound with: Historia animalium. Liber III, qui est De auium natura. Francofurdi : Ex officina typographica Ioannis Wecheli : Impensis Roberti Cambieri, 1585.

Elecresource

Mineral evolution

Smithsonian Libraries
The mineralogy of terrestrial planets evolves as a consequence of a range of physical, chemical, and biological processes. In pre-stellar molecular clouds, widely dispersed microscopic dust particles contain approximately a dozen refractory minerals that represent the starting point of planetary mineral evolution. Gravitational clumping into a protoplanetary disk, star formation, and the resultant heating in the stellar nebula produce primary refractory constituents of chondritic meteorites, including chondrules and calcium-aluminum inclusions, with ~60 different mineral phases. Subsequent aqueous and thermal alteration of chondrites, asteroidal accretion and differentiation, and the consequent formation of achondrites results in a mineralogical repertoire limited to ~250 different minerals found in unweathered meteorite samples. Following planetary accretion and differentiation, the initial mineral evolution of Earth's crust depended on a sequence of geochemical and petrologic processes, including volcanism and degassing, fractional crystallization, crystal settling, assimilation reactions, regional and contact metamorphism, plate tectonics, and associated large-scale fluid-rock interactions. These processes produced the first continents with their associated granitoids and pegmatites, hydrothermal ore deposits, metamorphic terrains, evaporites, and zones of surface weathering, and resulted in an estimated 1500 different mineral species. According to some origin-of-life scenarios, a planet must progress through at least some of these stages of chemical processing as a prerequisite for life. Biological processes began to affect Earth's surface mineralogy by the Eoarchean Era (~3.85-3.6 Ga), when large-scale surface mineral deposits, including banded iron formations, were precipitated under the influences of changing atmospheric and ocean chemistry. The Paleoproterozoic "Great Oxidation Event" (~2.2 to 2.0 Ga), when atmospheric oxygen may have risen to >1% of modern levels, and the Neoproterozoic increase in atmospheric oxygen, which followed several major glaciation events, ultimately gave rise to multicellular life and skeletal biomineralization and irreversibly transformed Earth's surface mineralogy. Biochemical processes may thus be responsible, directly or indirectly, for most of Earth's 4300 known mineral species. The stages of mineral evolution arise from three primary mechanisms: (1) the progressive separation and concentration of the elements from their original relatively uniform distribution in the pre-solar nebula; (2) an increase in range of intensive variables such as pressure, temperature, and the activities of H2O, CO2, and O2; and (3) the generation of far-from-equilibrium conditions by living systems. The sequential evolution of Earth's mineralogy from chondritic simplicity to Phanerozoic complexity introduces the dimension of geologic time to mineralogy and thus provides a dynamic alternate approach to framing, and to teaching, the mineral sciences.

Cocconeis crebra Fleming

NMNH - Botany Dept.

Water alteration of rocks and soils on Mars at the Spirit rover site in Gusev crater

Smithsonian Libraries
Gusev crater was selected as the landing site for the Spirit rover because of the possibility that it once held a lake. Thus one of the rover's tasks was to search for evidence of lake sediments. However, the plains at the landing site were found to be covered by a regolith composed of olivine-rich basaltic rock and windblown 'global' dust. The analyses of three rock interiors exposed by the rock abrasion tool showed that they are similar to one another, consistent with having originated from a common lava flow. Here we report the investigation of soils, rock coatings and rock interiors by the Spirit rover from sol (martian day) 1 to sol 156, from its landing site to the base of the Columbia hills. The physical and chemical characteristics of the materials analysed provide evidence for limited but unequivocal interaction between water and the volcanic rocks of the Gusev plains. This evidence includes the softness of rock interiors that contain anomalously high concentrations of sulphur, chlorine and bromine relative to terrestrial basalts and martian meteorites; sulphur, chlorine and ferric iron enrichments in multilayer coatings on the light-toned rock Mazatzal; high bromine concentration in filled vugs and veins within the plains basalts; positive correlations between magnesium, sulphur and other salt components in trench soils; and decoupling of sulphur, chlorine and bromine concentrations in trench soils compared to Gusev surface soils, indicating chemical mobility and separation.

Arthropod Diversity in a Tropical Forest

Smithsonian Libraries
Most eukaryotic organisms are arthropods. Yet, their diversity in rich terrestrial ecosystems is still unknown. Here we produce tangible estimates of the total species richness of arthropods in a tropical rainforest. Using a comprehensive range of structured protocols, we sampled the phylogenetic breadth of arthropod taxa from the soil to the forest canopy in the San Lorenzo forest, Panama. We collected 6144 arthropod species from 0.48 hectare and extrapolated total species richness to larger areas on the basis of competing models. The whole 6000-hectare forest reserve most likely sustains 25,000 arthropod species. Notably, just 1 hectare of rainforest yields >60% of the arthropod biodiversity held in the wider landscape. Models based on plant diversity fitted the accumulated species richness of both herbivore and nonherbivore taxa exceptionally well. This lends credence to global estimates of arthropod biodiversity developed from plant models.

Bardin 18-inch Celestial Globe

National Museum of American History
This globe is supported on a wooden tri-leg pedestal, surrounded by a wooden horizon circle, and is equipped with a brass meridian and a small brass circle around the north pole. It (and its terrestrial mate) belonged to the eminent chemist, Joseph Priestley. The cartouche in the southern hemisphere has a text that reads: “To the Rev. / NEVIL MASKELYNE, D.D. F.R.S. / Astronomer Royal / The New British Celestial Globe / containing the Positions of nearly 6000 Stars, Clusters, nebulae, Planetary / Nebulae &c. Correctly computed & laid down to the year 1800; from the latest observati / ons and discoveries by Dr Maskelyne, Dr Herschel, The Revd Mr Wollaston &c. &c. / Is respectfully Dedicated / by his most obedient hbl Servants / W. & T. M. Bardin” William Bardin (fl. 1730-1798) was a London artisan who began making globes around 1780. Around 1790, now in partnership with his son, Thomas Marriott Bardin (1768-1819), he began trading as W. & T. M. Bardin. The 18-inch globes were their most ambitious. They were introduced in 1798, and remained in production, by successor firms, for a half century. Ref: John Millburn and Tör Rossaak, “The Bardin Family, Globe Makers in London” Der Globusfreund (1992). Elly Dekker, Globes at Greenwich (Oxford, 1999), pp. 260-270.

Painting - Pendulum Momentum (Galileo)

National Museum of American History
The Greek mathematician Aristotle, who lived from about 384 BC through 322 BC, believed that heavy bodies moved naturally downward, while lighter substances such as air naturally ascended. Other forms of terrestrial motion required a sustaining force, which was not expressed mathematically. The Italian Galileo Galilei (1564–1642) challenged Aristotle. He held that motion was persistent and would continue until acted upon by an opposing, outside force. In a book entitled Dialogues Concerning the Two Chief World Systems, Galileo presented his ideas in a dispute between three men: Salviati, Sagredo, and Simplicio. Salviati, a spokesman for Galileo, explained his revolutionary ideas, one of which is illustrated by a diagram that was the basis for this painting. This image can be found in Crockett Johnson's copy of The World of Mathematics, a book by James R. Newman. It is probable that this image served as inspiration for this painting, although Johnson did not annotate this diagram. In Galileo's Dialogues, Salviati argued that if a lead weight is suspended by a thread from point A (see figure) and is released from point C, it will swing to point D, which is located at the same height as the initial point C. Furthermore, Salviati stated that if a nail is placed at point E so that the thread will snag on it, then the weight will swing from point C to point B and then up to point G, which is also located at the same height as the initial point C. The same occurs if a nail is placed at point F below the line segment CD. The painting is executed in purple that progresses from light tints to darker shades right to left. This gives the figure a sense of motion akin to that of a pendulum. The background is washed in gray and black. The line created by the initial and final height of the weight divides the background. Pendulum Momentum, a work in oil on masonite, is painting #13 in the Crockett Johnson series. It was executed in 1966 and is signed: CJ66. There is a wooden frame painted black.

Joslin 10-inch Celestial Globe

National Museum of American History
The cartouche reads “JOSLIN’S / Ten-Inch / CELESTIAL GLOBE / CONTAINING / all the Stars to the fifth Magnitude, inclusive. / From the Maps of the Stars, Published by the Society / for the Diffusion of Useful Knowledge. / Drawn and Engraved by W. B. Annin / BOSTON -- GILMAN JOSLIN.” This globe is supported on Joslin’s “full wood stand” with four short wooden legs, a wooden horizon circle and a brass meridian. Gilman Joslin (1804-about 1886) worked for Josiah Loring in Boston before issuing a globe under his own name in 1839. A mid-century account of Joslin’s manufactory noted that he employed three men and two women, and used a 3-horsepower steam engine. The women probably pasted the paper gores onto the globe balls. William B. Annin, the artist who drew and engraved the plates for this celestial globe, also worked for Loring. Ref: Gilman Joslin & Son, Joslin’s Terrestrial and Celestial Globes (Boston, 1885), p. 41. D. J. Warner, “The Geography of Heaven and Earth,” Rittenhouse 2 (1988): 100-103.

microscope

National Museum of American History
This is a compound monocular with coarse and fine focus, double nosepiece, square stage, inclination joint with handle, sub-stage diaphragm, sub-stage mirror, and horseshoe base. The inscription reads “E. Leitz Wetzlar / No 24997.” The serial number indicates a date of around 1892. The back of the base is marked “48?” This was used at the Department of Terrestrial Magnetism of the Carnegie Institution of Washington. Ref: Ernst Leitz, Petrological and Metallographic Microscopes (Wetzlar, 1910), pp. 14-17.

Atlantic reef fish biogeography and evolution

Smithsonian Libraries
Aim To understand why and when areas of endemism (provinces) of the tropical Atlantic Ocean were formed, how they relate to each other, and what processes have contributed to faunal enrichment. Location Atlantic Ocean. Methods The distributions of 2605 species of reef fishes were compiled for 25 areas of the Atlantic and southern Africa. Maximum-parsimony and distance analyses were employed to investigate biogeographical relationships among those areas. A collection of 26 phylogenies of various Atlantic reef fish taxa was used to assess patterns of origin and diversification relative to evolutionary scenarios based on spatio-temporal sequences of species splitting produced by geological and palaeoceanographic events. We present data on faunal (species and genera) richness, endemism patterns, diversity buildup (i.e. speciation processes), and evaluate the operation of the main biogeographical barriers and/or filters. Results Phylogenetic (proportion of sister species) and distributional (number of shared species) patterns are generally concordant with recognized biogeographical provinces in the Atlantic. The highly uneven distribution of species in certain genera appears to be related to their origin, with highest species richness in areas with the greatest phylogenetic depth. Diversity buildup in Atlantic reef fishes involved (1) diversification within each province, (2) isolation as a result of biogeographical barriers, and (3) stochastic accretion by means of dispersal between provinces. The timing of divergence events is not concordant among taxonomic groups. The three soft (non-terrestrial) inter-regional barriers (mid-Atlantic, Amazon, and Benguela) clearly act as 'filters' by restricting dispersal but at the same time allowing occasional crossings that apparently lead to the establishment of new populations and species. Fluctuations in the effectiveness of the filters, combined with ecological differences among provinces, apparently provide a mechanism for much of the recent diversification of reef fishes in the Atlantic. Main conclusions Our data set indicates that both historical events (e.g. Tethys closure) and relatively recent dispersal (with or without further speciation) have had a strong influence on Atlantic tropical marine biodiversity and have contributed to the biogeographical patterns we observe today; however, examples of the latter process outnumber those of the former.

"Lost Continent" Rises Again With New Expedition

Smithsonian Magazine

Tens of millions of years after it disappeared under the waters of the Pacific Ocean, scientists have completed the first explorations of what some scientists are calling a hidden continent, Naaman Zhou reports at the Guardian.

During a two-month ocean voyage this summer, a team of more than 30 scientists from 12 countries explored the submerged landmass of Zealandia on an advanced research vessel and collected samples from the seabed. Scientists were able to drill into the ocean floor at depths of more than 4,000 feet, collecting more than 8,000 feet of sediment cores that provides a window into 70 million years of geologic history, reports Georgie Burgess for ABC News.

More than 8,000 fossils from hundreds of species were also collected in the drilling, giving scientists a glimpse at terrestrial life that lived tens of millions of years ago in the area. "The discovery of microscopic shells of organisms that lived in warm shallow seas, and of spores and pollen from land plants, reveal that the geography and climate of Zealandia were dramatically different in the past," expedition leader Gerald Dickens said in a statement. While more than 90 percent of Zealandia is now submerged under more than a kilometer (two-thirds of a mile) of water, when it was above the surface, it likely provided a path that many land animals and plants could have used to spread across the South Pacific, notes Naaman Zhou of the Guardian.

The Geological Society of America officially endorsed the long-standing theory that a nearly 2 million-square-mile section of Pacific Ocean floor around the country of New Zealand was actually continental crust that had submerged beneath the water in a paper published by its journal in February. As Sarah Sloat reports for Inverse, this sinking, believed have taken place after the continent broke off from Australia around 60 to 85 million years ago, made New Zealand, and other seemingly disparate islands in the area, the remains of what was once a large landmass. 

However, classifying Zealandia as a continent is still a source of debate among scientists. In an interview with Michael Greshko of National Geographic in February, Christopher Scotese, a Northwestern University geologist was skeptical. “My judgment is that though Zealandia is continental, it is not a continent,” Scotese said. “If it were emergent, we would readily identify it with Australia, much like we identify Greenland with North America and Madagascar with Africa.” 

Scientists now plan to study the sediment cores and fossils to help create models of how the region looked and changed over the course of tens of millions of years, reports Sloat, and plans are always in the works for a return expedition next year.

Eagle with Snake

Smithsonian American Art Museum
The paintings of Awa Tsireh (1898-1955), who was also known by his Spanish name, Alfonso Roybal, represent an encounter between the art traditions of native Pueblo peoples in the southwestern United States and the American modernist art style begun in New York in the early twentieth century. The son of distinguished potters, Awa Tsireh translated geometic pottery designs into stylized watercolors that feature the ceremonial dancers and practices of Pueblo communities. But Awa Tsireh's work is more than an amalgam of traditional and modernist design. At a time when the U.S. Office of Indian Affairs attempted to restrict Pueblo cultural and religious practices, the watercolors of Awa Tsireh and other Pueblo artists helped to affirm the importance of ceremonial dance and tirual to cultural survival.

Awa Tsireh's paintings quickly found an audience among the artists, writers, and archaeologists who descended on Santa Fe in great numbers in the late 1910s and 1920s. Painter John Sloan and poet Alice Corbin Henderson took a particular interest and arranged for his watercolors to be exhibited in New York, Chicago, and elsewhere. Henderson shared with the young Pueblo painter books on European and American modernism and Japanese woodblock prints, as well as South Asian miniatures and ancient Egyptian art that provided soure material for his stylized paintings. In this way, he redefined contemporary Pueblo art and created a new, pan-Pueblo style.

The paintings in this exhibition were donated to the Smithsonian American Art Museum in 1979 by the Hendersons' daughter, Alice H. Rossin.

Ram and Antelope

Smithsonian American Art Museum
The paintings of Awa Tsireh (1898-1955), who was also known by his Spanish name, Alfonso Roybal, represent an encounter between the art traditions of native Pueblo peoples in the southwestern United States and the American modernist art style begun in New York in the early twentieth century. The son of distinguished potters, Awa Tsireh translated geometic pottery designs into stylized watercolors that feature the ceremonial dancers and practices of Pueblo communities. But Awa Tsireh's work is more than an amalgam of traditional and modernist design. At a time when the U.S. Office of Indian Affairs attempted to restrict Pueblo cultural and religious practices, the watercolors of Awa Tsireh and other Pueblo artists helped to affirm the importance of ceremonial dance and tirual to cultural survival.

Awa Tsireh's paintings quickly found an audience among the artists, writers, and archaeologists who descended on Santa Fe in great numbers in the late 1910s and 1920s. Painter John Sloan and poet Alice Corbin Henderson took a particular interest and arranged for his watercolors to be exhibited in New York, Chicago, and elsewhere. Henderson shared with the young Pueblo painter books on European and American modernism and Japanese woodblock prints, as well as South Asian miniatures and ancient Egyptian art that provided soure material for his stylized paintings. In this way, he redefined contemporary Pueblo art and created a new, pan-Pueblo style.

The paintings in this exhibition were donated to the Smithsonian American Art Museum in 1979 by the Hendersons' daughter, Alice H. Rossin.

Antelope

Smithsonian American Art Museum
The paintings of Awa Tsireh (1898-1955), who was also known by his Spanish name, Alfonso Roybal, represent an encounter between the art traditions of native Pueblo peoples in the southwestern United States and the American modernist art style begun in New York in the early twentieth century. The son of distinguished potters, Awa Tsireh translated geometic pottery designs into stylized watercolors that feature the ceremonial dancers and practices of Pueblo communities. But Awa Tsireh's work is more than an amalgam of traditional and modernist design. At a time when the U.S. Office of Indian Affairs attempted to restrict Pueblo cultural and religious practices, the watercolors of Awa Tsireh and other Pueblo artists helped to affirm the importance of ceremonial dance and tirual to cultural survival.

Awa Tsireh's paintings quickly found an audience among the artists, writers, and archaeologists who descended on Santa Fe in great numbers in the late 1910s and 1920s. Painter John Sloan and poet Alice Corbin Henderson took a particular interest and arranged for his watercolors to be exhibited in New York, Chicago, and elsewhere. Henderson shared with the young Pueblo painter books on European and American modernism and Japanese woodblock prints, as well as South Asian miniatures and ancient Egyptian art that provided soure material for his stylized paintings. In this way, he redefined contemporary Pueblo art and created a new, pan-Pueblo style.

The paintings in this exhibition were donated to the Smithsonian American Art Museum in 1979 by the Hendersons' daughter, Alice H. Rossin.

Sub Satellite, Particles and Fields, Apollo 16, Qualification Model

National Air and Space Museum
The Apollo 15 and Apollo 16 missions carried a small subsatellite designed to be released in lunar orbit just prior to the beginning of the astronauts' return flight to earth. Powered by six solar panels in 11 silver-cadmium batteries, the so-called "Particles and Fields subsatellites" contained three instruments: a magnetometer, an S-band transponder, and charged particle detectors. Instruments were designed to measure the strength and direction of interplanetary and terrestrial magnetic field, to detect variations in the lunar gravity field, and measure proton and electric flux from the solar wind.

The artifact here is the qualification model for the Particles and Fields subsatellite. It underwent extensive tests and demonstrations prior to the launch of the actual satellites. It was transferred from NASA to the Smithsonian in 1975.

[Apollo 16 Particle and Fields Subsatellite Mission to Earth's Moon]

Mission Type: Orbiter

Launch Vehicle: Saturn V SA-511

Launch Site: Eastern Test Range / launch complex 39A, Cape Canaveral, Fla., USA

Spacecraft Mass: 42 kg

Spacecraft Instruments: 1) magnetometer; 2) S-band transponder; and 3) charged-particle detectors

Spacecraft Dimensions: hexagonal cylinder 78 cm long and about 36 cm across opposite corners of the hexagon, plus 3 equally spaced booms, each 1.5 m long

Spacecraft Power: 6 solar panels and 11 silver-cadmium batteries

Maximum Power: 24 W

Maximum Data Rate: 128 bits/sec

References:

Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi

National Space Science Data Center, http://nssdc.gsfc.nasa.gov/

Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd.

Nearly identical to its predecessor, the Apollo 16 Particle and Fields Subsatellite was ejected from the Apollo 16 Command and Service Module (CSM) about 4 hours prior to the crew's trans-Earth injection burn, which sent them home from the Moon.

Because of problems with the Apollo CSM main engine, the crew was forced to release the subsatellite in a low lunar orbit of 100 x 100 kilometers at 10° inclination. The orbit was rapidly altered by gravitational perturbations, and the probe crashed onto the lunar surface after 34 days in orbit rather than the planned one year. Impact point was at 10.2° north latitude and 112° east longitude at 21:00 UT on 29 May 1972. However, because of its low orbit, the spacecraft did return some valuable low-altitude data.

Effects of mammalian herbivore declines on plant communities: observations and experiments in an African savanna

Smithsonian Libraries
* Herbivores influence the structure and composition of terrestrial plant communities. However, responses of plant communities to herbivory are variable and depend on environmental conditions, herbivore identity and herbivore abundance. As anthropogenic impacts continue to drive large declines in wild herbivores, understanding the context dependence of herbivore impacts on plant communities becomes increasingly important. * Exclosure experiments are frequently used to assess how ecosystems reorganize in the face of large wild herbivore defaunation. Yet in many landscapes, declines in large wildlife are often accompanied by other anthropogenic activities, especially land conversion to livestock production. In such cases, exclosure experiments may not reflect typical outcomes of human-driven extirpations of wild herbivores. * Here, we examine how plant community responses to changes in the identity and abundance of large herbivores interact with abiotic factors (rainfall and soil properties). We also explore how effects of wild herbivores on plant communities differ between large-scale herbivore exclosures and landscape sites where anthropogenic activity has caused wildlife declines, often accompanied by livestock increases. * Abiotic context modulated the responses of plant communities to herbivore declines with stronger effect sizes in lower-productivity environments. Also, shifts in plant community structure, composition and species richness following wildlife declines differed considerably between exclosure experiments and landscape sites in which wild herbivores had declined and were often replaced by livestock. Plant communities in low wildlife landscape sites were distinct in both composition and physical structure from both exclosure and control sites in experiments. The power of environmental (soil and rainfall) gradients in influencing plant response to herbivores was also greatly dampened or absent in the landscape sites. One likely explanation for these observed differences is the compensatory effect of livestock associated with the depression or extirpation of wildlife. * Synthesis. Our results emphasize the importance of abiotic environmental heterogeneity in modulating the effects of mammalian herbivory on plant communities and the importance of such covariation in understanding effects of wild herbivore declines. They also suggest caution when extrapolating results from exclosure experiments to predict the consequences of defaunation as it proceeds in the Anthropocene.

Black Mountain Lion and Black Fox

Smithsonian American Art Museum
The paintings of Awa Tsireh (1898-1955), who was also known by his Spanish name, Alfonso Roybal, represent an encounter between the art traditions of native Pueblo peoples in the southwestern United States and the American modernist art style begun in New York in the early twentieth century. The son of distinguished potters, Awa Tsireh translated geometic pottery designs into stylized watercolors that feature the ceremonial dancers and practices of Pueblo communities. But Awa Tsireh's work is more than an amalgam of traditional and modernist design. At a time when the U.S. Office of Indian Affairs attempted to restrict Pueblo cultural and religious practices, the watercolors of Awa Tsireh and other Pueblo artists helped to affirm the importance of ceremonial dance and tirual to cultural survival.

Awa Tsireh's paintings quickly found an audience among the artists, writers, and archaeologists who descended on Santa Fe in great numbers in the late 1910s and 1920s. Painter John Sloan and poet Alice Corbin Henderson took a particular interest and arranged for his watercolors to be exhibited in New York, Chicago, and elsewhere. Henderson shared with the young Pueblo painter books on European and American modernism and Japanese woodblock prints, as well as South Asian miniatures and ancient Egyptian art that provided soure material for his stylized paintings. In this way, he redefined contemporary Pueblo art and created a new, pan-Pueblo style.

The paintings in this exhibition were donated to the Smithsonian American Art Museum in 1979 by the Hendersons' daughter, Alice H. Rossin.

Skunks

Smithsonian American Art Museum
The paintings of Awa Tsireh (1898-1955), who was also known by his Spanish name, Alfonso Roybal, represent an encounter between the art traditions of native Pueblo peoples in the southwestern United States and the American modernist art style begun in New York in the early twentieth century. The son of distinguished potters, Awa Tsireh translated geometic pottery designs into stylized watercolors that feature the ceremonial dancers and practices of Pueblo communities. But Awa Tsireh's work is more than an amalgam of traditional and modernist design. At a time when the U.S. Office of Indian Affairs attempted to restrict Pueblo cultural and religious practices, the watercolors of Awa Tsireh and other Pueblo artists helped to affirm the importance of ceremonial dance and tirual to cultural survival.

Awa Tsireh's paintings quickly found an audience among the artists, writers, and archaeologists who descended on Santa Fe in great numbers in the late 1910s and 1920s. Painter John Sloan and poet Alice Corbin Henderson took a particular interest and arranged for his watercolors to be exhibited in New York, Chicago, and elsewhere. Henderson shared with the young Pueblo painter books on European and American modernism and Japanese woodblock prints, as well as South Asian miniatures and ancient Egyptian art that provided soure material for his stylized paintings. In this way, he redefined contemporary Pueblo art and created a new, pan-Pueblo style.

The paintings in this exhibition were donated to the Smithsonian American Art Museum in 1979 by the Hendersons' daughter, Alice H. Rossin.
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