How the 1963 Equal Pay Act and 1964 Civil Rights Act Shaped the Gender Gap in Pay.

In the 1960s, two landmark statutes-the Equal Pay and Civil Rights Acts-targeted the long-standing practice of employment discrimination against U.S. women. For the next 15 years, the gender gap in median earnings among full-time, full-year workers changed little, leading many scholars to conclude that the legislation was ineffectual. This article revisits this conclusion using two research designs, which leverage (i) cross-state variation in preexisting state equal pay laws and (ii) variation in the 1960 gender gap across occupation-industry-state-group cells to capture differences in the legislation's incidence. Both designs suggest that federal antidiscrimination legislation led to striking gains in women's relative wages, which were concentrated among below-median wage earners. These wage gains offset preexisting labor market forces, which worked to depress women's relative pay growth, resulting in the apparent stability of the gender gap at the median and mean in the 1960s and 1970s. The data show little evidence of short-term changes in women's employment but suggest that firms reduced their hiring and promotion of women in the medium to long term. The historical record points to the key role of the Equal Pay Act in driving these changes.

Integrative methods reveal multiple drivers of diversification in rice paddy snakes.

Divergence dating analyses in systematics provide a framework to develop and test biogeographic hypotheses regarding speciation. However, as molecular datasets grow from multilocus to genomic, sample sizes decrease due to computational burdens, and the testing of fine-scale biogeographic hypotheses becomes difficult. In this study, we use coalescent demographic models to investigate the diversification of poorly known rice paddy snakes from Southeast Asia (Homalopsidae: Hypsiscopus), which have conflicting dates of origin based on previous studies. We use coalescent modeling to test the hypothesis that Hypsiscopus diversified 2.5 mya during the Khorat Plateau uplift in Thailand. Additionally, we use ecological niche analyses to identify potential differences in the niche space of the two most widely distributed species in the past and present. Our results suggest Hypsiscopus diversified ~ 2.4 mya, supporting that the Khorat Plateau may have initiated the diversification of rice paddy snakes. We also find significant niche differentiation and shifts between species of Hypsiscopus, indicating that environmental differences may have sustained differentiation of this genus after the Khorat Plateau uplift. Our study expands on the diversification history of snakes in Southeast Asia, and highlights how results from smaller multilocus datasets can be useful in developing and testing biogeographic hypotheses alongside genomic datasets.

DNA barcoding of Chinese snakes reveals hidden diversity and conservation needs.

DNA barcoding has greatly facilitated studies of taxonomy, biodiversity, biological conservation, and ecology. Here, we establish a reliable DNA barcoding library for Chinese snakes, unveiling hidden diversity with implications for taxonomy, and provide a standardized tool for conservation management. Our comprehensive study includes 1638 cytochrome c oxidase subunit I (COI) sequences from Chinese snakes that correspond to 17 families, 65 genera, 228 named species (80.6% of named species) and 36 candidate species. A barcode gap analysis reveals gaps, where all nearest neighbour distances exceed maximum intraspecific distances, in 217 named species and all candidate species. Three species-delimitation methods (ABGD, sGMYC, and sPTP) recover 320 operational taxonomic units (OTUs), of which 192 OTUs correspond to named and candidate species. Twenty-eight other named species share OTUs, such as Azemiops feae and A. kharini, Gloydius halys, G. shedaoensis, and G. intermedius, and Bungarus multicinctus and B. candidus, representing inconsistencies most probably caused by imperfect taxonomy, recent and rapid speciation, weak taxonomic signal, introgressive hybridization, and/or inadequate phylogenetic signal. In contrast, 43 species and candidate species assign to two or more OTUs due to having large intraspecific distances. If most OTUs detected in this study reflect valid species, including the 36 candidate species, then 30% more species would exist than are currently recognized. Several OTU divergences associate with known biogeographic barriers, such as the Taiwan Strait. In addition to facilitating future studies, this reliable and relatively comprehensive reference database will play an important role in the future monitoring, conservation, and management of Chinese snakes.

A global reptile assessment highlights shared conservation needs of tetrapods.

Comprehensive assessments of species' extinction risks have documented the extinction crisis1 and underpinned strategies for reducing those risks2. Global assessments reveal that, among tetrapods, 40.7% of amphibians, 25.4% of mammals and 13.6% of birds are threatened with extinction3. Because global assessments have been lacking, reptiles have been omitted from conservation-prioritization analyses that encompass other tetrapods4-7. Reptiles are unusually diverse in arid regions, suggesting that they may have different conservation needs6. Here we provide a comprehensive extinction-risk assessment of reptiles and show that at least 1,829 out of 10,196 species (21.1%) are threatened-confirming a previous extrapolation8 and representing 15.6 billion years of phylogenetic diversity. Reptiles are threatened by the same major factors that threaten other tetrapods-agriculture, logging, urban development and invasive species-although the threat posed by climate change remains uncertain. Reptiles inhabiting forests, where these threats are strongest, are more threatened than those in arid habitats, contrary to our prediction. Birds, mammals and amphibians are unexpectedly good surrogates for the conservation of reptiles, although threatened reptiles with the smallest ranges tend to be isolated from other threatened tetrapods. Although some reptiles-including most species of crocodiles and turtles-require urgent, targeted action to prevent extinctions, efforts to protect other tetrapods, such as habitat preservation and control of trade and invasive species, will probably also benefit many reptiles.

The phylogenetic status of Limnonectes liui (Yang, 1983) (Anura: Dicroglossidae) based on mitochondrial genes and its taxonomic implications.

Limnonectes liui (Yang, 1983) is a poorly known frog from Yunnan Province, China, with a confusing taxonomic history. We use mitochondrial (mt) DNA sequence data from newly collected specimens to reconstruct the phylogenetic position of the species. Limnonectes liui was found to be deeply nested within the geographically widespread dicroglossid frog L. limborgi (Sclater, 1892), verifying its placement within the genus Limnonectes but casting doubt on its distinction as a species. Morphological comparisons of the holotype and newly collected specimens of L. liui to specimens of L. limborgi from across its range also corroborated the hypothesis that these two species are conspecific, and we recommend treating L. liui as a junior synonym of L. limborgi. Our study underscores the importance of making comparisons with species found beyond a countrys border when describing new species.

The Long-Run Effects of Recessions on Education and Income.

This paper examines the long-run effects of the 1980-1982 recession on education and income. Using confidential Census data, I estimate difference-in-differences regressions that exploit variation across counties in recession severity and across cohorts in age at the time of the recession. For individuals age 0-10 in 1979, a 10 percent decrease in earnings per capita in their county of birth reduces four-year college degree attainment by 15 percent and earnings in adulthood by 5 percent. Simple calculations suggest that, in aggregate, the 1980-1982 recession led to 1.3-2.8 million fewer college graduates and $66-$139 billion less earned income per year.

Giant Tree Frog diversification in West and Central Africa: Isolation by physical barriers, climate, and reproductive traits.

Secondary sympatry amongst sister lineages is strongly associated with genetic and ecological divergence. This pattern suggests that for closely related species to coexist in secondary sympatry, they must accumulate differences in traits that mediate ecological and/or reproductive isolation. Here, we characterized inter- and intraspecific divergence in three giant tree frog species whose distributions stretch across West and Central Africa. Using genome-wide single-nucleotide polymorphism data, we demonstrated that species-level divergence coincides temporally and geographically with a period of large-scale forest fragmentation during the late Pliocene. Our environmental niche models further supported a dynamic history of climatic suitability and stability, and indicated that all three species occupy distinct environmental niches. We found modest morphological differentiation amongst the species with significant divergence in tympanum diameter and male advertisement call. In addition, we confirmed that two species occur in secondary sympatry in Central Africa but found no evidence of hybridization. These patterns support the hypothesis that cycles of genetic exchange and isolation across West and Central Africa have contributed to globally significant biodiversity. Furthermore, divergence in both ecology and reproductive traits appear to have played important roles in maintaining distinct lineages. At the intraspecific level, we found that climatic refugia, precipitation gradients, marine incursions, and potentially riverine barriers generated phylogeographic structure throughout the Pleistocene and into the Holocene. Further studies examining phenotypic divergence and secondary contact amongst these geographically structured populations may demonstrate how smaller scale and more recent biogeographic barriers contribute to regional diversification.

La sympatrie secondaire parmi les espèces sœurs est fortement associée à la divergence génétique et écologique. Ce modèle suggère que pour que des espèces étroitement liées coexistent en sympatrie secondaire, elles doivent accumuler des différences dans les traits qui contribuent à l'isolement écologique ou reproductif. Ici, nous avons caractérisé la divergence inter- et intra-spécifique chez trois espèces de grenouilles arboricoles géantes dont les distributions s'étendent à travers l'Afrique de l'Ouest et Centrale. Avec des données génétiques, nous avons démontré que la divergence au niveau des espèces coïncide temporellement et géographiquement avec une période de fragmentation forestière à la fin du Pliocène. Nos modèles de niches environnementales ont soutenu une histoire dynamique de stabilité climatique, et ont indiqué que les trois espèces occupent des niches environnementales distinctes. Nous avons trouvé une différenciation morphologique modeste parmi les trois espèces mais une divergence significative dans le diamètre du tympan et les cris des mâles. De plus, nous avons confirmé que deux espèces sont présentes en sympatrie secondaire en Afrique Centrale mais n'avons trouvé aucune preuve d'hybridation. Ces résultats soutiennent l'hypothèse que les cycles d'échange génétique et d'isolement à travers l'Afrique de l'Ouest et Centrale ont contribué à une profonde concentration de biodiversité dans la région. De plus, la divergence des traits écologiques et reproducteurs semble avoir joué un rôle important dans le maintien de lignées distinctes. Au niveau intra-spécifique, nous avons constaté que les refuges climatiques, les gradients de précipitation, les incursions marines et potentiellement les barrières fluviales ont généré une structure phylogéographique pendant le Pléistocène et jusqu'à l'Holocène. Des études examinant la divergence phénotypique et le contact secondaire entre ces populations géographiquement structurées pourraient démontrer comment des barrières biogéographiques à échelle plus petite et plus récentes contribuent à la diversification régionale.

Hidden diversity of rock geckos within the Cnemaspissiamensis species group (Gekkonidae, Squamata): genetic and morphological data from southern Thailand reveal two new insular species and verify the phylogenetic affinities of C.chanardi and C.kamolnorranathi.

Two new insular rock geckos in the genus Cnemaspis are described from Ko Samui in Surat Thani Province and Ko Similan in Phang-nga Province, southern Thailand, based on a combination of morphological and mitochondrial NADH dehydrogenase subunit 2 (ND2) data. Both new species represent divergent lineages within the Cnemaspissiamensis species group. Cnemaspissamui sp. nov. is distinguished from other species in the group by having eight or nine supralabial and infralabial scales; 5-8 pore-bearing precloacal scales in males, pores rounded; 25-27 paravertebral tubercles, arranged randomly; 22-25 subdigital lamellae under 4th toe; enlarged median subcaudal scale row present; gular region, abdomen, limbs and subcaudal region yellowish only in males, and uncorrected pairwise divergences of 8.86-26.83% from all other species in the C.siamensis species group. Cnemaspissimilan sp. nov. is distinguished from other species in the group by having eight or nine supralabial and seven or eight infralabial scales; one pore-bearing precloacal scale in males, pore rounded; 24 or 25 paravertebral tubercles, arranged randomly; 23 or 24 subdigital lamellae under 4th toe; no enlarged median subcaudal scale row; pale yellow reticulum on head, neck, flanks, belly and limbs in male only, and uncorrected pairwise divergences of 9.34-27.11% from all other species in the C.siamensis species group. Cnemaspissamui sp. nov. is found along granitic rocky stream outcrops of Hin Lad Waterfall, Ko Samui, Gulf of Thailand, while Cnemaspissimilan sp. nov. occurs in granitic rocky outcrops near Ao Nguang Chang Bay, Ko Similan, Andaman Sea. The phylogenetic analyses confirmed that C.chanardi and C.kamolnorranathi are also nested within the C.siamensis species group, as previously hypothesized from morphology and color pattern characters.

A new species in the Cyrtodactylusoldhami group (Squamata, Gekkonidae) from Kanchanaburi Province, western Thailand.

Cyrtodactylusmonilatus sp. nov. is described from Si Sawat District, Kanchanaburi Province, in western Thailand. The new species superficially resembles C.zebraicus Taylor, 1962 from southern Thailand. However, differences between the new species from C.zebraicus and other congeners were supported by an integrative taxonomic analysis of molecular and morphological data. Phylogenetic analyses based on the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene showed that the new species is a member of the C.oldhami group and closely related to Cyrtodactylus sp. MT468911 from Thong Pha Phum National Park, Thong Pha Phum District, Kanchanaburi Province. Uncorrected pairwise genetic divergences (p-distances) between the new species and its congeners, including C.zebraicus, ranged from 7.7-17.7%. Cyrtodactylusmonilatus sp. nov. can also be distinguished from all members of the C.oldhami group by having a unique combination of morphological characters, including a snout to vent length of 53.7-63.3 mm in adult males and 58.6-75.8 mm in adult females; 22-34 paravertebral tubercles; 34-42 ventral scales; 30-39 enlarged contiguous femoroprecloacal scales; femoral pores and precloacal pores absent in both sexes; four or five rows of postprecloacal scales; enlarged median subcaudal scales absent; weak ventrolateral folds present; 4-7 rows of paired, paravertebral, dark-brown blotches edged in yellow or yellowish white; and two rows of small, diffuse, yellow or yellowish white spots on flanks. The new species occurs in a narrow range of forest at mid to low elevations associated with karst landscapes in the Tenasserim mountain range.

The Effect of Social Connectedness on Crime: Evidence from the Great Migration.

This paper estimates the effect of social connectedness on crime across U.S. cities from 1970 to 2009. Migration networks among African Americans from the South generated variation across destinations in the concentration of migrants from the same birth town. Using this novel source of variation, we find that social connectedness considerably reduces murders, rapes, robberies, assaults, burglaries, and motor vehicle thefts, with a one standard deviation increase in social connectedness reducing murders by 21 percent and motor vehicle thefts by 20 percent. Social connectedness especially reduces murders of adolescents and young adults committed during gang and drug activity.

A New Limnonectes (Anura: Dicroglossidae) from Southern Thailand.

A new species in the dicroglossid frog genus Limnonectes is described from Ko Pha-ngan, Ko Samui, and Ko Lanta Yai Islands in southern Thailand. Males of Limnonectes pseudodoriae sp. nov. lack a caruncle on top of the head and very closely resemble L. doriae (Boulenger, 1887) from Myanmar and western and southern Thailand. However, the new species is distinguished from L. doriae and its congeners using an integrative taxonomic approach of morphology, mitochondrial DNA, and bioacoustics. Limnonectes pseudodoriae sp. nov. differs from L. doriae and its congeners by having a unique combination of morphological characters, including body size; skin texture of the interorbital region, dorsum, and shank; toe webbing; relative size of the inner metatarsal tubercle; and coloration of the tympanum, venter, and ova. The advertisement call of the new species is also readily differentiated from that of L. doriae in temporal parameters. Limnonectes pseudodoriae sp. nov. is highly divergent in mitochondrial DNA from L. doriae and its congeners, but its phylogenetic position within the genus is not resolved. The natural history of the new species is presented, and the geographic range of L. doriae in Thailand is clarified.

Static and Dynamic Postannealing Strategies for Roll-to-Roll Fabrication of DC Magnetron Sputtered Bismuth Telluride Thin Films onto Polymer Webs.

High-throughput roll-to-roll processes are desirable to scale up the manufacture of flexible thermoelectric generators. While vacuum deposition onto a heated dynamic substrate presents a considerable engineering challenge, viable postdeposition in-line annealing processes are considered as an alternative to improve the functional performance of as-deposited films. The effect of infrared and electron-beam irradiations of 1 µm thick bismuth telluride thin films, produced by a vacuum roll-to-roll process for use as thermoelectric materials, was examined. A static vacuum oven and pulsed high-energy electron beam were also studied as control groups. All annealing strategies increased the crystallite size and decreased the Te content. Only the static vacuum oven treatment was shown to significantly improve the film's crystallinity. After 1 h annealing, the power factor improved by 400% (from 2.8 to 14 × 10-4 W/mK2), which, to the knowledge of the authors, is the highest reported thermoelectric performance of postannealed or hot-deposited Bi-Te films. As for in-line annealing, infrared and electron-beam post treatments improved the power factor by 146% (from 2.8 to 6.9 × 10-4 W/mK2) and 64% (from 2.8 to 4.6 × 10-4 W/mK2), respectively.

THE ECONOMIC IMPACT OF A HIGH NATIONAL MINIMUM WAGE: EVIDENCE FROM THE 1966 FAIR LABOR STANDARDS ACT.

This paper examines the short and longer-term economic effects of the 1966 Fair Labor Standards Act (FLSA) which increased the national minimum wage to its highest level of the 20th Century and extended coverage to an additional 9.1 million workers. Exploiting differences in the "bite" of the minimum wage due to regional variation in the standard of living and industry composition, this paper finds that the 1966 FLSA increased wages dramatically but reduced aggregate employment only modestly. However, the disemployment effects were significantly larger among African-American men, forty percent of whom earned below the new minimum wage in 1966.

GENDER DIFFERENCES IN CAREERS AND PAY: Changes in the US Gender Gap in Wages in the 1960s.

In the 1960s, landmark legislation targeted the long-standing practice of labor market discrimination against US women. The Equal Pay Act of 1963, an amendment to the Fair Labor Standards Act (FLSA), became the first piece of federal legislation mandating equal pay for equal work. Title VII of the Civil Rights Act followed in 1964 with a provision that more broadly prohibited any sex-based discrimination in employment. Complementing this legislation, the 1961 and 1966 FLSA amendments increased the real minimum wage by 24 percent by 1970 and almost doubled the number of workers it covered, extending the FLSA's provisions to an additional 22.6 million individuals (US Department of Labor 1961, 1970). These changes benefited many workers in some of the economy's lowest-earning industries, such as services, retail trade, and government (that is, schools and hospitals)-industries where many women worked.

A new fanged frog in the Limnonectes kuhlii complex (Anura: Dicroglossidae) from northeastern Cambodia.

The Limnonectes kuhlii complex is a group of morphologically similar species of fanged frogs distributed across much of mainland and insular Southeast Asia. Many new species in this complex have been described in recent years, primarily on the basis of mitochondrial DNA divergence corroborated by differences in linear measurements and qualitative characters. Males in this species complex develop enlarged heads at sexual maturity, but the degree of head enlargement varies among mature males, even within the same population. We evaluated the utility of body length (snout-vent length minus head length) in descriptive statistics and in size-adjusting measurements for traditional morphometric analysis, as well as a landmark-based geometric morphometric analysis of male head shape, in Indochinese species of the L. kuhlii complex. The analyses supported quantitative and qualitative morphological distinction of a divergent mitochondrial lineage of the L. kuhlii complex in northeastern Cambodia, and the lineage is described as a new species. Limnonectes fastigatus sp. nov. differs from its closest relatives and from geographically proximate members of the complex by having the combination of elongated, slender odontoids; nuptial pads on the first finger; immaculate belly; significantly different body length-adjusted measurements in both sexes; and a significantly different male head shape. The new species is the only member of the L. kuhlii complex known from Cambodia.

A new Leptobrachella (Anura: Megophryidae) from the Cardamom Mountains of Cambodia.

The species-rich, megophryid frog genus Leptobrachella Smith, 1925 is distributed throughout the uplands of mainland Southeast Asia but is conspicuously absent from the Cardamom Mountains of southwestern Cambodia, where it has been known only by a single, undetermined metamorphic specimen collected nearly two decades ago. We report two adult female specimens of Leptobrachella collected a decade later at a second locality in the Cardamom Mountains and use mitochondrial DNA, nuclear DNA, and morphology to show that it represents a distinct species. Leptobrachella neangi sp. nov., named after its collector, is most closely related in mitochondrial and nuclear DNA to L. fuliginosa (Matsui, 2006) and L. melanoleuca (Matsui, 2006) from western Thailand, but has uncorrected pairwise distances of 8.69-10.99% in a mitochondrial 16S gene fragment from its two sister species. The new species is also readily distinguished from these and other congeners by having the combination of (1) SVL 35.4-36.3 mm in two adult females, (2) distinct dorsolateral glandular line absent, (2) belly transparent, immaculate purplish gray in life, creamy white in preservative, (3) dark inguinal blotch absent, (4) tympanum with black coloration extending from line under supratympanic fold, (5) dorsal skin with small, irregular bumps and ridges, and (6) iris coppery orange around pupil, fading to gold at periphery, not distinctly bicolored. The new species is the first named Leptobrachella from the Cardamom Mountains and the third from Cambodia.

A new insular species of the Cyrtodactylus intermedius (Squamata: Gekkonidae) group from Cambodia with a discussion of habitat preference and ecomorphology.

An integrative taxonomic analysis based on mitochondrial and morphological data recovered the population of Cyrtodactylus on Koh Rong Island, Preah Sihanouk Province, Cambodiaa as an endemic insular species belonging to the Cyrtodactylus intermedius group. This brings the number of species in the C. intermedius group to at least 10 and the number of species in Cambodia to at least seven. Species of this relatively small group vary widely in habitat preference, occurring in general, terrestrial, karstic, or granitic habitats. Ancestral character state mapping recovered a general habitat preference as the ancestral condition from which all others independently evolved even though this did not covary with morphology. The description of another new species of reptile from Cambodia continues to underscore the potentially significant amount of unrealized biodiversity in Indochina and Southeast Asia and the continued need for field surveys in unexplored or poorly explored areas.

A new Liopeltis Fitzinger, 1843 (Squamata: Colubridae) from Pulau Tioman, Peninsular Malaysia.

Liopeltis is a genus of poorly known, infrequently sampled species of colubrid snakes in tropical Asia. We collected a specimen of Liopeltis from Pulau Tioman, Peninsular Malaysia, that superficially resembled L. philippina, a rare species that is endemic to the Palawan Pleistocene Aggregate Island Complex, western Philippines. We analyzed morphological and mitochondrial DNA sequence data from the Pulau Tioman specimen and found distinct differences to L. philippina and all other congeners. On the basis of these corroborated lines of evidence, the Pulau Tioman specimen is described as a new species, L. tiomanica sp. nov. The new species occurs in sympatry with L. tricolor on Pulau Tioman, and our description of L. tiomanica sp. nov. brings the number of endemic amphibians and reptiles on Pulau Tioman to 12.