The Species Problem: Nineteenth-Century Concepts of Racial Inferiority in the Origin of Man Controversy

The species problem and its implications in the origin of man controversy had grown in importance in prewar America owing largely to the question of slavery. Implicit in the problem was the position of the so-called inferior races in society. The monogenists, despite their emphasis on environmentalism, were no more favorable to the Negro, except in their remote theoretical stance. The Civil War—not Darwin—brought the controversy to an end in America, but it continued to rage in Europe. The apparent synthesis of the schools during the 1870s did not disturb the stereotyped ideas of racial inferiority. The "inferior races" remained the basis of evolutionary discussion, leaving them as remote outcasts of the evolutionary struggle.     

Ecology and Evolution of Social Organization in Arctic Sandpipers

A comparative analysis of sandpiper social systems on arcticand subarctic breeding grounds (24 species in the family Scolopacidae,subfamily Calidridinae) shows four major patterns. In a majorityof the species (15), populations are dispersed through a stronglydeveloped territorial system, with strong monogamous pair bondsand only minor yearly fluctuations in numbers. The second patternis seen in three species in which the female of a pair may laytwo sets of eggs in quick succession, one for each member ofthe pair to incubate. This opens opportunities for facultativepolygyny or polyandry (‘serial polygamy’) and forthe evolutionary weakening of the strong pair bond seen in thefirst pattern. The third and fourth patterns are those of polygyny(three species) and promiscuity (three species). These six speciesshow clumped dispersions; their year-to-year fluctuations tendto be strong; the males defend compressible, often small, territories;and high densities can occur locally. It is suggested that thepattern of overdispersion and monogamy represents a conservativemode of adapting to high-latitude environments, while the patternof clumped dispersion with polygyny or promiscuity representsan opportunistic mode in that the birds are concentrated intobreeding areas where and when weather, food, and/or some otherenvironmental factors are particularly favorable. Apparentlyfalling evolutionarily between these two basic patterns areseveral species conservative in their life-styles, but polygamousat least occasionally and showing some features of opportunism.There is thus a striking diversity of social systems in calidridinesandpipers, that is, in the styles of habitat exploitation theyhave evolved in the arctic and subarctic habitats to which theirbreeding is confined. A graphic model suggesting paths of evolutionarydevelopment and of interplay among factors considered criticalin the evolution of these systems is proposed.     

Stream amphibians as metrics of critical biological thresholds in the Pacific Northwest, U.S.A.: a response to Kroll et al.

1. Kroll, Hayes & MacCracken (in press) Concerns regarding the use of amphibians as metrics of critical biological thresholds: a comment on Welsh and Hodgson 2008 . Freshwater Biology, criticised our paper [ Welsh & Hodgson (2008) Amphibians as metrics of critical biological thresholds in forested headwater streams of the Pacific Northwest. Freshwater Biology, 53 , 1470–1488] proposing the use of headwater stream amphibians as metrics of stream status in the Pacific Northwest (PNW). They argued that our analysis of previously published data reflected circular reasoning because we reached the same conclusions as the earlier studies. In fact, we conducted a meta‐analysis to address new questions about the optimum values and thresholds (based on animal densities) for abiotic stream attributes that were found to be important to these amphibians in earlier studies. This is analogous to determining blood pressure thresholds or fat‐to‐weight ratios that facilitate predicting human health based on meta‐analyses of earlier data from studies that found significant correlations between these variables and relative health. 2. Kroll et al. argued that we should not make inference to environmental conditions across the PNW from data collected in California. We collected data from northern California and southern Oregon, the southern extent of the PNW. We made inference to the Klamath‐Siskiyou and North Coast bioregions, and argued that available research on these headwater species indicates that our results have the potential to be applied throughout the PNW with minimal regional adjustments. 3. Kroll et al. contended that we need reproductive success, survival estimates and density estimates, corrected for detection probabilities, to establish relationships between animal density and stream attributes. Reproductive success and survival estimates are important for demographic modelling and life tables, but they are not necessary to demonstrate meaningful relationships with abiotic conditions. Both corrected occupancy estimates and individual detection probabilities are unnecessary, and take multiple sampling efforts per site, or onerous mark release and re‐capture studies, respectively, to determine accurately. 4. Kroll et al. questioned the use of stream amphibians as a surrogate for measuring physical parameters, such as water temperature, claiming that measuring the physical parameters directly is more efficient. Here they misinterpreted the main point of our paper: stream organisms are integrators of what happens in a catchment, and carefully selected species can serve as surrogates for the biotic community and the relative condition of the network environment. 5. Kroll et al. claimed that we demonstrated weak inferences regarding ecosystem processes. We argue that by relating densities of stream amphibians with changes along abiotic environmental gradients that are commonly affected by anthropogenic activities, we are establishing biological links to gradients that represent important ecosystem processes and identifying biometrics that can be used to quantify the status (health) of these gradients.     

Growth Rate and Water Relations of Citrus Leaf Flushes

Growth rates of seasonal leaf flushes of ‘Valencia’orange [Citrus sinensis (L.) Osbeck] were measured and waterrelations characteristics of young (new) and over-wintered (old)citrus leaves were compared. New flush leaves had lower specificleaf weights and lower midday leaf water potentials than comparablyexposed old leaves. Spring and summer flush new leaves had higherosmotic potentials than old leaves. These differences becamenon-significant as the new leaves matured. During summer conditions,water-stressed new leaves reached zero turgor and stomatal conductancealso began to decrease in them at higher leaf water potentialsthan in old leaves. Old leaves were capable of maintaining openstomata at lower leaf water potentials. Opened flowers and newflush leaves lost more water, on a dry weight basis, than flowerbuds, fruit or mature leaves. The results illustrate differencesin leaf water potential and stomatal conductance which can beattributed to the maintenance of leaf turgor by decreases inleaf osmotic potentials as leaves mature. These changes in citrusleaf water relations are especially important since water stressresulting from high water loss rates of new tissues could reduceflowering and fruit set. Citrus sinensis (L.) Osbeck, orange, Citrus paradisi Macf., grapefruit, growth rate, leaf water relations, osmotic potential, water potential, stomatal conductance     

Micronuclear DNA from Paramecium tetraurelia: Serotype 51 A Gene Has Internally Eliminated Sequences

A method for the isolation of micronuclear DNA from Paramecium tetraurelia has been developed. After cell lysis, a low speed centrifugation at 1,000 g is used to remove all of the unbroken cells and macronuclei and approximately two thirds of the macronuclear fragments. Next a higher speed centrifugation of 9,000 g sediments the micronuclei and frees them from small particulates and soluble constituents. Advantage is then taken of the fact that micronuclei have a lower density than do macronuclear fragments in 45%–60% Percoll. Micronuclei float to the top during centrifugation at 24,000 g , while macronuclear fragments sediment. After several cycles of centrifugation in Percoll, the micronuclei, although heavily contaminated with cytoplasmic components, are essentially free of macronuclei and macronuclear fragments. Micronuclear DNA can then be extracted from the suspension. The whole procedure is very rapid and in about an hour micronuclear and macronuclear DNA can be separated. About 2 μ g of micronuclear DNA can be obtained from 6 times 10⁷ paramecia. We find that there are internal sequences in the micronuclear A gene DNA in wild type cells which are eliminated when the micronuclei develop into macronuclei. They yield unique restriction fragments for micronuclei and macronuclei. Therefore the purity of the preparations is easily monitored by probing Southern blots of restriction enzyme-digested DNA with the cloned A gene. No differences have been found between the micronuclear A gene in wild type and the d48 mutant.     

Winter Avian Community and Sparrow Response to Field Border Width

Abstract: Transformations of agricultural practices in the southeastern United States have drastically reduced preexisting quantities of strip-cover habitat along field margins. The National Conservation Buffer Initiative has promoted the establishment of herbaceous field borders to restore wildlife benefits once provided by such habitat. We evaluated effects of native warm-season grass field border establishment and width on winter bird response. Narrow (approx. 8-m) field borders represented a marginal improvement to non-bordered margins that were cropped ditch to ditch, whereas wide (approx. 30-m) borders significantly enhanced total avian conservation value, abundance, species richness, and sparrow abundance compared to non- or narrow borders. Furthermore, presence of wide borders altered bird use of row-crop fields. We observed increased sparrow (Emberizidae) abundances in agricultural fields adjacent to wide borders, which likely resulted from enhanced waste grain foraging opportunities. Given these benefits to wintering farmland birds, we advocate the integration of herbaceous field border habitat in agricultural landscapes, particularly borders of enhanced width.     

Digital Photography Improves Consistency and Accuracy of Bat Counts in Hibernacula

ABSTRACT The size and distribution of measurement errors associated with major techniques for estimating numbers of hibernating bats are unstudied, although this is the principle method of enumerating several endangered bat species. However, decisions concerning the listing status of a species under the Endangered Species Act require consistent and accurate estimation of population size and trends. Recent advances in digital photography have improved the ability to produce a quantitative record of the numbers of bats in hibernacula. We surveyed clusters of Indiana bats in a hibernaculum and compared results from counts of digital photographs of clusters to results from 4 variations of visual estimation. We counted bats in photographs using Geographic Information System digitization over the photograph. Total counts from 2 sets of photographs varied by <1.5%. Nonphotographic estimation techniques varied from 76% to 142% of counts from photographs for clusters for which estimation (rather than counting) was used. Where feasible, photography can improve status and trend information for species of concern, permitting more timely and specific management actions.