Race biology

BACKGROUND

The founders of Hereditas envisioned that race biology would be a major subject that had social applications with utmost importance in the near future. Anthropometrics was in this context understood to be the pure and eugenics the applied science. Sweden had a long tradition in physical anthropometry. Herman Lundborg, member of the advisory board of Hereditas, united the anthropometric and eugenic approaches in a synthesis. He was the first head of the Institute for Race Biology in Sweden. The contents of Hereditas reflect the development of race biology in the Nordic countries.

CONCLUSIONS

The initial enthusiasm for applied race biology did not last long. In the 1920's Hereditas carried papers on both physical anthropology and eugenics. Most paper dealt, however, with human genetics without eugenic content. Two papers, published in 1921 and 1939 show how the intellectual climate had changed from positive to negative. Finally only human genetics prevailed as the legitimate study of the human race or humankind. A belated defense of eugenics published in 1951 did not help; geneticists had abandoned anthropometrics for good around the year 1940 and eugenics about a decade later. In spite of that, eugenic legislation was amended astonishingly late, in the 1970's. The development was essentially similar in all Nordic countries.

A tale of two papers

Two papers published in HEREDITAS between 1921 and 1939 show how the attitude towards race biology changed in the course of the interwar period in the Nordic countries. In the early 1920s race biology was seen to constitute a legitimate science. Ordinary human genetics prevailed, however, over race biology already in the very beginning on the pages of HEREDITAS. Population thinking was introduced into the study of human heredity around the year 1930. It effectively contradicted the concept of the race. Interestingly, HEREDITAS does not carry a single paper on eugenics and sterilization. In 1939 we see a final repudiation of the doctrines on race. Times had changed and the National Socialists had usurped the doctrines of race in Germany.

Chromosome evolution in Neotropical butterflies

We list the chromosome numbers for 65 species of Neotropical Hesperiidae and 104 species or subspecies of Pieridae. In Hesperiidae the tribe Pyrrhopygini have a modal n = 28, Eudaminae and Pyrgini a modal n = 31, while Hesperiinae have n = around 29. Among Pieridae, Coliadinae have a strong modal n = 31 and among Pierinae Anthocharidini are almost fixed for n = 15 while Pierini vary with n = 26 as the most common chromosome number. Dismorphiinae show wide variation. We discuss these results in the context of chromosome numbers of over 1400 Neotropical butterfly species and subspecies derived from about 3000 populations published here and in earlier papers of a series. The overall results show that many Neotropical groups are characterized by karyotype instability with several derived modal numbers or none at all, while almost all taxa of Lepidoptera studied from the other parts of the world have one of n = 29-31 as modal numbers. Possibly chromosome number changes become fixed in the course of speciation driven by biotic interactions. Population subdivision and structuring facilitate karyotype change. Factors that stabilize chromosome numbers include hybridization among species sharing the same number, migration, sexual selection and possibly the distribution of chromosomes within the nucleus.

Ecotype differentiation in the face of gene flow within the diving beetle Agabus bipustulatus (Linnaeus, 1767) in northern Scandinavia

The repeated occurrence of habitat-specific polyphyletic evolved ecotypes throughout the ranges of widely distributed species implies that multiple, independent and parallel selection events have taken place. Ecological transitions across altitudinal gradients over short geographical distances are often associated with variation in habitat-related fitness, these patterns suggest the action of strong selective forces. Genetic markers will therefore contribute differently to differences between ecotypes in local hybrid zones. Here we have studied the adaptive divergence between ecotypes of the water beetle Agabus bipustulatus along several parallel altitudinal gradients in northern Scandinavia. This water beetle is well known for its remarkable morphological variation associated with mountain regions throughout the western Palaearctic. Two morphological ecotypes are recognised: a montane type with reduced flight muscles and a lowland type with fully developed muscles. Using a multilocus survey of allozyme variation and a morphological analysis with landmark-based morphometrics, across thirty-three populations and seven altitudinal gradients, we studied the local adaptive process of gene flow and selection in detail. Populations were sampled at three different elevations: below, at and above the tree line. The results indicate that the levels of divergence observed between ecotypes in morphology and allele frequencies at α-Glycerophosphate dehydrogenase relative to those shown by neutral molecular markers reflects local diversifying selection in situ. Four main lines of evidence are shown here: (1) A repeated morphological pattern of differentiation is observed across all altitudinal transects, with high reclassification probabilities. (2) Allele and genotype frequencies at the α-Gpdh locus are strongly correlated with altitude, in sharp contrast to the presumable neutral markers. (3) Genetic differentiation is two to three times higher among populations across the tree line than among populations at or below. (4) Genetic differentiation between ecotypes within independent mountain areas is reflected by different sets of allozymes.

Genetic load in northern populations of Drosophila subobscura

O-chromosomes were sampled from two natural populations in Finland, one population in Sweden and one population from Spain. Viability was assessed using the Va/Ba balanced lethal strain. The genetic load for lethals and semilethals was 0.165/0.065 in Helsinki and 0.151/0.101 in Tvärminne, Finland; 0.309/0.118 in Gävle, Sweden and 0.351/0.112 in Barcelona, Spain. With the exception of the Gävle population, the results confirm the general picture that marginal populations are characterized by light loads in comparison with the central ones. Homozygotes for normal or almost normal chromosomes from the Gävle population were less viable than corresponding homozygotes from other marginal populations. Random combinations of wild chromosomes from the Spanish and Finnish populations did not show increased viability over random Spanish heterozygotes.

Chromosomal evolution in the South American Nymphalidae

We give the chromosome numbers of about 80 species or subspecies of Biblidinae as well as of numbers of neotropical Libytheinae (one species), Cyrestinae (4) Apaturinae (7), Nymphalinae (about 40), Limenitidinae (16) and Heliconiinae (11). Libytheana has about n=32, the Biblidinae, Apaturinae and Nymphalinae have in general n=31, the Limenitidinae have n=30, the few Argynnini n=31 and the few species of Acraeni studied have also mostly n=31. The results agree with earlier data from the Afrotropical species of these taxa. We supplement these data with our earlier observations on Heliconiini, Danainae and the Neotropical Satyroid taxa. The lepidopteran modal n=29-31 represents clearly the ancestral condition among the Nymphalidae, from which taxa with various chromosome numbers have differentiated. The overall results show that Neotropical taxa have a tendency to evolve karyotype instability, which is in stark contrast to the otherwise stable chromosome numbers that characterize both Lepidoptera and Trichoptera.

Electrophoretic evidence for disomic inheritance and allopolyploid origin of the octoploid Cerastium alpinum (Caryophyllaceae)

The mode of inheritance of six enzyme markers in the octoploid alpine plant Cerastium alpinum was analyzed. Offspring from crosses between heterozygotes showed fixed heterozygosity at malate dehydrogenase-2, phosphoglucoisomerase-2, triosephosphate isomerase-2, and triosephosphate isomerase-3. Phosphoglucomutase-1 also showed fixed heterozygosity except in offspring from one cross. Fixed heterozygosity in five enzyme systems suggests that C. alpinum has originated through at least some allopolyploidization. Offspring from plants heterozygous for two alleles at the menadione reductase-1 (Mr-1) locus did not deviate significantly from a 1:2:1 ratio. The large proportion of homozygotes suggests disomic inheritance because any kind of polysomic inheritance would result in a substantially increased proportion of heterozygotes relative to disomic inheritance. Assuming a diploid model for Mr-1, this locus was used to analyze the population genetic structure within C. alpinum populations. Inbreeding was found in many alpine populations. This may help explain the large genetic distances found among alpine populations in a previous study. The analysis is only based on one segregating locus, and the results should therefore be treated with caution. However, by establishing the mode of inheritance through crosses, we have been able to use a codominant marker in population genetic analysis of an octoploid plant.

Asexuality alone does not explain the success of clonal forms in insects with geographical parthenogenesis

Asexual forms of invertebrates are relatively common. They are often more successful than their sexual progenitors. Especially in insects, the pattern called geographical parthenogenesis shows that asexuality is important in speciation and ecological adaptation. In geographical parthenogenesis the clones have a wider distribution than the sexual forms they originate from. This indicates that they have a broader niche they may utilize successfully. The cause of this apparent success is, however, hard to come by as the term asexuality covers separate phenomena that are hard to disentangle from the mode of reproduction itself. Asexual insects are often polyploid, of hybrid origin, or both and these phenomena have been argued to explain the distribution patterns better than clonality. In this study we survey the literature on arthropods with geographical parthenogenesis in an attempt to clarify what evidence there is for the different phenomena explaining the success of the clonal forms. We focus on the few species where knowledge of distribution of different ploidy levels allows for a distinction of contributions from different phenomena to be made. Our survey support that asexuality is not the only factor underlying the success of all asexuals. Evidence about the importance of a hybrid origin of the clones is found to be meagre as the origin of clones is unknown in the majority of cases. Asexuality, hybridity and polyploidy are intertwined phenomena that each and all may contribute to the success of clonal taxa. Polyploidy, however, emerges as the most parsimonious factor explaining the success of these asexual invertebrate taxa.

Enzyme Activities and Alcohol Tolerance in Isofemale Lines of Drosophila melanogaster Originating from Different Habitats

Enzyme activity variation was studied in a Drosophila melanogaster population from two villages (Tiszafüred and Tiszaszolos) in Hungary. Two habitats (distillery and farmyard) were sampled in both villages and 8-9 isofemale lines were established from each sample with a total of 35 lines. The activities of ADH, alphaGPDH, IDH and 6PGDH were determined on starch gel after electrophoresis in 10 F1 females of each of the 35 isofemale lines. Three sublines were established from three selected isofemale lines of all four samples (altogether 36 sublines). Alcohol tolerance of the adult flies was assayed in these sublines. The activity of ADH was similar in the two habitats; so was the sensitivity to ethanol. Accordingly, no differences in adaptation to environmental ethanol were detected between the two habitats. The deviations between the two habitats in average activities and in the total variation of enzyme activities were not consistent in the two villages. These results suggest that founder effects and genetic drift are more pronounced in distilleries than selection. The association among enzyme activities varied greatly both between the two villages and between the two habitats. The two parameters of alcohol tolerance were not significantly different between the two habitats in any of the two villages.

Does Drosophila melanogaster use ethanol as an energy source during starvation?

The influence of starvation on activities of three enzymes (ADH, ODH and alpha GPDH) was studied in Drosophila melanogaster. The changes were compared in two inbred lines which had different allelic combinations at the Odh and Aldox loci. We also studied the effect of ethanol on media which contained no sucrose ("starvation conditions"). The results show that there are large differences in the larval and adult alcohol utilization. The alcohol content of the medium, in the absence of sugar, appeared to be toxic for the larvae, while the adults appeared to utilize it as an energy source. The two strains differed little in their responses to starvation or to the ethanol treatment applied under starvation conditions. We conclude that the degree of toxicity of ethanol is highly dependent on the presence of sucrose.

The influence of the Odh-Aldox region of the third chromosome on the response of Drosophila melanogaster to environmental alcohol

Second instar larvae of Drosophila melanogaster were exposed to exogenous alcohol, which is known to influence the activities of several enzymes. In this study, the activity changes were followed in four enzymes (ADH, ODH, alpha GPDH and AOX) during ethanol exposure and compared in three inbred lines that had different allelic combinations at the Odh and Aldox loci. The results indicate that the Odh-Aldox region of the third chromosome may alter the general response to ethanol. The activity of ADH increased considerably in two strains in the larval stages in the presence of alcohol; nevertheless, strain 1, with the OdhS-AldoxF allelic combination, showed a delay in the ADH induction compared to strain 2, which had the OdhF-AldoxS combination. In strain 3 (OdhS*-AldoxS) larvae, ADH induction by environmental ethanol was not detected. Moreover, the activities of alpha GPDH and AOX in strains 2 and 3 were not affected by ethanol. In contrast, the activities of all four enzymes in strain 1 changed after exposure to ethanol.

Heritabilities and additive genetic variances of the activities of some enzymes in Drosophila melanogaster populations living in different habitats

Drosophila melanogaster samples were collected from a large population in two habitats: farmyards and distilleries. Samples were taken from two villages in each habitat. Three isofemale lines were established from all four samples and full-sib crosses were set in each isofemale line. Activities of four enzymes (ADH, alpha GPDH, IDH and 6PGDH) were measured in the offspring of each cross on starch gel after electrophoresis. Broad sense heritabilities and additive genetic variances were estimated in all four samples. Most of the activity variation was observed within the isofemale lines. The isofemale lines tended to be more different in the distilleries than in the farmyards. There was no significant difference in the average activities between the two habitats for any of the enzymes investigated. The additive genetic variance of the enzyme activities did not exhibit a consistent habitat pattern. In the farmyard habitat, we detected a higher activity variation in Tiszafüred than in the other village. Strong correlation was observed among the activities of the enzymes investigated. Correlation coefficients indicated higher level of correlation in the samples collected in Tiszafüred than in those originating from Tiszaszolos. The heritability values were rather high and they had a considerable variation both between the habitats and across the enzymes.

Evolution of clonality and polyploidy in a weevil system

The increased interest in asexual organisms calls for in-depth studies of asexual complexes that actively give rise to new clones. We present an extensive molecular study of the Otiorhynchus scaber (Coleoptera, Curculionidae) weevil system. Three forms have traditionally been recognized: diploid sexuals, triploid, and tetraploid parthenogens. All forms coexist in a small central area, but only the polyploid parthenogens have colonized marginal areas. Analyzing the phylogenetic relationship, based on three partial mitochondrial genes, of 95 individuals from 19 populations, we find that parthenogenesis and polyploidy have originated at least three times from different diploid lineages. We observe two major mitochondrial lineages, with over 2.5% sequence divergence between the most basal groups within them, and find that current distribution and phylogenetic relationships are weakly correlated. Quite unexpectedly, we also discover diploid clones that coexist with, and are morphologically indistinguishable from, the diploid sexual females. Our results support that these diploid clones are derived directly from the diploid sexuals. We also find that it is mainly an increase in ploidy level and not the benefits of asexual reproduction that confers to polyploid parthenogens the advantage over their diploid sexual relatives.

Structure of variation in enzyme activity in natural Drosophila melanogaster populations

Enzyme activity variation was assessed in several isofemale lines originating from two Hungarian Drosophila melanogaster populations. Samples from each population were taken from from two villages; 8-9 isofemale lines were established from each village. The activities of ADH, alphaGPDH, IDH and 6PGDH were determined in the adults (in the F1 generation) and in the larvae (in the F3 generation) as well. Enzyme activities were measured on starch gel after electrophoresis. The activity of the enzyme was detected in a single individual and it was also possible to determine its genotype. The results showed that most of the variation occurred within sites for all four enzymes. This within site variation was more or less equally partitioned into within and between isofemale line (family) components. A smaller portion of variation was attributable to the differences between the populations. Nevertheless, adult alphaGPDH, and larval IDH and 6PGDH activities exhibited significant differences between the two populations. Variation in larval activities of all enzymes was higher than that of the adults, but 6PGDH had considerably higher variation in the adults. The greater variation in larval activities probably reflected the greater environmental variation in the microhabitat of the larvae compared to that of the adults. Larval activities of the investigated enzymes showed much stronger correlation than adult activities. The correlation pattern in the adults differed greatly between the two populations.

Interaction between the Adh and Odh loci in response to ethanol in Drosophila melanogaster

Six Drosophila melanogaster strains were constructed from two isofemale lines. The strains had four allele combinations at the alcohol dehydrogenase (Adh) and octanol dehydrogenase (Odh) loci, while all alpha-glycerophosphate dehydrogenase (alpha Gpdh), malate dehydrogenase (Mdh), and aldehyde oxidase (Aldox) alleles were identical. Second-instar and early and late third-instar larvae were exposed to different concentrations of ethanol (0, 5, and 7.5%) and 3 days later fresh weights and the activities of ADH, ODH, alpha GPDH, and MDH were measured. Activity differences were observed between the two Adh genotypes: ADHF allozyme had considerably higher activity than ADHS. Exogenous ethanol resulted in the highest increase in ADH activity in the second- and early third-instar stages. This ADH induction depended on the allele combination at the Adh and Odh loci; e.g., in the strain having the AdhS-OdhS allele combination, increased ADH activity was observed only after exposure to 7.5% ethanol. ODH activities differed according to the Odh genotypes, in that the ODHS allozyme had a higher activity than ODHF. ODH activities did not appreciably respond to different ethanol treatments. All six strains had identical alleles at the Mdh and alpha Gpdh loci, but nevertheless, the responses of these enzymes to ethanol depended on the allele combinations at the Adh and Odh loci. alpha GPDH activity followed that of ADH in all experiments. MDH activities were not influenced by exogenous ethanol in the strains homozygous for the AdhS allele. In AdhF strains, however, exposure to 7.5% ethanol resulted in a considerable decrease in MDH activity in the second-instar larvae. Correlations among the response variables showed that ODH activities were strongly associated with fresh weight and the activities of all other enzymes, except for ADH. ADH activity, however, showed a significant correlation only with alpha GPDH activity throughout the larval life. Both MDH and ODH activities were found to be in strong negative correlation with ADH activity in the second-instar larvae. At this most sensitive life stage, the metabolic response to ethanol is highly correlated.

Enzymatic responses of Drosophila melanogaster to long- and short-term exposures to ethanol

The effects of environmental ethanol on larva-to-pupa survival and on the activities of four enzymes were investigated in three Drosophila melanogaster strains. The strains had different allelic combinations at the Odh and Aldox loci on their third chromosomes, but they all carried the Adh(S)-Gpdh(F) allelic combination on the second chromosome. Replicates of each of the strains were exposed to three different ethanol treatments: (i) no ethanol in the medium (control); (ii) 5% ethanol for a single generation (short-term exposure); (iii) 5% ethanol for 20 generations (long-term exposure). In all experiments, the activities of four enzymes (ADH, ODH, GPDH and AOX) were measured in larvae, pupae and adults. The results showed that (i) the larval and adult metabolic responses to environmental ethanol were different; (ii) enzyme activity changes under short-term exposure differed from those measured under long-term exposure; (iii) the activities of the allozymes common to all strains (ADH-S and GPDH-F), differed depending on the genetic background. Changes in larva-to-pupa survival were seen when the larvae of control and exposed lines of the three strains were confronted with various concentrations of ethanol. In all three strains, the exposed lines had significantly higher initial survival rate and ethanol tolerance than the control lines. Strain-specific differences were observed in the ethanol tolerance of both types of line.

Differences in environmental temperature, ethanol and sucrose associated with enzyme activity and weight changes in Drosophila melanogaster

Activity changes of three enzymes (ADH, ODH and AOX) of Drosophila melanogaster were followed under different environmental conditions. The influences of ethanol, starvation (no carbohydrates in the medium) and ethanol stress during starvation were studied at both 18 and 26 degrees C. Two strains that were monomorphic for different alleles at the Odh and Aldox loci but otherwise identical were used. The investigated environmental conditions affected ADH induction by exogenous ethanol differently in the two strains. The different allozymes of ODH and AOX also responded differently to the treatments. We observed that the sucrose content of the medium on which ethanol exposure took place and the temperature strongly affected the responses within any single strain. Correlations were estimated among the three enzymes in the larval and adult stages of each strain separately. At both temperatures, differences between strains were observed in the patterns of associations of the response variables, in the larval, but not in the adult stages.

Chloroplast DNA variation in the grass tribe Festuceae

Six grasses, Hordeum sativum, Dactylis glomerata, Festuca arundinacea, F. pratensis, F. rubra and Lolium multiflorum were subjected to chloroplast DNA analysis based on restriction endonuclease digestion fragments and end labeling with (35)S nucleotides. This method is compared with others in general use. The results indicate that Lolium multiflorum is closely affiliated with Festuca pratensis and F. arundinacea; in fact much closer than F. rubra is to any of them.

Insertion polymorphism in pea chloroplast DNA

The chloroplast DNA of higher plants is suitable for restriction endonuclease analysis due to its size and homogeneity. We have analysed 48 different cultivars of pea (Pisum sativum) with EcoRI and HindIII. Of these, only 24 show the standard genotype, the remaining 24 comprise four different classes of short insertions, three of which are found at the same site. Even though this kind of insertion polymorphism has not been detected elsewhere in the plant kingdom, it is consistent with the discovery that the chloroplast DNA of pea is destabilised through the loss of an inverted repeat.

A simple method for pharmacological separation of motivation attention and learning

A simple 2 X 2 factorial analysis provides separation of drive and learning aspects in a bar press escape learning. In addition, attentional measure is given considering the dispersion of results. This experimental design has been proved with Diazepam, a drug of rather well known effects, to assert the validity of the method.

Genetic polymorphism and evolution in parthenogenetic animals : Part 9: Absence of variation within parthenogenetic aphid clones

The enzyme gene variability within parthenogenetic clones of Acyrtosiphon pisum has been followed by gel electrophoresis. No variation was observed within any clone. One enzyme locus was found to vary between clones. No evidence was found to support gene recombination due to the alleged endomeiosis. This hypothesis is proven to be also theoretically untenable. The low average heterozygosity in aphids is explained as a result of directional selection operating upon the parthenogenetic aphid clones, as a consequence of which the heterozygosity is lowered.