Separate Breeding Populations Research Articles

Genetic markers separate breeding populations of the endangered Antipodean Albatross and allow for determination of provenance of birds killed at-sea

ABSTRACT Advances in technology and software have provided higher resolution of genetic data. Re-analysis of genetic data from the endangered Antipodean Albatross using STRUCTURE shows that samples from the two main breeding populations on Antipodes and Adams Islands can be assigned correctly to each population using a set of nine microsatellite markers. The new analyses allow for assignment of bycatch birds killed off the east coast of New Zealand with high accuracy and show all of them originated from Antipodes Island. This highlights not only the importance of using genetic markers to inform conservation and management of endangered species but also the important advances in bioinformatics and the value of existing datasets.

Accounting for population structure in genomic predictions of Eucalyptus globulus.

Genetic groups have been widely adopted in tree breeding to account for provenance effects within pedigree-derived relationship matrices. However, provenances or genetic groups have not yet been incorporated into single-step genomic BLUP ("HBLUP") analyses of tree populations. To quantify the impact of accounting for population structure in Eucalyptus globulus, we used HBLUP to compare breeding value predictions from models excluding base population effects and models including either fixed genetic groups or the marker-derived proxies, also known as metafounders. Full-sib families from 2 separate breeding populations were evaluated across 13 sites in the "Green Triangle" region of Australia. Gamma matrices (Γ) describing similarities among metafounders reflected the geographic distribution of populations and the origins of 2 land races were identified. Diagonal elements of Γ provided population diversity or allelic covariation estimates between 0.24 and 0.56. Genetic group solutions were strongly correlated with metafounder solutions across models and metafounder effects influenced the genetic solutions of base population parents. The accuracy, stability, dispersion, and bias of model solutions were compared using the linear regression method. Addition of genomic information increased accuracy from 0.41 to 0.47 and stability from 0.68 to 0.71, while increasing bias slightly. Dispersion was within 0.10 of the ideal value (1.0) for all models. Although inclusion of metafounders did not strongly affect accuracy or stability and had mixed effects on bias, we nevertheless recommend the incorporation of metafounders in prediction models to represent the hierarchical genetic population structure of recently domesticated populations.

The Biology of Secularization

Abstract For the past 500 years, to varying degrees, the processes of religious secularization have been occurring in what today are the wealthy, highly educated, industrialized nations of the world. They are causing organized religion, as a social institution, to go from being a very important influence on the lives of people and the nations in which they live to being a smaller influence, or almost no influence at all. Various disciplines from theology to psychology to sociology have tried to explain secularization, each discipline contributing something unique. One discipline that has not contributed has been biology. From a biological perspective, based on observation and reasoning, at least one of the ultimate functions of the physical forms associated with religion appear to be that of in-group marker for a breeding population, which, as will be shown, is how all religions start. Religions structure larger human populations into smaller “clusters” that are separate in-group breeding populations. The clustering into smaller in-group breeding populations prevents the spread of contagious diseases and creates inter-group competition and intra-group cooperation, both of which have contributed to human eusociality, a very rare type of social organization that will be explained. As the physical forms of religion are losing this in-group-marker function of clustering populations with modernity, a general biological principle comes into play, which is “form follows function, and as function wanes, so does form.” When applied to religion, “form” means the physical components by which all religions are built. The specific meaning of “physical,” as used here, will be explained in the article. This biological perspective, which is counter-intuitive and can generate testable hypotheses, should complement, not compete, with perspectives from other disciplines. Physical forms in biology can and often do have more than one function, so the same form with a biological function can also have psychological and theological functions. The physical forms of religion are its objects of natural (genetic and cultural) selection. As socio-economic modernity spreads through the world, the evolutionary biological trajectory suggests that religion, as a social institution, will eventually become extinct.

The Mouse Lemur, a Genetic Model Organism for Primate Biology, Behavior, and Health.

Systematic genetic studies of a handful of diverse organisms over the past 50 years have transformed our understanding of biology. However, many aspects of primate biology, behavior, and disease are absent or poorly modeled in any of the current genetic model organisms including mice. We surveyed the animal kingdom to find other animals with advantages similar to mice that might better exemplify primate biology, and identified mouse lemurs (Microcebus spp.) as the outstanding candidate. Mouse lemurs are prosimian primates, roughly half the genetic distance between mice and humans. They are the smallest, fastest developing, and among the most prolific and abundant primates in the world, distributed throughout the island of Madagascar, many in separate breeding populations due to habitat destruction. Their physiology, behavior, and phylogeny have been studied for decades in laboratory colonies in Europe and in field studies in Malagasy rainforests, and a high quality reference genome sequence has recently been completed. To initiate a classical genetic approach, we developed a deep phenotyping protocol and have screened hundreds of laboratory and wild mouse lemurs for interesting phenotypes and begun mapping the underlying mutations, in collaboration with leading mouse lemur biologists. We also seek to establish a mouse lemur gene “knockout” library by sequencing the genomes of thousands of mouse lemurs to identify null alleles in most genes from the large pool of natural genetic variants. As part of this effort, we have begun a citizen science project in which students across Madagascar explore the remarkable biology around their schools, including longitudinal studies of the local mouse lemurs. We hope this work spawns a new model organism and cultivates a deep genetic understanding of primate biology and health. We also hope it establishes a new and ethical method of genetics that bridges biological, behavioral, medical, and conservation disciplines, while providing an example of how hands-on science education can help transform developing countries.

Year-round spatial movements and trophic ecology of Trindade Petrels (Pterodroma arminjoniana)

Trindade Petrels (Pterodroma arminjoniana) are vulnerable gadfly petrels that breed on the remote Trindade Island, located ~1100 km off the Brazilian coast. Little is known about their spatial ecology, and their trophic ecology has only been described for the breeding season. We tagged four Trindade Petrels with global location sensing loggers (GLS) from October 2013 to November 2014 and sampled the blood and feathers (innermost primary and the eighth secondary) of 14 individuals to evaluate their year-round spatial and isotopic ecology. We examined individual distributions, habitat use and suitability, activity, and isotopic values during the breeding, migration, and non-breeding periods. Trindade Petrels used areas in the southwest Atlantic Ocean (between 10°N and 50°S in latitude) during the breeding season. They migrated through pelagic waters of the tropical Atlantic to the northwest Atlantic, where they spent the non-breeding season. Trindade Petrels used mostly tropical to subtropical waters in areas of intermediate to high wind speeds and low marine productivity. Individuals spent more time foraging at night than during the day. During the breeding season, birds in northerly areas had higher carbon-13 values, and birds that used more pelagic areas foraged on prey at a higher trophic level (higher nitrogen-15 values) than those in more southern and coastal areas. Isotopic values during the breeding, migration, and non-breeding periods differed, possibly due to differences among individuals in their at-sea distribution throughout the year. We confirmed the non-breeding distribution of Trindade Petrels, which was previously known only from vessel sightings and stranded birds. Our results also suggest a strong temporal segregation in the at-sea distribution and trophic ecology between two groups of individuals, which might indicate the existence of two separate breeding populations.

Evaluating confidence in climate‐based predictions of population change in a migratory species

AbstractAimForecasting ecological responses to climate change is a common objective, but there are few methods for evaluating confidence in such predictions. For migratory species, in particular, it is also essential to consider the extent of spatial synchrony among separate breeding populations in range‐wide predictions. We develop a quantitative method to evaluate the accuracy of climate‐based ecological predictions and use this approach to assess the extent of spatio‐temporal synchrony among distinct regions within the breeding range of a single migratory population.LocationWe model weekly site‐specific summer abundances (1996–2011) of monarch butterflies (Danaus plexippus) in the Midwestern USA as a function of climate conditions experienced during a shared spring migration/breeding phase in Texas and separate summer recruitment periods in Ohio and Illinois.MethodsUsing negative binomial regression models, we evaluate spatio‐temporal synchrony between monarchs in the two states and develop a novel quantitative assessment approach to determine the temporal predictive strength of our model with BayesianP‐values.ResultsMonarchs breeding in the Midwest exhibit spatio‐temporal synchrony in Ohio and Illinois; cooler spring temperatures, average to above average precipitation in Texas and cooler than average summer temperatures are associated with higher population abundances in both states. At least 10 years of data are needed for adequate model predictability of average future counts. Because annual spring weather conditions in Texas primarily drive yearly abundances, as opposed to localized summer effects, year‐specific counts are often difficult to predict reliably, specifically when predictive spring conditions are outside the range of typical regional conditions.Main conclusionsOur assessment method can be used in similar analyses to more confidently interpret ecological responses to climate change. Our results demonstrate the relative importance of climatic drivers in predicting abundances of a migratory species and the difficulties in producing reliable predictions of animal populations in the face of climate change.

Combining genetic and distributional approaches to sourcing introduced species: a case study on the Nile monitor (Varanus niloticus) in Florida

Three separate breeding populations of the Nile monitor (Varanus niloticus) have been identified in Florida, USA, located in Cape Coral, West Palm Beach and Homestead Air Reserve Base. This large, predatory lizard could have negative effects on Florida's native wildlife. Here, we infer the source of the introduced populations using genetic and statistical approaches, as well as estimate the potential non-native distribution of V. niloticus in North America. We collected genetic data from 25 Florida individuals as well as utilized genetic datasets from reference individuals spanning the full native distribution throughout sub-Saharan Africa. Using occurrence data from the inferred source population and the full species range, we built ecological niche models (ENMs) and projected them onto North America to determine regions with suitable climate. Our results indicated that the introduced populations resulted from three separate introduction events, and all originated from the southern coastal region of West Africa. The ENM built from the West African source population predicted only the southernmost portions of North America to be suitable. Conversely, the model derived from the full species’ range predicted suitable climates across a large portion of the United States. This information can be used to focus management and eradication efforts.

Connectedness among test series in mixed linear models of genetic evaluation for forest trees

In forest tree species with large natural ranges, there are usually several to many separate breeding populations, each designed to capture elite material suited to a particular geographic region. Separate test series are often dedicated to each population. Because the aim is to optimise gain in the meta-population, it is important to ensure that test series are linked so that individuals can be compared across test series as well as within. Computer simulation was used to determine the most efficient strategy for obtaining linkage. The average accuracy of a genetic value contrast between individuals in the same and in different test series was used as the criterion for assessing the optimal level of linkage. Accuracy is a function of the elements of the inverse coefficient matrix for a mixed linear model within a best linear unbiased prediction framework (BLUP). Material used to link test series was either common test families, common check-lots such as seed orchard bulks, or families generated by inter-crossing parents from different test series. Use of common test families was the most efficient strategy for the scenarios tested, which included having 50 parents crossed to produce 50 test families in each of three populations. For a low-heritability scenario, the amount of linkage material, relative to test material, needed to be 8 and 12 %, for progeny and parents, respectively, in order for a contrast between individuals in different test series to have equivalent accuracy as a contrast between individuals in the same test series. Other strategies were less efficient in terms of the amount of linkage material needed to obtain this equivalency.

A review of the subspecies status of the Icelandic Purple Sandpiper Calidris maritima littoralis

The Icelandic Purple Sandpiper Calidris maritima littoralis (C.L. Brehm, 1831) represents one member of a poorly understood subspecies complex. Currently, differences in size define two other subspecies: Calidris maritima belcheri Engelmoer & Roselaar, 1998, which breeds in north-eastern Canada along the Hudson Bay and James Bay, and Calidris maritima maritima (Brunnich, 1764), which breeds along the Arctic coasts elsewhere in northern Canada, Greenland, Svalbard, Scotland, and Fennoscandia, to northern central Siberia. There are large size differences amongst populations of C. m. maritima, however. As an Arctic/Alpine breeding bird, C. m. littoralis could provide an interesting perspective on the evolutionary changes following a northwards expansion of a species after glacial retreat. Considering the extent of the ice sheet in the northern hemisphere during the last glaciation, and the short period of time since it ended, the correct attribution of subspecies status for C. m. maritima may reflect either rapid diversification from a single population or ancestral splits of distinct evolutionary lineages that survived in isolation at southern latitudes. We applied morphometric subspecies criteria, diagnosability by Amadon’s rule, and genetic analysis of five nuclear introns, and the mitochondrial DNA markers cytochrome oxidase c subunit I (COI) and NADH dehydrogenase subunit 2 (ND2), to geographically separate breeding populations in order to examine the subspecies status of the Icelandic population. The results do not provide support for the subspecies status of the Icelandic population because the nominate and Icelandic subspecies fail to uphold Amadon’s rule, and genetic analyses indicate that the study populations derive from a single shared refugium.

Population structure of humpback whales in the western and central South Pacific Ocean determined by vocal cultural exchange

Male humpback whales (Megaptera novaeangliae) produce a continually evolving vocal sexual display, or “song,” which is shared by all males within a population. The rapid cultural transmission of this display between distinct but interconnected populations within the western and central South Pacific region presents a unique opportunity to investigate population connectivity based on a vocal display. Quantitative analyses were conducted on eleven years of data to investigate vocal groupings based on song types shared between populations, to produce an acoustically derived population structure for the region. Four distinct vocal groupings resulted; the western group contained a single population, off eastern Australia, the central group was comprised of whales around New Caledonia, Tonga and American Samoa, and finally the whales of the eastern region were split into two groups, one around the Cook Islands and the other in the waters of French Polynesia. These groupings broadly agree with results obtained using genetic and photo-identification methods, and confirm that humpback whales are likely to form separate breeding populations rather than panmictic subpopulations. This study demonstrates the utility of using culturally transmitted vocal patterns as a way of defining populations, at least in this species.

Subspecies identification with mtDNA and morphometrics in captive palm cockatoos, Probosciger aterrimus

The European breeding programme (EEP) for palm cockatoos Probosciger aterrimus has managed two subspecies, P. a. goliath and P. a. aterrimus , separately since it was found that only these two subspecies were distinct genetic lineages. Until recently a captive palm cockatoo was assigned to one or the other subspecies relying solely on morphology, P. a. goliath being reputedly larger than P. a. aterrimus . This study aimed at first to determine the subspecies of 78 captive palm cockatoos – mainly members of the EEP population – by sequencing a mitochondrial marker which had proved relevant for wild specimens. We also collected several anatomical measurements in order to compare the morphology with the molecular marker and to assess the presumed link between morphology and subspecies. Ten different haplotypes were found over 54 non-related samples, which could be arranged into two groups consistent with the subspecies P. a. goliath and P. a. aterrimus . Morphometric analyses revealed significant differences between the two subspecies, although there was some overlap between values for P. a. goliath and P. a. aterrimus . A stepwise discriminant analysis, which included one criterion for females and two criteria for males, allowed a correct assignation of 95% on average for our sample. These results allowed us to confirm that the captive population of palm cockatoos consists of two distinct genetic subgroups, which overall match with morphotypes. Therefore to preserve these two different conservation units we advise that P. a. goliath and P. a. aterrimus continue to be managed as two separate breeding populations. Morphology using a recommended set of measurements gives a fairly reliable insight into the subspecies identity for a newly introduced palm cockatoo, but testing mtDNA is highly recommended to confirm the correct subspecies determination.

Origin of Three Red-Crowned Cranes <i>Grus japonensis</i> Found in Northeast Honshu and West Hokkaido, Japan, from 2008 to 2012

The Red-crowned Crane Grus japonensis is an endangered species that has two separate breeding populations, one in the Amur River basin and the other in north and east Hokkaido, Japan. So far, only two (Gj1 and Gj2) and seven (Gj3-Gj9) haplotypes in D-loop of mtDNA were identified in Japan and in the continent, respectively. We obtained feathers from three cranes found in northeast Honshu. The crane in Akita in 2008, which also arrived at west Hokkaido, had a novel haplotype (Gj10). Another crane in Akita in 2009 showed a heteroplasmy (Gj7 and a novel type, Gj12). The third crane in Miyagi in 2010 also showed another type, Gj11. These results suggest that three Red-crowned Cranes appeared in Honshu and west Hokkaido were from the continent.

Winter rainfall predicts phenology in widely separated populations of a migrant songbird

Climate change is affecting behaviour and phenology in many animals. In migratory birds, weather patterns both at breeding and at non-breeding sites can influence the timing of spring migration and breeding. However, variation in responses to weather across a species range has rarely been studied, particularly among populations that may winter in different locations. We used prior knowledge of migratory connectivity to test the influence of weather from predicted non-breeding sites on bird phenology in two breeding populations of a long-distance migratory bird species separated by 3,000 km. We found that winter rainfall showed similar associations with arrival and egg-laying dates in separate breeding populations on an east-west axis: greater rainfall in Jamaica and eastern Mexico was generally associated with advanced American redstart (Setophaga ruticilla) phenology in Ontario and Alberta, respectively. In Ontario, these patterns of response could largely be explained by changes in the behaviour of individual birds, i.e., phenotypic plasticity. By explicitly incorporating migratory connectivity into responses to climate, our data suggest that widely separated breeding populations can show independent and geographically specific associations with changing weather conditions. The tendency of individuals to delay migration and breeding following dry winters could result in population declines due to predicted drying trends in tropical areas and the tight linkage between early arrival/breeding and reproductive success in long-distance migrants.

Large-Scale Survey of Mitochondrial D-Loop of the Red-Crowned Crane <i>Grus japonensis</i> in Hokkaido, Japan by Convenient Genotyping Method

The Red-crowned Crane, Grus japonensis, is an endangered species of crane that has two separate breeding populations, one in the Amur River basin (continental population) and the other in eastern or northern Hokkaido, Japan (island population). So far, only two haplotypes (Gj1 and Gj2) have been identified in the mitochondrial D-loop in island population, whereas seven haplotypes have been found in continental population (Gj3-Gj9). We developed a rapid and inexpensive method of extensive genotyping of D-loop haplotypes in Red-crowned Cranes, based on amplification refractory mutation system (ARMS) PCR assay. Two hundred and three cranes in eastern Hokkaido were studied with this method and supplemental DNA sequencing. Only two haplotypes, Gj1 and Gj2, were confirmed in eastern Hokkaido with Gj2 as a major haplotype. Additionally, only Gj2 was identified in twelve feathers from both sexes found in northern Hokkaido. These results suggest scarce genetic diversity in island population of Red-crowned Cranes in Hokkaido, Japan.

Flyway evolution is too fast to be explained by the modern synthesis: proposals for an ‘extended’ evolutionary research agenda

In this paper, I argue that to fully grasp the generation and maintenance of variation in the migratory phenotypes of (shore-)birds we need to expand our scientific search image and include developmental processes and non-genetic pathways of inheritance in the explanatory frameworks. Traditionally, studies of micro-evolution of migratory phenotypes were restricted to comparative studies on migratory versus non-migratory taxa, and artificial selection and heritability experiments on quantitative behavioural traits related to migration. Such studies had a focus on the genetic axis of inheritance and were restricted to songbirds. In avian groups such as the shorebird families Scolopacidae and Charadriidae, all but a few island species are migrants, which precludes comparative studies at the species level. Like other taxa, shorebirds have geographically separate breeding populations (either or not recognized as subspecies on the basis of morphological differences) which differentiate with respect to the length, general direction and timing of migration, including the use of fuelling at staging sites and the timing of moult. However, their breeding systems preclude artificial selection and heritability experiments on quantitative traits. This would seem to limit the prospects of evolutionary analysis until one realizes that the speed of evolutionary innovation in shorebird migratory life-histories may be so fast as to necessitate other avenues of explanation and investigation. According to our best current estimates based on mitochondrial gene sequence variation, in Red Knots Calidris canutus considerable phenotypic variation has evolved since the Last Glacial Maximum ca. 20,000 years ago, to the extent that six subspecies are currently recognized. This would be too short a time for the origin of the qualitatively and quantitatively distinct and non-overlapping traits to be explained by random point mutations followed by natural selection, although we cannot dismiss the possibility of previously unexpressed (standing) genetic variation followed by selection. I argue that, to understand the flyway evolution of such shorebirds in the ‘extended’ evolutionary framework, we need to give due attention to developmental versatility and broad-sense epigenetic evolutionary mechanisms. This means that experimental studies at the phenotypic level are now necessary. This could involve a combination of observational studies in our rapidly changing world, common garden experiments, and even experiments involving global-scale displacements of particular migratory phenotypes at different phases of development. I provide suggestions on how such experiments could be carried out.

Reproduction of Heterodontus portusjacksoni in Victoria, Australia: evidence of two populations and reproductive parameters for the eastern population

Significant differences in the length–frequency composition of catch samples, mass–length relationships and length-at-maturity found between Heterodontus portusjacksoni from western and far-eastern Victoria, suggest the presence of at least two separate breeding populations off south-eastern Australia, with some mixing between these regions. In each region females attain a larger size than males, and collectively those sharks in western Victoria are smaller, present higher mass-at-length, and lower length-at-maturity than those in far-eastern Victoria. These regional differences might be a result of sampling bias, length-selective fishing mortality, environmental conditions, or genetic differences. However, tagging evidence from previous studies and the presence of two bio-geographic provinces in the region support the hypothesis of two separate breeding populations. The essential reproductive parameters for H. portusjacksoni population analysis in far-eastern Victoria were determined, using a novel method to estimate fecundity and the ovarian cycle of an egg-laying species. In this region, females have between 6 and 20 pre-ovulatory oocytes (average = 14, n = 29, standard deviation = 3.71) before the reproductive season. The species has an annual reproductive cycle correlated with water temperature, with ovulation starting during late winter to early spring and a ~6 month egg-laying period. The period from the onset of vitellogenesis to ovulation of oocytes is ~18 months.

An investigation into the occurrence and nature of genotype by environment interaction inPinus patula

SYNOPSIS This study was conducted as part of a joint venture between the tree improvement teams of Safcol and the CSIR to develop a breeding, production and conservation strategy for Pinus patula. The results of the investigation into genotype by environment interaction in two progeny trials of P. patula established over 5 sites in the highveld, middleveld and lowveld regions of Mpumalanga, South Africa are presented. The data from seven and eight-year old progeny trials were analysed and the genetic colt-elations and results of regression analysis are discussed in the light of breeding strategies und genotype by environment interaction. The heritabilities for growth rate were greater than those for stem and crown form on all sites. Heritabilities for volume ranged between 0,196 (middleveld site) and 0,246 (highveld site) in trial PF4008 1 09, and 0,256 and 0,400 in trial PF4011. The genetic correlations of growth between sites on the highveld (1733m altitude) and the lower altitude site (1152m) indicated that it is possible to avoid two separate breeding populations for these site types, although there is significant genotype by environment interaction (GEI) and the genetic merit of indirect selection indicated that direct selection will give more genetic gains on the respective sites. Genetic correlations of growth between the sites in the low and middleveld of 0,56 to 0,73 indicated sufficient degree of stability to enable selection for robust genotypes in these regions. Considering several factors, including the sizes of the commercial planting areas of the various site types and the genetic correlations between site types, it was recommended that the breeding population be established on two sites in the middle to lowveld region. Recommendations were made to introduce a testing procedure to ensure that highveld production clones are well suited for that region. Regression analysis techniques allowed an investigation into the stability and behaviour of genotypes. Regression techniques proved useful as an aid in selection when selecting over a range of sites.

Spatial subdivision within a population of tropical pythons (Liasis fuscus) in a superficially homogeneous habitat

Abstract Based on 10 years of intensive fieldwork, we describe the spatial and temporal distribution of water pythons (Liasis fuscus) on the Adelaide River floodplain, Northern Territory, Australia. Our study provides a cautionary tale, because it was only after several years’ work that we realized that our apparently panmictic study ‘population’ in fact consisted of three subpopulations that were separated during breeding activities although they intermingled for most of the year. The partitioning of the populations is due to the restricted availability and spatial separation of suitable nest‐sites (varanid burrows vs root complexes of paperbark trees). Groups of snakes using each type of nest‐site comprise quite separate breeding populations, because females move to these sites prior to mating. Snakes return to the same breeding sites year after year, with little dispersal between populations (even though snakes from each population often move through other breeding sites during the non‐breeding period). The three subpopulations differed in many traits, including body‐size distributions, age structures, the proportions of reproductive animals, survival rates, timing of reproduction, and reproductive frequencies. Thus, if our study had involved only one of the subpopulations (as would typically be the case with studies of this kind), we would have obtained a misleading view of the ‘real’ (i.e. average) ecological characteristics of our study organisms.

Structure of Dairy Cattle Breeding in Western Europe and Comparisons with North America

The cattle population of Western Europe is slightly smaller than that of the United States but contains 32million dairy cows versus 11million. The dairy herd provides 80% of the beef produced against 20% in the United States. The dairy cow population in the European Economic Community consists of 15million Friesian type cows and 10million non-Friesian, making up 29 separate breeding populations. The structure and organization of the breeding program in these 29 populations are described. A strong inflow of North American genetic material (Holstein into the Friesian populations, Brown Swiss and Red Holstein into the others), which has been going on for some years, is quantified. Many European populations will be more than 50% North American in genetic constitution within a decade. The reasons for this shift in breeding policy are discussed.A method is introduced for describing the effectiveness of an artificial insemination bull selection program by numbers of bulls tested per million inseminations and lifetime usage of selected bulls. This method is used to compare the breeding programs of 10 North American breeding organizations with those of 20 European and 2 New Zealand populations. In general, the European populations are making much higher investments in bull testing, whereas the North American organizations tend to have higher rates of bull usage.

Intraspecific variation in the soluble nuclear eye lens proteins of the sandbar shark, Carcharhinus Milberti (Müller and Henle)

1. 1. The technique for studying genitically based molecular variation by electrophoretic separation of nuclear lens protein was applied for the first time in sharks. 2. 2. The protein was extracted from lens nuclei of 23 sandbar shark pups in a saline-urea solution and electrophoretically separated on cellulose acetate. 3. 3. The protein patterns formed ten types, reflecting genetic heterogeneity. 4. 4. This approach can be used in sharks to study intraspecific genetic variation and to identify separate breeding populations, as in teleosts. 5. 5. Older sharks have a decreased amount of soluble nuclear lens protein, which may be due to ontogenetic factors or denaturation effects of intrinsic urea.