The covariation patterns of the postcranial skeleton in eight species of moas (Aves, Dinornithidae) from the Pleistocene of New Zealand are described using multiple factor analysis. Rotation schemes include an orthogonal Varimax and oblique (direct quartimin) simple structure solutions.

Four major patterns of covariation are resolved: a length factor, primarily that of leg length; a width factor, including pelvis width and long bone widths; a sternal breadth factor; and a sternal length-posterior pelvis length factor. The first two patterns represent a functional separation between body size and those aspects of the skeleton, scaling allometrically, adapted to support body weight. The sternal breadth factor may indicate that features contributing to trunk support are independent from those width measurements of the pelvis and hindlimb bones. The sternal length-posterior pelvis length factor reveals a pattern of covariation that is somewhat independent of other patterns (long bone lengths) determining variability in body size.

Late Eocene to middle Oligocene floras from the area of the present Rio Grande depression represent a time sequence from the upper part of mixed subtropical forest (Bernalillo flora), to an ecotone between broadleaved sclerophyll and mixed conifer forest (Red Rock Ranch flora), to subalpine conifer forest (Hillsboro and Hermosa floras). The implied difference in mean annual temperature of ~ 11°C suggests that altitude increased 2,000 m in 6–8 my. Construction of the Datil-Mogollon volcanic pile, averaging about 1,200 to 1,500 m thick, is thought to be largely responsible for the forest zonation, but regional doming accompanying volcanism may also be involved. The Oligocene subalpine conifer forests now occur in the piñon-juniper belt 900 and 1,200 m below the present subalpine zone, consistent with the subsidence that formed the Rio Grande rift beginning in the late Oligocene/early Miocene and continuing to the present. Later epeirogenic uplift of ~ 1200 m is implied by fossil plants in the Galisteo (~ 40 my bp), Creede (~ 27 my bp) and Tesuque (~ 14 my bp) Formations that border, or are in the rift.

The claw equipped forelimbs have been shown to be an important hunting weapon for modern felids. In light of its functional importance, the claw retractile mechanism for modern felids was compared with that of the saber-toothed felids. In this regard, the functional anatomy of claw retraction for saber-toothed felids was found to be the same as that of modern forms. Body proportions of modern felids were also compared with saber-toothed felids and the relationship of their morphology to habitat structure and habitat utilization were studied. It was found that the relative body proportions for Hoplophoneus and Smilodon were similar to modern forest felids (dwellers of high structured dense forest), while Dinictis and Machairodus could probably compete in more open terrain (open woodland, meadow). It is postulated that saber-toothed felids used their claw equipped forelimbs to grasp and hold their prey as do modern felids. In this fashion, the enlarged upper canines could then be used to kill the victim, and this was probably done by a stab to the nape of the neck. It is also thought that Smilodon, like the modern lion, adapted to open habitats by forming prides.

A computer simulation was developed which estimates the effects of differential preservation on the value of taxonomic diversity in fossil assemblages. Taxonomic diversity was measured with the Shannon-Weaver index, H′ and with evenness, J. Preservation markedly alters quantitative measurements of taxonomic diversity. The degree of alteration can, however, be predicted on the basis of the species-abundance distribution and on the distributions of species of varying preservability. The indices of diversity H′ and J measure different aspects of diversity, but respond to differential preservation in a similar manner. Evenness, J, is recommended for paleoecologic use. The computer model can be used to revise fossil diversity data. A simple form of such a model has been used, and suggests that some previous interpretations of paleoecologic diversity may be in error.

Small mammal species distribution, density, and composition of modern and Pleistocene faunas from the eastern United States provide information about environmental gradients. Higher summer temperatures and less effective moisture along a transect from the northeast to the southwest can be correlated with the distribution of small mammals as well as decreases in the total number of shrew and vole species. Relative frequencies of “boreal”, “deciduous”, and “steppe” species are more equal in late Wisconsin than modern faunas which are predominantly composed of only one group. A higher vole species density is prevalent in each late Wisconsin fauna and eleven of twelve of these faunas have a higher shrew species density than the corresponding modern fauna. Many shrew and vole species that are today endemic to the boreal provinces were cosmopolitan during the late Wisconsin. Moderate environmental gradients of the equable late Wisconsin climates allowed integration of boreal species with resident species in the south.

Genetic and morphologic differentiation in the bryozoan Schizoporella errata parallel each other over a distance of 102 km along the southern shore of Cape Cod. This is seen in the allele frequencies of two marker genes and in the length of the avicularium (a type of defensive polymorph of the bryozoan colony). These changes appear to be part of the continuing evolutionary adaptation to local environmental conditions, perhaps characteristic of marine species whose dispersal ability is very limited. The length scale of significant changes in allele frequencies at the two loci is as low as 10–11 km, and for avicularium length is 13 km.

The beginnings of biospheric evolution had far-reaching biogeochemical consequences for the related evolutions of atmosphere, hydrosphere, and lithosphere. Feedback to the sedimentary record from these several simultaneously interacting aspects of crustal evolution provides the evidence from which historical biogeology is reconstructed. The interpretation of that evidence, however, is beset with pitfalls. Both biogenicity and a primary origin need to be demonstrated, or confidence limits established for each supposed morphological and biochemical fossil. Relevance to biospheric or related evolutions must be critically evaluated for every geochemical and sedimentological anomaly.

Indirect evidence suggests primitive, oxygen-generating autotrophy by ∼ 3.8 × 109 years ago (3.8 Gyr or gigayears), while free O2 first began to accumulate only ∼ 2 Gyr ago. Various reduced substances in the atmosphere and in solution functioned as oxygen sinks, keeping photolytic and biogenic O2 at levels tolerable by primitive anaerobic and microaerophilic procaryotes.

The oldest demonstrably biogenic and certainly primary microstructures are procaryotes from ∼ or > 2 Gyr old strata around Lake Superior. Improved biologic O2 mediation, continued carbon segregation, and filling of O2 sinks initiated atmospheric O2 buildup, leading to an ozone screen ∼ or < 2 Gyr ago. Consequences were essential termination of banded iron formation, onset of red beds, and O2 shielding of anaerobic intracellular processes, heralding the eucaryotic cell.

Probable eucaryotes appear in ∼ 1.3 Gyr old rocks in California as large unicells and large-diameter, branched, septate filaments. Likely consequences of eucaryotic evolution were increased atmospheric O2, increased carbonate and sulfate ion, and the rise of sexuality. Meiosis had definitely evolved > 0.7 Gyr ago and probably > 1.3 Gyr ago, perhaps simultaneously with the mitosing cell. Whatever the timing, it completed the evolution of the eucaryotic heredity mechanism and foreshadowed (given sufficient free O2) the differentiation of tissues, organs, and advanced forms of life—with all their potential for biogeochemical feedback to sedimentary, diagenetic, and metallogenic processes. The first Metazoa appeared ∼ 0.7 Gyr ago. Being dependent on simple diffusion for O2, they lacked exoskeletons. The latter appeared, perhaps 0.6 Gyr ago, when increasing O2 levels favored the emergence of more advanced respiratory systems.

For the past twenty years, Ralph Gordon Johnson contributed significantly in three areas of paleobiology: understanding the dynamics of benthic marine communities, exploring the mode of formation of fossil assemblages, and describing the remarkably preserved Mazon Creek fauna.