Evolution of genetic networks for human creativity.

The genetic basis for the emergence of creativity in modern humans remains a mystery despite sequencing the genomes of chimpanzees and Neanderthals, our closest hominid relatives. Data-driven methods allowed us to uncover networks of genes distinguishing the three major systems of modern human personality and adaptability: emotional reactivity, self-control, and self-awareness. Now we have identified which of these genes are present in chimpanzees and Neanderthals. We replicated our findings in separate analyses of three high-coverage genomes of Neanderthals. We found that Neanderthals had nearly the same genes for emotional reactivity as chimpanzees, and they were intermediate between modern humans and chimpanzees in their numbers of genes for both self-control and self-awareness. 95% of the 267 genes we found only in modern humans were not protein-coding, including many long-non-coding RNAs in the self-awareness network. These genes may have arisen by positive selection for the characteristics of human well-being and behavioral modernity, including creativity, prosocial behavior, and healthy longevity. The genes that cluster in association with those found only in modern humans are over-expressed in brain regions involved in human self-awareness and creativity, including late-myelinating and phylogenetically recent regions of neocortex for autobiographical memory in frontal, parietal, and temporal regions, as well as related components of cortico-thalamo-ponto-cerebellar-cortical and cortico-striato-cortical loops. We conclude that modern humans have more than 200 unique non-protein-coding genes regulating co-expression of many more protein-coding genes in coordinated networks that underlie their capacities for self-awareness, creativity, prosocial behavior, and healthy longevity, which are not found in chimpanzees or Neanderthals.

Madagascar's lemurs.

These primates can tell us a great deal about our own evolutionary past. But many species are already extinct, and the habitats of those that remain are shrinking fast.

Diet and the Neanderthals.

The ultimate goal of paleoanthropological studies is to develop the most accurate and exhaustive portraits possible of our extinct human relatives, and of the history by which we became what we are. This endeavor includes, in the first place, the essential processes of establishing the basic parameters of hominid diversity, and of elucidating the potential evolutionary relationships among the components of that diversity. But our efforts clearly need to go farther than this; for the overall picture of human evolution is quite evidently incomplete without consideration of early hominid lifeways, and of how now-vanished hominid species interacted with their environments. Among the most important interactions of this kind is, unquestionably, feeding behavior and the expression of such behaviors in diet. For, at least short of breathing, feeding is the most fundamental of all the subsistence activities in which a terrestrial species can engage. And we will never be able to claim to understand the lifeways of ancient hominids without at least some insight into how they sustained themselves. Self-evident as these remarks might be, however, they should not be taken to imply that--especially among eurytopes such as hominids--diet can, or should ever be regarded as, monolithic, or as an intrinsic property of any species. Nor do they mean that we can ever look upon hominid populations as "adapted" to particular food resources. Indeed, primates in general are remarkably varied in the diets that may be chosen by different populations of the same species, both seasonally and geographically [see, for example, the review of dietary variation among Malagasy strepsirhines in Tattersall, 1982]. Rather, amongst most if not all-living primates that have been studied, it appears--not surprisingly--that the factor, which most importantly controls immediate dietary intake, is the spectrum of potential food resources available within the local environment. Not to put too fine a point on it, most primates are opportunists.

Significance of some previously unrecognized apomorphies in the nasal region of Homo neanderthalensis.

For many years, the Neanderthals have been recognized as a distinctive extinct hominid group that occupied Europe and western Asia between about 200,000 and 30,000 years ago. It is still debated, however, whether these hominids belong in their own species, Homo neanderthalensis, or represent an extinct variant of Homo sapiens. Our ongoing studies indicate that the Neanderthals differ from modern humans in their skeletal anatomy in more ways than have been recognized up to now. The purpose of this contribution is to describe specializations of the Neanderthal internal nasal region that make them unique not only among hominids but possibly among terrestrial mammals in general as well. These features lend additional weight to the suggestion that Neanderthals are specifically distinct from Homo sapiens.

A new genus and species of adapid primate from the middle Eocene of Alsace, and a new genus for 'Adapis' ruetimeyeri Stehlin, 1912.

A new primate genus and species, represented by isolated teeth, is described from the middle Eocene Alsatian site of Bouxwiller. This new form is closely related to Egerkingen 'Adapis' ruetimeyeri, for which a new genus is proposed because of the important distinctions from type Adapis present in its dentition. Nonetheless, both new genera are closely related to Adapis and Leptadapis.

The human chin revisited: what is it and who has it?

Although the presence of a "chin" has long been recognized as unique to Homo sapiens among mammals, both the ontogeny and the morphological details of this structure have been largely overlooked. Here we point out the essential features of symphyseal morphology in H. sapiens, which are present and well-defined in the fetus at least as early as the fifth gestational month. Differences among adults in expression of these structures, particularly in the prominence of the mental tuberosity, are developmental epiphenomena and serve to emphasize the importance of studying this region in juveniles whenever possible. A survey of various middle to late Pleistocene fossil hominids for which juveniles are known reveals that these features are present in some late Pleistocene specimens assigned to H. sapiens, but not in all of the presumed anatomically modern H. sapiens (i.e., Qafzeh 8, 9, and 11). The adult specimens from Skhul, as well as the adult Qafzeh 7 specimen, are similarly distinctive in symphyseal morphology. Neanderthals are quite variable in their own right, and they as well as other middle to late Pleistocene fossils lack the symphyseal features of H. sapiens. Some of the latter are, however, seen in the Tighenif (Ternifine) mandibles.

Cycles of activity, group composition, and diet of Lemur mongoz mongoz Linnaeus 1766 in Madagascar.

A preliminary study of the ecology and behavior of Lemur mongoz mongoz was carried out in the northwest of Madagascar. The animals were observed for approximately 250 h in July till August, 1973, and for 50 h in June, 1974. L.m.mongoz has been reported to be diurnal and to live in groups of 6-8 individuals. However, we found the animals to be nocturnal and that groups contained an adult male, an adult female and their offspring (groups numbering from 2 to 4 individuals). L.m.mongoz is thus the only species of the genus Lemur studied to date that is active exclusively at night and that lives in family groups. L.m.mongoz was also found to have a very specialized diet. During our study, it was observed to feed on only five species of plant and mainly on the nectar-producing parts (flowers and nectaries) of four of these species. It spent most of its feeding time licking nectar from the flowers of the kapok tree, Ceiba pentandra, and is probably a major pollinator of this tree in Madagascar. In Africa and South and Central America, the kapok tree is usually bat-pollinated. A dietary preference for nectar, although common among bats, has not previously been observed in primates.

Relationships of Microadapis sciureus (Stehlin, 1916), and two new primate genera from the Eocene of Switzerland.

We review the fossil material from the Swiss middle Eocene site of Egerkingen allocated to Adapis sciureus and transferred to the new genus Microadapis. Three species at least are represented in this assemblage. Microadapis sciureus is represented only by the holotype, whose affinities appear to lie with the North American Smilodectes. Most of the original hypodigm is allocable to the new genus Simonsia, which does bear the affinities to Adapis suggested by earlier authors for sciureus. Two specimens are placed in the new genus, Chasselasia, which may be related to the extant galagids.

Morphology, paleoanthropology, and Neanderthals.

Morphology carries the primary signal of events in the evolutionary history of any group of organisms but has been relatively neglected by paleoanthropologists, those who study the history of the human species. Partly this is the result of historical influences, but it is also due to a rather fundamentalist adherence among paleoanthropologists to the tenets of the Neodarwinian Evolutionary Synthesis. The result has been a general paleoanthropological desire to project the species Homo sapiens back into the past as far and in as linear a manner as possible. However, it is clear that the human fossil record, like that of most other taxa, reveals a consistent pattern of systematic diversity--a diversity totally unreflected in the conventional minimalist interpretation of that record. Thus, the Neanderthals, both morphologically and behaviorally as distinctive a group of hominids as ever existed, are conventionally classified simply as a subspecies of our own species Homo sapiens--a classification that robs these extinct relatives of their evolutionary individuality. Only when we recognize the Neanderthals as a historically distinctive evolutionary entity, demanding understanding in its own terms, will we be able to do them proper justice. And we will only be able to do this by restoring morphology to its proper place of primacy in human evolutionary studies.

Dietary and dental variations in the genus Lemur, with comments concerning dietary-dental correlations among Malagasy primates.

Field studies of feeding in the lemur subspecies Lemur fulvus rufus and L. f. mayottensis have revealed that feeding patterns within a single species can be markedly different, both regionally and seasonally. Thus L. f. rufus is a dietary specialist (3 plant species accounting for 80-90% of feeding time), and is highly folivorous, especially during the dry season (90% of feeding time spent eating leaves during the dry season, and 53% during the wet season). On the other hand, L. f. mayottensis is more generalized dietarily (the parts of 12 plant species accounting for 90% of feeding time), and is primarily frugivorous (64% of feeding time spent eating fruit, with a monthly maximum during the wet season of 79%. In both these respects, L. f. mayottensis resembles L. catta are more closely thant it does L. f. rufus. When size differences are corrected for, Lemur fulvus rufus has significantly longer second lower molar shearing crests than does L. f. mayottensis. Other folivorous Malagasy strepsirhines also tend to have long shearing crests than frugivorous forms. Some data on cheirogaleines also suggest that the more insectivorous species have better developed molar crests than frugivorous species. Some apparent exceptions to this pattern are noted, especially for Lemur catta, which in certain functional respects dentally more closely resembles L. f. rufus than L. f. mayottensis. The problems of dietary classifications are discussed.