Influence of Plio-Pleistocene aridification on human evolution: evidence from paleosols of the Turkana Basin, Kenya

New stable carbon isotope measurements, coupled with paleoprecipitation estimates, both from Plio-Pleistocene paleosols of the Turkana Basin, Kenya, provide a high-resolution record of aridification and increasing C4 biomass during the past 4.3 Ma. This aridification trend is marked by several punctuations at 3.58-3.35, 2.52-2, and 1.81-1.58 Ma, during which the running mean and variance of delta13C and paleoaridity estimates increase, suggesting that the proportion of C4 biomass increases in savanna mosaics during periods of heightened aridity. Increase in C4 biomass during these aridification events not only increases the proportion of open habitats, but increases the spatial neg-entropy, or heterogeneity of the ecosystem. The aridification events identified correspond to intervals of increased turnover, but more importantly, increased diversity of bovids. Although the record of hominins from the Turkana Basin lacks the temporal resolution and diversity of the bovid record, the aridification intervals identified are marked by similar increases in the diversity and turnover of hominins. These results support the hypothesis that hominins evolved in savanna mosaics that changed through time, and suggest that the evolution of bovids and hominins was driven by shifts in climatic instability and habitat variability, both diachronic and synchronic.     

Changing crop biodiversity and resource use efficiency of traditional versus introduced crops in the cold desert of the northwestern Indian Himalaya: a case of the Lahaul valley

This paper studies the crop biodiversity and its changing patterns across an altitudinal gradient of three highland village agroecosystems: Hinsa (2700 m), Jahlma (3000 m) and Khoksar (3200 m). It also deals with energy (kilocalorie (physiological); kcal or Megajoules; MJ) and monetary (Indian rupee; Rs) efficiency of traditional crops versus recently introduced cash crops in the cold desert of the Lahaul valley. Newly introduced cash crops like hop, pea and potato have drastically reduced the crop biodiversity along the increasing altitudes. Of the total cropped area, 70% is occupied by these cash crops. Organic manure, mainly derived from forests and night soil, accounted for 90 and 77% of the total energy input in traditional and introduced cash crops in all the three selected villages, respectively. The energy output/input for traditional crops ranged in Hinsa from 0.6 (Kuth (Sausurea lappa, family Asteraceae) — a root crop of medicinal use) to 6.1 (amaranths); for the introduced cash crops it varied from 0.9 (potato) in Hinsa to 2.8 (pea) in Jahlma. In terms of energy, traditional crops are richer and more viable than the introduced cash crops. Monetary output/input of traditional crops was 0.8 (maize) to 11.8 (Kuth) and for introduced cash crops it was from 1.8 (potato) to 6.2 (hop). Overall, the average monetary efficiency of introduced crops was higher than that of traditional ones. Taking the average of the three villages, the energy and monetary output/input for the introduced cash crops was 1.4 and 3.3, respectively. However, for the purpose of food security and environmental conservation there is a need to establish a balance between traditional and introduced cash crops. This will make farming sustainable in the cold desert environment where crop growth period is limited. The Lahaul valley is landlocked and due to heavy snow deposits at Rohtang pass (3978 m), its main entry from Kullu valley remains accessible only for 5 months (July–November).     

Prioritization of medicinal plants on the basis of available knowledge, existing practices and use value status in Uttaranchal, India

In order to understand the pattern of indigenous uses of medicinal plants available in the Uttaranchal state of the Indian Himalaya, this study was undertaken through literature survey and fieldwork in various parts of the state. A list of all the major and most of the lesser categories of ailments was prepared and categorized with the help of medical practitioners. A total of 300 plant species used in curing 114 ailments prevailing in various ethnic and non-ethnic communities of Uttaranchal were documented. These 114 ailments were further grouped into 12 broad classes of diseases in order to project the indigenous uses of medicinal plants for various ailments. It was found that herbs contributed the highest number of medicinal plants (65%), followed by shrubs (19%) and trees (16%). The maximum number of plant species were used to cure generalized body aches and colic, followed by gastrointestinal and dermatological problems. Vitex negundo was the most important species, used for the treatment of more than 48 ailments. Azadirachta indica, Woodfordia fruticosa, Centella asiatica, Aegle marmelos, Cuscuta reflexa, Butea monosperma, Phyllanthus emblica, and Euphorbia hirta were among other important medicinal plants based on their high use values. The underground parts of the plant were used in the majority of cases. Of 300 medicinal plants, 35 were rare and endangered species, of which about 80% was restricted to the high altitude alpine region of Uttaranchal Himalaya. A priority list of 17 medicinal plant species was prepared on the basis of endemism, use value, mode of harvesting and rarity status. Strategies for long-term conservation of these valuable medicinal plants are discussed.     

Revision of the Early Miocene Hyracoidea (Mammalia) of East Africa

Three genera of hyracoids were recorded from the Early Miocene of East Africa by Whitworth [18], but there has been considerable divergence of opinion about their status. Despite differences in cranial and dental morphology from Megalohyrax and Bunohyrax, Whitworth [18] classified two species in these genera that are recorded from much earlier deposits (Early Oligocene) in the Fayum, Egypt. One of his genera (Meroehyrax) was new. His classification has been the subject of debate, with some researchers [6,13] doubting the hyracoid status of one of his species (Bunohyrax sp), and changing the generic status of another (Megalohyrax championi). Meyer [6] recorded a fourth genus (Prohyrax) from Kenya, linking it to material from Namibia described by Stromer [16,17]. New samples of two hyracoid species collected by the Uganda Palaeontology Expedition throw light on their systematic position and taxonomy. It is concluded that there are three hyracoid genera (Afrohyrax, Brachyhyrax and Meroehyrax) in the Early Miocene deposits of East Africa, the first two of which are new. A fourth genus (Prohyrax) occurs in southern Africa, but is not reliably known from East Africa. To cite this article: M. Pickford et al., C. R. Palevol 3 (2004).

Résumé

Révision des Hyracoidea (Mammalia) du Miocène inférieur de l'Afrique de l’Est. Trois espèces d’Hyracoidea ont été signalées dans le Miocène inférieur d’Afrique orientale par Whitworth [18]. Malgré des différences importantes de la morphologie cranio-dentaire, deux des espèces kenyanes étaient classées dans Megalohyrax et Bunohyrax, genres connus dans les dépôts beaucoup plus anciens du Fayoum en Égypte. Le troisième genre décrit par Whitworth (Meroehyrax) était nouveau. La classification proposée [18] a été débattue ; certains auteurs [6,13] ont remis en cause le statut d’Hyracoïde d’une de ses espèces et ont modifié le statut générique d’une autre. Meyer [6] a signalé un quatrième genre (Prohyrax) au Kenya, sur la base des ressemblances avec le genre namibien décrit par Stromer [16,17]. De nouveaux spécimens récoltés par l’Uganda Palaeontology Expedition permettent d’éclaircir la position systématique et la taxonomie de deux des espèces. Nous concluons qu’il n’existe que trois genres d’Hyracoïdes dans les dépôts du Miocène inférieur d’Afrique orientale (Afrohyrax, Brachyhyrax et Meroehyrax), dont les deux premiers sont nouveaux. Par ailleurs, un quatrième genre (Prohyrax) est connu d’Afrique australe. Pour citer cet article : M. Pickford et al., C. R. Palevol 3 (2004).     

Establishment of trophic continuum in the food web of the Yellow Sea and East China Sea ecosystem: Insight from carbon and nitrogen stable isotopes

Stable carbon and nitrogen isotope ratios (δ¹³C and δ¹⁵N) are used to study the trophic structure of food web in the Yellow Sea and East China Sea ecosystem. The trophic continuum of pelagic food web from phytoplankton to top preyer was elementarily established, and a trophic structure diagram in the Yellow Sea and East China Sea was outlined in combination with carbon isotopic data of benthic organisms, which is basically consistent with and makes some improvements on the simplified Yellow Sea food web and the trophic structure diagram drawn based on the biomass of main resource population during 1985–1986. This result indicates that the stable isotope method is a potential useful means for further studying the complete marine food web trophic continuum from viruses to top predators and food web stability.     

Bioluminescence of Aequorea macrodactyla, a Common Jellyfish Species in the East China Sea

Studies of the bioluminescent mechanisms of jellyfish have been mainly confined to one species, Aequorea victoria. We describe the luminescent system of another species, Aequorea macrodactyla, which is commonly found in the warmer waters on the coastal region of East China Sea. The luminescent system of this species consists of a green fluorescent protein (GFP) and one or more aequorins. The GFP gene is 1042 bp. It encompasses a coding sequence of 717 bp organized as 3 exons, and it is predicted to specify a 27-kDa peptide, which shares 80% amino acid sequence identity with the GFP of A. victoria. The entire coding sequence was cloned into the pTO-T7 expression vector and expressed in Escherichia coli. Compared with GFP of A. victoria, the purified expressed protein exhibited an excitation peak at a higher wavelength of 476 nm and an emission peak at a lower wavelength of 496 nm, with a higher quantum yield of 1.0. The other photoprotein, aequorin, is encoded in a single open reading frame of 585 bp specifying a 23-kDa apoprotein. The gene was cloned in to the same expression vector and expressed in E. coli. The activity of the photoprotein was reconstituted by incubating the expressed apoprotein with coelenterazine f. In the presence of Ca²⁺ the reconstituted aequorin exhibits an emission peak at 470 nm. The kinetics of regeneration and the photoactivities of the reconstituted aequorins of the 2 species of jellyfish are similar. Nevertheless, Aequorea macrodactyla is expected to appear brighter and more ``blue' than Aequorea victorea because of the differences in the photoactivity of their GFPs.     

Structure and function of shisham forests in central Himalaya,India: dry matter dynamics

The biomass and net primary productivity (NPP) of 5- to 15-year-old Shisham (Dalbergia sissoo Roxb.) forests growing in central Himalaya were estimated. Allometric equations were developed for all above- and below-ground components of trees and shrubs for each stand. Understorey forest floor biomass and litter fall were also estimated in forest stands. The biomass (dry matter), forest floor biomass (standing crop litter), tree litter fall and NPP of trees and shrubs increased with increasing age of the forest stand, whereas the dry matter and herb NPP decreased significantly (P < 0.001) with increasing age of the forest. Total forest biomass and NPP ranged from 58.7 (5-year-old stand) to 136.1 t ha(-1) (15-year-old stand) and 12.6 (5-year-old stand) to 20.3 t ha(-1) year(-1) (15-year-old stand), respectively. Of these values, tree biomass accounted for 85.7 (5-year-old stand) to 90.1% (15-year-old) of total forest biomass, and tree NPP for 72.2 (5-year-old) to 82.3% (15-year-old) of total forest NPP. The biomass accumulation ratio (BAR) of the bole component (bole wood + bole bark) increased with increasing age of the forest stand. The bole BAR was 5.8 (5-year-old stand) to 7.9 (15-year-old stand). However, total BAR of the forest stand ranged from 5.5 (5-year-old) to 7.5 (15-year-old).     

Acitivity measurements as a tool to characterize the microbial composition of methanogenic environments

A rapid and reliable method to assess the potential specific activity of methagenic sludge is presented. The method is based on the gas chromatographic analysis for methane in the headspace of closed vials. Gas is sampled with a pressure lock syringe, which allows quantification independent of the pressure prevailing in the vials.The influence of various parameters as substrates, pH, NaCl and NH₄ Cl concentrations on the activity of methaogenic sludge was investigated with this method. Data on the methanogenic activities on different substrate are discussed in terms of different physiological groups present in the sludge.     

The phylogeny of the genus Lasioserica inferred from adult morphology – implications on the evolution of montane fauna of the south Asian orogenic belt (Coleoptera: Scarabaeidae: Sericini)

The species of Lasioserica are highly diversified within the south Asian orogenic belt, such as the Himalaya, south‐eastern Tibet and the mountains of northern Indochina. The study presents a preliminary phylogeny of Lasioserica based on adult morphology. Sixty‐one species were examined for the cladistic analysis based on parsimony using successive approximations weighting and including 84 characters. As a result of the phylogenetic hypothesis on Lasioserica elaborated here, the taxonomic definition of Lasioserica and the validity of Amiserica are questionable and need to be revised. Taxonomic conclusions are here limited so far to the genus assignment of Amiserica antennalis ( Nomura 1974 ) comb. n. The cladistic analysis revealed a large monophyletic clade of Lasioserica containing almost all species assigned to this group so far. Among this monophylum the following pattern have become evident: (1) a number of ancestral lineages from the eastern Himalaya and Indochina, (2) a large clade with almost exclusively Himalayan species and (3) one clade with only Chinese and Indochinese taxa. Based on this topology we may suggest that the more recent evolution of Lasioserica was more independent in these two major regions (Himalaya/Indochina). There is comparatively good evidence from range positions of closely related species for allopatric geographical speciation in Lasioserica with the majority of closely related central Himalayan species occurring allopatrically or parapatrically. The tree topology does not permit conclusions whether speciation progressed more often from east to west or vice versa. More easterly distributed lineages in the Himalaya seem to contrast this pattern with a greater part of closely related species occurring sympatrically. Since cumulative ranges of the major lineages of the Himalayan clade overlap in all respects, diversification of the almost strictly Himalayan clade of Lasioserica should be attributed to a rather long and persistent evolution within the Himalaya.