Four new avian mitochondrial genomes help get to basic evolutionary questions in the late cretaceous

Good phylogenetic trees are required to test hypotheses about evolutionary processes. We report four new avian mitochondrial genomes, which together with an improved method of phylogenetic analysis for vertebrate mt genomes give results for three questions in avian evolution. The new mt genomes are: magpie goose (Anseranas semipalmata), an owl (morepork, Ninox novaeseelandiae); a basal passerine (rifleman, or New Zealand wren, Acanthisitta chloris); and a parrot (kakapo or owl-parrot, Strigops habroptilus). The magpie goose provides an important new calibration point for avian evolution because the well-studied Presbyornis fossils are on the lineage to ducks and geese, after the separation of the magpie goose. We find, as with other animal mitochondrial genomes, that RY-coding is helpful in adjusting for biases between pyrimidines and between purines. When RY-coding is used at third positions of the codon, the root occurs between paleognath and neognath birds (as expected from morphological and nuclear data). In addition, passerines form a relatively old group in Neoaves, and many modern avian lineages diverged during the Cretaceous. Although many aspects of the avian tree are stable, additional taxon sampling is required.     

Estimating brocket deer (<Emphasis Type="Italic">Mazama gouazoubira</Emphasis> and <Emphasis Type="Italic">M. americana</Emphasis>) abundance by dung pellet counts and other indices in seasonal Chiquitano forest habitats of Santa Cruz,Bolivia

We assessed dung and track counts for indexing brocket deer abundance in seasonal habitats on a ranch where hunting is not practiced in the Bolivian lowlands. Surveys were replicated along four 10-km trails (totaling 180 km in the wet season and 90 km in the dry season) through four semideciduous forest habitats. Dung pellets and tracks were identified as belonging to Mazama gouazoubira or M. americana by size and shape. Pellet groups lasted more than 1 month during the dry season, but decayed within 1–2 weeks in the wet season. Mean density estimates based on dung counts varied widely between seasons for gray brockets (from 6.77±4.0 to 30.57±23.5 ind/km²; mean±SD) but not for reds (from 3.52±4.6 to 6.98±7.2 ind/km²). These values were probably too high due to underestimation of daily deposition rate, and were reduced during the wet season because of dung decay. We found consistently more dung in the dry season and more tracks in the wet season. Sightings of red brockets were too few for line-transect analysis (n=6), but those of gray brockets (n=42) produced an overall estimate of 5.6 ind/km² (95% CI=3.5–9.0 ind/km²). Different estimates indicated that gray brockets were more abundant than reds in all situations, except perhaps in the riverine forest. Environmental factors affected these indices of abundance differently, and while we recommend the use of dung counts in dry-season scenarios, we think that index reliability should be assessed locally before conducting population comparisons.     

Pollen-rain-vegetation relationships along a forest-savanna transect in southeastern Cameroon

Modern soil and litter samples from southeastern Cameroon, collected along a continuous forest–savanna transect were analysed for pollen content to define modern pollen–vegetation relationships. The pollen results, completed and compared with botanical inventories, leaf area index and basal area measurements performed in the same area, clearly registered the physiognomy, the main floristic composition and floral richness of the two sampled ecosystems. Distortions were observed between sampled vegetations and their pollen rain, related to important differences in pollen production and dispersal of plant species: this is a general feature in many tropical regions. The pollen data in the area studied reflected well the recent transgression of forest versus savanna. This permitted us to define inside the forest ecosystem more successional vegetation communities than the botanical surveys allowed.     

The current state of korean paleoanthropology

The hominid fossil and Paleolithic archaeology records from the Korean Peninsula are extensive, but relatively little is known about the Korean human evolutionary record outside this region. The Korean paleoanthropological record is reviewed here in light of major research issues, including the hominid fossil record, relative and chronometric dating, lithic analysis, hominid subsistence, and the presence of bone tools, art and symbolism. Some of the major conclusions drawn from this review include: (1) hominid fossils have been found in nine separate sites on the Korean Peninsula; (2) possible Homo erectus fossils are present in North Korea; (3) Ryonggok Cave, in North Korea, has exposed the remains of at least five archaic Homo sapiens individuals; (4) a possible burial of an anatomically modern Homo sapiens child, discovered in Hungsu Cave in South Korea, has been tentatively dated to roughly 40,000 years ago; (5) handaxes and cleavers have been found at a number of sites near Chongokni and they appear to date to at least 100,000 years ago; and (6) taphonomic studies are necessary for addressing issues related to determining the nature of hominid-carnivore interaction over similar resources (e.g. carcasses and shelter); and the presence/absence of Early Paleolithic bone tools, art, and symbolism in Korea.     

Nonhuman primate hybridization and the taxonomic status of Neanderthals

The present study examines the taxonomic status of Middle Paleolithic Neanderthals by comparing their observed minimum genetic divergence from Upper Paleolithic modern humans in Europe with that observed between macaque species from Sulawesi that are known to hybridize and fully intergrade in the wild. The genetic divergence, and differentiation between Neanderthals and Upper Paleolithic modern humans, as indicated by pairwise minimum genetic distances and F(ST) values calculated from the estimated minimum genetic relationship (R) matrix derived from craniometric data, are significantly greater than those observed both between hybridizing and noninterbreeding Sulawesi macaque species, suggesting that mate recognition and the possibility of gene flow between Neanderthals and Upper Paleolithic modern humans might have been greatly reduced. These results support a species-level taxonomic distinction for the Neanderthals as suggested by proponents of the replacement model. Furthermore, assumptions regarding the monophyletic origin of modern humans from outside Europe are likely valid.     

Absence of regional affinities of Neandertal DNA with living humans does not reject multiregional evolution

The recent extraction of mitochondrial DNA sequences from three European Neandertal fossils has led many to the conclusion that ancient DNA analysis supports the African replacement model of modern human origins and rejects models of multiregional evolution that propose some Neandertal ancestry in living humans. This conclusion is based, in part, on the lack of regional affinity of Neandertal DNA to that from living Europeans. Consideration of migration matrix models shows that this conclusion is premature, since under a model of interregional gene flow we expect to see similar levels of Neandertal ancestry in all contemporary regions, and living Europeans should not necessarily show closer affinity. The absence of regional affinity in Neandertal DNA does not distinguish between replacement and multiregional models.     

Vocal behaviour and neighbour spatial arrangement during vocal displays in eagle owls (Bubo bubo)

We quantified temporal and spatial patterns of adult eagle owl Bubo bubo vocal behaviour throughout an entire year. The duration of adult eagle owl vocal displays showed significant differences during different periods of the year: there was one major peak in the pre-laying period, when duets of mates were also more frequent. The daily distribution of adult vocalizations showed a similar pattern among the different periods, with vocal activity being most intense at sunset and sunrise. Analyses of the characteristics of call posts showed that the choice of such focal points was guided by the trade-off between the need to defend the territory and within-pair communication inside the core areas, as well as efficient communication with neighbours.     

东亚现代人来源的考古学思考:证据与解释

现代人的起源与扩散是当今古人类学界极具争议的问题。目前,"多地区进化"假说和非洲起源为主的"同化"假说是该争议的两大阵营。在"多地区进化"假说的基础上,立足中国的化石材料,吴新智提出了中国乃至东亚古人类"连续演化、附带杂交"的假说,认为中国的现代人主要由本地古老类型人类演化而来。本文从现代人扩散关键时段的考古材料出发,讨论氧同位素5～3阶段(大约13～3万年)考古材料在研究中国现代人形成中的作用和存在的挑战。首先,概括介绍现代人起源的主要假说和现代人扩散的假定路线——南线和北线的多重证据;其次,在此背景下,通过对中国境内考古材料的概括,分析不同石器技术可能反映的现代人来源;最后,简要探讨立足考古材料研究现代人起源与扩散的挑战。总体而言,氧同位素5～3阶段的旧石器考古材料支持中国北方南部和中国南方古人类的连续演化,同时也指示了非洲扩散而出的现代人人群自西北地区和南方地区进入中国的可能性。该模式支持中国古人类"连续演化、附带杂交"假说,然而我们也认识到中国现代人起源研究的考古基础仍十分薄弱,使用考古学材料研究现代人扩散的理论基础也需探讨。目前,细化、完善基础考古数据仍是中国旧石器时代考古学和古人类学学者努力的主要方向之一。如此,我们才能够更加有效地将人类化石与考古学证据融合,进而结合分子生物学的研究,更为全面地理解现代人的起源与演化。