Nasb macarthur study bible

The cave bear (Ursus spelaeus) is one of the Late Pleistocene megafauna species that faced extinction at the over of the last ice age.

Bạn đang xem: Nasb macarthur study bible

Although it is represented by one of the largest fossil records in Europe and has been subject khổng lồ several interdisciplinary studies including palaeogenetic research, its fate remains highly controversial. Here, we used a combination of hybridisation capture & next generation sequencing to lớn reconstruct 59 new complete cave bear mitochondrial genomes (mtDNA) from 14 sites in Western, Central và Eastern Europe. In a Bayesian phylogenetic analysis, we compared them lớn 64 published cave bear mtDNA sequences lớn reconstruct the population dynamics và phylogeography during the Late Pleistocene. We found five major mitochondrial DNA lineages resulting in a noticeably more complex biogeography of the European lineages during the last 50,000 years than previously assumed. Furthermore, our calculated effective female population sizes suggest a drastic cave bear population decline starting around 40,000 years ago at the onset of the Aurignacian, coinciding with the spread of anatomically modern humans in Europe. Thus, our study supports a potential significant human role in the general extinction & local extirpation of the European cave bear và illuminates the fate of this megafauna species.

Today in the Holocene epoch, the northern hemisphere is zoologically impoverished in large terrestrial species1,2. Astonishingly, this is a relatively recent phenomenon. During the Late Pleistocene, until around 50,000 years ago, the continents were still populated with spectacular fauna consisting of some of the largest mammals that ever roamed the earth2. More than 150 genera of megafauna such as mammoths, woolly rhinoceros, & sabre-toothed cats inhabited the steppes of Eurasia & North America1,2. However, by 11,000 years ago, these ecosystems had lost between around 36% & 72% of their large-bodied (>45 kg) mammalian genera, respectively3, & at least 97 genera in total1. This extinction wave affecting the largest members of the herbivorous guild had cascading consequences on terrestrial ecosystems with consequences still khổng lồ be seen in modern ecosystems4,5,6. Understandably, the potential causes of these incisive extinctions have remained subject to highly controversial debates. The discussed explanations include an anthropogenic contribution, climate and environmental changes or a combination of both2,3. However, with a growing toàn thân of data, the patterns and processes of these extinctions appear more complex. According khổng lồ Lorenzen & colleagues3, for example, while the proportion of dwindling megafauna species was greatest on continents that underwent the most dramatic climatic and environmental changes, the extinction events in North America and australia rather coincided with the arrival of anatomically modern humans1,3. The circumstances are apparently in contradiction with cross-taxa response lớn global climatic or anthropogenic factors, indicating a species-specific response lớn one or both factors. Nevertheless, recent publications promote rapid climatic shifts and oscillations, especially the Dansgaard-Oeschger warming events, as the main cause of megafauna extinctions, suggesting only a synergistic role of humans in these processes7,8; although this hypothesis does not receive unanimous approbation9. Furthermore, it was previously argued by Lorenzen và colleagues3 that the population development of different taxa is contingent on the geographic as well as temporal scale & the methodological approaches applied3. For instance, while the woolly mammoth and cave lion experienced sudden losses of genetic diversity & subsequent population stability long before their final extinction3,10, it was shown that genetic diversity in bison và musk ox declined gradually through the course of the Late Pleistocene3.

Xem thêm: Xem Phim Mỹ Nhân Tâm Kế Tập 10 Vietsub + Thuyết Minh Full Hd

The latter pattern of withering away was also assumed for the Pleistocene cave bear Ursus spelaeus sensu lato11. As this Late Quaternary mammal is represented by a largest fossil record in Europe12, the cave bear is a useful mã sản phẩm to study the causes of the extinction of a species, especially in the context of population dynamics, climate instability và changing human impact. Descending from the Middle Pleistocene Ursus deningeri13, as indicated by morphological and molecular studies14, the Late Pleistocene cave bear established a vast distribution extending eastwards from Northwest Spain across Central Europe và the Urals khổng lồ Arctic North-Eastern Siberia và the Altai Mountains15,16. Due to their high intra-specific morphological variability observed across the Eurasian cave sites, several taxonomic groups have been previously proposed mostly on the basis of morphological và metrical studies of the teeth, metapodials & the cranium17,18,19. These primarily differentiate Eurasian large-bodied cave bears from small-bodied cave bears endemic to lớn high-altitude areas of the Alps, the Caucasus and the Altai mountains17,18,19. If these suggested morphological groupings indeed represent valid & distinct phylogenetical groups on species or subspecies màn chơi remains controversial20, especially since recent analyses indicate a more complex evolutionary relationship21. However, despite its substantial diversity và distribution, the cave bear became extinct at the beginning of the Last Glacial Maximum (LGM)12,22,23,24. The timing of its final extinction as well as the cause of the extinction, with climate change in the context of its herbivorous diet25,26,27,28 or human hunting impact29 commonly regarded as potential factors12, remain the subject of controversial debates. While comprehensive radiocarbon dating indicates that the extinction took place at the onset of the LGM around 28–26 ka years before present12,22,23,24, a small number of fossils younger than 26,000 calibrated years BP23,24 documents the survival of fragmented populations during the maximum extent of the ice sheets30,31. In fact, Stiller and colleagues11 demonstrated based on population size reconstruction that 25,000 years of genetic decline preceded not only the cave bear extinction, but also the onset of the LGM. Since this circumstance eliminates a correlation between cave bear population decline & substantial climate change, human impact, either due to lớn direct hunting or resource competition32,33,34,35,36,37,38 emerges as the major extinction cause, albeit, archaeological evidence remains sparse for now24,36,37,38. In this context, molecular analysis of ancient DNA (aDNA) from cave bear fossils has provided substantial insights into cave bear evolution & extinction, since it allows us to identify even subtle demographic developments invisible in the palaeontological record39. However, previous ancient DNA studies were based on relatively small sample sizes40 or focused on geographically limited areas41. The majority of these studies was restricted khổng lồ the mitochondrial D-loop sequence42, a 285 base pair short fragment comprising only ~1.7% of the whole bear mitogenome. As demonstrated by previous studies43,44, inferred genealogical reconstructions based on the D-loop region tend lớn contradict inferences based on the entire mitogenome. Thus, the current knowledge regarding cave bear population dynamics và phylogeography during the Late Pleistocene is substantially constrained. Khổng lồ overcome these limitations, here we analysed 59 new complete mitochondrial DNA sequences, representing populations from a Europe-wide time transect. Moreover, we present the first mitochondrial genome of a specimen morphologically classified as Ursus spelaeus ladinicus as well as the youngest cave bear mtDNA sequences thus far, which dates khổng lồ 19,656 14C years before present (23,907–23,461 cal. Yr. BP). Our data can help khổng lồ illuminate the fate of the European cave bear before its final extinction.