《科学》（20230526出版）一周论文导读

地球科学Earth Science

▲ 作者：SOPHIE BONNET, CÉCILE GUIEU et al.

▲ 链接：

https://www.science.org/doi/10.1126/science.abq4654

▲ 摘要：

在这项研究中，我们表明沿汤加火山弧（南太平洋）发射的流体通过垂直扩散对光层中的铁浓度有实质性影响。这种富集刺激了生物活性，导致大面积的叶绿素斑块（36万平方公里）。

富铁水域的重氮营养盐活性比邻近未施肥水域高2至8倍，碳输出通量比未施肥水域高2至3倍。我们的发现揭示了一种新的机制，即海洋中的天然铁肥为大气中二氧化碳的区域热点汇提供燃料。

▲ Abstract：

In this work, we show that fluids emitted along the Tonga volcanic arc (South Pacific) have a substantial impact on iron concentrations in the photic layer through vertical diffusion. This enrichment stimulates biological activity, resulting in an extensive patch of chlorophyll (360,000 square kilometers). Diazotroph activity is two to eight times higher and carbon export fluxes are two to three times higher in iron-enriched waters than in adjacent unfertilized waters. Such findings reveal a previously undescribed mechanism of natural iron fertilization in the ocean that fuels regional hotspot sinks for atmospheric CO₂.

▲ 作者：CASSANDRA M. ALLSUP, ISABELLE GEORGE, AND RICHARD A. LANKAU

▲ 链接：

https://www.science.org/doi/10.1126/science.adf2027

▲ 摘要：

在此，我们发现接种了来自干燥、温暖或寒冷地区的微生物群落的树苗在面临干旱、炎热或寒冷威胁时分别表现出更高的存活率。微生物介导的耐旱性与丛枝菌根真菌多样性的增加有关，而耐寒性与真菌丰富度的降低有关，则可能反映了非适应真菌群的负担减轻。了解微生物介导下的气候耐受性可以增加我们预测和管理森林生态系统对气候变化适应性的能力。

▲ Abstract：

Here, we show that tree seedlings inoculated with microbial communities sourced from drier, warmer, or colder sites displayed higher survival when faced with drought, heat, or cold stress, respectively. Microbially mediated drought tolerance was associated with increased diversity of arbuscular mycorrhizal fungi, whereas cold tolerance was associated with lower fungal richness, likely reflecting a reduced burden of nonadapted fungal taxa. Understanding microbially mediated climate tolerance may enhance our ability to predict and manage the adaptability of forest ecosystems to changing climates.

▲ 作者：MAYA F. STOKES, DAEMIN KIM et al.

▲ 链接：

https://www.science.org/doi/10.1126/science.add9791

▲ 摘要：

山区地形的高水平生物多样性表明地质过程和生物进化之间可能存在联系。高度的淡水生物多样性不仅存在于构造活跃的环境中，而且也存在于构造静止的山区（如阿巴拉契亚山脉）。我们发现，不同岩石类型的侵蚀推动了绿鳍镖鲈谱系之间的异域分化，绿鳍鲷是美国田纳西河流域流出变质岩的河流中特有的一种鱼类。

过去，这种鱼类偏爱的变质岩分布更广，但随着侵蚀作用暴露出其他岩石类型，该物种的谱系逐渐在上游仍有变质岩的支流中分离出来。我们的研究结果表明，在构造活动停止后很长一段时间内，山区的异源多样性开始存在地质机制。

▲ Abstract：

The high levels of biodiversity supported by mountains suggest a possible link between geologic processes and biological evolution. Freshwater biodiversity is high not only in tectonically active settings but also in tectonically quiescent montane regions such as the Appalachian Mountains. We show that erosion through different rock types drove allopatric divergence between lineages of the Greenfin Darter (Nothonotus chlorobranchius), a fish species endemic to rivers draining metamorphic rocks in the Tennessee River basin in the United States. In the past, metamorphic rock preferred by N. chlorobranchius was more widespread, but as erosion exposed other rock types, lineages of this species were progressively isolated in tributaries farther upstream, where metamorphic rock remained. Our results suggest a geologic mechanism for initiating allopatric diversification in mountains long after tectonic activity ceases.

生物学Biology

▲ 作者：HELEN E. CHMURA, CASSANDRA DUNCAN et al.

▲ 链接：

https://www.science.org/doi/10.1126/science.adf5341

▲ 摘要：

北极地区的气候变暖非常迅速，但这对生物系统的影响尚不清楚。因为在这个数据匮乏的地区，很少有将生物生理过程与环境条件联系起来的长期研究。在对阿拉斯加北极地区一项25年研究中，我们证明了气候变化正在影响永久冻土活土层冻融循环的时间，并改变北极地松鼠的生理情况。土壤冻结被延后，作为回应，北极地松鼠在冬眠期间上调产热以防止冻结的时间也延后了。

此外，雌性地松鼠每十年会提前4天结束春季冬眠，而雄性则没有。持续的变暖和物候变化将改变冬眠能量学，改变这一重要被捕食动物的季节性，从而可能破坏种内相互作用。

▲ Abstract：

Climate warming is rapid in the Arctic, yet impacts to biological systems are unclear because few long-term studies linking biophysiological processes with environmental conditions exist for this data-poor region. In our study spanning 25 years in the Alaskan Arctic, we demonstrate that climate change is affecting the timing of freeze-thaw cycles in the active layer of permafrost soils and altering the physiology of arctic ground squirrels (Urocitellus parryii). Soil freeze has been delayed and, in response, arctic ground squirrels have delayed when they up-regulate heat production during torpor to prevent freezing. Further, the termination of hibernation in spring has advanced 4 days per decade in females but not males. Continued warming and phenological shifts will alter hibernation energetics, change the seasonal availability of this important prey species, and potentially disrupt intraspecific interactions.

▲ 作者：ULRIKE PFREUNDT, JONASZ S?OMKA et al.

▲ 链接：

https://www.science.org/doi/10.1126/science.adf2753

▲ 摘要：

在此，我们发现束毛藻可以快速调节它们的形状，在几分钟内对环境条件的变化做出反应。结合视频显微镜和数学模型，我们发现这种重组是由“智能逆转”介导的，其中当滑动细丝藻丝与其他藻丝的重叠减少时，它们就会转变。

通过调节智能逆转，藻丝可以在没有中央协调的情况下控制整体结构。我们认为藻丝对运动的调节是束毛藻聚集行为的决定因素，并最终决定了其在海洋中的生物地球化学作用。

▲ Abstract：

Here, we report that Trichodesmium aggregates can rapidly modulate their shape, responding within minutes to changes in environmental conditions. Combining video microscopy and mathematical modeling, we discovered that this reorganization is mediated by “smart reversals” wherein gliding filaments reverse when their overlap with other filaments diminishes. By regulating smart reversals, filaments control aggregate architecture without central coordination. We propose that the modulation of gliding motility at the single-filament level is a determinant of Trichodesmium’s aggregation behavior and ultimately of its biogeochemical role in the ocean.

人类遗传学Human Genetics

▲ 作者：LUKE ANDERSON-TROCM?, DOMINIC NELSON et al.

▲ 链接：

https://www.science.org/doi/10.1126/science.add5300

▲ 摘要：

群体遗传模型只提供了现实中祖先的大致描述。我们使用了从400万教区记录和来自2276名法国人和20451名法裔加拿大人的基因型数据中编译的家谱，通过空间和时间精细地建模和追踪法裔加拿大人的祖先。

法国祖先人口结构的丧失和空间、区域结构的出现，凸显了广泛的人口扩张模式。地理特征影响了迁徙情况，我们在魁北克地区的河流网络中发现了丰富的迁徙、遗传和家谱关系模式。

最后，我们提供了一个可以免费访问的模拟全基因组序列数据集，其中包含1426749个个体的时空元数据，反映了复杂的法裔加拿大人口结构。这种真实的种群模拟为研究种群遗传学提供了机会。

▲ Abstract：

Population genetic models only provide coarse representations of real-world ancestry. We used a pedigree compiled from 4 million parish records and genotype data from 2276 French and 20,451 French Canadian individuals to finely model and trace French Canadian ancestry through space and time. The loss of ancestral French population structure and the appearance of spatial and regional structure highlights a wide range of population expansion models. Geographic features shaped migrations, and we find enrichments for migration, genetic, and genealogical relatedness patterns within river networks across regions of Quebec. Finally, we provide a freely accessible simulated whole-genome sequence dataset with spatiotemporal metadata for 1,426,749 individuals reflecting intricate French Canadian population structure. Such realistic population-scale simulations provide opportunities to investigate population genetics at an unprecedented resolution.