The earliest modern humans outside Africa Hershkovitz, Israel; Weber, Gerhard W; Quam, Rolf ...
Science (American Association for the Advancement of Science),
01/2018, Letnik:
359, Številka:
6374
Journal Article
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To date, the earliest modern human fossils found outside of Africa are dated to around 90,000 to 120,000 years ago at the Levantine sites of Skhul and Qafzeh. A maxilla and associated dentition ...recently discovered at Misliya Cave, Israel, was dated to 177,000 to 194,000 years ago, suggesting that members of the
clade left Africa earlier than previously thought. This finding changes our view on modern human dispersal and is consistent with recent genetic studies, which have posited the possibility of an earlier dispersal of
around 220,000 years ago. The Misliya maxilla is associated with full-fledged Levallois technology in the Levant, suggesting that the emergence of this technology is linked to the appearance of
in the region, as has been documented in Africa.
The proactive brain: memory for predictions Bar, Moshe
Philosophical transactions of the Royal Society of London. Series B. Biological sciences,
05/2009, Letnik:
364, Številka:
1521
Journal Article
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It is proposed that the human brain is proactive in that it continuously generates predictions that anticipate the relevant future. In this proposal, analogies are derived from elementary information ...that is extracted rapidly from the input, to link that input with the representations that exist in memory. Finding an analogical link results in the generation of focused predictions via associative activation of representations that are relevant to this analogy, in the given context. Predictions in complex circumstances, such as social interactions, combine multiple analogies. Such predictions need not be created afresh in new situations, but rather rely on existing scripts in memory, which are the result of real as well as of previously imagined experiences. This cognitive neuroscience framework provides a new hypothesis with which to consider the purpose of memory, and can help explain a variety of phenomena, ranging from recognition to first impressions, and from the brain's 'default mode' to a host of mental disorders.
The living world is largely divided into autotrophs that convert CO2 into biomass and heterotrophs that consume organic compounds. In spite of widespread interest in renewable energy storage and more ...sustainable food production, the engineering of industrially relevant heterotrophic model organisms to use CO2 as their sole carbon source has so far remained an outstanding challenge. Here, we report the achievement of this transformation on laboratory timescales. We constructed and evolved Escherichia coli to produce all its biomass carbon from CO2. Reducing power and energy, but not carbon, are supplied via the one-carbon molecule formate, which can be produced electrochemically. Rubisco and phosphoribulokinase were co-expressed with formate dehydrogenase to enable CO2 fixation and reduction via the Calvin-Benson-Bassham cycle. Autotrophic growth was achieved following several months of continuous laboratory evolution in a chemostat under intensifying organic carbon limitation and confirmed via isotopic labeling.
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•Conversion of obligate heterotroph to full autotrophy over laboratory timescales•Non-native Calvin cycle operation generates biomass carbon from CO2 in E. coli•Formate is oxidized by heterologous formate dehydrogenase to provide reducing power•Chemostat-based directed evolution led to complete trophic mode change in ≈200 days
Metabolic rewiring and directed evolution led to the emergence of E. coli clones that use CO2 as their sole carbon source, while formate is oxidized to provide all the reducing power and energy demands.
Rather than passively ‘waiting’ to be activated by sensations, it is proposed that the human brain is continuously busy generating predictions that approximate the relevant future. Building on ...previous work, this proposal posits that rudimentary information is extracted rapidly from the input to derive analogies linking that input with representations in memory. The linked stored representations then activate the associations that are relevant in the specific context, which provides focused predictions. These predictions facilitate perception and cognition by pre-sensitizing relevant representations. Predictions regarding complex information, such as those required in social interactions, integrate multiple analogies. This cognitive neuroscience framework can help explain a variety of phenomena, ranging from recognition to first impressions, and from the brain's ‘default mode’ to a host of mental disorders.
The outbreak of COVID-19 leads to emergence of the global pandemic, but there is no specific vaccine recommended for COVID-19. More than 216 countries are struggling against the transmission of the ...disease, recovery and motility. Till date more than 0.948 million deaths out of 30.369 million confirmed cases are reported by WHO. Most of the nations adopted partial or complete ‘lockdown’ and imposed ‘social distancing’ to control the rapid transmission of COVID-19 and its consequence. Though global economic growth declined due to nationwide lockdown, there are certain positive impacts on environment. This review article has discussed the effects of nationwide lockdown aiming to community transmission COVID-19 on animal life behaviour and atmospheric environment in different aspects. In the lockdown period, the levels of NO
2
and carbon emission remarkably decrease in atmosphere due to restricted consumption of fossil fuel by industries, thermal power stations and air transportations. The concentration of NO
2
dropped by 45–54% in the atmosphere of most populated cities in Europe. The intensities of particulate matters PM
2.5
and PM
10
decreased by 43% and 31% respectively, at lower atmosphere indicating improvement in air qualities in different parts of world caused by less traffic and construction activities. SPM reduced up to 15.9%, showing improvement in surface water quality. New deserted bank has developed due to less river activities in this period. Noise pollution remarkably dropped below 60 db even in crowded cities. Thus, the atmospheric environment has resumed some extent in all respect by means of such global-wide lockdown aiming to control COVID-19 pandemic. The behavioural changes of wild animals, birds, butterfly, pets and street animals that reflected on ecosystem of their relative region indicate the non-interference of human activities on lives of natural creatures during lockdown period. There is certain correlation between atmospheric change with the behavioural changes of natural creature during lockdown period. The objective of this study is to focus the critical analysis of the effect of human activities on atmospheric environment for sustainable ecosystem in long term. Significantly, there is ample scope of research on sustainable development of atmospheric environment and ecosystem of creature in absence of human being.
Qafzeh Cave, the burial grounds of several anatomically modern humans, producers of Mousterian industry, yielded archaeological evidence reflecting their modern behavior. Dated to 92
ka
BP, the lower ...layers at the site contained a series of hearths, several human graves, flint artifacts, animal bones, a collection of sea shells, lumps of red ochre, and an incised cortical flake. The marine shells were recovered from layers earlier than most of the graves except for one burial. The shells were collected and brought from the Mediterranean Sea shore some 35
km away, and are complete
Glycymeris bivalves, naturally perforated. Several valves bear traces of having been strung, and a few had ochre stains on them.
SnS and SnS2 are layered semiconductors, with potential promising properties for electro‐ and photocatalytic hydrogen (H2) production. The vast knowledge in preparation and modification of layered ...structures was still not employed successfully in this system to fully maximize its potential. Here, the first report of structural transformation of SnS2 into SnS with Mo‐doping as a bifunctional catalyst for the hydrogen evolution reaction (HER) is reported. The structural phase transition optimized the properties of the material, providing a more delicate morphology with additional catalytic sites. The electrochemical studies showed overpotential of 377 mV at 10 mA cm−2 for HER with Tafel slopes of 100 mV dec−1 in 0.5 m H2SO4 for 10 % Mo‐SnS. The same structure acts as an efficient photocatalyst in the generation of H2 from water under visible illumination with rate of 0.136 mmol g−1 h−1 of H2, which is 20 times higher than pristine SnS2 under visible light.
The doping of the layered SnS2 with Mo produces phase transformation to SnS. Mo‐doped SnS showed a delicate nanoflower morphology with thinner petals. The doped material is an improved electrocatalyst and photocatalyst towards hydrogen evolution.
The biomass distribution on Earth Bar-On, Yinon M.; Phillips, Rob; Milo, Ron
Proceedings of the National Academy of Sciences - PNAS,
06/2018, Letnik:
115, Številka:
25
Journal Article
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A census of the biomass on Earth is key for understanding the structure and dynamics of the biosphere. However, a global, quantitative view of how the biomass of different taxa compare with one ...another is still lacking. Here, we assemble the overall biomass composition of the biosphere, establishing a census of the ≈550 gigatons of carbon (Gt C) of biomass distributed among all of the kingdoms of life. We find that the kingdoms of life concentrate at different locations on the planet; plants (≈450 Gt C, the dominant kingdom) are primarily terrestrial, whereas animals (≈2 Gt C) are mainly marine, and bacteria (≈70 Gt C) and archaea (≈7 Gt C) are predominantly located in deep subsurface environments. We show that terrestrial biomass is about two orders of magnitude higher than marine biomass and estimate a total of ≈6 Gt C of marine biota, doubling the previous estimated quantity. Our analysis reveals that the global marine biomass pyramid contains more consumers than producers, thus increasing the scope of previous observations on inverse food pyramids. Finally, we highlight that the mass of humans is an order of magnitude higher than that of all wild mammals combined and report the historical impact of humanity on the global biomass of prominent taxa, including mammals, fish, and plants.
A key event in human evolution is the expansion of modern humans of African origin across Eurasia between 60 and 40 thousand years (kyr) before present (bp), replacing all other forms of hominins. ...Owing to the scarcity of human fossils from this period, these ancestors of all present-day non-African modern populations remain largely enigmatic. Here we describe a partial calvaria, recently discovered at Manot Cave (Western Galilee, Israel) and dated to 54.7 ± 5.5 kyr bp (arithmetic mean ± 2 standard deviations) by uranium-thorium dating, that sheds light on this crucial event. The overall shape and discrete morphological features of the Manot 1 calvaria demonstrate that this partial skull is unequivocally modern. It is similar in shape to recent African skulls as well as to European skulls from the Upper Palaeolithic period, but different from most other early anatomically modern humans in the Levant. This suggests that the Manot people could be closely related to the first modern humans who later successfully colonized Europe. Thus, the anatomical features used to support the 'assimilation model' in Europe might not have been inherited from European Neanderthals, but rather from earlier Levantine populations. Moreover, at present, Manot 1 is the only modern human specimen to provide evidence that during the Middle to Upper Palaeolithic interface, both modern humans and Neanderthals contemporaneously inhabited the southern Levant, close in time to the likely interbreeding event with Neanderthals.
Glycymeris shell beads found in Middle Palaeolithic sites are understood to be artifacts collected by modern humans for symbolic use. In Misliya Cave, Israel, dated to 240-160 ka BP, Glycymeris ...shells were found that were neither perforated nor manipulated; nevertheless, transportation to the cave is regarded as symbolic. In about 120 ka BP at Qafzeh Cave, Israel, modern humans collected naturally perforated Glycymeris shells also for symbolic use. Use-wear analyses backed by experiments demonstrate that the Qafzeh shells were suspended on string, thus suggesting that the collection of perforated shells was intentional. The older Misliya shells join a similar finding from South Africa, while the later-dated perforated shells from Qafzeh resemble other assemblages from North Africa and the Levant, also dated to about 120 ka BP. We conclude that between 160 ka BP and 120 ka BP there was a shift from collecting complete valves to perforated ones, which reflects both the desire and the technological ability to suspend shell beads on string to be displayed on the human body.
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