Research roundup

A look at the most exciting scientific discoveries and news of the past month

Genetic analysis reveals social interactions between Neanderthals and early Modern Humans

Neanderthals are the closest genetic ancestor to early modern humans (homo sapiens) and are studied to understand more about the ancestral history of early modern humans. Studying Neanderthal genetic composition, however, is no small feat. Approximately 40,000 years ago, these archaic humans had all but vanished, leaving very little remains from which to glean genetic data. Some scientists speculate their disappearance is closely related to the advent of homo sapiens, who may have hunted them to extinction. Others that it was the Neanderthals failure to adapt to harsh environmental conditions that lead to their demise, or a combination of both. The resulting lack of access to high quality genomic data of Neanderthals has made it difficult for scientists to reconstruct their history and genetic contribution to present-day humans.

Recently however, a massive collaboration between scientists in America and Europe utilised an improved DNA analysis technology, that allows the reconstruction of DNA sequences from bone samples that are contaminated or not well preserved. With this technology in hand, the scientists analysed 45,500 year old bone fragments from a female Neanderthal found in a cave in Croatia. This helped them piece together a clearer picture of their social interactions with early modern humans and the social dynamics within their own populations.

Smaller genetic variance in this female Neanderthal’s DNA was observed, suggesting that Neanderthals lived in small population groups numbering around 3000 individuals. The data also indicated a significant degree of inbreeding within the population of this female Neanderthal, with her parents being related at the level of half-siblings. The DNA sequence generated from these bone samples was compared with present-day human DNA sequences, revealing that 10-20% more of Neanderthal DNA is found in present-day humans. The genotypes acquired from Neanderthals by humans were on the whole considered to be deleterious, affecting our susceptibility to diseases with some of the genotypes being linked to schizophrenia, eating disorders and rheumatoid arthritis.

American Court rules against Open-Access website Sci-Hub in lawsuit filed by American Chemical Society

A US court in the district of Virginia recently ruled against SciHub, an illicit website which provides free access to paywalled scientific papers published by the likes of Nature, Science and the American Chemical Society (ACS). The lawsuit was filed by ACS for copyright infringement, trademark counterfeiting and trademark infringement and SciHub have been ordered to pay 4.8 million dollars in damages to the publication.

This is not the first time a lawsuit has been brought against SciHub. Publishing giant Elsevier brought a similar lawsuit against SciHub earlier this year, which SciHub also lost and were ordered to pay 15 million dollars in damages. The website, founded by Neuroscientist Alexandra Elbakyan, is unlikely to pay out anything to either publications however, as they are based in Russia, outside of the court’s jurisdiction. It is estimated that SciHub contains as much as 98.8% of all papers published by ACS and 85% of papers from all other paywalled journals.

The court also ordered search engines, internet service providers (ISPs) and web-hosting sites to cease facilitating any domains and websites which may host SciHub. This is unlikely to stop SciHub either, as previous attempts have been made to shut the website down, only for it to pop up again using a different domain. Search engines and ISPs may, too, be hesitant to delist the website as many of them adhere to the internet freedom movement and open access to scientific research. The topic has long been a controversial one, with some individuals siding with SciHub in providing free access to scientific papers in the face of exorbitant fees charged by publishers for access. Undoubtedly, there will be plenty more legal wrangling to come.

Material scientists develop new metal organic framework technology for confidential information encryption/decryption

Researchers at the Shanghai Jiao Tong University have developed a new lead-based metal organic framework (MOF). These are chemical structures involving a metal atom centre with organic (carbon-based) ligands surrounding them that pack on top of one another to form crystal structures. The MOF exhibits interesting optical and electronic properties, whereby it is invisible in ambient light but when reacted with a halide salt, forms perovskite (a type of crystal structure) nanocrystals which become luminescent in the presence of UV light. The lead MOF was successfully printed onto different paper and foil surfaces via inkjet printing to form detailed images and symbols, invisible in ambient light, but once reacted with the halide salt and activated with UV light, revealed the images and symbols in high resolution. Further investigation by the researchers revealed that the formation of the perovskite nanocrystals was not a destructive process, and they could recover the original lead-based MOF by washing the nanocrystal with a polar solvent such as methanol, which easily dissolves the ionic perovskite nanocrystals, quenching the luminescent activity. Exploiting the robustness of their MOF, they demonstrated an ON/OFF switch whereby they printed out invisible symbols and images on a paper surface using their lead-MOF, and then made it luminescent with the halide salt before quenching it with methanol and repeating the cycle again.

What is particularly exciting about this technology is its genuine potential for application in confidential information encryption and decryption for information storage and anti-counterfeiting in money. Where previous materials of this kind failed was in their insufficient luminescent performances, lack of an ON/OFF switch, tedious synthesis and high cost, and could also be easily exploited to steal confidential information due to their innate photoluminescence activity. This new MOF must first be reacted with a halide salt before it becomes luminescent providing an in-built security feature.

Dinosaur extinction allowed for mammals to transition from a nocturnal lifestyle to greater daytime activity

Mammals today generally exhibit a striking bias in their morphological features of eye shape, retinal composition and visual pathways towards nocturnal activity, but even still many exhibit diurnal (daytime) activity. A popular theory proposed by scientists, known as the ‘nocturnal bottleneck’, is these morphological and physiological traits of nocturnality are a result of an ancestral legacy of mammals avoiding diurnal predatory dinosaurs during the Mesozoic period between approximately 252 and 66 million years ago.

To prove this theory, researchers reconstructed the ancestral behavioural traits of 2415 different species based on taxonomic analysis of their morphological and physiological traits associated with nocturnal activity and diurnal activity. Using statistical analysis of the resulting data set, the researchers estimated that the onset of diurnal activity in mammals occurred around 65 million years ago, coinciding with the K-Pg mass extinction event which wiped out most of the dinosaurs. The results indicate that the advent of daytime activity in mammals probably came opportunistically, no longer having to contend with predatory diurnal dinosaurs, and lends further credence to the ‘Nocturnal bottleneck’ theory.