Interlocking logs from 476,000 years ago found in Zamibia 100,000 yrs older than oldest human fossil

ScientiFix, our weekly feature, offers you a summary of the top global science stories of the week, with links to their sources.

Modified wood tools from site BLB, Kalambo Falls, 2019 | Photo courtesy: University of Liverpool

New Delhi: Researchers from the University of Liverpool and Aberystwyth University have found a pile of interlocking logs from 476,000 years ago at the Kalambo Falls archaeological site in Zambia. This shows that early humans were using wood to build structures much earlier than previously believed.

The study — published in the journal, Nature, on Wednesday — is significant because the oldest Homo Sapiens fossils are 315,000 years old,  which means these logs are older by more than 100,000 years.

Wooden artefacts from the Early Stone Age are very rare in archaeological records because wood usually does not last for such a long time. However, the logs in Zambia were preserved because they were in waterlogged deposits as the Kalambo Falls have always had high water levels, creating unique conditions for preservation.

Submerged wood gets preserved because the limited oxygen supply slows decay, and over time sediment deposition on the wood also creates a fossilised structure.

The logs also show a kind of woodworking that is not seen anywhere else in Africa or Eurasia during the Paleolithic era, says the study.

Apart from the logs, scientists also recovered a wedge, a digging stick, a cut log and a notched branch from the Kalambo site.

By examining the cut marks on wooden remains, researchers concluded that early humans crafted and assembled large logs. The assumption is that they used it to create structures, like foundations or parts of dwellings, which is a revelation for archaeologists.

Early examples of wood use are restricted to weapons like spears and digging sticks, but the new discoveries could prove intentional woodwork done half a million years ago. Read more.

First RNA analysis of extinct animals 

Scientists have achieved a breakthrough in the field of palaeogenomics by extracting and analysing ribonucleic acid (RNA) from the muscle and skin tissue of an 130-year-old Tasmanian tiger — a species that is now extinct. This is the first time that RNA has been obtained from preserved specimens of an extinct species.

Paleogenomics is a field which delves into the genetic material of ancient and extinct species to understand their evolution, population changes, and ecological roles.

While DNA sequencing has been a valuable tool in this field, it has its limitations. It can’t reveal specific information about how genes are turned on or off in different tissues, their roles in cells, or how genes are regulated. To get this level of detail, researchers turn to RNA — a molecule involved in gene expression.

The study, published in Genome Research journal which was made public earlier this month, states that the RNA revealed valuable insights about the Tasmanian tiger’s genetic activity, such as muscle types and blood-related features.

The research also improved the annotation of the Tasmanian tiger’s genome, which means identifying and describing the parts of the genome. The researchers also found new genetic elements and microRNAs that were not known before. Moreover, the study suggested that there might be ancient RNA viruses in the tissue, which could help us understand how some viruses evolved.

This study broke new ground by shedding light on gene expression dynamics in an extinct species using RNA, offering exciting prospects for further research in the field and expanding our understanding of ancient life through genetic insights. Read more.

New spider silk produced

Scientists from China’s Donghua University have made a new kind of spider silk that is very strong and tough by using genetically modified silkworms. The new spider silk is six times stronger than Kevlar, which is used to make bulletproof vests.

The study, which was published in the journal Matter Wednesday, explained that the scientists made spider silk fibres, which were both strong and tough, by combining the properties of silk and polyamide fibres.

The scientists wanted to make fibres that are good for the environment and can be made easily. Synthetic fibres like nylon and Kevlar are strong and durable, but they are not natural. Spider silk is a natural fibre that is very tough, but it has been difficult for scientists to reproduce it commercially.

Scientists have not been able to understand how spiders make their silk and how it could be mass-produced at low cost. They studied the mechanical properties of nylon and Kevlar and then found a new structure in silk.

This helped them to make spider silk in silkworms — a process they called localisation. This new invention, scientists believe, can have a huge impact on the commercialisation of sustainable spider silk for a variety of purposes like textile and surgical material. Read more.

Can mothers hear babies’ cries?

Do mothers ‘instinctively’ respond when their babies cry? Yes, says a new study by researchers from the New York University School of Medicine, who found a neural pathway that carries auditory signals (infant cries) to the neurons that make oxytocin in the mothers’ brains.

Oxytocin is a chemical that plays a crucial role in maternal processes like childbirth and nursing in both humans and animals. It is released when a mother feeds her baby, helping with milk production, and during childbirth.

The researchers did their study on mother mice and their babies, which was published in the journal Nature Wednesday.

They used special techniques — electrophysiological recordings and photometry— to measure the neural signals in the mice. They found that the neural pathway for oxytocin in the mothers was activated in response to the cries of their babies, but not to other sounds.

The sound of the baby’s cry goes to the oxytocin neurons through a part of the brain called the posterior intralaminar thalamus. This part of the brain can also make the oxytocin neurons more active for a long time if it is stimulated repeatedly.

This neural pathway acts like a switch, controlling when oxytocin is released and affecting how mothers behave when they hear their babies cry. It demonstrates how sensory cues from the baby are integrated into the mother’s brain, ensuring that her body responds appropriately for efficient parenting. Read more.

Co2 on Jupiter’s moon 

Scientists have found carbon dioxide on Europa, a moon of Jupiter that has a hidden ocean under its icy surface. This is a major discovery because carbon dioxide is an important chemical for life as we know it.

The data came from the National Aeronautics and Space Administration’s (NASA) James Webb Space Telescope, which used a special instrument called NIRSpec to scan Europa’s surface, NASA said in a press release Wednesday.

The carbon dioxide was found in a region called Tara Regio, where the surface is relatively young and has signs of geological activity. This region also has salt that comes from the ocean below. This suggests that the carbon dioxide also came from the ocean, and not from external sources like meteorites.

Europa has long been considered a possible candidate for extraterrestrial life owing to the presence of a subsurface ocean beneath its icy crust. However, until now, researchers have not confirmed whether this ocean contained the crucial chemical ingredients for life, particularly carbon.

This finding raises the possibility that Europa’s ocean may have the chemical diversity necessary to support life.

NASA’s upcoming Europa Clipper spacecraft, set to launch in October 2024, will conduct close flybys of Europa to further investigate its potential habitability. This recent discovery underscores the importance of understanding Europa’s chemistry and its potential as a habitat for life beyond Earth. Read more.

(Edited by Richa Mishra)