What are stalagmites? Stalagmites grow in thin layers each year and any change in temperature alters their chemical composition. The layers therefore preserve a natural archive of climate change over many thousands of years. The researchers examined stalagmites in two Romanian caves, which revealed more detailed records of climate change in continental Europe than had previously been available. From looking closely at the layers of the stalagmites, the archaeologists were able to identify a series of prolonged cold and dry periods in Europe between 44,000 and 40,000 years ago. Temperatures would gradually cool, staying very cold for centuries or even millennia, and then warm up again very abruptly.
Neanderthal presence declined during cold periods
These cold periods coincide with the timings of a near complete absence of archaeological artefacts from the Neanderthals. From this, it has been suggested that changes in climate had a significant impact on the long-term survival of Neanderthal man. [caption id="attachment_8774" align="aligncenter" width="500"]
A model an adult Neanderthal male head and shoulders on display in the Hall of Human Origins in the Smithsonian Museum of Natural History in Washington, D.C. Credit: Tim Evanson[/caption]
Dr Vasile Ersek is co-author of the study and a senior lecturer in physical geography in Northumbria University’s Department of Geography and Environmental Sciences. He explains: “The Neanderthals were the human species closest to ours and lived in Eurasia for some 350,000 years. However, around 40,000 years ago – during the last Ice Age and shortly after the arrival of anatomically modern humans in Europe – they became extinct.
“For many years we have wondered what could have caused their demise. Were they pushed ‘over the edge’ by the arrival of modern humans, or were other factors involved? Our study suggests that climate change may have had an important role in the Neanderthal extinction.”
Why did modern humans survive cold periods?
The researchers have stated that modern humans survived these cold conditions – known as stadial periods – because they were more adaptable to their environment. [caption id="attachment_8773" align="aligncenter" width="500"]
Credit: Le Moustier Neanderthals by Charles R Knight, 1920[/caption]
While Neanderthals were skilled hunters and were able to use fire, their diet wasn’t as diverse as that of modern humans. They lived mainly on meat, so when that food source became more scarce during colder periods, Neanderthals became vulnerable.
By this time, modern humans had begun to incorporate fish and plants into their diet – potentially marking them for survival.
The 3.32 million-year-old foot from an Australopithecus afarensis toddler shown in different angles. Credit: Jeremy DeSilva & Cody Prang[/caption]
Eyebrows on fleek: Model of a modern human skull next to Kabwe 1.
Horse Evolution Mystery Solved?
The genetic ancestors of the modern horse were animals with five toes. Generally, it is believed that horses evolved to have fewer digits, but new research is challenging that theory and arguing that remnants of the five toes are still present in modern hooves.
Humans and horses actually evolved from the same common ancestor, a creature with five digits. As a consequence of living on open grassland, horses adapted to move across these plains. Scientist’s widely believe that this adaption saw horses evolve to have fewer digits. The first horse only had four digits, its later descendant had three, while modern horses have just a central digit, known as the metacarpal.
In research published in a recent issue of Royal Society Open Science, a team of scientists are proposing that rather than horses simply losing four digits, all five merged to form the compacted forelimbs with hooves seen today.
Currently, scientists accept that splints, small bones found along the outer sides of the metacarpal in modern horses, are partially formed remnants of second and fourth digits. Tapering mid-way down the metacarpal, these fragments were inherited from an earlier ancestor, but ceased to develop into fully formed digits in modern horses. The authors of the new paper claim that this theory is incomplete, failing to account for the animals’ first and fifth digits.
“With a distinct surface from the metacarpal, we know the splints on today’s horses to be the remnants of the second and fourth digits,” said Nikos Solounias, a paleontologist from New York Institute of Technology (NYITCOM) and an author on the study. “However, these partially formed digits also appear to contain their own elevated surfaces which hold additional evolutionary clues. We find these ridges, located on the posterior of each splint, to be the partially formed remains of the first and fifth digits, which were once connected to the cartilages of the hoof.”
Key to the research are the famous Laetoil footrprints in Tanzania, which show that the famous, eight-million-year-old horse known as Hipparion primigenium walked alongside early humans and had three digits. According to a NYITCOM statement, Solounias analysed the footprints and came to the conclusion that Hipparion actually had five compacted toes, the forelimb divided into five sections – suggesting the small toes had binded together.
“Interestingly, we not only find hints of the missing digits on the modern horse, but also its ancestors, such as Hipparion and Mesohippus, two species believed to have three toes,” said Solounias.
Neurovascular evidence has provided further support to the NYITCOM researchers’ theory, with dissections of modern equine foetus forelimbs revealing a greater number of arteries and nerves than would be expected in a single digit.
“If today’s horse does indeed have one digit per forelimb, we would expect each forelimb to have a total of two veins, two arteries, and two nerve bundles,” said Melinda Danowitz, a recent NYITCOM graduate who worked with Solounias on the study. “However, our dissections found between five and seven neurovascular bundles per forelimb, suggesting that additional toes begin to develop, but do not become fully differentiated.”
King Ramses Statue Moved to New Home
A colossal, 83 tonne, 3,200 year old statue of the Ancient Egyptian King Ramses II has been moved to a new home, according to Reuters. The complex operation, which saw the statue moved 400m to Cairo’s new Grand Egyptian Museum, required army engineers and specialist contractors.
Reuters reports that the statue was put inside a cage, mounted on a truck and suspended from a steel beam to help reduce the impact of any jolts during the journey. Road surfaces on the route were treated with special materials to ensure they could adequately take the massive weight of the statue.
The entire operation cost 13.6 million Egyptian pounds ($770,000).
The statue was first discovered at the Mit Rahina archaeological site in 1820. Brought to Ramses Square in Cairo in 1955, it was moved again in 2006 due to pollution and congestion, according to Reuters. It was placed in a storage area away from public view, until now.
It will be the first site visitors to the Grand Egyptian Museum will see. The museum is set to partially open this year, before its full launch in 2022.
Featured image: Reconstruced maxilla from microCT images of the jawbone discovered in Israel. Image credit: Gerhard Weber, University of Vienna, Austria]]> 
