10-Apr-2019: New species of ancient human discovered in the Philippines
The human family tree has grown another branch, after researchers unearthed remains of a previously unknown hominin species from a cave in the Philippines. They have named the new species, which was probably small-bodied, Homo luzonensis.
The discovery is likely to reignite debates over when ancient human relatives first left Africa. And the age of the remains — possibly as young as 50,000 years old — suggests that several different human species once co-existed across southeast Asia.
The first traces of the new species turned up more than a decade ago, when researchers reported the discovery of a foot bone dating to at least 67,000 years old in Callao Cave on the island of Luzon, in the Philippines. The researchers were unsure which species the bone was from, but they reported that it resembled that of a small Homo sapiens.
Hominin history: H. luzonensis is the second new human species to be identified in southeast Asia in recent years. In 2004, another group announced the discovery of Homo floresiensis — also known as the Hobbit — a species that would have stood just over a metre in height, on the Indonesian island of Flores.
The Callao Cave remains are distinct from those of H. floresiensis and other hominins — including a species called Homo erectus thought to have been the first human relative to leave Africa, some 2 million years ago.
The newly discovered molars are extremely small compared with those of other ancient human relatives. Elevated cusps on the molars, like those in H. sapiens, are not as pronounced as they were in earlier hominins. The shape of the internal molar enamel looks similar to that of both H. sapiens and H. erectus specimens found in Asia. The premolars discovered at Callao Cave are small but still in the range of those of H. sapiens and H. floresiensis. But the authors report that the overall size of the teeth, as well as the ratio between molar and premolar size, is distinct from those of other members of the genus Homo.
The shape of the H. luzonensis foot bones is also distinct. They most resemble those of Australopithecus — primitive hominins, including the famous fossil Lucy, thought not to have ever left Africa. Curves in the toe bones and a finger bone of H. luzonensis suggest that the species might have been adept at climbing trees.
The researchers are cautious about estimating H. luzonensis’ height, because there are only a few remains to go on. But given its small teeth, and the foot bone reported in 2010, its body size might be within the range of small H. sapiens, such as members of some Indigenous ethnic groups living on Luzon and elsewhere in the Philippines today, sometimes known collectively as the Philippine Negritos. Men from these groups living in Luzon have a recorded mean height of around 151 centimetres and the women about 142 centimetres.
Genetic material from the remains could help scientists to identify the species’ relationship to other hominins, but efforts to extract DNA from H. luzonensis have failed so far. However, the bones and teeth were dated to at least 50,000 years old. This suggests that the species might have been roaming southeast Asia at the same time as H. sapiens, H. floresiensis and a mysterious group known as the Denisovans, whose DNA has been found in contemporary humans in southeast Asia.
Island southeast Asia appears to be full of palaeontological surprises that complicate simple scenarios of human evolution.
1-May-2019: Denisovans lived in Tibetan Plateau
Analysis of a fossil jawbone containing molars recovered from Baishiya Karst cave in Xiahe, Gansu, China shows Denisovans lived in the Tibetan Plateau some 1,60,000 years ago.
The first evidence for Denisovans or Denisova hominins was first discovered in 2008 in a cave in the Altai mountains in Siberia. This is the first time evidence of Denisovan presence has been found outside the Denisova cave. The mandible was so well preserved that it allowed for a virtual reconstruction of the two sides of the mandible.
Contrary to popular belief that high altitude regions were inhabited only by modern humans dating back to less than 40,000 years, the fossil remains conclusively prove that Denisovans lived in the Tibetan Plateau at an altitude of 3,280 metres much earlier — 1,60,000 years ago. The Denisova cave in Siberia is at an altitude of just 700 metres.
Previous genetic studies have found that modern humans living in the Tibetan Plateau carried a special gene variant — EPAS1 (Endothelial PAS Domain Protein 1) — that allowed them to cope with low oxygen (hypoxia) environments typical of high altitude. This gene variant has been found in Denisovans.
Since the Denisova cave is at an altitude of just 700 metres, it was not clear why and how the Denisovans possessed this adaptation. The discovery of a Denisovan sample in the Tibetan plateau at a high altitude provides the answer.
The possible explanation for the presence of this gene variant in the hominin is that Denisovans lived for a long time in the plateau leading to the gene mutation. This mutation has later been passed on to modern humans.
Though the jawbone is well preserved, there was no evidence for the preservation of ancient DNA. A team led by three researchers extracted proteins from one of the molars and carried out protein analysis. Though the proteins were highly degraded, protein analysis conclusively proved that the jawbone belonged to Denisovans. The carbonate matrix adhering to the sample was dated using Uranium-Thorium and the age was determined to be 1,60,000 years.
Protein analysis shows that the Xiahe mandible belonged to a hominin population that was closely related to the Denisovans from Denisova Cave.
14-Mar-2019: Gurkhas of the British Army
The British Army announced this week that it would create a new Specialised Infantry Battalion by recruiting more than 800 Nepalese Gurkha servicepersons this year. Currently, the Gurkhas comprise up to 3% of the British Army, and in 2015 completed 200 years of service there.
The Anglo-Nepalese War of 1814-16 was a victory for the East India Company, but not without heavy casualties inflicted on them by soldiers of the Gorkha Kingdom. Impressed by their discipline and ferocity, the British decided to recruit these soldiers starting in 1815. Since then, the Gurkhas have fought on the side of the British Empire in almost every war, including both World Wars.
Upon Independence in 1947, the question of allotting the 10 regiments of Gurkha soldiers arose. This was settled by the Britain-India-Nepal Tripartite Agreement, which assigned the 1st, 3rd, 4th, 5th, 8th, and 10th Gurkha Rifles regiments to India, and the 2nd, 6th, 7th, and 10th regiments to Britain. In 1948, India created an 11th Gurkha Rifles regiment to accommodate the Gurkhas who refused to depart with the now-British regiments.
Later, the British Army amalgamated their four regiments into a combined Royal Gurkha Rifles (RGR) regiment consisting of three battalions. The RGR was subsequently deployed in Britain’s remaining colonies in Asia, including Malaysia, Singapore, and Hong Kong, to fill the vacuum created by departing Indian regiments such as the Sikhs, which were stationed there earlier.
The Gurkhas are recruited every year at the British Gurkha camp at Pokhara in Nepal. The camp enlists fresh recruits not only for the British Army, but also for the counter-terror arm of the Singapore Police Force. British Army scouts roam the Nepalese countryside to identify potential recruits, who then undergo a rigorous training process before joining.
Regarded as fierce and loyal, the Gurkhas are held in high esteem in the British Army. They are enlisted not only in the infantry, but also in the engineering corps and as logisticians. Their signature weapon, the khukri, famous for the inwardly curved shape of its blade and its legendary utility, forms part of the Gurkha regimental insignia in Britain as well as in India.
Queen Elizabeth II of Britain is guarded by two personal Gurkha officers. Former Singaporean Prime Minister Lee Kuan Yew is known to have preferred Gurkha police officers for his protection.
The working conditions of the Gurkhas have improved significantly over the past few decades, and they now have the same service conditions as the regular British Army, with the option of British citizenship upon retirement. British Army Gurkhas have been active during the Falklands campaign, the Gulf Wars, as wells as in Afghanistan and Iraq. Currently, they are stationed at British garrisons in Brunei and the UK.