The Greatest Archaeological Discovery Ever? Ancient Human Fossils Rewrite Evolution

One problem that paleoarchaeologists and paleoanthropologists, who study ancient humans, face is that they frequently disagree on what classifies as a human species, and they also disagree on which species to classify specific specimens. In fact, a purebred human being does not exist, and never has. It was once thought that Neanderthaloids possibly evolved from the East Asian strains of Java Man and Peking Man, and spread along the foothills of the Eurasian Mountains into Europe, during the lush 3rd interglacial period. Researchers recognized a southern route along the Zagros Mountains in Iran, and extending eastwards towards Pakistan and Afghanistan. They found evidence for a potential northern route during interglacials, which would have permitted hominin movements and species interactions to and from East Asia. For several hundred thousand years, Neanderthals were the most modern humans in Europe. They cared for their sick, drew pictures on cave walls, controlled fire for warmth and cooking, and hunted the largest prey as an apex predator. Neanderthals were also the most widespread humans in their time, ranging from the furthest western north of Europe to as far south as Israel and Palestine, and east into Central Asia and Siberia. New evidence that Neanderthals lived in East Asia, and interbred with the local hominid population there around 100,000 years ago has been found by scientists in Central China, according to a peer-reviewed study in the journal Science. In fact, scientists recently described another 300,000-year-old skull from Central China as being part-human part-Neanderthal. Writing in the journal Science, researchers described the Pleistocene-era skulls as having a morphological mosaic with differences from and similarities to their western contemporaries. The brow ridges and skull mass resembled early modern humans of the old world, the skulls had a flat brainpan like other eastern Eurasian humans of the time, but their ear canals and large back section of the skull resemble Neanderthals. In fact, during the last few decades, great progress has been made in several domains, particularly paleogenetics, which have revealed the complex ancestry of early humans. This progress is providing important new biogeographical hypotheses. Homo erectus was a type of hominin, the group to which early and modern humans belong. Homo erectus warped upright, had a thick skull with a brain a little smaller than our own and used stone tools. The first Java man fossils of the species were found on Java, Indonesia, in 1892 by Eugène Dubois. Nearly 30 years later, more Homo erectus fossils were found thousands of miles away during excavations of the Zucaudian cave system just outside of Beijing. The famous fossils of an early relative of modern humans commonly called Peking Man may be 200,000 years older than previously thought, a new study finds. The revised date could change the timeline and number of migrations of the Homo erectus species out of Africa and into Asia. It also suggests that Peking Man endured many glacial climates. The Homo genus, which includes modern humans, likely originated in Africa with Homo habilis about 2.5 million years ago. Homo erectus likely derived from some early version of Homo habilis around 2 million years ago, anthropologists think. It's a species that had legs, referring to the distances traveled. Aside from Homo sapiens, it's the most widespread hominin species. Previous studies estimated that Homo erectus fossils found nearly a century ago in China were from about 500,000 years ago. The authors of the new study sought to redate the fossils using a relatively new method that looks at the radioactive decay of aluminium and beryllium in quartz exposed to cosmic radiation. With this method, they pinned a date closer to 780,000 years ago. Understanding the history of Homo erectus is of interest to scientists because the populations of the species that lived in Africa are implicated in the ancestry of modern humans. Given the new dating, this means that this was one of the few ancient human groups that survived the population bottleneck around 800,000 to 900,000 years ago, meaning that Peking Man could have given rise to the ancestors of Neanderthals and modern humans, as well as Denisovans. However, many investigators believe that the Denisovans actually could be considered a sister group to Neanderthals, rather than a separate species, but the concept of human species is controversial. Nevertheless, they are a distinct type of hominin, and genetic studies have shown that there exist three distinct lineages of Neanderthaloids and or Denisovans in Asia and Papua. Peking Man, an extinct hominin of the species Homo erectus, known from fossils found at Zhukoudian near Beijing. Peking Man was identified as a member of the human lineage in 1927, on the basis of a single tooth. Later excavations yielded several skull caps and mandibles, facial and limb bones, and the teeth of about 40 individuals. Evidence suggests that the Zhukoudian fossils date from about 770,000 years ago. Before being assigned to Homo erectus, they were variously classified as Pythocanthropus and Synanthropus. Peking Man is characterized by a cranial capacity averaging about 1,000 cubic centimeters, though some individual skull capacities approached 1,300 cubic centimeters, nearly the size of modern man's. Peking Man had a skull that was flat in profile, with a small forehead, a keel along the top of the head for attachment of powerful jaw muscles, very thick skull bones, heavy brow ridges, an occipital torus, a large palate, and a large, chinless jaw. The teeth are essentially modern, though the canines and molars are quite large, and the enamel of the molars is often wrinkled. Meanwhile, the limb bones are indistinguishable from those of modern humans. The original fossils were under study in 1941 when, with Japanese invasion imminent, an attempt was made to smuggle them out of China and to the United States. The bones disappeared and have never been recovered, leaving only plaster casts for study. Renewed excavation in the caves, beginning in 1958, brought new specimens to light. In addition to fossils, core tools and primitive flaked tools were also found. These caves turned out to be one of the most important Paleolithic sites in the world. After the first fossil was found, anthropologists eventually turned up skulls and bones representing at least 40 Homo erectus individuals, popularly known as Peking Man, other mammal fossils and tens of thousands of stone artifacts. Pushing back the date of the Zookoudian fossils to nearly 800,000 years ago puts them in closer range to fossils found in open basins and plains around the cave system that were originally dated to be much older than the Zookoudian fossils. It also shows that Homo erectus lived in the area during glacial periods as well as during interglacial periods. Many scientists thought that the species moved north with the interglacials and south with the glacials. However, this new date shows they hung around during colder periods. These glacial cycles didn't involve mounds of snow and ice as one might think, rather it was just a colder, drier period. The new date also shed some light on how and when Homo erectus got to the area in the first place. Some scientists had proposed that the Java population later migrated up to present-day China, but the new date for the Zookoudian fossils lends credence to the idea that there could have been more than one migration route. Maybe there could have been two dispersals. One route could have extended along the coast of Asia to Java, and another through the interior of Eurasia to Zookoudian, and the surrounding areas. Also supporting the double migration idea is the fact that the Himalayas and a huge swath of primal forest unfriendly to hominin habitation lie in the way of a direct migration from Java to China. Cinching this argument would likely require finding more sites with Homo erectus fossils along the migration route. Peking Man postdates Java Man and is considered more advanced in having a larger cranial capacity, a forehead, and non-overlapping canines. Solo Man, prehistoric human known from 11 fossil skulls, without facial skeletons, and two leg bone fragments that were recovered from terraces of the Solo River at Ngandong Java in 1931. Cranial large capacity overlaps that of modern man. The skulls are flattened in profile, with thick bones and heavy brow ridges forming a torus, and the limb bones are indistinguishable from those of modern man. Skull bases were broken, indicating that the heads may have been taken as trophies and the brains eaten. Solo Man has been thought to date to the late Pleistocene, possibly during the last glaciation, about 30,000 years ago, but his age remains uncertain. Solo Man's resemblance to Java Man and Peking Man has led some scholars to consider him a late example of Homo erectus in Asia, Homo erectus soloensis. Nevertheless, others believe Solo Man is a regional variant of widespread early Homo sapiens populations, also including the Neanderthaloid peoples of Europe and the Rhodesioid peoples of Africa.