Footprint fossils reveal the location and mode of modern human migration.
Three studies on human footprint fossils published in 2020 revealed many new information, such as where ancient humans had been and how they acted in groups. Different from physical fossils, footprints (and other "trace fossils") present more like a "screenshot" of a scene at a certain time point or in a very short time interval.
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65438+February 2020, Matthew? r？ Bennett and his colleagues published the longest human footprint fossil ever discovered. This footprint was formed about 1. 1.5 million years ago to 1.3 million years ago, and it is about 1.3 kilometers long, which is equivalent to the length of 1.4 football fields. These footprints were left by a woman or a young man, holding a child of two or three years old in his hand. The terrain he passed was rugged and dangerous.
How did we get this information? As can be seen from the footprints, the footprints of adults will pause from time to time, waiting for the footprints of children to catch up and meet. The lines connected by the footprints are straight and clear, and it can be seen that the walking speed is very fast, indicating that this person is moving towards a clear goal. Then the footprints turned around and came back, but this time there were no young children around.
So, did humans always act alone in the Pleistocene? The answer is of course no.
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In May 2020, Kevin of Chatham University? Hatara et al. released the analysis results of the largest footprint fossil group in Africa. About 6,000 to 1.9 million years ago, a group of modern humans walked through a mudflow at the foot of ol doinyo lengai Mountain, leaving 408 footprints of 17 people. These footprints can not only help us understand their height and weight, but also make a statistical analysis by using the foot size data of modern humans, and judge that this group of humans may include 14 women and 2 men. The research team compared these analysis results with the ethnographic data of modern ethnic groups such as Haza in Tanzania, and concluded that these footprints may have been left by adult women during a food gathering, during which several adult men occasionally visited or accompanied them.
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Footprints can also tell us that human beings have actually set foot in some places that we used to think were uninhabited. Max. Michael of the Planck Institute of Human History Science? Petraglia and her colleagues found some human and animal footprints on the surface of an ancient lake in the desert of Saudi Arabia. These footprints are 654.38+200,000 years old. Prior to this, the earliest evidence that humans entered the Arabian hinterland can only be traced back to 85,000 years ago.
Fossils show that ancient primates also traveled long distances.
These discoveries, which are directly related to human evolutionary history, are of course important, but it is equally exciting to study the global survival, reproduction and migration history of extinct primates.
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June 5438 +2020 10, the team led by Nina of Pennsylvania State University? The research team led by Gaby Lonski and Ji of Yunnan Institute of Cultural Relics and Archaeology in China discovered three new species of monkey fossils in Yunnan Province, which were formed in the late Miocene of Tertiary about 6.4 million years ago. These fossils show that this monkey lived in Asia for almost the same time as the apes. China monkeys can adapt to many different ecological environments. Modern Asian colobus monkeys may be their descendants, and their habitats have obvious seasonal changes and extreme conditions, indicating that they have also continued this trend.
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Speaking of extremes, researchers found that monkeys may have "walked on a bamboo raft" and drifted across the Atlantic Ocean. In April 2020, Eric of the University of Southern California? Seifert and his colleagues announced the discovery of a brand-new monkey, which is only the size of a can. They found four teeth fossils in the Amazon rainforest of Peru. This newly discovered monkey species is called Ucayalipithecus perdita, belonging to the extinct primate family parapithecids in Africa. Today, parapithecids has become the third mammal to successfully complete the transatlantic journey from Africa to South America, with a journey of more than 900 miles (about 1.440 km). Most likely, they crossed the ocean along the coastal zone with plants that were broken in the storm. It sounds incredible, but as long as there is enough food (such as fruits growing on plants), monkeys can survive without fresh water.
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In September 2020, Christopher of Hunter University? c？ The research team led by Gilbert announced the discovery of another new primate, Kapi ramnagarensis molar fossil, in northern India, which was formed about130,000 years ago. This discovery advances the fossil record of gibbons for about 5 million years, and reflects an important message: the ancestors of modern gibbons migrated from Africa to Asia at about the same time as the ancient apes.
New ancient human fossils have been found at the archaeological site in Derimoren, South Africa.
However, all the important discoveries related to human evolution are indispensable to the fossil evidence left by ancient humans. In this regard, the archaeological site of Mollen in Delhi, South Africa is undoubtedly the biggest winner in 2020.
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First, in July 2020, Andy of La Trobe University? Me? r？ The research team led by Harris announced the discovery of two new fossils, namely robustus (No.DNH 152) and Homo erectus (No.DNH 134), which were formed about 2.04 million years ago and1950,000 years ago, respectively, which are the oldest fossil records of these two ancient humans. This discovery shows that these two kinds of ancient humans and Australopithecus once lived in this place at the same time. The fossil with the number DNH 134 advanced the origin time of Homo erectus by 15 to 200,000 years.
The work of paleoanthropologists is not simple. When the DNH 143 fossil was discovered in 20 15, Jessie? Martin and Angelina? Lisi is also a student in the teaching and research base of the Morren Archaeological Site in Delhi, and is responsible for cleaning and repairing the skulls of ancient humans. They are responsible for 150 samples, all from a child of about three years old. When handling samples, they should not cough, sneeze, talk or even breathe carefully for more than 40 minutes at a time.
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The archaeological site of Derimoren seems to be a treasure trove, constantly giving us new fossils. In 20 18, this research team discovered two new human fossils, including an adult male skull with a history of about 2 million years, numbered DNH 155. Jesse from La Trobe University? Martin's analysis report on it was published on June 5438+065438+ 10, 2020, in which the fossil was specially compared with that of an adult male Robbins found in Derimoren, South Africa. It is found that some differences previously attributed to gender differentiation are actually the result of "micro-evolution" of this early ancient human being affected by ecological changes.
Scientists found the DNA of Denisova in cave sediments and modern humans.
Let's go back to the theme of "migration". After staying at home for so long, everyone should miss the feeling of being able to play around, right? )
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In June, 5438+last year 10, scientists first discovered the exact evidence left by the Denisova people on the Qinghai-Tibet Plateau, which is about 740 miles away from the Denisova Cave in Siberia10, which became one of the most important news in 2020. Decades ago, a Buddhist monk found a fractured mandible in Baishiyadong, Gansu Province, which was formed about 6.5438+0.6 million years ago. There is a hypothesis that this jawbone may be the remains of Denisova. The research team led by Zhang Dongju of Lanzhou University verified this hypothesis. First, in 20 19, they used a new technique based on protein mutation to judge that this jawbone really belongs to Denisova. However, people are still skeptical about this hypothesis, because this technology is too new and the exact location of the mandible when it was found in the cave is not clear. Determined to find more evidence, Zhang Dongju's team returned to the cave for further investigation. In order to avoid being disturbed by admirers, they only dig in winter nights. Everything comes to him who waits. They successfully found the mitochondrial DNA of Denisova people in cave sediments, which is 6,543,800 to 60,000 years ago, or even as short as 45,000 years ago. In addition, they also found charcoal, stone tools and animal bone fossils in the fire remains left by the Denisova people in the cave.
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Also in June 2020 10, by Max? Svante of Planck Institute of Evolutionary Anthropology? Pablo and Deando? Mahilani's research team analyzed a modern human female skull with a history of about 34,000 years discovered by miners in 2006 (this is the only known Pleistocene human fossil from Mongolia). And a 40,000-year-old modern human male skull excavated from the pastoral cave in China. It was found that both skull fossils contained Neanderthal and Denisovan DNA. The significance of this discovery is quite complicated, because the DNA sequence of Denisova found in these two fossils does not exist in modern Oceania (including Australian aborigines and New Guineans), but in modern East Asians, indicating that modern humans must have exchanged genes with two different Denisova people, one living in Southeast Asia and the other living in the Asian continent. This means that the Denisovans once occupied a considerable area in Asia. Next, scientists may find more fossils of Denisovans.
In the meantime, museums all over the world are still promoting digital projects so that scientists can study museum collections during the epidemic. For example, the National Museum of Kenya and the Smithsonian Institution of the United States have been working hard to present the original appearance of fossils in 3D for researchers all over the world to study. If you miss visiting the museum, you can look at the fossils like this and stay indoors. While expecting more Denisova fossils, we can also use virtual reality technology to see the world through the eyes of Neanderthals and even get in close contact with mammoths. (leaves)