Complete Guide to the Denisovans, Newer Hominid Species

The Denisovans are a recently identified hominin species, related to but different from the other two hominid species (early modern humans and Neanderthals) who shared our planet during the Middle and Upper Paleolithic periods. Archaeological evidence of the existence of Denisovans is so far limited, but genetic evidence suggests they were once widespread across Eurasia and interbred with both Neanderthals and modern humans. Key Takeaways: Denisovans Denisovan is the name of a hominid distantly related to Neanderthals and anatomically modern humans.Discovered by genomic research in 2010 on bone fragments from Denisova Cave, SiberiaEvidence is primarily genetic data from the bone and modern humans who carry the genes  Ã‚  Positively associated with the gene which allows humans to live at high altitudesA right mandible was found in a cave in the Tibetan Plateau The earliest remains were tiny fragments found in the Initial Upper Paleolithic layers of Denisova Cave, in the northwestern Altai Mountains some four miles (six kilometers) from the village of Chernyi Anui in Siberia, Russia. The fragments held DNA, and the sequencing of that genetic history  and the discovery of remnants of those genes in modern human populations  has important implications for the human habitation of our planet. Denisova Cave The first remains of the Denisovans were two teeth and a small fragment of finger-bone from Level 11 at Denisova Cave, a level dated between 29,200 to 48,650 years ago. The remains contain a variant of initial Upper Paleolithic cultural remains found in Siberia called Altai. Discovered in 2000, these fragmentary remains have been the target of molecular investigations since 2008. The discovery came after researchers led by Svante Pà ¤Ãƒ ¤bo at the Neanderthal Genome Project at the Max Planck Institute for Evolutionary Anthropology successfully completed the first mitochondrial DNA (mtDNA) sequence of a Neanderthal, proving that Neanderthals and early modern humans are not very closely related at all. In March 2010, Pà ¤Ãƒ ¤bos team reported the results of the examination of one of the small fragments, a phalanx (finger bone) of a child aged between 5 and 7, found within Level 11 of Denisova Cave. The mtDNA signature from the phalanx from Denisova Cave was significantly different from both Neanderthals or early modern humans (EMH). A complete mtDNA analysis of the phalanx was reported in December of 2010, and it continued to support the identification of the Denisovan individual as separate from both Neanderthal and EMH. Pà ¤Ãƒ ¤bo and colleagues believe that the mtDNA from this phalanx is from a descendant of people who left Africa a million years after Homo erectus, and half a million years before the ancestors of Neanderthals and EMH. Essentially, this tiny fragment is evidence of human migration out of Africa that scientists were completely unaware of before this discovery. The Molar The mtDNA analysis of a molar from Level 11 in the cave and reported in December 2010 revealed that the tooth was likely from a young adult of the same hominid as the finger bone and clearly a different individual since the phalanx is from a child. The tooth is an almost complete left and probably third or second upper molar, with bulging lingual and buccal walls, giving it a puffy appearance. The size of this tooth is well outside the range for most Homo species. In fact, it is closest in size to Australopithecus. It is absolutely not a Neanderthal tooth. Most importantly, the researchers were able to extract DNA from the dentin within the root of the tooth, and preliminary results reported its identification as a Denisovan. The Culture of the Denisovans What we know about the culture of the Denisovans is that it was apparently not much different from other Initial Upper Paleolithic populations in the Siberian north. The stone tools in the layers in which the Denisovan human remains were located are a variant of Mousterian, with the documented use of parallel reduction strategy for the cores, and a large number of tools formed on large blades. Decorative objects of bone, mammoth tusk, and fossilized ostrich shell were recovered from the Denisova Cave, as were two fragments of a stone bracelet made of dark green chlorite. The Denisovan levels contain the earliest use of an eyed-bone needle known in Siberia to date. Genome Sequencing In 2012, Pà ¤Ãƒ ¤bos team reported the mapping of the complete genome sequencing of the tooth. Denisovans, like modern humans today, apparently share a common ancestor with Neanderthals  but had a completely different population history. While Neanderthal DNA is present in all populations outside of Africa, Denisovan DNA is only found in modern populations from China, island Southeast Asia, and Oceania. According to the DNA analysis, the families of present-day human and Denisovans split apart about 800,000 years ago  and then reconnected some 80,000 years ago. Denisovans share the most alleles with Han populations in southern China, with Dai in northern China, and with Melanesians, Australian aborigines, and southeast Asian islanders. The Denisovan individuals found in Siberia carried genetic data that matches that of modern humans and is associated with dark skin, brown hair and brown eyes. Tibetans, Denisovan DNA, and Xiahe Looking through the entire Jiangla River Valley at the upper reach of the valley. Biashiya Karst Cave is at the end of the valley. Dongju Zhang, Lanzhou University A DNA study published by population geneticist Emilia Huerta-Sanchez and colleagues in the journal  Nature  focused on the genetic structure of people who live on the Tibetan Plateau at 4,000 meters above sea level  and discovered that Denisovans may have contributed to the Tibetan ability to live at high altitudes. The gene EPAS1 is a mutation which reduces the amount of hemoglobin in blood required for people to sustain and thrive at high altitudes with low oxygen. People who live at lower altitudes adapt to low-oxygen levels at high altitudes by increasing the amount of hemoglobin in their systems, which in turn increases the risk of cardiac events. But Tibetans are able to live at higher elevations without increased hemoglobin levels. The scholars sought for donor populations for EPAS1 and found an exact match in Denisovan DNA. Denisova Cave is only about 2,300 feet above sea level; the Tibetan Plateau averages 16,400 ft asl. A team led by paleontologist Jean-Jacques Hublin (Chen 2019) searched through archived Tibetan paleontological remains and identified a mandible which had been discovered in Baishiya Karst Cave, Xiahe, Gansu province, China in 1980. The Xiahe mandible is 160,000 years old and it represents the earliest known hominin fossil found on the Tibetan Plateau—the caves elevation is 10,700 ft asl. Although no DNA remained in the Xiahe mandible itself, there was extant proteome in the dentine of the teeth—albeit highly degraded, it was still clearly distinguishable from contaminating modern proteins. A proteome is the set of all expressed proteins in a cell, tissue, or organism; and the observed state of a particular single amino acid polymorphisms within the Xiahe proteome helped establish the identification of the Xiahe as Denisovan. The scholars believe that this human adaptation to extraordinary environments may have been facilitated by gene flow from Denisovans who had adapt ed to the climate first. Now that researchers have an indication of what Denisovan jaw morphology looks like, it will be easier to identify possible Denisovan candidates. Chen et al. also suggested two more East Asian bones which fit the morphology and time frame of Xiahe cave, Penghu 1 and Xuijiayo. Family Tree When anatomically modern humans left Africa about 60,000 years ago, the regions they arrived in were already populated: by Neanderthals, earlier Homo species, Denisovans and possibly Homo floresiensis. To some degree, the AMH interbred with these other hominids. The most current research indicates that all of the hominid species are descended from the same ancestor, a hominin in Africa; but the exact origins, dating, and spread of hominids throughout the world was a complex process that needs much more research to identify. Research studies led by Mondal et al. (2019) and Jacobs et al. (2019) have established that modern populations containing admixtures of Denisovan DNA are found throughout Asia and Oceania, and it is becoming clear that interbreeding between anatomically modern humans and Denisovans and Neanderthals occurred several times over the course of our history on planet earth. Selected Sources à rnason, Úlfur. The Out of Africa Hypothesis and the Ancestry of Recent Humans: Cherchez La Femme (Et Lhomme). Gene 585.1 (2016): 9–12. Print.Bae, Christopher J., Katerina Douka, and Michael D. Petraglia. On the Origin of Modern Humans: Asian Perspectives. Science 358.6368 (2017). Print.Chen, Fahu, et al. A Late Middle Pleistocene Denisovan Mandible from the Tibetan Plateau. Nature  (2019). Print.Douka, Katerina, et al. Age Estimates for Hominin Fossils and the Onset of the Upper Palaeolithic at Denisova Cave. Nature 565.7741 (2019): 640–44. Print.Garrels, J. I. Proteome. Encyclopedia of Genetics. Eds. Brenner, Sydney and Jefferey H. Miller. New York: Academic Press, 2001. 1575–78. PrintHuerta-Sanchez, Emilia, et al. Altitude Adaptation in Tibetans Caused by Introgression of Denisovan-Like DNA. Nature 512.7513 (2014): 194–97. Print.Jacobs, Guy S., et al. Multiple Deeply Divergent Denisovan Ancestries in Papuans. Cell 177.4 (2019): 1010–21.e3 2. Print.Mondal, Mayukh, Jaume Bertranpetit, and Oscar Lao. Approximate Bayesian Computation with Deep Learning Supports a Third Archaic Introgression in Asia and Oceania. Nature Communications 10.1 (2019): 246. Print.Slon, Viviane, et al. The Genome of the Offspring of a Neanderthal Mother and a Denisovan Father. Nature 561.7721 (2018): 113–16. Print.Slon, Viviane, et al. A Fourth Denisovan Individual. Science Advances 3.7 (2017): e1700186. Print.

The Effects Of Drug And Alcohol Addiction - 3284 Words

Abstract Through studying multiple papers that have assessed the genetic contribution to addiction of drugs and alcohol, it is easy to show that genetics does have a major influence. Some people are born with a predisposition to become addicts, but genetics does not determine if you will become one. Environmental factors do show some effects as to whether the genes responsible for certain behaviors or tendencies are expressed to the point of addiction. By looking at twins, we can see that genetics can have a direct affect on symptoms within the same substance and cross substance effects. There are some receptors that could be potentially used to treat behaviors of addiction, but we are still a long ways from developing the right techniques and methods to safely alter genetics to help treat those who suffer from the effects of drug and alcohol addiction. This paper should serve to show that genetics does have an impact. 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Comparison Hector in Iliad vs. Hector in Troy Free Essays

Heroes possess five timeless qualities. They are always willing to accept a challenge, they are courageous, self-sacrificing, they can overcome struggle with strength and dignity, and they have superior yet human qualities. Over different eras, other qualities that are attributed to heroes change based on society’s changing morals and ethics. We will write a custom essay sample on Comparison: Hector in Iliad vs. Hector in Troy or any similar topic only for you Order Now The two versions of Hector display the many differences between the Greeks perspective on heroes and the modern contemporary perspective on heroes.To begin with, it is implied that modern heroes are sympathetic and do not love to kill, while heroes in Greek perspectives love basking in glory over defeat of any of their enemies. Hector in the Iliad gloats over the sight of dying Patroclus, taunting him in his last moments alive, whereas Hector in Troy is remorseful when he finds out that it was not Achilles who he fought. He kills Patroclus to stop his suffering and says that it is enough fighting for one day, even though the war has just barely begun. This shows how modern heroes are dutiful to their cause, while not truly liking the violence involved.On the other hand, heroes in Greek perspectives are shown to be individuals who lust to kill and feel no compassion as long as they achieve victory. This ties into how the respect shown towards rivals differs greatly from one time period to another. Hector in the Iliad does not show respect to his enemies, therefore continuously taunting Patroclus. This is unlike Hector in the film who displays his respect for Patroclus by killing him. Hector’s respect in the modern version versus his lack of respect is evidence as to how heroes were believed to feel after defeating their enemy.Finally, these versions show that heroes by Greek definitions are opportunists, while modern heroes will complete a task through their own physical power. Hector in the Iliad is presented as an opportunist, diving in to kill Patroclus after Apollo has already injured him. This is unlike Hector in the film who fights Patroclus all on his own. This shows how the dependency of heroes has changed over time. Even though there are many differences between the perspectives of the Greeks and the modern contemporary, there are also quite a few similarities.First of all, both versions of Hector are displayed as fierce individuals. We can see this from the Hector in the Iliad through the diction used when describing him stabbing Patroclus. Their situation is compared to one of a lion and a tireless wild boar, where the â€Å"lion beats him down with sheer brute force as the boar fights for breath (Line 963-964). † By comparing Hector to such a tough animal and using â€Å"sheer brute force† when explaining how he stabbed Patroclus, his strength is shown. As well, showing that Hector has defeated a â€Å"wild boar† also contributes to showing his superiority. In Troy, just by his leadership and methods of fighting, one can see that he is very powerful. In addition, both are very loyal to their cities. They fight with courage and stay focused toward their goal. Even if Hector in the film commands the war to be over for the day, he still knows he has to be faithful to his city and fight again. Hector in the Iliad being the opportunist that he is, also shows his loyalty by finishing off his enemies with pride. All in all, through observing the attitudes and behaviors of the two versions of Hector, it is easy to interpret how these time periods felt about heroes.All heroes possess five timeless qualities in addition to other qualities which are believed to be important during their own time period. Sometimes, one may see that these qualities are quite similar, and other times, they are the exact opposite of each other. In conclusion, descriptions of heroes are created by looking at what will appeal to the readers or viewers based on morals and ethics valued during that time. For this reason, the two versions of Hector possess some of the same qualities, but also some very different ones. How to cite Comparison: Hector in Iliad vs. Hector in Troy, Papers