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Nairaland Forum / Nairaland / General / Culture / One Human Species (3816 Views)
On The One Hand Species Dependent / Skull Suggests Single Human Species Emerged From Africa, Not Several / New Monkey Species Discovered In Africa (2) (3) (4)
One Human Species by Nebeuwa(m): 2:22pm On Apr 03, 2012 |
There seems to be so much division in this world, but genetically speaking, there is only one Human species. There is not much genetic variation between someone who lives in Africa and someone who lives in Asia or Europe. The reason people have different complexions, height, weight etc is due the environment that our earliest human ancestors found themselves in. One Human Species After several million years of human evolution, only one hominid species remains: Homo sapiens. We have spread across every continent into a wide range of environments—and in the process, minor differences between people living in separate regions developed over the course of thousands of years. As a result, humans today have a variety of skin colors, body types and facial features. But studies of human DNA reveal that all humans are remarkably similar—we are 99.9% genetically identical. One in a thousand Only one out of every thousand bits of DNA information differs between any two people. The other 999 of these chemical units, abbreviated as A, T, C and G, are identical. Altogether, human DNA contains more than three billion information units. This information shapes the development and function of nearly everything about the human body. Our earliest migrations Soon after modern humans evolved in Africa more than 150,000 years ago, some of them began spreading across the continent. Later, many waves of modern humans flowed out of Africa. Over thousands of years they journeyed across seas and mountain ranges. In each new home, they learned to find and eat local foods and to survive different climate conditions. This map shows probable pathways of the very earliest human movements to different regions—countless later migrations mixed these early groups with one another. The map is based on information from fossilized bones, ancient artifacts and the DNA of living people all over the world. http://www.amnh.org/exhibitions/permanent/humanorigins/species/ |
Re: One Human Species by Nebeuwa(m): 2:26pm On Apr 03, 2012 |
The Discovery of Mitochondrial Eve In January 1987, Rebecca Cann, Mark Stoneking, and Allan Wilson published a paper in Nature that dropped a bombshell of our understanding of human evolution. Until then, the prevailing theory held that different groups of humans had evolved separately in different regions, beginning about two million years ago. Their groundbreaking work revealed all humans carried mitochondrial DNA in their cells that dated back to a single woman who had lived just 200,000 years ago. This woman was dubbed Mitochondrial Eve. Though their research was initially met with tremendous controversy, the death knell of the multiregional hypothesis had already been struck. The idea here was that our predecessor Homo erectus had left Africa two million years ago and spread out around the entire world. Then, these different populations adapted to their new environments by evolving into Homo sapiens, although constant gene flow and interbreeding between these different populations meant that everyone remained part of the same species. This model was seen as the best way to explain all the Homo erectus fossils found throughout Africa, Eurasia, and Australia. The discovery of Mitochondrial Eve gave crucial support to the Recent African Origin model, which held that modern humans only evolved once, most likely in East Africa, somewhere between 150,000 and 200,000 years ago. All older fossils discovered elsewhere represented hominid lineages that had since gone extinct. And while we've recently seen some strange fossil findings that could complicate the picture yet again, the basic tenets of the Recent African Origin model are now well-established. So how did Mitochondrial Eve manage to rewrite the entire story of human evolution? For that matter, what exactly is Mitochondrial Eve? Unlike her biblical namesake, she wasn't the only woman on Earth. In a sense, she's just a quirk of statistics. But if that's the case, then she's easily the most important quirk of statistics who ever lived. http://io9.com/5878996/how-mitochondrial-eve-connected-all-humanity-and-rewrote-human-evolution |
Re: One Human Species by Nebeuwa(m): 2:27pm On Apr 03, 2012 |
What Mitochondrial Eve Really Means In sexual reproduction, a person will only pass on half of his or her genes, and their contribution to ensuing generations will continually divide by half. After a thousand years, any one ancestor's genetic contribution will drop to effectively nothing. That actually means that the most recent common ancestor of all human beings, or MRCA, who lived anywhere from 2,000 to 40,000 years ago, is more a statistical curiosity than a genetic benefactor, and he or she is related to all of us today in only the most technical of senses. In order to find a common ancestor whose genetics have passed on, we need to look for things that are passed down from generation to generation with little or no alteration. Both genders pass along one thing that is unchanged during sexual reproduction. For women, this is the mitochondrial DNA, which is a distinct subset of genetic material found not in the cell nucleus but rather in the mitochondria, the power plants of the cell. In most species, including humans, the female egg cells completely destroy the mitochondria in the male sperm cell shortly after fertilization, leaving only the female mitochondria behind. This is where we get the term "Mitochondrial Eve", made popular on shows like the Battlestar Galactica reboot. This individual passed down her mitochondria relatively unchanged to every human alive today, and all females will continue to pass down her mitochondria indefinitely. By tracing the subtle mutations to mitochondrial DNA that have accumulated over the millennia, we can figure out which groups are most closely related, and ultimately fix the existence of Mitochondrial Eve to a fairly specific time in the past, which is currently estimated at about 200,000 years ago. That pretty much rules out the idea of multiple origins for humanity — otherwise Mitochondrial Eve would have to date back a couple million years, and mitochondrial analysis shows that that simply isn't the case. It's worth noting that Mitochondrial Eve would not have been exceptional during her own life. She certainly wasn't the only woman alive at the time, merely the only one who can trace descent to everyone alive right now. All the other women alive at the same time as her either left no living descendants or are only related to some smaller subset of the people alive today. ![]() |
Re: One Human Species by ektbear: 3:36pm On Apr 03, 2012 |
Yep. At the end of the day, we are all the same. |
Re: One Human Species by Nebeuwa(m): 4:19pm On Apr 03, 2012 |
Human Migration ![]() |
Re: One Human Species by ektbear: 4:20pm On Apr 03, 2012 |
Any approximate dates associated with those arrows? |
Re: One Human Species by Nebeuwa(m): 4:22pm On Apr 03, 2012 |
ekt_bear: Any approximate dates associated with those arrows? National Geographic provides a detailed map concerning human migration. ![]() |
Re: One Human Species by Nebeuwa(m): 4:29pm On Apr 03, 2012 |
The San of Southern Africa are the "oldest" representative of the human race. ![]() |
Re: One Human Species by Nebeuwa(m): 4:42pm On Apr 03, 2012 |
Meet the ancestors: DNA study pinpoints Namibia as home to the world's most ancient race Scientists have long known that humans originated in Africa, but now a groundbreaking DNA study has revealed our 'Garden of Eden' is likely to be on the South African-Namibian border. For it is the San people, hunter-gatherers in this area for thousands of years, who researchers now believe are the oldest human population on Earth. They are descended from the earliest human ancestors from which all other groups of Africans stem and, in turn, to the people who left the continent to populate other corners of the planet. ![]() Researchers conducting the largest study of African genetic diversity came to this conclusion as the San were shown to be the most diverse. The origin of a species is taken to be the place where people show the most genetic diversity because of the time it takes for genes to evolve. The DNA tests therefore suggest the San are the oldest continuous population of humans on the Earth. The research published today in the online journal Science also showed that nearly three-quarters of African-Americans can trace their ancestry to West Africa. The 10-year-study was led by Professor Sarah Tishkoff, a geneticist at the University of Pennsylvania. She trekked across remote and dangerous areas of the continent with an international team collecting DNA samples from more than 3,000 modern Africans from 121 distinct populations. Often working in primitive conditions, the researchers sometimes had to resort to using a car battery to power their equipment. The tests revealed they had all descended from just 14 ancestral populations, and the languages they spokes were closely correlated with the variation of their genes. The study also suggests that a small group of 150 Africans, who went on to populate the rest of the world, first left their continent from the Red Sea. The researchers found people who lived in Sudan had genetic markers which suggested they were related to the group who moved abroad 50,000 years ago. 'The human genome describes the complexity of our species,' added Muntaser Ibrahim of the department of molecular biology at the University of Khartoum, Sudan. 'Now we have spectacular insight into the history of the African population ... the oldest history of mankind. 'Everybody's history is part of African history because everybody came out of Africa.' Before this study very little was known about the genetic variation in Africans, knowledge that is vital to understanding why diseases have a greater impact in some groups than others and in designing ways to counter those illnesses. Scott M. Williams of Vanderbilt University noted that constructing patterns of disease variations can help determine which genes predispose a group to a particular illness. This study 'provides a critical piece in the puzzle', he said. For example, there are clear differences in prevalence of diseases such as hypertension and prostate cancer across populations, Mr Williams said. ![]() Christopher Ehret from the University of California, Los Angeles, compared genetic variation among people to variations in language. There are an estimated 2,000 distinct language groups in Africa broken into a few broad categories, often but not always following gene flow. Movement of a language usually involves arrival of new people, Mr Ehret noted, bringing along their genes. But sometimes language is brought by a small 'but advantaged' group which can impose their language without significant gene flow. The study also found that about 71 per cent of African-Americans can trace their ancestry to western African origins. They also have between 13 per cent and 15 per cent European ancestry and a smaller amount of other African origins. There was 'very little' evidence for American Indian genes among African-Americans, Tishkoff said. Ehret added that only about 20 per cent of the Africans brought to North America made the trip directly, while most of the rest went first to the West Indies. And, he added, some local African-American populations, such as the residents of the sea islands off Georgia and South Carolina, can trace their origins to specific regions such as Sierra Leone and Guinea. The study was funded by the National Cancer Institute, the National Institutes of Health, the Advanced Computing Center for Research and Education at Vanderbilt University, the L.S.B. Leakey and Wenner Gren Foundation, the National Science Foundation, the David and Lucile Packard and Burroughs Wellcome foundations. Read more: http://www.dailymail.co.uk/sciencetech/article-1176140/Meet-ancestors-DNA-study-pinpoints-Namibia-home-worlds-ancient-race.html#ixzz1qzaBnYv2 |
Re: One Human Species by PAGAN9JA(m): 4:18pm On Apr 04, 2012 |
we are also 99% identical in DNA to chimps, but that doesnt mean we start breeding with them. |
Re: One Human Species by Nebeuwa(m): 4:34pm On Apr 04, 2012 |
PAGAN 9JA: Chimpanzees are a different species from humans. Homo sapiens = Humans, Simia troglodytes = Chimpanzees. Even though we are part of the same Hominidae family, that does not make us the same. However, with humans, the differences amongst human groups are so minuscule, there is no such thing as a race, which is a social construct. |
Re: One Human Species by PAGAN9JA(m): 6:27pm On Apr 04, 2012 |
Nebeuwa: That is just your personal opinion. The difference between us and that bush-animal is also miniscule of only ).10% . Yet, The reality is that there is Race and there is Tribe and there is differences. The Purer the people, the better. I am not trying to be hitler, but that is FACT. PROUD TO BE HAUSA. ![]() |
Re: One Human Species by PAGAN9JA(m): 6:30pm On Apr 04, 2012 |
and all those AA's who parade around saying Black Pride and Black Race, let me remind them that they are nothing but mixed-race fellows. |
Re: One Human Species by Nebeuwa(m): 8:54pm On Apr 04, 2012 |
PAGAN 9JA: No, this is not my personal opinion. This is based on genetics, which cannot be refuted. There is no such thing as race, since man socially constructed such a term. No society is composed of genetically “pure” people. You say you are Hausa, but that may mean you have genes that can be traced from semitic people, who spread their religion amongst your people. And do you know that Africa has the most genetic variation found on the planet? You may even have genes that are found in other African groups. |
Re: One Human Species by Nebeuwa(m): 8:55pm On Apr 04, 2012 |
PAGAN 9JA: I take offense, being someone whose maternal lineage is African American. Even though many African Americans have European genes dating back to slavery, the majority of African Americans are of African descent. |
Re: One Human Species by PAGAN9JA(m): 11:59pm On Apr 04, 2012 |
Nebeuwa: ha! I KNEW IT! i have noticed ovver the years that only AA's will post such a thing. you AA's will never understand us AFRICANS. you just want us to breed with each other andd create a mixed world and become corrupted like you fellows. I know your kind. you are certainly not the first. ![]() ![]() |
Re: One Human Species by Nebeuwa(m): 12:31am On Apr 05, 2012 |
PAGAN 9JA: Get a hold of yourself. ![]() |
Re: One Human Species by PAGAN9JA(m): 12:57am On Apr 05, 2012 |
Nebeuwa: that still makes you mixed. anyway, apart from that, are you aware of the fact that i am Maguzawa? why then should i mix with arabs ![]() ![]() ![]() ![]() ![]() also Hausa peoples just try to behave like arabs. they did not actually mix with them. we have kept our blood strong. the only problem arises with certain peoples marrying Fuulbe. howeve r they are aware of their ancestry and call themsef Hausa-Fulani. but technically, they have no place in any tribe. |
Re: One Human Species by morpheus24: 5:44pm On Apr 05, 2012 |
Nebeuwa:@ nebeuwa you are not going to get too much of a head way with some nigerians on this forum who obviously still believ in things like 'the curse of ham' or the debunked three race theory: caucasoid, mongoloid and negroid coined in 18th and 19th century scientific study. You are indeed correct in asserting that 'biologically" There is only one human species. Homo sapien sapien and indeed "race' is a social construct. You however will encounter individuals who are so ingrained in these 'constructs' that anything outside of that normal definition will seem nonsensical to them. Differences in phenotypical and genotypical makeups of humans are factors that contribute to our 'differences" but the underlying framework is the same for this one species that differentiates them from other closer relatives as in chimps and great apes. I would suggest that you be careful with studying the "out of Africa' hypothesis that you are obviously drawing reference from and keep and open mind to changing definitions, cause its science is continually changing. For example it was recently discovered that every other human except for sub saharan Africans have as much as 1- 4% of neandethal and denisova genes in them, proving that the migrants from Africa bred with outside of Africa evolved hominids and laying to rest the proposition that they were several distinct human species. |
Re: One Human Species by morpheus24: 5:53pm On Apr 05, 2012 |
PAGAN 9JA: There is nothing such as a pure Hausa person. You share genetic makeup with several sahelian groups stretching across the Nile to Sene-gambia. your groups simply stoped migrating and ended up setting up a home in what is known as northern Nigeria today. PS "biologically speaking". The purer and isolated people genetically and geographically are, the less likely their numbers survive over time. Human dispersal across the continents ensured our survival as a species. |
Re: One Human Species by ChinenyeN(m): 4:58am On Apr 06, 2012 |
Just out of curiosity, is this topic for information purposes, or is it intended to convey a point? |
Re: One Human Species by Nebeuwa(m): 7:48am On Apr 06, 2012 |
ChinenyeN: Just out of curiosity, is this topic for information purposes, or is it intended to convey a point? Is there a difference? Conveying a point can provide information for those who wish to learn. |
Re: One Human Species by Nebeuwa(m): 8:02am On Apr 06, 2012 |
morpheus24: That news has already been circulating since 2010, when the New York Times had an article on that subject. It caused a little firestorm in the blogosphere, because you had people claiming that Africans are the only pure homo sapiens. We all know how views on "race" can muddy the water. I even heard some people try to say that Neanderthals matings with modern humans created the perfect hybrid that allows their offspring to conquer the rest of the world. I still think the the genes are negligible, since there is evidence that early humans mated with Homo erectus and also Homo habilis as well. The human genome is fascinating. What was the spark that allowed us to conquer the natural world? I ponder these questions at times. |
Re: One Human Species by Nebeuwa(m): 8:06am On Apr 06, 2012 |
A more comprehensive map of the human family tree. ![]() |
Re: One Human Species by PAGAN9JA(m): 1:27pm On Apr 06, 2012 |
morpheus24: yes we are Sahelian that is true. but we have broken away from them, so how does that make us mixed ![]() and you did not test my blood so no point making false claim of me being mixed with arabs. ![]() |
Re: One Human Species by morpheus24: 2:50pm On Apr 06, 2012 |
PAGAN 9JA: I never claimed that Hausa are mixed with anything. The point I am trying to convey is that human populations are a continium from earlier groups of people that diverge, bottle neck and cross breed with each other. Therefore the notion that anyone is pure is based on sentimentality and a yearning to be unique. We are not that special, sorry!! |
Re: One Human Species by morpheus24: 2:59pm On Apr 06, 2012 |
Nebeuwa: I recall the frenzy it caused. A lot of "people" of course hijacked the info to claim all sorts of things regarding the ability to adapt quicker to certain environments, prosper and conquer the world. I have a simpler and less abrasive theory which requires the application of common sense regarding "people' being able to conquer the world. Its called the exponential transfer of knowledge basis. As humans accumulate knowledge and transfer from generation to generation. the locations closest to the these pools of knowledge will undoubtedly acquire these knowledge basis and if socially engineered are able to create a class of "populations" with exponential knowledge. Populations that are barricaded by formidable barriers for example "the Sahara" and isolated in an interior of a particular continent will be excluded from these exponential possibilities. |
Re: One Human Species by Nebeuwa(m): 8:10pm On Apr 06, 2012 |
morpheus24: I am intrigued by your theory. And you do have a point. I do feel that the Sahara provided a barrier for the "populations" south of the Sahara in terms of knowledge. While the rest of the world was connected through the silk road and the Mediterranean sea, excluding the Americas, different groups were able to exchange knowledge from one society to another. That is why these groups had a wealth of knowledge in terms of technology compared to the more isolated groups whose pool of knowledge was quite limited. The Sahara was both a blessing and a curse, because it protect the southern groups from constant invasion and diseases, but it was also a curse, because once the cultures north of the Sahara were able to get past it, they were able to have an advantage over the cultures who had less contact with them. I still ponder if genetics also play a role. When I look at the long distance runners from Kenya and Ethiopia, there success has to be due to genetics. Or what about the height of the Dinka in Southern Sudan, they probably adapted to the harsh climate that they live in. |
Re: One Human Species by PAGAN9JA(m): 8:45pm On Apr 06, 2012 |
morpheus24: No! i get your point but the basic law of nature states that once a species gets isolated into separate sections (usually due to physical barriers such as a mountain range, a rive, climate, etc.), they develop and gradually evolve into Newer species. No. before you accuse me of saying that Hausa is a different species from Han Chinese (which i disagree), i wish to put forward a point. when homo-sapiens evolved from ape man, he gradually spread around all over the world. We were still at that raw stage. Later, this homo-sapiens settled down in different places to form Tribes. The Tribesmen all over the world are purer than hybrid-humans for 2 reasons: 1.They were largely isolated before the populations grew. So they were already in that stage of gradual evolution and started developing separate racial characteristics, cultures, lifestyles, and even diets. (The Innuit were/are known to survive almost entirely on raw-meat, something which many of our stomachs cant survive on for the entire lifetime.) 2.It is also possible that during the evolution stage of apeman to current homo-sapien form itse;f, we already started getting isolated. Because Homo Eructus and other Palaeolithic finds have been found across many parts of the globe, ranging from Africa, to Europe and even as far as Vietnam and India. This more plausible and I have another bigger theoretical proof which i will soon publish here on Nairaland. it might sound a bit foolish but it makes a lot of sense. now these tribes developed stronger separate racial features but due to interaction between different tribes, the racial evolution stage dropped as diet, migrations, climatic change, etc were faced by these tribes. There were no more any stable conditions. which is how we have existed to date. Being a religious man, to add a touch of spirituality, i must say that the Gods meant us to be as such and our wider spiritual beliefs were the same. the mixed races are destroying this natural order of evolution and us tribesmen must unite. There might have been a little mixing done in the tribes, (i say might), but the stronger blood has prevailed and diluted it, so it doesnt matter. The tribes understood it, so till now, we have largely never mixed. The West however has been trying to destroy this natural order of things. ![]() ![]() ![]() ![]() |
Re: One Human Species by morpheus24: 8:56pm On Apr 06, 2012 |
Nebeuwa: exactly right. An example would be when civilizations in and around the mediterenean including North Africa were evolving and modern settlements began springing up. A notable civilization would be Egypt. The acquired knowledge of domestication of Horses, Camels and donkeys would largely facilitate trade with neighbouring settlments around the mediternean. This activity would of course transfer knowledge basis via the goods that were exchanged all the way down to south asia. The interior or Africa south of the sahara and the sahel did not use these forms of transportation( imagine the use of horses and carriages in the thick interior rainforests of Yoruba land 3000 years ago) and so would only be able to travel shorter distances( possibly via canoe or on foot) and acquire/exchange knowledge in smaller spirts. Nebeuwa: Humans beings often adapt desirable physical and biological traits tha are suited to their environment. It is not a coincidence that darker people live in regions where the sun shines all year round and the lightest in areas where the sun is much less availble. |
Re: One Human Species by morpheus24: 9:02pm On Apr 06, 2012 |
PAGAN 9JA: Am not really sure of the above hypothesis. To repeat my earlier point. There is nothing really like a hybrid human being unless of course you subscribe to the notion that human beings are different species based on racial lines. Human beings are a continium of a spectrum of gradial morphological/physical transformations i.e. ADAPTATIONS. This is different from a spring forward in evolutionary terms. PAGAN 9JA:Racial characteristics are translated as physical ADAPTATIONS based on traits that are naturally selected for survival in a specific condition. They do not make one human purer than another. They are simply changes to the physical as a result of selective breeding and diet. They are not anatomical. PAGAN 9JA: Homo sapiens are one species of human that originiate in africa and disperse to other parts of the world to encounter other so called human species i.e neanderthal man and denisova hominin in other parts of the world. Homo sapiens remain the only group that survive in and outside of Africa. The remaining die off. The isolated groups in Africa retain their original adaptations to the environment and so do other several groups outside of Africa. Others retain certain traits and discard other traits as they continue to migrate. The evidence that points to this fact is the largest array of genetic makeup inside of Africa as opposed to outside of it, which gives homosapien its origins in Africa and everyother mutated variant outside of it. PAGAN 9JA:Again there is no racial evolution state. There are only adaptations that exist which create varieties within a given species. Therefore a racial evolution stage cannot exist nor can it be dropped. PAGAN 9JA: Human beings align with what they consider as similar characteristics they can relate to in other persons whether it be language, skin color, accent, dressing, food, cultures, e.t.c. However these are conjectures we create in trying to understand and control the world around us. Whether that is a human flaw or a form of self preservation is debatable. The idea of a mixed 'race' of people is simply a way of structuring the world in a way you can understand it or manipulate it. It is not necessarily absolute truth. I will repeat again. Human beings are simply a continium of a spectrum of physical traits that have been adapted, retained and passed on from one generation to another. it does not convey any special status if one trait is absent only in as much as it is related to our conjectures of self preservation. |
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