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Katelyn Meakin Recitation: Thurs 10:20

Research Question: Early Hominids and their Relatives

1. Toro-Moyano, Isidro, Bienvenido Martínez-Navarro, Jordi Agustí, Caroline Souday, José María Bermúdez De Castro, María Martinón-Torres, Beatriz Fajardo, Mathieu Duval, Christophe Falguères, Oriol Oms, Josep Maria Parés, Pere Anadón, Ramón Julià, José Manuel García-Aguilar, Anne-Marie Moigne, María Patrocinio Espigares, Sergio Ros-Montoya, and Paul Palmqvist. The Oldest Human Fossil in Europe, from Orce (Spain).Journal of Human Evolution 65.1 (2013): 1-9. Online. This article discusses the finding of the oldest human fossil yet to e discovered in Europe. This new discovery leads scientists to believe that humans ventured to Europe from Africa earlier than what was previously thought to be the case.

2. Gruber, Karl. "Discovery of Oldest DNA Scrambles Human Origins Picture." National Geographic 4 Dec. 2013. Online.

DNA found in Europe does not match up with how the dispersion from Africa was originally thought to happen. The DNA found in Europe closely resembles the Denisovans rather than the neantdrathals who were thought to reside in Europe at the time. The Denisovans were thought to reside in the Siberian region. This DNA suggests there was more overlap between the two "subspecies" of humans than previous research had suggested.

3. Duval, Mathiau, Rainer Grun, and John Hellstrum. "The Challenge of Dating Early Pleistocene Fossil Teeth by the Combined Uranium Series–electron Spin Resonance Method: The Venta Micena Palaeontological Site (Orce, Spain)." Journal of Quaternary Science 26.6 (2011): 603-15.

This article discusses how exactly the teeth found in Orce, Spain were tested and an age estimate was calculated. The method used is called the Uranium Series-electron Spin Resonance Method (US-ESR). This test showed a large difference in age for the five teeth collected from two separate sites differed. The teeth collected at one site tested to be much older than the teeth at another. This could be due to the fact that the ESR testing is very sensitive, especially when dating such old teeth.

4.Moyano, Isidro Toro, Deborah Barsky, and Henry De Lumley. "The Archaic Stone Tool Industry from Barranco León and Fuente Nueva 3, (Orce, Spain): Evidence of the Earliest Hominin Presence in Southern Europe." Quaternary International 243.1 (2011): 80-91.

Prior to the discovery of the human fossil in southern europe, archeologists were excavating sites and finding growing evidence that human ancestors resided in the area before what was previously believed. Stone tools were found in the area that seemed to suggest that humans had been present in the area prior to 1 million years ago.

5. Palmqvist, Paul. "Presence of the African MachairodontMegantereon Whitei(Broom, 1937) (Felidae, Carnivora, Mammalia) in the Lower Pleistocene Site of Venta Micena (Orce, Granada, Spain), with Some Considerations on the Origin, Evolution and Dispersal of the Genus." Journal of Archeological Science 22.4 (1995): 569-82.

This journal discusses what is already known, thought orb known about early human diffusion throughout Europe and Asia. It also expresses the need for more research to be done on the topic so that more connections can be made about how different groups separated and evolved. Research on more than just the hominid species is needed to understand their environmental conditions and diet, and how these things shaped them.

Part 2: Katelyn Meakin

Wikipedia Project Part II

3 ways article could be improved: 1) Needs to discuss hominid movement from Africa in more detail

2) The article only mentions the possibility of denisovan mating with melanasians, new evidence shows that denisovan DNA has been found in parts of Europe too.

3) The article doesn’t needs to talk about how new evidence has found that hominid like bones have now been found in Western Europe (Spain) that show the movement of hominids from Africa to Europe was over double as long as Archeologists had previously thought.

Sentence and citation DNA discovered in Spain suggests that Denisovans at some point resided in Western Europe, where Neandrathals were thought to be the only inhabitants.

Page edited: https://en.wikipedia.org/wiki/Denisovan

FINAL DRAFT

Early Homonids and their Relatives in Europe

The approximate time in history for when our ancestors, homo sapiens, and their relatives, the Denisovans and Neanderthals, ventured from their previous lives in Africa together as one to throughout the world was thought to be understood. The spread of the different groups from Africa and the relative time of departure are being challenged in light of new evidence. This new evidence brings about new questions about how these groups lived together and thrived, and what led to the innevitable demise of all our other ancestral relatives, but somehow the homo sapiens pulled through. The movement from Africa to Europe is one of the most challenging things for some evolutionary biologists to put together due to this appearance of new evidence that proves old theories as incorrect. These new discoveries reveal the possibility that there may be even more extinct human populations yet to be discovered. The theory for the movement of humans to Europe from Africa is that three lines of human ancestors shared a common ancestor who resided in Africa until about 500,000 years ago. From Africa, the large group of the common ancestor was split. One of the smaller groups stayed in Africa, evolving over many thousands of years into modern human’s ancestor the homo sapien. The other group that had moved away to undiscovered parts of the world differentiated from the homo sapien group for about 200,000 years. Even further along, about 300,000 years ago, this exploratory, founder, group split again into what eventually evolved into the Neanderthals and the Denisovans. These changes from a single ancestral group to three subspecies demonstrates the effects that evolution takes over many thousands of year. The founder group that first left Africa was smaller that the group left behind in Africa. Because of this, the gene pool in the group was smaller, which would have made it a lot easier for certain originally less common alleles to fixed in the population. This also demonstrates the effects of all four methods of evolution; migration, mutation, natural selection, and genetic drift. These four modes of evolution are seen as the biggest reason why this once single group was able to split into three rather distinct subspecies. The migration from Africa to other parts of the world would have caused some alleles to become more popular in the new population and others to no longer exist just through random chance. Due to the chance fitness of these alleles, they could’ve become fixed in the population or disappeared completely. This is an example of genetic drift in which the allelic frequencies change between generations due to random chance. Mutation would have introduced new alleles into the population that had not existed before. Natural selection acts on these mutations by selecting for the ones that increase the organism’s fitness and ridding of deleterious mutant alleles. The Neanderthals are thought to have moved west into parts of Europe. The Denisovans, on the otherhand, were thought to have ventured east to parts of Siberia and Asia. There is a great deal of bones and DNA evidence that supports this theory was the case for these extinct lines of human relatives. That was until recently, when new evidence was found that challenged these hypotheses. Until recently, there were thought to only be two lines of ancient humans at the time of the arise of modern humans. These groups were the modern homonids and the Neanderthals. This theory held true for what was being discovered archeologically at the time. In 2010 an 80,000 year old finger bone fossil was discovered in Denisova cave in Siberia. From this finger bone the entire genome of the specimen was able to be sequenced. When this genome was looked at closer, scientists realized that it was not made up of either Neanderthal or homo sapien genes. This led scientists to question the possibility of a third human relative around the same time as the existence of the other previously recognized relatives. They named the new specimen a Denisovan, after the cave in which the finger bone was discovered. This discovery led scientists to think that there was a split in the group that ventured from Africa some 500,000 years ago. The estimated split was about 300,000 years ago, which would explain the great range of distance between the two separate groups. The thought that a whole subspecies of human relatives had been missed for so long brings about questions about how much more is out there, buried and undiscovered. It made the scientists question whether the actual history of hominids could ever be truly known as a concrete truth. This new hypothesis was challenged when even more evidence was discovered. In 2013, a pile of 400,000 year old bones was discovered in a cave in Spain. The bones were assumed to be that of early Neanderthals who were known to reside and diversify from the other subspecies in Europe. Scientists drilled into a thigh bone in attempt to collect the ancient DNA and sequence it. This sequence of DNA is the oldest to date, with the previous oldest being a mere 120,000 years old. What was discovered led to many new theories about how early hominids moved across the world. This new sequence of DNA was found to not be early Neanderthal, but more similar to that of the Denisovan DNA. This made archeologists questions what happened in early hominid evolution. The mitochondrial DNA found in one of the bones, a thighbone, was found to be more similar to that of the finger bone found in Siberia, Denisovan, than to Neanderthal DNA. Contrarily, the appearance of the bones was more similar to that of the Neanderthals. This led to questions as to whether the Denisovans and Neanderthals lived together in Europe for some time before splitting off and this bone was of a mix between the two, if the bones were from a common ancestral/ median group before evolutionary forces had more clearly subdivided the two, or if this could possibly be a different line altogether. Although the DNA discovered most similarly reflected that of the Denisovans of Siberia and Asia, the relationship wasn’t definitively close. The relationship between the two specimens (thighbone found in Spain and finger bone from Siberia) was about as similar as the relationship between modern humans and Neanderthals. This could be explained by the hundreds of thousands of years between the lives of the two creatures, or maybe something even more complicated. Scientists were led to believe that perhaps this was a different lineage altogether that preceeded the Denisovans, or that perhaps some sort of interbreeding occurred that would make this specimen more relate to Denisovans. What happened in this stage of human history where many distinct groups ventured around together is unknown. To better understand, more information in terms of fossils and DNA is needed. As more information is discovered, a better map for the actual migration of hominids throughout the world is able to be painted. Modern humans did not venture out of Africa until about 60,000 years ago. At this time, the relationship between modern humans and the other two lineages was pretty distinct, but not so distinct as that they were different species. The Biological Species concept defines a species as members of a population that actually or have the possibility of interbreeding in nature. Under these conditions, differences in appearance are not enough to define a species. The lineages cannot be considered different species under this concept, but subspecies of a single hominid species. This can be stated because modern humans are known to have interbred with the Denisovans in Asia and the Neanderthals in Europe. This is supported by DNA evidence. Scientists have discovered through DNA comparisons from modern humans that interbreeding occurred between our Homo Sapien ancestors, Neanderthals, and Denisovans. It was found that Asians share DNA with Denisovans. In particular, Melanesians, an island group in Papau New Guineau, share about three to five percent of their DNA with the Denisovans. Neanderthals also made their contribution into all of modern humans outside of Africa. About 2% of human DNA, other than in Africa, is due to interbreeding between humans and Neanderthals. This interbreeding between Neanderthals and humans is calculated to have happened about 50,000 to 60,000 years ago when modern humans were first moving from Africa. This leads scientists to believe that this mating between “relatives” occurred somewhere in the Middle East, before modern humans reached Asia and Europe. This is supported through DNA obtained from bones in Europe that are about 40,000 years old. These bones contain DNA more closely related to the Neanderthals, which allowed scientists to calculate that the Neanderthal DNA was introduced about 232-430 generations earlier. The reason why the other two lineages of humans are no longer thriving in today’s world brings up many different hypotheses. The Neanderthals and Denisovans had thrived throughout Europe and Asia for hundreds of thousands of years before Homo Sapiens had even made the venture to this land. Some hypotheses link the differences between the genomes of humans and our ancient relatives as the reason that we have survived into modern time. Scientists have found 23 marked known areas of the human genome that are not shared with either Neanderthals or Denisovans. Eight of these twenty– three sites are linked to the brain and its development. This poses questions as to whether Homo Sapiens have survived into modern times due to their brain. This would make sense for Homo Sapiens taking over due to higher fitness compared to the other lineages. For this scenario, Neanderthals and Denisovans just would not be able to compete for resources as well as the Homo Sapiens, and would eventually go extinct. Although the newly discovered evidence of a third human relative creates many questions, it also helps answer questions. Knowledge of how the subspecies differentiated through mutation, genetic drift, natural selection, and migration is very useful to understand how the evolution occurred to begin with. Because the 400,000 year old fossil found in Spain was the oldest genome so far to be sequenced, it still helps scientists better look at exactly how our ancestors moved from Africa and spread out around the world. This genome also helps scientists better identify when splits from a common ancestor and interbreeding occurred. It poses many questions, such as if there are more undiscovered missing links in the evolution of humans and their relatives. Scientists are in need of more evidence to make the newly found information better fit into the description of how we came to be, and why our relatives didn’t make it here with us.

Sources: 1.	Toro-Moyano, Isidro, Bienvenido Martínez-Navarro, Jordi Agustí, Caroline Souday, José María Bermúdez De Castro, María Martinón-Torres, Beatriz Fajardo, Mathieu Duval, Christophe Falguères, Oriol Oms, Josep Maria Parés, Pere Anadón, Ramón Julià, José Manuel García-Aguilar, Anne-Marie Moigne, María Patrocinio Espigares, Sergio Ros-Montoya, and Paul Palmqvist. The Oldest Human Fossil in Europe, from Orce (Spain).Journal of Human Evolution 65.1 (2013): 1-9. Online. 2.	Gruber, Karl. "Discovery of Oldest DNA Scrambles Human Origins Picture." National Geographic 4 Dec. 2013. Online. 3.	Duval, Mathiau, Rainer Grun, and John Hellstrum. "The Challenge of Dating Early Pleistocene Fossil Teeth by the Combined Uranium Series–electron Spin Resonance Method: The Venta Micena Palaeontological Site (Orce, Spain)." Journal of Quaternary Science 26.6 (2011): 603-15. 4.	Moyano, Isidro Toro, Deborah Barsky, and Henry De Lumley. "The Archaic Stone Tool Industry from Barranco León and Fuente Nueva 3, (Orce, Spain): Evidence of the Earliest Hominin Presence in Southern Europe." Quaternary International 243.1 (2011): 80-91. 5.	Palmqvist, Paul. "Presence of the African MachairodontMegantereon Whitei(Broom, 1937) (Felidae, Carnivora, Mammalia) in the Lower Pleistocene Site of Venta Micena (Orce, Granada, Spain), with Some Considerations on the Origin, Evolution and Dispersal of the Genus." Journal of Archeological Science 22.4 (1995): 569-82. 6.	Hirst, Kris. “When Did Early Modern Humans Get to Europe.” Archeology.about.com. (2013) 7.	Zimmer, Carl. “Baffling 400,000-Year-Old Clue to Human Orgins.” New York Times: Science. The New York Times Company. 4 December 2013. 8.	Matthias Meyer, Martin Kircher, Marie-Theres Gansauge, Heng Li, Fernando Racimo, Swapan Mallick, Joshua G. Schraiber, Flora Jay, Kay Prüfer, Cesare de Filippo, Peter H. Sudmant, Can Alkan, Qiaomei Fu, Ron Do, Nadin Rohland, Arti Tandon, Michael Siebauer, Richard E. Green, Katarzyna Bryc, Adrian W. Briggs, Udo Stenzel, Jesse Dabney, Jay Shendure, Jacob Kitzman, Michael F. Hammer, Michael V. Shunkov, Anatoli P. Derevianko, Nick Patterson, Aida M. Andrés, Evan E. Eichler, Montgomery Slatkin, David Reich, Janet Kelso, Svante Pääbo. “A High-Coverage Genome Sequence from an Archaic Denisovan Individual.” Science Magazine 6104 (2012): 222-226.

Editing to Page

Until recently, there were thought to be only two lineages of ancient humans at the time of the arise of modern humans. In 2010 though, a new group was discovered in Densisova cave, Siberia through the sequencing of DNA from an 80,000 year old finger bone. This DNA was compared to the genomes of both Neanderthals and Homo Sapiens. Through these comparisons, scientists were able to confirm that the genome was neither of the two and that there was a third human relative around at the same time. This new human relative was named a Denisovan after the cave of it's discovery. Comparison of the DNA of Neanderthals and Homo sapiens suggests that the Neanderthals diverged from a common ancestor around 500,000 years ago in Africa. The group that left Africa evolved on its own until about 300,000 years ago, when a second split is thought to have happened. The first group, who eventually evolved into Neanderthals, resided in modern day Europe while the second group, the Denisovans, resided in modern day Asia and Siberia. Modern day humans did not venture from Africa until about 60,000 years ago. Interbreeding between the Neanderthal and Homo Sapien lineages is thought to have happened somewhere in the middle east, not long after Homo Sapiens first left Africa. This is supported by DNA evidence from genomes sequenced of Homo Sapien bones about 40,000 years. From these bones, it is able to be calculated that Neanderthal DNA was introduced about 232- 430 generations earlier. Neanderthal DNA is still able to be seen in Homo Sapeins, as it accounts for about 2% of all non -Africans. The fact that these two groups were able to reproduce viable offspring leads scientists to believe that they are actually not two separate species, but instead two subspecies of a single hominid species. There is much debate over this particular part of human evolution as new evidence arises and changes what was previously thought to be known.

Page editied: https://en.wikipedia.org/wiki/Neanderthal In Origin section