Related Research Articles
Homininae, also called "African hominids" or "African apes", is a subfamily of Hominidae. It includes two tribes, with their extant as well as extinct species: 1) the tribe Hominini ―and 2) the tribe Gorillini (gorillas). Alternatively, the genus Pan is sometimes considered to belong to its own third tribe, Panini. Homininae comprises all hominids that arose after orangutans split from the line of great apes. The Homininae cladogram has three main branches, which lead to gorillas and to humans and chimpanzees. There are two living species of Panina and two living species of gorillas, but only one extant human species. Traces of extinct Homo species, including Homo floresiensis have been found with dates as recent as 40,000 years ago. Organisms in this subfamily are described as hominine or hominines.
Genomic imprinting is an epigenetic phenomenon that causes genes to be expressed or not, depending on whether they are inherited from the female or male parent. Genes can also be partially imprinted. Partial imprinting occurs when alleles from both parents are differently expressed rather than complete expression and complete suppression of one parent's allele. Forms of genomic imprinting have been demonstrated in fungi, plants and animals. In 2014, there were about 150 imprinted genes known in mice and about half that in humans. As of 2019, 260 imprinted genes have been reported in mice and 228 in humans.
Early modern human (EMH), or anatomically modern human (AMH), are terms used to distinguish Homo sapiens that are anatomically consistent with the range of phenotypes seen in contemporary humans, from extinct archaic human species. This distinction is useful especially for times and regions where anatomically modern and archaic humans co-existed, for example, in Paleolithic Europe. Among the oldest known remains of Homo sapiens are those found at the Omo-Kibish I archaeological site in south-western Ethiopia, dating to about 233,000 to 196,000 years ago, the Florisbad site in South Africa, dating to about 259,000 years ago, and the Jebel Irhoud site in Morocco, dated about 315,000 years ago.
Microcephaly is a medical condition involving a smaller-than-normal head. Microcephaly may be present at birth or it may develop in the first few years of life. Brain development is often affected; people with this disorder often have an intellectual disability, poor motor function, poor speech, abnormal facial features, seizures and dwarfism.
Abnormal spindle-like microcephaly-associated protein, also known as abnormal spindle protein homolog or Asp homolog, is a protein that in humans is encoded by the ASPM gene. ASPM is located on chromosome 1, band q31 (1q31). The ASPM gene contains 28 exons and codes for a 3477 amino‐acid‐long protein. The ASPM protein is conserved across species including human, mouse, Drosophila, and C. elegans. Defective forms of the ASPM gene are associated with autosomal recessive primary microcephaly.
The indigenous peoples of Western New Guinea in Indonesia and Papua New Guinea, commonly called Papuans, are Melanesians. There is genetic evidence for two major historical lineages in New Guinea and neighboring islands: a first wave from the Malay Archipelago perhaps 50,000 years ago when New Guinea and Australia were a single landmass called Sahul and, much later, a wave of Austronesian people from the north who introduced Austronesian languages and pigs about 3,500 years ago. They also left a small but significant genetic trace in many coastal Papuan peoples.
David C. Page is an American biologist and professor at the Massachusetts Institute of Technology (MIT), the director of the Whitehead Institute, and a Howard Hughes Medical Institute (HHMI) investigator. He is best known for his work on mapping the Y-chromosome and on its evolution in mammals and expression during development. He was cited by Bryan Sykes in Adam's Curse: A Future Without Men.
Microcephalin (MCPH1) is a gene that is expressed during fetal brain development. Certain mutations in MCPH1, when homozygous, cause primary microcephaly—a severely diminished brain. Hence, it has been assumed that variants have a role in brain development. However, in normal individuals no effect on mental ability or behavior has yet been demonstrated in either this or another similarly studied microcephaly gene, ASPM. However, an association has been established between normal variation in brain structure, as measured with MRI but only in females, and common genetic variants within both the MCPH1 gene and another similarly studied microcephaly gene, CDK5RAP2.
Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Introgression is a long-term process, even when artificial; it may take many hybrid generations before significant backcrossing occurs. This process is distinct from most forms of gene flow in that it occurs between two populations of different species, rather than two populations of the same species.
The size of the brain is a frequent topic of study within the fields of anatomy, biological anthropology, animal science and evolution. Measuring brain size and cranial capacity is relevant both to humans and other animals, and can be done by weight or volume via MRI scans, by skull volume, or by neuroimaging intelligence testing. The relationship between brain size and intelligence remains a controversial although frequently investigated question.
Human evolutionary genetics studies how one human genome differs from another human genome, the evolutionary past that gave rise to the human genome, and its current effects. Differences between genomes have anthropological, medical, historical and forensic implications and applications. Genetic data can provide important insights into human evolution.
Feldhofer 1 or Neanderthal 1 is the scientific name of the 40,000-year-old type specimen fossil of the species Homo neanderthalensis, discovered in August 1856 in a German cave, the Kleine Feldhofer Grotte, in the Neandertal valley, 13 km (8.1 mi) east of Düsseldorf. In 1864, the fossil's description was first published in a scientific magazine and officially named. Neanderthal was not the first Neanderthal fossil discovery. Other Neanderthal fossils had been discovered earlier, but their true nature and significance had not been recognized, and, therefore, no separate species name was assigned.
There is much to be discovered about the evolution of the brain and the principles that govern it. While much has been discovered, not everything currently known is well understood. The evolution of the brain has appeared to exhibit diverging adaptations within taxonomic classes such as Mammalia and more vastly diverse adaptations across other taxonomic classes. Brain to body size scales allometrically. This means as body size changes, so do other physiological, anatomical, and biochemical constructs connecting the brain to the body. Small bodied mammals have relatively large brains compared to their bodies whereas large mammals have a smaller brain to body ratios. If brain weight is plotted against body weight for primates, the regression line of the sample points can indicate the brain power of a primate species. Lemurs for example fall below this line which means that for a primate of equivalent size, we would expect a larger brain size. Humans lie well above the line indicating that humans are more encephalized than lemurs. In fact, humans are more encephalized compared to all other primates. This means that human brains have exhibited a larger evolutionary increase in its complexity relative to its size. Some of these evolutionary changes have been found to be linked to multiple genetic factors, such as proteins and other organelles.
The 10,000 Year Explosion: How Civilization Accelerated Human Evolution is a 2009 book by anthropologists Gregory Cochran and Henry Harpending. Starting with their own take on the conventional wisdom that the evolutionary process stopped when modern humans appeared, the authors explain the genetic basis of their view that human evolution is accelerating, illustrating it with some examples.
The multiregional hypothesis, multiregional evolution (MRE), or polycentric hypothesis, is a scientific model that provides an alternative explanation to the more widely accepted "Out of Africa" model of monogenesis for the pattern of human evolution.
The Denisovans or Denisova hominins(di-NEE-sə-və) are an extinct species or subspecies of archaic human that ranged across Asia during the Lower and Middle Paleolithic, and lived, based on current evidence, from 285 to 25 thousand years ago. Denisovans are known from few physical remains; consequently, most of what is known about them comes from DNA evidence. No formal species name has been established pending more complete fossil material.
Neanderthals are an extinct group of archaic humans who lived in Eurasia until about 40,000 years ago. The type specimen, Neanderthal 1, was found in 1856 in the Neander Valley in present-day Germany.
Interbreeding between archaic and modern humans occurred during the Middle Paleolithic and early Upper Paleolithic. The interbreeding happened in several independent events that included Neanderthals and Denisovans, as well as several unidentified hominins.
Recent human evolution refers to evolutionary adaptation, sexual and natural selection, and genetic drift within Homo sapiens populations, since their separation and dispersal in the Middle Paleolithic about 50,000 years ago. Contrary to popular belief, not only are humans still evolving, their evolution since the dawn of agriculture is faster than ever before. It has been proposed that human culture acts as a selective force in human evolution and has accelerated it; however, this is disputed. With a sufficiently large data set and modern research methods, scientists can study the changes in the frequency of an allele occurring in a tiny subset of the population over a single lifetime, the shortest meaningful time scale in evolution. Comparing a given gene with that of other species enables geneticists to determine whether it is rapidly evolving in humans alone. For example, while human DNA is on average 98% identical to chimp DNA, the so-called Human Accelerated Region 1 (HAR1), involved in the development of the brain, is only 85% similar.
Genetic studies on Neanderthal ancient DNA became possible in the late 1990s. The Neanderthal genome project, established in 2006, presented the first fully sequenced Neanderthal genome in 2013.
References
- 1 2 Hopkin, Karen (29 August 2005). "Rebel with a Lab". The Scientist. Retrieved 27 February 2018.
- ↑ "VectorBuilder and Landau enter into strategic partnership to establish world's first primate gene therapy R&D center". The Scientist. 15 October 2021. Retrieved 23 June 2022.
- ↑ Technology Review Bio. (biography) 2013, "MIT Technology Review."
- ↑ Searle Scholars Bio. Archived 2015-01-13 at the Wayback Machine (biography) 2009, "Searle Scholars."
- ↑ UChicago News Profile. (biography) 2015, "UChicago News".
- ↑ HHMI Investigator Alumni Bio. (biography) 2015, "HHMI".
- 1 2 Lahn's Lab Website Archived May 13, 2010, at the Wayback Machine
- 1 2 Could interbreeding between humans and Neanderthals have led to an enhanced human brain? Howard Hughes Medical Institute, November 6, 2006
- ↑ Lahn's analysis of genes indicates human brain continues to evolve
- ↑ Scientist's Study Of Brain Genes Sparks a Backlash. June 16, 2006. Wall Street Journal. Accessed 2015-04-07.
- ↑ Lahn, Bruce T.; Ebenstein, Lanny (8 October 2009). "Let's celebrate human genetic diversity". Nature. 461 (7265): 726–728. Bibcode:2009Natur.461..726L. doi:10.1038/461726a. PMID 19812654. S2CID 205050141.
- ↑ Mekel-Bobrov N, Posthuma D, Gilbert SL, Lind P, Gosso MF, Luciano M, et al. (March 2007). "The ongoing adaptive evolution of ASPM and Microcephalin is not explained by increased intelligence" (PDF). Human Molecular Genetics. 16 (6): 600–8. doi: 10.1093/hmg/ddl487 . PMID 17220170.
- ↑ Timpson N, Heron J, Smith GD, Enard W (August 2007). "Comment on papers by Evans et al. and Mekel-Bobrov et al. on Evidence for Positive Selection of MCPH1 and ASPM". Science. 317 (5841): 1036, author reply 1036. Bibcode:2007Sci...317.1036T. doi:10.1126/science.1141705. PMID 17717170.
- ↑ Rushton JP, Vernon PA, Bons TA (April 2007). "No evidence that polymorphisms of brain regulator genes Microcephalin and ASPM are associated with general mental ability, head circumference or altruism". Biology Letters. 3 (2): 157–60. doi:10.1098/rsbl.2006.0586. PMC 2104484 . PMID 17251122.
- ↑ Pennisi E (February 2009). "Neandertal genomics. Tales of a prehistoric human genome". Science. 323 (5916): 866–71. doi:10.1126/science.323.5916.866. PMID 19213888. S2CID 206584252.
- ↑ Green RE, Krause J, Briggs AW, Maricic T, Stenzel U, Kircher M, et al. (May 2010). "A draft sequence of the Neandertal genome". Science. 328 (5979): 710–722. Bibcode:2010Sci...328..710G. doi:10.1126/science.1188021. PMC 5100745 . PMID 20448178.
- ↑ Chen, Fei; Cai, Bing; Gao, Yong; Yuan, Xiaofeng; Cheng, Fuyi; Wang, Tao; Jiang, Meihua; Zhou, Yijia; Lahn, Bruce T.; Li, Weiqiang; Xiang, Andy Peng (February 2013). "Suicide gene-mediated ablation of tumor-initiating mouse pluripotent stem cells". Biomaterials. 34 (6): 1701–1711. doi:10.1016/j.biomaterials.2012.11.018. PMID 23218839.
- ↑ Jiang, Mei Hua; Cai, Bing; Tuo, Ying; Wang, Jiancheng; Zang, Zhi Jun; Tu, Xiang'an; Gao, Yong; Su, Zhijian; Li, Weiqiang; Li, Guilan; Zhang, Min; Jiao, Jianwei; Wan, Zi; Deng, Chunhua; Lahn, Bruce T; Xiang, Andy Peng (21 November 2014). "Characterization of Nestin-positive stem Leydig cells as a potential source for the treatment of testicular Leydig cell dysfunction". Cell Research. 24 (12): 1466–1485. doi:10.1038/cr.2014.149. PMC 4260348 . PMID 25418539.