In 2005, a Turkish neuroscientist and evolutionary biologist named Dr. Uner Tan discovered a family with a very unique condition: five of them walk on all fours with a quadrupedal gait. In addition to quadrupedalism, affected individuals showed severe mental retardation and what he described as “primitive speech.” The presence of these three characteristic symptoms became known as Uner Tan Syndrome. The Ulas family was discovered in a small village near Iskenderun in southern Turkey. At the time of their identification, there were 12 normal children and 7 disabled children, one of whom died. Of the 6 remaining affected children, 5 of them displayed habitual quadrupedal walking. The Ulas family is highly consanguineous (second cousins), and neither of the founders possesses any of the symptoms. This suggested that the genetic basis for Uner Tan Syndrome is autosomal recessive (Harrison and Holt). One family in Brazil, and another in Iraq have also shown segregation for similar phenotypes to varying degrees of severity (Türkmen et al.; Ozcelik et al.).
Habitual bipedal gait, articulated language, and the ability form complex thoughts are characteristics that have long been thought to separate human beings from animals. When Dr. Tan initially described Uner Tan Syndrome, he claimed that the affected individuals were “genetic throwbacks.” He hypothesized that a single gene mutation would be found in this family could shed some light on human evolution, and the transition into bipedalism. Initially, the physical manifestations of the syndrome seemed to support this claim. The first hint was the fact that the affected individuals walked with what is described as a diagonal-sequence quadrupedal gait. This is an unusual foot...
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... Nicholas, John R. Skoyles, and Roger Keynes. Human Hand-Walkers: Five Siblings Who Never Stood up. London, UK: London School of Economics and Political Science, 2005. LSE Research Online.
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Ozcelik, T. et al. “Mutations in the Very Low-Density Lipoprotein Receptor VLDLR Cause Cerebellar Hypoplasia and Quadrupedal Locomotion in Humans.” Proceedings of the National Academy of Sciences 105.11 (2008): 4232–4236.
Türkmen, Seval et al. “CA8 Mutations Cause a Novel Syndrome Characterized by Ataxia and Mild Mental Retardation with Predisposition to Quadrupedal Gait.” Ed. Gregory S. Barsh. PLoS Genetics 5.5 (2009): e1000487.
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The evolution of man is constantly in question. While we are reasonably sure that modern humans and primates are both related to the same common ancestor, there is constant debate over what initially caused the two species to split into early hominids and apes. According to some, our longest and most popular theory on the division of man and ape is profoundly wrong. However, those same individuals usually offer an equally controversial theory as a substitute, one that is almost impossible to scientifically test or prove. Both the Savanna Theory and the Aquatic Ape Theory offer solutions to how and why humans evolved into bipedal toolmakers. But with enough questioning, each loses its accountability to rhetorical science.
Twin studies have been used to distinguish between genetic and environmental factors for many disorders in the general population including ectodermal dysplasia, Ellis-van Creveld, and anencephaly. This review focuses on genetic disorders affecting monozygotic, dizygotic, and conjoined twins to gain a better understanding of them. Many studies focus on twins because they have a nearly identical genome, which eliminates environmental factors. In case studies, the concordance rates in monozygotic twins have supported that certain disorders were caused by genetics and not the environment. The discordant values in twins will also be evaluated briefly. Twinning studies have also shown linkages between specific disorders and the genes responsible for them. Knowing the location of these genes allows patients to be treated quickly and efficiently. This paper will discuss the possible causes of twinning and the various methods of identifying abnormalities in twins. These methods also allow preventive measures against the rise of birth defects during prenatal development. Epigenetics in twins is also viewed through the perspective of effects on them. Treatments for genetic disorders in twins are reviewed, ranging from the restoration of malformed teeth to the separation of conjoined twins. Support groups for twins in treatment, and their families are also briefly reviewed.
The MECP2 gene makes a protein, also called MECP2, believed to play a pivotal role in silencing, turning off or regulating the activity of other genes. The MECP2 mutation (change in the gene) causes the turn-off/regulatory mechanism to fail, allowing other genes to function abnormally(Rett Syndrome - NORD). Rett syndrome is a genetic disorder of developmental failure of brain maturation. This is thought to occur when subsets of neurons and their connections are disrupted during a dynamic phase of brain development. This deviation occurs at the end of pregnancy or in the first few months of life during the critical phases of synapse development. How mutations in MeCP2 lead to Retts is not well understood but is the focus of intense research.
If you were to live during the tertiary period, this would be one of the things you would often see. All of the mammals that existed during that time period were terrestrial. They all were land dwelling mammals. Before J. G. M. Thewissen and colleagues’ discovery in Pakistan, many scientists believed, since the constant new discoveries twenty years ago, in what the numerous fossils from North America, Pakistan, and Egypt have revealed, “…these early cetaceans had mobile elbows and external hind limbs with articulated knees. However, they were fully aquatic, except for Ambulocetus, which was amphibious-much like sea lions” (Walking with Whales).
Lunn, J.S., Sakowski, S,A., Kim, B., Rosenberg, A.A., Feldman, E.L. (2009). Vascular endothelial growth factor prevents G93A-SOD1 induced motor neuron degeneration. Dev Neurobiology 69, 871-884
The disease is found in a mutation on the HEXA gene. The HEXA gene makes beta-Hexosaminidase A, an enzyme that is necessary for proper spinal cord and brain development. This works to break down GM2 ganglioside, a fatty substance. When a mutation occurs here, the GM2 ganglioside can’t be broken down, accumulating to harmful levels in neurons of the brain and spinal cord, which results in the damaging symptoms of the disease.
Bipedalism is a unique attribute of hominids and is pivotal in human evolution. There exist several Hypotheses of Bipedalism. Four hypotheses that are explored are Locomotion Efficiency (Long Distance Travel), Thermoregulation (Cooling), Freeing the Hands, and Visual Surveillance. A summary of each hypotheses’ main points and applied relevancy of each, postulating the locomotion theory as the best of the four hypothesizes.
Bipedalism had many advantages, but it also had many disadvantages and provided dangers to early hominids. Some of these disadvantages included i...
Bindon, Jim 2004 Fossil Hominids. ANT 270 Notes. http://www.as.ua.edu/ant/bindon/ant270/lectures/ hominids1.pdf Delson, Eric 1981
Bipedalism is anatomically important because it now demonstrates to us modern day humans the cycle of how we came to be. This skill was vital to human evolution because it differentiates early hominins from apes. By being able to walk further distances, they brought them to a diverse new diet that enabled their brains to get bigger. Bipedal animals usually walk greater distances because less energy is needed with their longer strides. The stone stools show evidence of abstract thinking and it shows the early hominins adapting and using their environment to survive, which is a skill that we as modern humans have surpassed.
"Down syndrome." South African Medical Journal 101.1 (2011): 6. Health Reference Center Academic. Web. 16 Apr. 2014.
One of the most important and pivotal physical and biological adaptations that separate humans from other mammals is habitual bipedalism. According to Darwin, as restated by Daniel Lieberman, “It was bipedalism rather than big brains, language, or tool use that first set th...
Hopkins, W. D., et al. "Handedness For Tool Use In Captive Chimpanzees (Pan Troglodytes): Sex Differences, Performance, Heritability And Comparison To The Wild." Behaviour 146.11 (2009): 1463. Publisher Provided Full Text Searching File. Web. 16 Apr. 2014.
Most individuals are either related to or know someone who is effected by some type of disability. Many of these disabilities are caused by genetic disorders. Genetic disorders may alter physical appearance and cause mild to severe mental retardation. Fragile X syndrome, Down syndrome, Turners syndrome and many other syndromes result from a mutation of a chromosome, an extra chromosome, or too few chromosomes.