Dean Falk | |
|---|---|
 Falk in 2017 | |
| Born | June 25, 1944 (age 79) |
| Nationality | American |
| Alma mater | University of Michigan |
| Occupation | Anthropologist |
| Organization | Florida State University |
Dean Falk (born June 25, 1944) is an American academic neuroanthropologist who specializes in the evolution of the brain and cognition in higher primates. She is the Hale G. Smith Professor of Anthropology and a Distinguished Research Professor at Florida State University.
As an undergraduate, Falk studied mathematics and anthropology. Since receiving her PhD from the University of Michigan in 1976, she has taught courses in anatomy, neuroanatomy, and anthropology. Falk is interested in the evolution of the brain and cognition. She formulated the “radiator theory” that cranial blood vessels were important for hominin brain evolution, and the “putting the baby down” hypothesis that prehistoric mothers and infants facilitated the emergence of language.
She and colleagues described the brain of Homo floresiensis ("Hobbit") in 2005. In 2013, Falk and colleagues described the cerebral cortex of Albert Einstein from recently emerged photographs of his whole brain. In 2017, Falk coauthored a study with Charles Hildebolt on warfare in small-scale and state societies, which found that people are no less violent today than they were in the past. Falk coauthored a 2018 book on Asperger's syndrome with her 24-year-old granddaughter who has Asperger's, [1] and, in 2019, published a refutation of the allegation that Hans Asperger was a Nazi sympathizer. This was in turn refuted by the original author, Herwig Czech, who opined that Falk's paper abounded "with mistranslations, misrepresentations of the content of sources, and basic factual errors, and omits everything that does not support the author’s agenda of defending Hans Asperger’s record." He declared that the paper should never have passed the peer review process and should be retracted. [2] Falk responded to Czech’s refutation point-by-point, enumerated numerous factual errors that it contained, and concluded that Czech’s “criticism of the anonymous peer reviewers of my paper (who were quite helpful) and his call for its retraction are, at best, unconstructive. Because of the xenophobic and racist prejudices that shape current political events in the United States, Europe, and elsewhere, it is essential that details about Nazism, including the Nazi euthanasia program, continue to be deliberated. I, for one, am grateful to JADD for publishing the present back-and-forth discussion, and I stand by my paper.” [3]
After the skeletal remains of a "Hobbit"-sized human (museum number LB1) that are now dated to over 65,000 years ago were discovered on the Indonesian island of Flores in 2003 they were identified as a new species labelled Homo floresiensis (“Hobbit”). Some scientists thought that the specimen must have been a pygmy or a microcephalic — a human with an abnormally small skull. Falk undertook a collaborative study in 2005 that described Hobbit's endocast and supported the claim that the find represented a new species.
Falk's 2005 study was criticized by other experts. [4] In response, in 2007 with an international team of experts, Falk compared detailed maps of imprints left on the ancient hominid's braincase (endocasts) with those from microcephalic individuals and concluded that LB1, indeed, represented a new species that may have been descended from either Homo erectus or an earlier small-bodied hominin. Falk's team have repeatedly asserted that their findings confirm that the species cataloged as LB1, Homo floresiensis, is definitely not a human born with microcephalia — a somewhat rare pathological condition that still occurs today. She has also participated in other studies that refute the idea that LB1 had Laron syndrome or Down syndrome. Today, most experts do not think that LB1 was a diseased human. As noted by Westaway et al. (MC Westaway et al. [2015]. Mandibular evidence supports Homo floresiensis as a distinct species. PNAS 112[7], E604-E605), "Many interesting questions about the Liang Bua fossils remain unanswered, but whether LB1 is a pathological H. sapiens is not one of them".
Falk led a team that described the entire cerebral cortex of Albert Einstein in 2013, [5] and collaborated with Weiwei Men et al. in analyzing his corpus callosum. [6]
In 2014, Dean Falk published her work on "Interpreting sulci on hominin endocasts: old hypotheses and new findings in Frontiers in Human Neuroscience". Her work summarized what paleoneurologists could potentially learn about human brain evolution from fossils, which is confined to information about the evolution of brain size and how limited parts of the cerebral cortex became reorganized during evolution. Falk noted that the cerebral cortex is a highly evolved part of the human brain and that it facilitates conscious thought, planning, language, social skills, and scientific, artistic, and musical creativity. The cerebral cortex may leave imprints in skulls which are sometimes reproduced on endocasts. Falk observed that these studies exclude the internal brain structures that cannot be described by paleoneurologists because they do not show up on endocasts. These parts of the brain also evolved, and they are extremely important for processing memories, gut-level feelings, and social interactions in ways that set humans apart from other animals.
In 2018, Falk and colleagues published an in vivo MRI study of the cerebral cortices of eight adult chimpanzees in which they identified sulcal patterns and compared them to those known from australopithecines and Homo naledi. This study showed that the frontal lobe sulcal patterns of australopiths (and H. naledi) were not derived compared to extant apes, contrary to Falk's 2014 paper.
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 via the tribe Hominini and subtribes Hominina and Panina. 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.
Homo rudolfensis is an extinct species of archaic human from the Early Pleistocene of East Africa about 2 million years ago (mya). Because H. rudolfensis coexisted with several other hominins, it is debated what specimens can be confidently assigned to this species beyond the lectotype skull KNM-ER 1470 and other partial skull aspects. No bodily remains are definitively assigned to H. rudolfensis. Consequently, both its generic classification and validity are debated without any wide consensus, with some recommending the species to actually belong to the genus Australopithecus as A. rudolfensis or Kenyanthropus as K. rudolfensis, or that it is synonymous with the contemporaneous and anatomically similar H. habilis.
Brodmann area 10 is the anterior-most portion of the prefrontal cortex in the human brain. BA10 was originally defined broadly in terms of its cytoarchitectonic traits as they were observed in the brains of cadavers, but because modern functional imaging cannot precisely identify these boundaries, the terms anterior prefrontal cortex, rostral prefrontal cortex and frontopolar prefrontal cortex are used to refer to the area in the most anterior part of the frontal cortex that approximately covers BA10—simply to emphasize the fact that BA10 does not include all parts of the prefrontal cortex.
The longitudinal fissure is the deep groove that separates the two cerebral hemispheres of the vertebrate brain. Lying within it is a continuation of the dura mater called the falx cerebri. The inner surfaces of the two hemispheres are convoluted by gyri and sulci just as is the outer surface of the brain.
Homo floresiensis( also known as "Flores Man") is an extinct species of small archaic human that inhabited the island of Flores, Indonesia, until the arrival of modern humans about 50,000 years ago.
The Taung Child is the fossilised skull of a young Australopithecus africanus. It was discovered in 1924 by quarrymen working for the Northern Lime Company in Taung, South Africa. Raymond Dart described it as a new species in the journal Nature in 1925.
Liang Bua is a limestone cave on the island of Flores, Indonesia, slightly north of the town of Ruteng in Manggarai Regency, East Nusa Tenggara. The cave demonstrated archaeological and paleontological potential in the 1950s and 1960s as described by the Dutch missionary and archaeologist Theodor L. Verhoeven.
Pachygyria is a congenital malformation of the cerebral hemisphere. It results in unusually thick convolutions of the cerebral cortex. Typically, children have developmental delay and seizures, the onset and severity depending on the severity of the cortical malformation. Infantile spasms are common in affected children, as is intractable epilepsy.
The brain of Albert Einstein has been a subject of much research and speculation. Albert Einstein's brain was removed within seven and a half hours of his death. His apparent regularities or irregularities in the brain have been used to support various ideas about correlations in neuroanatomy with general or mathematical intelligence. Studies have suggested an increased number of glial cells in Einstein's brain.
The size of the brain is a frequent topic of study within the fields of anatomy, biological anthropology, animal science and evolution. Brain size is sometimes measured by weight and sometimes by volume. Neuroimaging intelligence testing can be used to study the volumetric measurements of the brain. Regarding "intelligence testing", a question that has been frequently investigated is the relation of brain size to intelligence. This question is controversial and will be addressed further in the section on intelligence. The measure of brain size and cranial capacity is not just important to humans, but to all mammals.
In human brain anatomy, an operculum, may refer to the frontal, temporal, or parietal operculum, which together cover the insula as the opercula of insula. It can also refer to the occipital operculum, part of the occipital lobe.
In neuroanatomy, a sulcus is a depression or groove in the cerebral cortex. It surrounds a gyrus, creating the characteristic folded appearance of the brain in humans and other mammals. The larger sulci are usually called fissures.
The empathising–systemising (E–S) theory is a theory on the psychological basis of autism and male–female neurological differences originally put forward by English clinical psychologist Simon Baron-Cohen. It classifies individuals based on abilities in empathic thinking (E) and systematic thinking (S). It measures skills using an Empathy Quotient (EQ) and Systemising Quotient (SQ) and attempts to explain the social and communication symptoms in autism spectrum disorders as deficits and delays in empathy combined with intact or superior systemising.
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.
In brain anatomy, the lunate sulcus or simian sulcus, also known as the sulcus lunatus, is a fissure in the occipital lobe variably found in humans and more often larger when present in apes and monkeys. The lunate sulcus marks the transition between V1 and V2.
Paleoneurobiology is the study of brain evolution by analysis of brain endocasts to determine endocranial traits and volumes. Considered a subdivision of neuroscience, paleoneurobiology combines techniques from other fields of study including paleontology and archaeology. It reveals specific insight concerning human evolution. The cranium is unique in that it grows in response to the growth of brain tissue rather than genetic guidance, as is the case with bones that support movement. Fossil skulls and their endocasts can be compared to each other, to the skulls and fossils of recently deceased individuals, and even compared to those of other species to make inferences about functional anatomy, physiology and phylogeny. Paleoneurobiology is in large part influenced by developments in neuroscience as a whole; without substantial knowledge about current functionality, it would be impossible to make inferences about the functionality of ancient brains.
The evolution of nervous systems dates back to the first development of nervous systems in animals. Neurons developed as specialized electrical signaling cells in multicellular animals, adapting the mechanism of action potentials present in motile single-celled and colonial eukaryotes. Primitive systems, like those found in protists, use chemical signalling for movement and sensitivity; data suggests these were precursors to modern neural cell types and their synapses. When some animals started living a mobile lifestyle and eating larger food particles externally, they developed ciliated epithelia, contractile muscles and coordinating & sensitive neurons for it in their outer layer.
Professor Michael John Morwood was a New Zealand archaeologist best known for discovering Homo floresiensis. In 2012, he received the Rhys Jones Medal by the Australian Archaeological Association.
Homo naledi is an extinct species of archaic human discovered in 2013 in the Rising Star Cave, Cradle of Humankind, South Africa dating to the Middle Pleistocene 335,000–236,000 years ago. The initial discovery comprises 1,550 specimens, representing 737 different elements, and at least 15 different individuals. Despite this exceptionally high number of specimens, their classification with other Homo species remains unclear.
Mata Menge is an early Middle Pleistocene paleoanthropological site located in the Ola Bula Formation in the So'a Basin on the island of Flores, Indonesia. Lithic artefacts and hominin remains have been discovered at the site. The level of sophistication of the Mata Menge lithic artefacts is described as being 'simple'.
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