Tag Archives: #face

International Team Identifies Genetic Link Between Face and Brain Shape (Neuroscience)

An interdisciplinary team led by KU Leuven and Stanford has identified 76 overlapping genetic locations that shape both our face and our brain. What the researchers didn’t find is evidence that this genetic overlap also predicts someone’s behavioural-cognitive traits or risk of conditions such as Alzheimer’s disease. This means that the findings help to debunk several persistent pseudoscientific claims about what our face reveals about us.

There were already indications of a genetic link between the shape of our face and that of our brain, says Professor Peter Claes from the Laboratory for Imaging Genetics at KU Leuven, who is the joint senior author of the study with Professor Joanna Wysocka from the Stanford University School of Medicine. “But our knowledge on this link was based on model organism research and clinical knowledge of extremely rare conditions,” Claes continues. “We set out to map the genetic link between individuals’ face and brain shape much more broadly, and for commonly occurring genetic variation in the larger, non-clinical population.”

Brain scans and DNA from the UK Biobank

To study genetic underpinnings of brain shape, the team applied a methodology that Peter Claes and his colleagues had already used in the past to identify genes that determine the shape of our face. Claes: “In these previous studies, we analysed 3D images of faces and linked several data points on these faces to genetic information to find correlations.” This way, the researchers were able to identify various genes that shape our face.

For the current study, the team relied on these previously acquired insights as well as the data available in the UK Biobank, a database from which they used the MRI brain scans and genetic information of 20,000 individuals. Claes: “To be able to analyse the MRI scans, we had to measure the brains shown on the scans. Our specific focus was on variations in the folded external surface of the brain – the typical ‘walnut shape’. We then went on to link the data from the image analyses to the available genetic information. This way, we identified 472 genomic locations that have an impact on the shape of our brain. 351 of these locations have never been reported before. To our surprise, we found that as many as 76 genomic locations predictive of the brain shape had previously already been found to be linked to the face shape. This makes the genetic link between face and brain shape a convincing one.”

The team also found evidence that genetic signals that influence both brain and face shape are enriched in the regions of the genome that regulate gene activity during embryogenesis, either in facial progenitor cells or in the developing brain. This makes sense, Wysocka explains, as the development of the brain and the face are coordinated. “But we did not expect that this developmental cross-talk would be so genetically complex and would have such a broad impact on human variation.”

No genetic link with behaviour or neuropsychiatric disorders

At least as important is what the researchers did not find, says Dr Sahin Naqvi from the Stanford University School of Medicine, who is the first author of this study. “We found a clear genetic link between someone’s face and their brain shape, but this overlap is almost completely unrelated to that individual’s behavioural-cognitive traits.”

Concretely: even with advanced technologies, it is impossible to predict someone’s behaviour based on their facial features. Peter Claes continues: “Our results confirm that there is no genetic evidence for a link between someone’s face and that individual’s behaviour. Therefore, we explicitly dissociate ourselves from pseudoscientific claims to the contrary. For instance, some people claim that they can detect aggressive tendencies in faces by means of artificial intelligence. Not only are such projects completely unethical, they also lack a scientific foundation.”

In their study, the authors also briefly address conditions such as Alzheimer’s, schizophrenia, and bipolar disorder. Claes: “As a starting point, we used the results that were previously published by other teams about the genetic basis of such neuropsychiatric disorders. The possible link with the genes that determine the shape of our face had never been examined before. If you compare existing findings with our new ones, you see a relatively large overlap between the genetic variants that contribute to specific neuropsychiatric disorders and those that play a role in the shape of our brain, but not for those that contribute to our face.” In other words: our risk of developing a neuropsychiatric disorder is not written on our face either.

This research is a collaboration between KU Leuven, Stanford University School of Medicine, University of Pittsburgh, Pennsylvania State University, Indiana University Purdue University Indianapolis, Cardiff University, and George Mason University.

Featured image credit: Public domain


Reference: Naqvi, S., Sleyp, Y., Hoskens, H. et al. Shared heritability of human face and brain shape. Nat Genet (2021). https://www.nature.com/articles/s41588-021-00827-w https://doi.org/10.1038/s41588-021-00827-w


Provided by KU Leuven

New Genetic Comparison Technique Enables Meticulous Study of Evolution of the Human Brain and Face (Biology)

In separate studies, researchers compared gene regulation related to brain and face development in humans and chimpanzees using a new technique. In both cases, they discovered new genetic differences between these species.

One of the best ways to study human evolution is by comparing us with nonhuman species that, evolutionarily speaking, are closely related to us. That closeness can help scientists narrow down precisely what makes us human, but that scope is so narrow it can also be extremely hard to define. To address this complication, researchers from Stanford University have developed a new technique for comparing genetic differences.

Through two separate sets of experiments with this technique, the researchers discovered new genetic differences between humans and chimpanzees. They found a significant disparity in the expression of the gene SSTR2 – which modulates the activity of neurons in the cerebral cortex and has been linked, in humans, to certain neuropsychiatric diseases such as Alzheimer’s dementia and schizophrenia – and the gene EVC2, which is related to facial shape. The results were published March 17 in Nature and Nature Genetics, respectively.

“It’s important to study human evolution, not only to understand where we came from, but also why humans get so many diseases that aren’t seen in other species,” said Rachel Agoglia, a recent Stanford genetics graduate student who is lead author of the Nature paper.

The Nature paper details the new technique, which involves fusing human and chimpanzee skin cells that had been modified to act like stem cells – highly malleable cells that can be prodded to transform into a variety of other cell types (albeit not a full organism).

“These cells serve a very important specific purpose in this type of study by allowing us to precisely compare human and chimpanzee genes and their activities side-by-side,” said Hunter Fraser, associate professor of biology at Stanford’s School of Humanities and Sciences. Fraser is senior author of the Nature Genetics paper and co-senior author of the Nature paper with Sergiu Pașca, associate professor of psychiatry and behavioral sciences in the Stanford School of Medicine.

Close comparisons

The Fraser lab is particularly interested in how the genetics of humans and other primates compare at the level of cis-regulatory elements, which affect the expression of nearby genes (located on the same DNA molecule, or chromosome). The alternative – called trans-regulatory factors – can regulate the expression of distant genes on other chromosomes elsewhere in the genome. Due to their broad effects, trans-regulatory factors (such as proteins) are less likely to differ among closely related species than cis-regulatory elements.

But even when scientists have access to similar cells from humans and chimpanzees, there is a risk of confounding factors. For example, differences in the timing of development between species is a significant hurdle in studying brain development, explained Pașca. This is because human brains and chimpanzee brains develop at very different rates and there is no exact way to directly compare them. By housing human and chimpanzee DNA within the same cellular nucleus, scientists can exclude most confounding factors.

For the initial experiments using these cells, Agoglia coaxed the cells into forming so-called cortical spheroids or organoids – a bundle of brain cells that closely mimics a developing mammalian cerebral cortex. The Pașca lab has been at the forefront of developing brain organoids and assembloids for the purpose of researching how the human brain is assembled and how this process goes awry in disease.

“The human brain is essentially inaccessible at the molecular and cellular level for most of its development, so we introduced cortical spheroids to help us gain access to these important processes,” said Pașca, who is also the Bonnie Uytengsu and Family Director of Stanford Brain Organogenesis.

As the 3D clusters of brain cells develop and mature in a dish, their genetic activity mimics what happens in early neurodevelopment in each species. Because the human and chimpanzee DNA are bound together in the same cellular environment, they are exposed to the same conditions and mature in parallel. Therefore, any observed differences in the genetic activity of the two can reasonably be attributed to actual genetic differences between our two species.

Through studying brain organoids derived from the fused cells that were grown for 200 days, the researchers found thousands of genes that showed cis-regulatory differences between species. They decided to further investigate one of these genes – SSTR2 – which was more strongly expressed in human neurons and functions as a receptor for a neurotransmitter called somatostatin. In subsequent comparisons between human and chimpanzee cells, the researchers confirmed this elevated protein expression of SSTR2 in human cortical cells. Further, when the researchers exposed the chimpanzee cells and human cells to a small molecule drug that binds to SSTR2, they found that human neurons responded much more to the drug than the chimpanzee cells.

This suggests a way by which the activity of human neurons in cortical circuits can be modified by neurotransmitters. Interestingly, this neuromodulatory activity may also be related to disease since SSTR2 has been shown to be involved in brain disease.

“Evolution of the primate brain may have involved adding sophisticated neuromodulatory features to neural circuits, which under certain conditions can be perturbed and increase susceptibility to neuropsychiatric disease,” said Pașca.

Fraser said these results are essentially “a proof of concept that the activity we’re seeing in these fused cells is actually relevant for cellular physiology.”

Investigating extreme differences

For the experiments published in Nature Genetics, the team coaxed their fused cells into cranial neural crest cells, which give rise to bones and cartilage in the skull and face, and determine facial appearance.

“We were interested in these types of cells because facial differences are considered some of the most extreme anatomical differences between humans and chimps – and these differences actually affect other aspects of our behavior and evolution, like feeding, our senses, brain expansion and speech,” said David Gokhman, a postdoctoral scholar in the Fraser lab and lead author of the Nature Genetics paper. “Also, the most common congenital diseases in humans are related to facial structure.”

In the fused cells, the researchers identified a gene expression pathway that is much more active in the chimpanzee genes of the cells than in the human genes – with one specific gene, called EVC2, appearing to be six times more active in chimpanzees. Existing research has shown that people who have inactive EVC2 genes have flatter faces than others, suggesting that this gene could explain why humans have flatter faces than other primates.

What’s more, the researchers determined that 25 observable facial features associated with inactive EVC2 are noticeably different between humans and chimpanzees – and 23 of those are different in the direction the researchers would have predicted, given lower EVC2 activity in humans. In follow-up experiments, where the researchers reduced the activity of EVC2 in mice, the rodents, too, developed flatter faces.

Another tool in the toolbox

This new experimental platform is not intended to replace existing cell comparison studies, but the researchers hope it will support many new findings about human evolution, and evolution in general.

“Human development and the human genome have been very well studied,” said Fraser. “My lab is very interested in human evolution, but, because we can build on such a wealth of knowledge, this work can also reveal new insights into the process of evolution more broadly.”

Looking forward, the Fraser lab is working on differentiating the fused cells into other cell types, such as muscle cells, other types of neurons, skin cells and cartilage to expand their studies of uniquely human traits. The Pașca lab, meanwhile, is interested in investigating genetic dissimilarities related to astrocytes – large, multi-functional cells in the central nervous system often overlooked by scientists in favor of the flashier neurons.

“While people often think about how neurons have evolved, we should not underestimate how astrocytes have changed during evolution. The size difference alone, between human astrocytes and astrocytes in other primates, is massive,” said Pașca. “My mentor, the late Ben Barres, called astrocytes ‘the basis of humanity’ and we absolutely think he was onto something.”

Additional Stanford co-authors for the Nature paper are former research assistant Danqiong Sun, postdoctoral scholar Fikri Birey, senior research scientist Se-Jin Yoon, postdoctoral scholar Yuki Miura and former research associate Karen Sabatini.

This work was funded by a Stanford Bio-X Interdisciplinary Initiatives Seed Grant, the National Institutes of Health, the Department of Defense, the Stanford Center for Computational, Evolutionary and Human Genomics, the Stanford Medicine’s Dean’s Fellowship, MCHRI, the American Epilepsy Society, the Stanford Wu Tsai Neurosciences Institute’s Big Idea Grants on Brain Rejuvenation and Human Brain Organogenesis, the Kwan Research Fund, the New York Stem Cell Robertson Investigator Award, and the Chan Zuckerberg Ben Barres Investigator Award.

Additional Stanford co-authors for the Nature Genetics paper are graduate student Maia Kinnebrew; former undergraduate Wei Gordon; former technician Danqiong Sun; postdoctoral research fellows Vivek Bajpai and Sahin Naqvi; Dmitri Petrov, the Michelle and Kevin Douglas Professor in the School of Humanities and Sciences; Joanna Wysocka, the Lorry Lokey Professor and professor of developmental biology; and Rajat Rohatgi, associate professor of biochemistry and of medicine. Researchers from University of California, San Francisco; University of Michigan, Ann Arbor; Yerkes National Primate Research Center; Emory University School of Medicine; and University of Pennsylvania are also co-authors.

This work was funded by the Human Frontier, Rothschild and Zuckerman fellowships, and the National Institutes of Health.

Featured image: An image, from previous research, of human cortical spheroids derived in the lab of Sergiu Pașca, associate professor of psychiatry and behavioral sciences. (Image credit: Timothy Archibald)


Reference: (1) Agoglia, R.M., Sun, D., Birey, F. et al. Primate cell fusion disentangles gene regulatory divergence in neurodevelopment. Nature (2021). https://doi.org/10.1038/s41586-021-03343-3 (2) Gokhman, D., Agoglia, R.M., Kinnebrew, M. et al. Human–chimpanzee fused cells reveal cis-regulatory divergence underlying skeletal evolution. Nat Genet (2021). https://doi.org/10.1038/s41588-021-00804-3


Provided by Stanford University

Genes for Face Shape Identified (Biology)

Study identifies thirty-two gene regions, including nine novel gene regions, associated with facial features including the shape of the face, lips, and nose.

Genes that determine the shape of a person’s facial profile have been discovered by a UCL-led research team.

The researchers identified 32 gene regions that influenced facial features such as nose, lip, jaw, and brow shape, nine of which were entirely new discoveries while the others validated genes with prior limited evidence.

The analysis of data from more than 6,000 volunteers across Latin America was published today in Science Advances.

The international research team, led from UCL, Aix-Marseille University and The Open University, found that one of the genes appears to have been inherited from the Denisovans, an extinct group of ancient humans who lived tens of thousands of years ago.

The team found that the gene, TBX15, which contributes to lip shape, was linked with genetic data found in the Denisovan people, providing a clue to the gene’s origin. The Denisovans lived in central Asia, and other studies suggest they interbred with modern humans, as some of their DNA lives on in Pacific Islanders and Indigenous people of the Americas.

Co-corresponding author Dr Kaustubh Adhikari (UCL Genetics, Evolution & Environment and The Open University) said: “The face shape genes we found may have been the product of evolution as ancient humans evolved to adapt to their environments. Possibly, the version of the gene determining lip shape that was present in the Denisovans could have helped in body fat distribution to make them better suited to the cold climates of Central Asia, and was passed on to modern humans when the two groups met and interbred.”

Co-first author Dr Pierre Faux (Aix-Marseille University) said: “To our knowledge this is the first time that a version of a gene inherited from ancient humans is associated with a facial feature in modern humans. In this case, it was only possible because we moved beyond Eurocentric research; modern-day Europeans do not carry any DNA from the Denisovans, but Native Americans do.”

Co-first author Betty Bonfante (Aix-Marseille University) added: “It is one of only a few studies looking for genes affecting the face in a non-European population, and the first one to focus on the profile only.”

Researchers have only been able to analyse complex genetic data from thousands of people at once over the last two decades, since the mapping of the human genome enabled the use of genome-wide association studies to find correlations between traits and genes. This study compared genetic information from the study participants with characteristics of their face shape, quantified with 59 measurements (distances, angles and ratios between set points) from photos of the participants’ faces in profile.

Co-corresponding author Professor Andres Ruiz-Linares (Fudan University, UCL Genetics, Evolution & Environment, and Aix-Marseille University) said: “Research like this can provide basic biomedical insights and help us understand how humans evolved.”

The findings of this research could help understand the developmental processes that determine facial features, which will help researchers studying genetic disorders that lead to facial abnormalities.

The results also contribute to the understanding of the evolution of facial appearance in human and other species. One of the newly discovered genes found in this study is VPS13B, which influenced nose pointiness; the researchers also found that this gene affects nose structure in mice, indicating a broadly shared genetic basis among distantly related mammal species.

Featured image: The researchers identified 32 gene regions that influenced facial features such as nose, lip, jaw, and brow shape, nine of which were entirely new discoveries while the others validated genes with prior limited evidence. Image is in the public domain


Reference: Betty Bonfante, Pierre Faux, Nicolas Navarro, Javier Mendoza-Revilla, Morgane Dubied, Charlotte Montillot, Emma Wentworth, Lauriane Poloni, Ceferino Varón-González, Philip Jones, Ziyi Xiong, Macarena Fuentes-Guajardo, Sagnik Palmal, Juan Camilo Chacón-Duque, Malena Hurtado, Valeria Villegas, Vanessa Granja, Claudia Jaramillo, William Arias, Rodrigo Barquera, Paola Everardo-Martínez, Mirsha Sánchez-Quinto, Jorge Gómez-Valdés, Hugo Villamil-Ramírez, Caio C. Silva de Cerqueira, Tábita Hünemeier, Virginia Ramallo, Fan Liu, Seth M. Weinberg, John R. Shaffer, Evie Stergiakouli, Laurence J. Howe, Pirro G. Hysi, Timothy D. Spector, Rolando Gonzalez-José, Lavinia Schüler-Faccini, Maria-Cátira Bortolini, Victor Acuña-Alonzo, Samuel Canizales-Quinteros, Carla Gallo, Giovanni Poletti, Gabriel Bedoya, Francisco Rothhammer, Christel Thauvin-Robinet, Laurence Faivre, Caroline Costedoat, David Balding, Timothy Cox, Manfred Kayser, Laurence Duplomb, Binnaz Yalcin, Justin Cotney, Kaustubh Adhikari, Andrés Ruiz-Linares, “A GWAS in Latin Americans identifies novel face shape loci, implicating VPS13B and a Denisovan introgressed region in facial variation”, Science Advances 05 Feb 2021: Vol. 7, no. 6, eabc6160 DOI: 10.1126/sciadv.abc6160 https://advances.sciencemag.org/content/7/6/eabc6160


Provided by University College London

Imagining a Face Reactivates Face-detecting Neurons in Humans (Neuroscience)

Neurons encode different faces through distinct activity patterns that reactivate during recall.

Face-sensitive neurons in humans employ distinct activity patterns to encode individual faces; those patterns reactivate when imagining the face, according to research recently published in JNeurosci.

Face-selective neurons fire after seeing a face (left) and just before imagining a face (right). © Khuvis et al., JNeurosci 2021

Human social interaction hinges on faces. In fact, faces are so important that the brain contains entire regions in the ventral temporal cortex devoted to facial recognition. In humans, the fusiform facial area activates in response to faces, and monkeys have single neurons that fire when shown a face. However, experimental limitations have prevented us from knowing how the human brain responds to and processes faces at the level of the single neuron.

To close this gap, Khuvis et al. measured the electrical activity of neurons in the ventral temporal cortex of eight adults undergoing invasive epilepsy monitoring. The participants viewed images of faces and other objects and then tried to remember and describe as many as possible. Groups of face-sensitive neurons activated in unique patterns while the participants viewed faces. That same group of neurons reactivated in the same pattern when a participant envisioned one of the faces they saw. Based on the activity pattern, the researchers were able to decode which face a person was seeing — and even was thinking about.

Reference: Simon Khuvis, Erin M. Yeagle, Yitzhak Norman, Shany Grossman, Rafael Malach and Ashesh D. Mehta, “Face-selective units in human ventral temporal cortex reactivate during free recall”, Journal of Neuroscience 11 January 2021, JN-RM-2918-19; DOI: https://doi.org/10.1523/JNEUROSCI.2918-19.2020 https://www.jneurosci.org/content/early/2021/01/05/JNEUROSCI.2918-19.2020

Provided by Society for Neuroscience

Can Eating Mangoes Reduce Women’s Facial Wrinkles? (Medicine)

Mangoes, like other orange fruits and vegetables, are rich in beta-carotene and provide antioxidants that may delay cell damage. A new study from researchers at the University of California, Davis, finds eating Ataulfo mangoes, also known as honey or Champagne mangoes, may have another benefit — reducing facial wrinkles in older women with fairer skin. The study was published in the journal Nutrients.

©Gettyimages

Postmenopausal women who ate a half cup of Ataulfo mangoes four times a week saw a 23 percent decrease in deep wrinkles after two months and a 20 percent decrease after four months.

“That’s a significant improvement in wrinkles,” said lead author Vivien Fam, a doctoral student in the UC Davis Department of Nutrition. But the findings are very specific and come with a caveat.

“Women who ate a cup and a half of mangoes for the same periods of time saw an increase in wrinkles. This shows that while some mango may be good for skin health, too much of it may not be,” Fam said.

Researchers said it’s unclear why consuming more mango would increase the severity of wrinkles but speculate that it may be related to a robust amount of sugar in the larger portion of mangoes.

QUANTIFIABLE RESULTS

The randomized clinical pilot study involved 28 postmenopausal women with Fitzpatrick skin types II or III (skin that burns more easily than tans). Women were divided into two groups: one group consumed a half cup of mangoes four times a week for four months, and another consumed a cup and a half for the same period of time. Facial wrinkles were evaluated using a high-resolution camera system.

“The system we used to analyze wrinkles allowed us to not just visualize wrinkles, but to quantify and measure wrinkles,” said Robert Hackman, professor in the Department of Nutrition and corresponding author of the study. “This is extremely accurate and allowed us to capture more than just the appearance of wrinkles or what the eye might see.”

The study looked at the severity, length and width of fine, deep and emerging wrinkles. Fam said the group that consumed a half cup of mangoes saw improvements in all categories.

Fam said further research is needed to learn the mechanisms behind the reduction in wrinkles. She said it may be due to the beneficial effects of carotenoids (orange or red plant pigments), and other phytonutrients that could help build collagen.

References: Fam, V.W.; Holt, R.R.; Keen, C.L.; Sivamani, R.K.; Hackman, R.M. Prospective Evaluation of Mango Fruit Intake on Facial Wrinkles and Erythema in Postmenopausal Women: A Randomized Clinical Pilot Study. Nutrients 2020, 12(11), 3381. https://www.mdpi.com/2072-6643/12/11/3381 https://doi.org/10.3390/nu12113381

Provided by University of California–Davis

Why Chinese Look Like Chinese? Indians Look like Indians?…… Well, I Have An Answer (Biology)

Did we look different from each other, right from the past..?? Today by just looking at faces we can differentiate if the person belongs to China, India, Russia etc.. But what if I say, we all look same in the past.. Yeah its true, there were no countries, no religion, no discrimination, no hate.. We used to live with each other happily like a family.. Wanna know lets travel back 3 lakh years before..

We all used to live in Africa at that time. The environment was warm and naturally rich. We all looked same. Our only objective was ‘survival’. As one couldn’t able to survive alone, we used to live and hunt in groups and stay at one place. Earth was actually the heaven at that time as there were no racism. And yeah, our ancestors prefer grass bedding to create comfortable areas for sleeping and working on, at least 2 lakh years ago.

These beds consisting of sheaves of grass of the broad-leafed Panicoideae subfamily were placed near the back of the cave on ash layers. The layers of ash was used to protect our ancestors against crawling insects while sleeping. Our ancestors also used hot springs as a cooking resource to boil fresh kills, long before humans are thought to have used fire as a controlled source for cooking.

But around 1.3 lakh years before, an interglacial period changed everything. Climate of the earth started increasing rapidly and this started melting icy routes which goes out of Africa. So, some of our ancestors decided to migrate to other countries, while others decided to stay in Africa. Our migrating ancestors took only required food with them, while shared remaining with others. This act of kindness we call today, ‘Law of Sharing’.

Out of Africa, our ancestors went to levantine regions first and started spreading to Syria, Lebanon, Jordan, Israel, Palestine and Turkey.. And just after 1000 years, some of them migrated towards europe and asia. And for 40000 years, our ancestors had spread to India and China. And that’s how 4 human raeces born.

Do you know, that 4 human races? They are white/Caucasian, Mongoloid/Asian, Negroid/Black, and Australoid. According to darwin theory of evolution, Indians are the mixture of Caucasian, australiazoid and mongoloid. North India people have more caucasoin genes, South India have more Australiazoid genes. While, North East have mongoloid genes..

But what about china? Well friends, they all belongs to mongolian races. But the question is, why they have small eyes and flat faces. Friends, its not because god created them like this, that was the gift given to them by evolution through natural selection. Yeah friends, when they came to siberia from africa. It was necessary to protect eyes from snow blindness and natural selection given them low exposure eyes i.e. squinty eyes, to protect them against it..

But what about their flat facial features? You know well about the siberia’s extreme cold temperatures. In order to survive such extreme cold temperatures it is necessary to prevent heat loss. So, natural selection bought changes in their facial features and had given them extra face fat. It also helped them to eat icy-meats. Epicanthel fold is also believed to have evolved in them in order to provide defense from the extreme cold and extreme light that occur in Eurasian arctic and northern regions.

But what about Europeans? How they got their pale colour? Ancestors who were migrated to northern latitudes often don’t get enough UV to synthesize vitamin D in their skin so natural selection has favored two genetic solutions to that problem—evolving pale skin that absorbs UV more efficiently or favoring lactose tolerance to be able to digest the sugars and vitamin D naturally found in milk. That’s why we look different from each other. Share it as much as you can and make people aware of truth.. Because knowledge can only save this beautiful world from ‘destruction’ which may cause from ‘discrimination’..

You can read more about the evolution of human face on the article given below:

https://theuncoverreality.wordpress.com/2020/10/05/why-your-face-looks-different-from-a-chimps-biology/

Copyright of this article totally belongs to uncover reality.. Author of this article is S. Aman.. One is allowed to use it only by giving proper credit to author and to us.

Why Your Face Looks Different From a Chimp’s? (Biology)

The face: it’s personal, yet universal. It’s how we recognize each other and communicate our emotions—and yet there’s more to it than immediately meets the eye. Beneath the skin and muscles that form our smirks and scowls are 14 different bones that house parts of the digestive, respiratory, visual, and olfactory systems—enabling us to sniffle, chew, blink, and much more.

Thanks to the discovery of fossils, researchers are able to observe how faces have evolved over time, from extinct hominin species walking the Earth millions of years ago, to Neanderthals, to the only remaining hominin species—Homo sapiens, or humans. Analyzing the visages of our ancestors provides clues about why our faces have grown shorter and flatter over millennia. Which environmental and cultural factors influenced the structure of our modern faces, and how might climate change reshape them yet again?

Two years ago, Rodrigo Lacruz, associate professor of basic science and craniofacial biology at NYU College of Dentistry, gathered a group of leading human evolution experts at a conference in Madrid, Spain, to discuss the evolutionary roots of the modern human face. Their detailed account of its history—which appears April 15 in Nature Ecology & Evolution—covers roughly 4 million years and integrates many different lines of research, given the numerous factors that contribute to facial shape. The researchers conclude that the face’s appearance is a combination of biomechanical, physiological, and social influences.

NYU Dentistry’s Rodrigo Lacruz

NYU News asked Lacruz to describe how we came to look the way we do.

How does the human face differ from that of our predecessors—and our closest living relatives?

In broad terms, our faces are positioned below the forehead, and lack the forward projection that many of our fossil relatives had. We also have less prominent brow ridges, and our facial skeletons have more topography. Compared to our closest living relatives, the chimpanzees, our faces are more retracted and are integrated within the skull rather than being sort of pushed in front of it.

How has our diet played a role?

Diet has been considered as an important factor, especially when it comes to the mechanical properties of foods consumed—soft versus hard objects. For instance, some early hominins had bony structures that suggested the presence of powerful muscles for mastication, or chewing, and they had very large chewing teeth, indicating that they were likely adapted for processing harder objects. These fossils had unusually flat faces. In more recent humans, the transition from being hunter-gatherers to settlers also coincides with changes in the face, specifically the face becoming smaller. However, many of the details of this interaction between diet and facial shape are unclear because diet affects certain parts of the face more than others. This reflects how modular the face is.

A raised eyebrow, grimace, and squint all signal very different things. Did the human face evolve to enhance social communication?

We think that enhanced social communication was a likely outcome of the face becoming smaller, less robust, and with a less pronounced brow. This would have enabled more subtle gestures and hence enhanced non-verbal communication. Let’s consider chimpanzees, for example, which have a smaller repertoire of facial expressions compared to us, and a very different facial shape. The human face, as it evolved, likely gained other gestural components. Whether social communication by itself was the driver for facial evolution is much less likely.

Climate also plays a role in evolution. How have factors like temperature and humidity influenced the evolution of the face?

We see that perhaps more clearly in Neanderthals, which adapted to live in colder climates and had large nasal cavities. This would have enabled an increased capacity for warming and humidifying the air they inhaled. The expansion of the nasal cavity modified their faces by pushing them somewhat forward, which is more evident in the midface (around and below the nose). The likely ancestors of the Neanderthals, a group of fossils from the Sima de los Huesos site in Spain that also lived in somewhat colder conditions, also showed some expansion of the nasal cavity and a midface that jutted forward. While temperature and humidity affect the parts of the face involved in breathing, other areas of the face may be less impacted by climate.

In the Nature article, you mention that climate change could affect human physiology. How could a warming planet change our faces?

The nasal cavity and upper respiratory tract (the area at the back of the nose near the pharynx) influence the shape of the face. Part of this knowledge derives from studies in modern people by some of our collaborators. They have shown that the shape of the nasal cavity and nasopharynx differ between people living cold and dry climates and those in hot and humid climates. After all, the nose helps warm and humidify inhaled air before it reaches the lungs.

The expected rise in global temperatures could have an effect on human physiology—specifically, how we breathe—over time. The extent of these changes in the face will depend, among other things, on how much warmer it grows. But if predictions of a 4°C (~7°F) rise in temperatures are correct, changes in the nasal cavity might be anticipated. In these scenarios, we should also take into account the high mobility of gene flow, which is an important factor as well, so the effects of climate change can be difficult to predict.

References: Lacruz, R.S., Stringer, C.B., Kimbel, W.H. et al. The evolutionary history of the human face. Nat Ecol Evol 3, 726–736 (2019). https://doi.org/10.1038/s41559-019-0865-7

Provided by New York University

Most People Are Really Bad At Matching A Face To An ID Picture (Psychology)

It’s routine whether you’re going through airport security or hitting up your favorite bar: You have to show your ID. But how effective is that, really? Who’s to say you’re not carrying the ID of someone who just looks like you? It turns out that that’s a very good question. Over and over, studies show that most people are lousy at matching pictures of unfamiliar faces, regardless of training. Yet we keep checking IDs just the same.

Here’s just one of many examples. In 2014, a research team out of Australia published a study looking into how passport officers compared to regular people when it came to matching pictures of unfamiliar faces. They had 30 passport officers perform three experiments. In the first, real people showed the officer an ID, some of which had the person’s real image, some of which had an image of a person who looked a bit like them. Even though the circumstances were actually easier than the real world (the ID photos were taken just days before the experiment, and the fake IDs just had a roughly identical photo that probably wouldn’t be good enough for someone who really wanted to fool an officer), the officers were lousy. They accepted 14 percent of the fakes and rejected six percent of the real IDs, for an overall error rate of 10 percent. That may sound small, but it adds up. When 100,000 people pass through an airport’s security line on a given day, that’s 10,000 ID-matching mistakes.

You might think that in the second experiment, where they just had to tell if two photos taken two years apart were of the same person, officers would do better. They didn’t: Their error rate was nearly 20 percent. They also weren’t any better than the general public: Their scores on a basic face-matching test were the same as population norms, and years on the job had no effect on performance in either of the experiments.

In a 2017 study, volunteers had to decide whether each of these pairs were of the same or different people. They accepted 24% of incorrect matches..

more recent study in an August 2017 issue of the Journal of Experimental Psychology found that novices did perform slightly worse than trained police officers on a photo-matching test — but everyone still botched the job. Police officers in that study accepted 25 percent of fake IDs, compared to 26 percent by novices. That’s nothing to brag about.

Want to see how you’d perform in a face-matching challenge? Take this test to find out if you’re a “super-recognizer.” (A score of 10/14 or more suggests you may have special skills. The test starts easy, but gets significantly harder by the end.)

This is one of many areas where artificial intelligence can come in handy. You may notice that Facebook and certain photo apps can identify your friends’ faces in a snapshot with unsettling accuracy. Facebook, Google, and other researchers have all boasted artificial intelligence systems that perform better than humans at matching faces. What’s more, many of those systems can go a step further by identifying who the person is from a photo. Artificial intelligence checking our IDs may smack of a dystopian sci-fi novel, but it’s certainly more accurate than what we’ve got now. We, for one, welcome our new robot bar bouncers.

This Research Shows Why You Should Face Your Fears (Psychology / Phobia)

Whether it’s to get over an irrational fear of spiders or a perfectly rational fear of jumping out of an airplane, the common advice is to face your fears head-on. If you do, the logic goes, you’ll find out they’re not so scary after all, and you may even learn to enjoy them. Of course, that’s not always the case — sometimes forcing someone to re-experience something traumatic just causes further trauma. With that risk, anyone offering the advice to “face your fears!” should be absolutely sure that it really can be helpful. Luckily, new neuroscience research is giving the practice a green light by demonstrating just what happens in your brain when you face your fears.

Scientists are still a little bit hazy on the nature of memories — how they form, how they’re stored, and how you recall them, specifically. For example, just last year, MIT scientists stumbled upon the fact that long-term memories form completely differently than we thought and Columbia University researchers found that the brain remembers events in the opposite order it experienced them.

It isn’t that surprising, then, that researchers from the École Polytechnique Fédérale de Lausanne (EPFL) felt the need to find out how exactly the brain gets rid of traumatic memories when a person faces their fears. Facing one’s fears is the centerpiece of exposure therapy: the most effective treatment for easing fears and phobias, according to the Mayo Clinic. It involves gradual, repeated exposure to the source of your fear. If you’re afraid of spiders, for example, you might first talk about spiders, then look at pictures of spiders, then sit across a room from a spider, then get closer until you can actually touch the spider.

The researchers were working with two theories that might explain how exposure therapy actually works in the brain: On the one hand, it’s possible that the formation of a new, non-fearful memory (touching a spider and nothing going wrong) just quiets the old, fearful memory (ack! spiders!); on the other hand, it’s also possible that the old, fearful memory is actually rewritten to become the new, non-fearful memory.

For a study published last month in the journal Science, the EPFL researchers worked with a special type of mice that were engineered to automatically “tag” active brain cells with a specific molecule. That helped the scientists know where exactly their memories were being stored and what was happening to them. Then, they gave the mice a phobia: They put each mouse in a small box and then administered some mild electric shocks. Sure enough, when the researchers returned the mice to the box a few months later, they froze — a classic fear response. That memory of their former trauma caused the brain cells storing it to fire, labeling themselves in the process.

Next came the exposure therapy. The researchers kept returning the mice to the box without shocking them, and little by little, their fear response began to subside. And here’s the clincher: Every time they revisited the box, certain groups of brain cells fired, and the more closely those groups matched the original groups responsible for the fear memory, the faster the mice became unafraid. In fact, when the researchers gave the mice a chemical to shut off the cells responsible for the fear memory, they didn’t respond as well to exposure therapy; on the contrary, when they boosted the activity of those cells, the mice got over the fear even faster. This shows that exposure therapy works by actually modifying the brain cells responsible for the original fear memory.

There are some limitations, including the fact that this memory-tagging technique isn’t failsafe — the new memories only partially overlapped with the old ones, so the old memories might not actually be rewritten and could still be under there somewhere. But it’s still powerful evidence that to extinguish your fears, you have to experience them again. It can be tempting to simply avoid the fear trigger, but the American Psychological Association says that could just make your problem bigger. “Although this avoidance might help reduce feelings of fear in the short term,” they write, “over the long term it can make the fear become even worse.” So face your fears. You’ll be glad you did.