Episode 1 - Into the Brain
Part 1
Part 2
Part 3
Part 4
Part 5
Saturday, 6 August 2011
Friday, 5 August 2011
Why Cry? Evolutionary Biologists Show Crying Can Strengthen Relationships - 2009
New analysis by Dr. Oren Hasson of TAU's Department of Zoology shows that tears still signal physiological distress, but they also function as an evolution-based mechanism to bring people closer together.
"Crying is a highly evolved behavior," explains Dr. Hasson. "Tears give clues and reliable information about submission, needs and social attachments between one another. My research is trying to answer what the evolutionary reasons are for having emotional tears.
"My analysis suggests that by blurring vision, tears lower defences and reliably function as signals of submission, a cry for help, and even in a mutual display of attachment and as a group display of cohesion," he reports.
His research, published recently in Evolutionary Psychology, investigates the different kinds of tears we shed — tears of joy, sadness and grief — as well as the authenticity or sincerity of the tears. Crying, Dr. Hasson says, has unique benefits among friends and others in our various communities.
Approaching the topic with the deductive tools of an evolutionary biologist, Dr. Hasson investigated the use of tears in various emotional and social circumstances. Tears are used to elicit mercy from an antagonistic enemy, he claims. They are also useful in eliciting the sympathy — and perhaps more importantly the strategic assistance — of people who were not part of the enemy group.
"This is strictly human," reasons Dr. Hasson. "Emotional tears also signal appeasement, a need for attachment in times of grief, and a validation of emotions among family, friends and members of a group."
Crying enhances attachments and friendships, says Dr. Hasson, but taboos are still there in certain cases. In some cultures, societies or circumstances, the expression of emotions is received as a weakness and the production of tears is suppressed. For example, it is rarely acceptable to cry in front of your boss at work — especially if you are a man, he says.
Multiple studies across cultures show that crying helps us bond with our families, loved ones and allies, Dr. Hasson says. By blurring vision, tears reliably signal your vulnerability and that you love someone, a good evolutionary strategy to emotionally bind people closer to you.
"Of course," Dr. Hasson adds, "the efficacy of this evolutionary behavior always depends on who you're with when you cry those buckets of tears, and it probably won't be effective in places, like at work, when emotions should be hidden.
"Dr. Hasson, a marriage therapist, uses his conclusions in his clinic. "It is important to legitimize emotional tears in relationships," he says. "Too often, women who cry feel ashamed, silly or weak, when in reality they are simply connected with their feelings, and want sympathy and hugs from their partners."
Retrieved from: http://www.sciencedaily.com/releases/2009/08/090824141045.htm
"Crying is a highly evolved behavior," explains Dr. Hasson. "Tears give clues and reliable information about submission, needs and social attachments between one another. My research is trying to answer what the evolutionary reasons are for having emotional tears.
"My analysis suggests that by blurring vision, tears lower defences and reliably function as signals of submission, a cry for help, and even in a mutual display of attachment and as a group display of cohesion," he reports.
His research, published recently in Evolutionary Psychology, investigates the different kinds of tears we shed — tears of joy, sadness and grief — as well as the authenticity or sincerity of the tears. Crying, Dr. Hasson says, has unique benefits among friends and others in our various communities.
For crying out loud (and behind closed doors)
Approaching the topic with the deductive tools of an evolutionary biologist, Dr. Hasson investigated the use of tears in various emotional and social circumstances. Tears are used to elicit mercy from an antagonistic enemy, he claims. They are also useful in eliciting the sympathy — and perhaps more importantly the strategic assistance — of people who were not part of the enemy group.
"This is strictly human," reasons Dr. Hasson. "Emotional tears also signal appeasement, a need for attachment in times of grief, and a validation of emotions among family, friends and members of a group."
Crying enhances attachments and friendships, says Dr. Hasson, but taboos are still there in certain cases. In some cultures, societies or circumstances, the expression of emotions is received as a weakness and the production of tears is suppressed. For example, it is rarely acceptable to cry in front of your boss at work — especially if you are a man, he says.
Streets awash with tears?
Multiple studies across cultures show that crying helps us bond with our families, loved ones and allies, Dr. Hasson says. By blurring vision, tears reliably signal your vulnerability and that you love someone, a good evolutionary strategy to emotionally bind people closer to you.
"Of course," Dr. Hasson adds, "the efficacy of this evolutionary behavior always depends on who you're with when you cry those buckets of tears, and it probably won't be effective in places, like at work, when emotions should be hidden.
"Dr. Hasson, a marriage therapist, uses his conclusions in his clinic. "It is important to legitimize emotional tears in relationships," he says. "Too often, women who cry feel ashamed, silly or weak, when in reality they are simply connected with their feelings, and want sympathy and hugs from their partners."
Retrieved from: http://www.sciencedaily.com/releases/2009/08/090824141045.htm
Monday, 11 July 2011
Genetic Switch for Limbs and Digits Found in Primitive Fish - 2011
Genetic instructions for developing limbs and digits were present in primitive fish millions of years before their descendants first crawled on to land, researchers have discovered.
Genetic switches control the timing and location of gene activity. When a particular switch taken from fish DNA is placed into mouse embryos, the segment can activate genes in the developing limb region of embryos, University of Chicago researchers report in Proceedings of the National Academy of Sciences. The successful swap suggests that the recipe for limb development is conserved in species separated by 400 million years of evolution. "The genetic switches that drive the expression of genes in the digits of mice are not only present in fish, but the fish sequence can actually activate the expression in mice," said Igor Schneider, PhD, postdoctoral researcher in the Department of Organismal Biology and Anatomy at the University of Chicago and lead author on the paper. "This tells us how the antecedents of the limb go back in time at every level, from fossils to genes."
The genetic hunt was inspired by a famous fossil find -- the 2004 discovery of the transitional fossil Tiktaalik in the Canadian Arctic by a team led by Neil Shubin of the University of Chicago. A transitional species between fish and the four-legged tetrapods, Tiktaalik possessed fins containing a skeletal structure similar to the limbs of later land-dwelling animals.
Those similarities -- particularly the wrist and hand-like compartments present in the fins of Tiktaalik and its peers -- inspired a laboratory experiment to look at the homology, or shared physical and genetic traits, of fish and limbed animals.
"This is really a case where knowing something about the fossils and the morphology led us to think about genetic experiments," said Shubin, PhD, the Robert R. Bensley Professor of Organismal Biology and Anatomy and senior author of the study. "Tiktaalik and its cousins showed us that this limb compartment is not an utter novelty in tetrapods, as was thought for a long time. So an antecedent of that program must exist."
The research team compared a genetic switch region called CsB, known to regulate limb development in humans, with similar regions in mice, chickens, frogs, and two fish species: the zebrafish and the skate. Because the last common ancestor of all these species pre-dates Tiktaalik-like "fishapods," the comparison offered a glimpse at biology before animals made their first steps on land.
Schneider and colleagues compared the CsB regions from all five species and found that certain sequences were shared between the fish species and the tetrapods. The conservation allowed the researchers to try swapping switch sequences between species to see if they could still drive gene expression in the fin or limb. Remarkably, mouse CsB could turn on gene expression at the outer edge of the developing fin region of zebrafish, and both skate and zebrafish CsB were capable of activating gene expression in the wrist and proximal digits of the mouse limb.
"These sequences function in these organisms despite 400 million years of separation," Schneider said. "The homologies that are perhaps not evident by morphology -- just comparing a hand and a fin -- can be traced back to the genome, where you find that the regulatory regions that control the making of those structures are actually present and shared between these organisms."
The results contradict a previous finding that a developmental switch from pufferfish DNA was not capable of gene expression in the limbs of mice, suggesting that tetrapods evolved a novel developmental system. But the new experiments suggest that the genetic switch controlling limb development was in fact present deep in Earth's evolutionary tree.
"There previously was the idea that these switches had to be generated from scratch de novo, but no, they already existed, they were already there," said Marcelo Nobrega, MD, PhD, assistant professor of human genetics at the University of Chicago Medical Center and another author of the study. "Maybe the key was expressing a gene earlier or later or in a specific territory, but it was just a modification of a program that was already encoded in the genomes of fish almost half a billion years ago and remains there to this day."
"These new results are actually in line with both the fossil data and the expression data," Schneider said. "So now we can tell a story where the fossils and gene expression make sense in light of the genetic regulation."
Future experiments will focus more closely on how the gene regulation system functions, examining the differences between the segments in fish and tetrapods that control development of either a fin or a limb. Subtle changes in the timing or location of gene expression may produce the dramatic differences in anatomy that first allowed animal life on Earth to explore land.
"There is a whole universe of questions that are opened up by this discovery," Shubin said.
The paper, "Appendage expression driven by the Hoxd global control region is an ancient gnathostome feature," will be published online the week of July 11 by the Proceedings of the National Academy of Sciences.
Retrieved from: http://www.sciencedaily.com/releases/2011/07/110711151453.htm
The genetic hunt was inspired by a famous fossil find -- the 2004 discovery of the transitional fossil Tiktaalik in the Canadian Arctic by a team led by Neil Shubin of the University of Chicago. A transitional species between fish and the four-legged tetrapods, Tiktaalik possessed fins containing a skeletal structure similar to the limbs of later land-dwelling animals.
Those similarities -- particularly the wrist and hand-like compartments present in the fins of Tiktaalik and its peers -- inspired a laboratory experiment to look at the homology, or shared physical and genetic traits, of fish and limbed animals.
"This is really a case where knowing something about the fossils and the morphology led us to think about genetic experiments," said Shubin, PhD, the Robert R. Bensley Professor of Organismal Biology and Anatomy and senior author of the study. "Tiktaalik and its cousins showed us that this limb compartment is not an utter novelty in tetrapods, as was thought for a long time. So an antecedent of that program must exist."
The research team compared a genetic switch region called CsB, known to regulate limb development in humans, with similar regions in mice, chickens, frogs, and two fish species: the zebrafish and the skate. Because the last common ancestor of all these species pre-dates Tiktaalik-like "fishapods," the comparison offered a glimpse at biology before animals made their first steps on land.
Schneider and colleagues compared the CsB regions from all five species and found that certain sequences were shared between the fish species and the tetrapods. The conservation allowed the researchers to try swapping switch sequences between species to see if they could still drive gene expression in the fin or limb. Remarkably, mouse CsB could turn on gene expression at the outer edge of the developing fin region of zebrafish, and both skate and zebrafish CsB were capable of activating gene expression in the wrist and proximal digits of the mouse limb.
"These sequences function in these organisms despite 400 million years of separation," Schneider said. "The homologies that are perhaps not evident by morphology -- just comparing a hand and a fin -- can be traced back to the genome, where you find that the regulatory regions that control the making of those structures are actually present and shared between these organisms."
The results contradict a previous finding that a developmental switch from pufferfish DNA was not capable of gene expression in the limbs of mice, suggesting that tetrapods evolved a novel developmental system. But the new experiments suggest that the genetic switch controlling limb development was in fact present deep in Earth's evolutionary tree.
"There previously was the idea that these switches had to be generated from scratch de novo, but no, they already existed, they were already there," said Marcelo Nobrega, MD, PhD, assistant professor of human genetics at the University of Chicago Medical Center and another author of the study. "Maybe the key was expressing a gene earlier or later or in a specific territory, but it was just a modification of a program that was already encoded in the genomes of fish almost half a billion years ago and remains there to this day."
"These new results are actually in line with both the fossil data and the expression data," Schneider said. "So now we can tell a story where the fossils and gene expression make sense in light of the genetic regulation."
Future experiments will focus more closely on how the gene regulation system functions, examining the differences between the segments in fish and tetrapods that control development of either a fin or a limb. Subtle changes in the timing or location of gene expression may produce the dramatic differences in anatomy that first allowed animal life on Earth to explore land.
"There is a whole universe of questions that are opened up by this discovery," Shubin said.
The paper, "Appendage expression driven by the Hoxd global control region is an ancient gnathostome feature," will be published online the week of July 11 by the Proceedings of the National Academy of Sciences.
Retrieved from: http://www.sciencedaily.com/releases/2011/07/110711151453.htm
Saturday, 18 June 2011
Friday, 17 June 2011
Poison Could Have Set the Stage for the Origins of Life - 2011
Formaldehyde, a poison and a common molecule throughout the universe, is likely the source of the solar system's organic carbon solids -- abundant in both comets and asteroids. Scientists have long speculated about the how organic, or carbon-containing, material became a part of the solar system's fabric. New research from Carnegie's George Cody, along with Conel Alexander and Larry Nittler, shows that these complex organic solids were likely made from formaldehyde in the primitive solar system. "We may owe our existence on this planet to interstellar formaldehyde," Cody said. "And what's ironic about it is that formaldehyde is poisonous to life on Earth."
During the early period of the inner solar system's formation, much of the organic carbon that wasn't trapped in primitive bodies was lost to space, along with much of the water. Prior to this study numerous competing ideas emerged to explain the existence of primitive organic solids. Cody, of the Geophysical Laboratory, along with Alexander and Nittler, of the Department of Terrestrial Magnetism, and the team decided to study primitive solar system objects using advanced methods. What they discovered clearly pointed to a polymer formed from formaldehyde.
They tested their conclusion with experiments to reproduce the type of organic matter found in carbonaceous chondrites, a type of organic-rich meteorite, starting with formaldehyde. They found that their formaldehyde-synthesized organic material was not only similar to that found in carbonaceous chondrites, but also similar to organic material found in a comet named 81P/Wild 2, pieces of which were collected in space by NASA's Stardust mission, as well as in interplanetary dust particles, or particles from space that likely originated from comets and asteroids.
Their results make sense, because formaldehyde is relatively abundant throughout the galaxy and the polymerization process would have been possible under conditions of the primitive solar system.
"Establishing the likely origin of the principal source of organic carbon in primitive solar system bodies is extremely satisfying," Cody said.
Retrieved from: http://www.sciencedaily.com/releases/2011/04/110404151351.htm
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