https://medicalxpress.com/news/2021-04-neural-plasticity-noncoding-rna-journey.html

"A new study from scientists at Scripps Research and the Max Planck Florida Institute for Neuroscience finds a central role for one signaling molecule, a long, noncoding RNA that the scientists named ADEPTR.

"Using a variety of technologies, including confocal and two-photon microscopy, they track ADEPTR's moves, watching as it forms, travels, amasses at the synapse and activates other proteins upon a neuron's stimulation.

"Its journey to the far reaches of a brain cell is made possible by a cellular carrier that that tiptoes along a dendrite's microtubule scaffolding. Called a kinesin motor, it deposits ADEPTR near the synapse junction, where it activates other proteins.

"The team also found that if ADEPTR is silenced, new synapses don't form during stimulation.

***

"'Here we report activity-dependent dendritic targeting of a newly transcribed long noncoding RNA for modulating synapse function, and describe its underlying mechanisms," Puthanveettil says. "These studies bring novel insights into the functions of long noncoding RNAs at the synapse."

***

"A long noncoding RNA is a type of RNA that exceeds 200 nucleotides, and does not get translated into protein. There are thousands of these long noncoding RNA in our cells, but in most cases, their function isn't yet known. What is known is that usually, they tend to stay within the cell nucleus. Some regulate the transcription of genes.

"'It was surprising to see a long noncoding RNA move from nucleus to the synapse so rapidly and robustly," Grinman says. (my bold)

"The hippocampus is the part of the brain where learning, memory and emotions reside. Working in hippocampal neurons from mice, the team stimulated the neurons with pharmacological activators of learning-related signaling. They found through molecular and high-resolution imaging techniques that the ADEPTR long noncoding RNA was rapidly expressed and transported to the outer arms of the cell. There, the ADEPTR molecules interact with proteins that play a role in structural organization of synapses, proteins called spectrin 1 and ankyrin B.

"They found that ADEPTR became downregulated if exposed to an inhibitory neurotransmitter, GABA.

"'These findings add another layer of complexity in synapse modulation and plasticity," Puthanveettil says. "Synaptically localized long noncoding RNA are important regulators of adaptive neuronal function.'"

Comment: Note the bold. Why are they so surprised at the finding? The deeper they go the more complexity will be found, until it is finally recognized universally there must be a designing mind creating. GABA has a long history of recognition as a major player in the brain .

https://mindmatters.ai/2020/09/the-human-brain-has-given-researchers-a-big-surprise/

"Scientists have long thought that white matter didn’t play an active role in the brain, but new research has shown that this is untrue and that white matter actively affects both how the brain learns and how it dysfunctions.

***

"But a new study suggests that our mental circuitry is more like Manhattan’s organised grid than London’s chaotic tangle. It consists of sheets of fibres that intersect at right angles, with no diagonals anywhere to be seen.

"Van Wedeen from Massachusetts General Hospital, who led the study, says that his results came as a complete shock. “I was expecting it to be a pure mess,” he says. Instead, he found a regular criss-cross pattern like the interlocking fibres of a piece of cloth.

"Wedeen’s maps may not reveal all the details about the brain’s network, but it does show how that network is structured. “If you look at brain connections in an adult human, it’s really a massive puzzle how something so complex can emerge,” says Behrens. “If we can establish any sort of organisation, we get a clue about how these things grow. If it obeys some rules, you could start to work out how it follows those rules. You have something to hang onto.”

***

"Many surprises. Scientists have been amazed to see that, instead of chaos, the connecting fibers are organized into an orderly 3D grid, where axons run up and down and left and right, minus any diagonals or tangles. Science magazine compares the brain’s 3D layout to New York City, with its streets running in two directions and buildings’ elevators running up and down. Strangely, in flat areas of the grid, the fibers overlap at precise 90 degree angles and weave together much like a fabric, the scientists say.

***

"while the healthy brain is a small-world network, the schizophrenic brain is measurably less so—it can still be organized into modules, but those modules aren’t as densely connected. If small-worldness helps the brain undertake a variety of processes effectively and efficiently, its lack in the schizophrenic brain could someday help to explain the disease’s symptoms."

Comment: this strict organization reeks of design. The comment on Schizophrenia simply tells us we have to use the brain we are given and make me more sure of dualism as I view it.

https://www.nature.com/articles/d41586-020-02586-w?utm_source=Nature+Briefing&utm_c...

“Catherine Dulac has done amazing work that has really transformed the field,” says biologist Lauren O’Connell, at Stanford University, California. Dulac’s team provided the first evidence that male and female mouse brains have the same neural circuitry associated with parenting, which is just triggered differently in each sex1. “It went against the dogma that for decades said that male and female brains are organized differently,” says O’Connell.

***

"In the 1990s, Dulac isolated the pheromone receptors in mice that govern sex-specific social behaviours. Virgin male mice usually attack other males and kill pups. But Dulac found that if their pheromone receptors were blocked, they would attempt to mate with both males and females, and virgin males would even care for pups. Pheromone-blind females, by contrast, would attempt to mount males.

"To elucidate the neural mechanisms at play, Dulac identified a protein called galanin that is expressed by neurons involved in parenting. Killing the neurons in females stopped them parenting, while activating them in virgin males made them maternal. “It’s like an on-and-off switch for parenting,” says Dulac. “It’s extraordinary.” Her team then used the galanin marker to track the specific circuitry associated with the motivational, hormonal and behavioural changes needed for nurturing.

"O’Connell says that the studies “set the stage for a better understanding of the flexibility of human and primate brains”, and could one day be relevant for treating disorders such as post-partum depression."

Comment: The male and female brains are the same neurologically except for the female neurons that make galanin. Female mice have no concept that previous pleasurable sex with a male produced her pups later on. But parenting is essential for survival. How did galanin arrive through evolution? Not from mouse thought. Not by chance. This vital function must be designed.

https://medicalxpress.com/news/2020-07-neurons-immune-cells-paths-brain.html

"In recent years, scientists have discovered that the brain's dedicated immune cells, called microglia, can help get rid of unnecessary connections between neurons, perhaps by engulfing synapses and breaking them down. But the new study, published July 1, 2020 in Cell, finds microglia can also do the opposite—making way for new synapses to form by chomping away at the dense web of proteins between cells, clearing a space so neurons can find one another.

***

"...neurobiologists are starting to realize that the ECM, which makes up about 20 percent of the brain, actually plays a role in important processes like learning and memory. At a certain point in brain development, for example, the solidifying ECM seems to put the brakes on the rapid pace at which new neuronal connections turn over in babies, seemingly shifting the brain's priority from the breakneck adaptation to the new world around it, to a more stable maintenance of knowledge over time. Scientists also wonder if a stiffening of the extracellular matrix later in life might somehow correspond to the memory challenges that come with aging.

***

"Knowing that microglia chew away at obsolete synapses, they expected that disrupting microglia function would cause the number of synapses in the hippocampus to shoot up. Instead, synapse numbers dropped. And where they thought they'd find pieces of synapses being broken down in the "bellies" of microglia, instead they found pieces of the ECM.

"'In this case microglia were eating something different than we expected," Molofsky said. "They're eating the space around synapses—removing obstructions to help new synapses to form."

***

"Before springing into action, the microglia wait for a signal from neurons, an immune molecule called IL-33, indicating that it's time for a new synapse to form, the study found.

***

"'I'm in love with the extracellular matrix," Molofsky said. "A lot of people don't realize that the brain is made up not just of nerve cells, but also cells that keep the brain healthy, and even the space in between cells is packed with fascinating interactions."

Comment: The brain ECM is very fatty and has the consistency of jello. The fat is the insulation that protects from short circuits. We see how the processes work, but this does not tell us about the guiding information that the cells use to alter the brains connection and networks. Note the same molecule is at work during the development of the baby brain in utero and after.

https://cosmosmagazine.com/science/biology/understanding-how-brains-fold-and-misfold/

"In a pre-clinical study using animal models, a team led by Australia’s RMIT University identified the genes linked with the development of the two types of brain folds – inward and outward – in the brain’s grey matter.

"Writing in the journal Cerebral Cortex, they report finding differences in both genetic expression and neuron shape during the folding process.

***

"The researchers say previous studies have focussed on white matter or looked at animals with smooth brains rather than folded ones, largely overlooking grey matter. Grey matter is made up of neuron bodies and their connecting arms; white matter comprises the neurons’ long nerve fibres and their protective layer of fat.

"The latest evidence suggests grey matter in the developing brain expands faster than white matter, creating mechanical instability that leads to brain folding. The resulting “hill” and “valley” folds follow a similar pattern in all folded brains of the same species.

"Tolcos and colleagues investigated the genetic and microstructural differences in future grey matter, the cortical plate, in the parts of the brain just beneath the “hills” and “valleys”. These areas were analysed at three points of development: when the brain was smooth, semi-folded and fully folded.

“'We found some genes have higher expression in regions that fold outward and lower expression in regions that fold inwards. Other genes reverse this pattern,” says RMIT’s Sebastian Quezada Rojas.

“'Together, these genetic expression patterns might explain why the cortical folding pattern is so consistent between individuals of the same species.”

"These genetic differences are also correlated with changes in grey matter neurons, with the study finding variations in the number of arms – or dendrites – that neurons grow in these regions during the folding process.

“'We believe the regions that fold outward and inward are programmed to behave differently, and the shape of the neurons affects the way these areas fold,” Quezada Rojas says."

Comment: The old idea that rapid growth forced the folding is incorrect. These folds are purposely planned. More evidence of purposeful design.

https://medicalxpress.com/news/2020-05-brain-complex.html

"The human brain is a highly advanced information processor composed of more than 86 billion neurons. Humans are adept at recognizing patterns from complex networks, such as languages, without any formal instruction. Previously, cognitive scientists tried to explain this ability by depicting the brain as a highly optimized computer, but there is now discussion among neuroscientists that this model might not accurately reflect how the brain works.

***

"this new model shows that the ability to detect patterns stems in part from the brain's goal to represent things in the simplest way possible. Their model depicts the brain as constantly balancing accuracy with simplicity when making decisions.

***

"Using tools from information theory and reinforcement learning, the researchers were able to use this data to implement a metric of complexity called entropy. "Being very random is the least complex thing you could do, whereas if you were learning the sequence very precisely, that's the most complex thing you can do. The balance between errors and complexity, or negative entropy, gives rise to the predictions that the model gives," says Lynn.

"Their resulting model of how the brain processes information depicts the brain as balancing two opposing pressures: complexity versus accuracy. "You can be very complex and learn well, but then you are working really hard to learn patterns," says Lynn. "Or, you have a lower complexity process, which is easier, but you are not going to learn the patterns as well."

"With their new model, the researchers were also able to quantify this balance using a parameter beta. If beta is zero, the brain makes a lot of errors but minimizes complexity. If beta is high, then the brain is taking precautions to avoid making errors. "All beta does is tune between which is dominating," says Lynn. In this study, 20% of the participants had a small beta, 10% had high beta values, and the remaining 70% were somewhere in between. "You do see this wide spread of beta values across people," he says.

***

"And what about the role of making mistakes? Their model provides support for the idea that the human brain isn't an optimal learning machine but rather that making mistakes, and learning from them, plays a huge role in behavior and cognition. It seems that being able to look at complex systems more broadly, like stepping away from a pointillist painting, gives the brain a better idea of overall relationships.

"'Understanding structure, or how these elements relate to one another, can emerge from an imperfect encoding of the information. If someone were perfectly able to encode all of the incoming information, they wouldn't necessarily understand the same kind of grouping of experiences that they do if there's a little bit of fuzziness to it," says Kahn.

"'The coolest thing is that errors in how people are learning and perceiving the world are influencing our ability to learn structures. So we are very much divorced from how a computer would act," says Lynn.

"The researchers are now interested in what makes the modular network easier for the brain to interpret and are also conducting functional MRI studies to understand where in the brain these network associations are being formed. They are also curious as to whether people's balance of complexity and accuracy is fluid, whether people can change on their own or if they are "set,"and also hope to do experiments using language inputs sometime in the future."

Comment: We certainly don't act like computers in our form of pattern recognition. Without question, our brain is built to help us understand what we are seeing. I find this explanation kind of muddy.

DAVID: Many adaptations for sapiens speech: high arched palate, dropped larynx, epiglottis airway protection, improved lip and tongue control for a bigger variety of phonemes, recently found cerebellar circuits. Of course a direct line, while it is the cause we debate.

dhw: Yes indeed. So do you think your God intervened in order to dabble these adaptations? If not, we have a natural progression. If he intervened, and if his sole purpose was to directly design H. sapiens, why do you think he did a mini-dabble 20 million years ago instead of getting on with the only speech mechanism he actually wanted?

DAVID: You keep forgetting that I view God as evolving from bacteria to humans in a slow progression as noted by the recognized time line of evolution. Part of the original plan. No corrective dabble.

dhw: I am not questioning the theory that there was a slow progression from bacteria to all life forms including humans. I am surprised to hear you say there was no dabble. The only theistic alternative you have offered us is a 3.8 billion-year-old programme for all species, innovations, lifestyles, natural wonders etc. Is that what you mean by “the original plan”. A short time ago, you decided that most advances were dabbles. I thought that included the palate, larynx, epiglottis etc. And if it’s neither programme nor dabble, what is the alternative?

A long time ago I proposed God either pre-planned evolution or did a course correction dabble now and then, based on my decision to conclude God ran the process of evolution starting with bacteria (Archaea). As a human making such a guess about God's actions, perhaps I am missing a third approach. Dabbling comes from a doubt that God is absolutely prescient in seeing the future without error, as religions claim. And that admits I am conceding some weakness in God, which is a form of humanizing Him. It is certainly possible that an all-powerful, all- knowing God never has to dabble. It is my distrust of religious descriptions of God that had me thinking in that manner. dhw gets worried when I change my mind, but all of us are allowed a re-think! dhw constantly/rigidly holds me to previous thoughts, which is unfair as new thinking occurs, based in part on his reasonable/unreasonable criticisms, and my own constant self-analysis. Even if he is on his picket fence, his thoughts are not higher than mine.

dhw: Yes indeed. So do you think your God intervened in order to dabble these adaptations? If not, we have a natural progression. If he intervened, and if his sole purpose was to directly design H. sapiens, why do you think he did a mini-dabble 20 million years ago instead of getting on with the only speech mechanism he actually wanted?

DAVID: You keep forgetting that I view God as evolving from bacteria to humans in a slow progression as noted by the recognized time line of evolution. Part of the original plan. No corrective dabble.

I am not questioning the theory that there was a slow progression from bacteria to all life forms including humans. I am surprised to hear you say there was no dabble. The only theistic alternative you have offered us is a 3.8 billion-year-old programme for all species, innovations, lifestyles, natural wonders etc. Is that what you mean by “the original plan”. A short time ago, you decided that most advances were dabbles. I thought that included the palate, larynx, epiglottis etc. And if it’s neither programme nor dabble, what is the alternative?

QUOTE: "Scientists have discovered an earlier origin to the human language pathway in the brain, pushing back its evolutionary origin by at least 20 million years."

DAVID: As usual I view it as God's preplanning evolution. It is simple to conclude God knew where He was headed.

dhw: It is simple to conclude that there is a direct line between us and our anthropoid ancestors. If I remember rightly, you used to tell us that your God must have intervened to give us the apparatus for human speech. But I’ll wait for you to confirm this before drawing any conclusions

DAVID: Many adaptations for sapiens speech: high arched palate, dropped larynx, epiglottis airway protection, improved lip and tongue control for a bigger variety of phonemes, recently found cerebellar circuits. Of course a direct line, while it is the cause we debate.

dhw: Yes indeed. So do you think your God intervened in order to dabble these adaptations? If not, we have a natural progression. If he intervened, and if his sole purpose was to directly design H. sapiens, why do you think he did a mini-dabble 20 million years ago instead of getting on with the only speech mechanism he actually wanted?

You keep forgetting that I view God as evolving from bacteria to humans in a slow progression as noted by the recognized time line of evolution. Part of the original plan. No corrective dabble. In my last book I noted a neurosurgeon who spotted an anticipatory vertebral change in a primate ancestor 22 million years ago.

DAVID: As usual I view it as God's preplanning evolution. It is simple to conclude God knew where He was headed.

dhw: It is simple to conclude that there is a direct line between us and our anthropoid ancestors. If I remember rightly, you used to tell us that your God must have intervened to give us the apparatus for human speech. But I’ll wait for you to confirm this before drawing any conclusions

DAVID: Many adaptations for sapiens speech: high arched palate, dropped larynx, epiglottis airway protection, improved lip and tongue control for a bigger variety of phonemes, recently found cerebellar circuits. Of course a direct line, while it is the cause we debate.

Yes indeed. So do you think your God intervened in order to dabble these adaptations? If not, we have a natural progression. If he intervened, and if his sole purpose was to directly design H. sapiens, why do you think he did a mini-dabble 20 million years ago instead of getting on with the only speech mechanism he actually wanted?

DAVID: We disagree about the blank slate concept of baby brains. My view is they are a blank slate before any new experience, but have an inherited background of tendencies for types of personality development. dhw's view was much more strict, noting that if the brain arrived with tendencies, it couldn't be called blank. A lot of semantic nothingness debate.

QUOTES: These neurophysiological measures were used to assess error-related negativity (ERN), which is a negative dip in the electrical signal recorded from the brain that occurs following incorrect responses on computerized tasks.

This study highlights the enduring nature of early temperament on adult outcomes and suggests that neurophysiological markers such as error-related negativity may help identify individuals most at risk for developing internalizing psychopathology in adulthood.

dhw: If the neurophysiological markers are present at birth, I don’t see how you can call the brain a blank at birth. It was you who used the word in the first place. I agree that it’s a nothingness debate. Quite clearly the brain is not a blank at birth.

We still take different views of blank slate, with no real difference.

QUOTE: "Scientists have discovered an earlier origin to the human language pathway in the brain, pushing back its evolutionary origin by at least 20 million years.

DAVID: As usual I view it as God's preplanning evolution. It is simple to conclude God knew where He was headed.

dhw: It is simple to conclude that there is a direct line between us and our anthropoid ancestors. If I remember rightly, you used to tell us that your God must have intervened to give us the apparatus for human speech. But I’ll wait for you to confirm this before drawing any conclusions

Many adaptations for sapiens speech: high arched palate, dropped larynx, epiglottis airway protection, improved lip and tongue control for a bigger variety of phonemes, recently found cerebellar circuits. Of course a direct line, while it is the cause we debate.

DAVID: As usual I view it as God's preplanning evolution. It is simple to conclude God knew where He was headed.

It is simple to conclude that there is a direct line between us and our anthropoid ancestors. If I remember rightly, you used to tell us that your God must have intervened to give us the apparatus for human speech. But I’ll wait for you to confirm this before drawing any conclusions

QUOTES: These neurophysiological measures were used to assess error-related negativity (ERN), which is a negative dip in the electrical signal recorded from the brain that occurs following incorrect responses on computerized tasks.

This study highlights the enduring nature of early temperament on adult outcomes and suggests that neurophysiological markers such as error-related negativity may help identify individuals most at risk for developing internalizing psychopathology in adulthood.

If the neurophysiological markers are present at birth, I don’t see how you can call the brain a blank at birth. It was you who used the word in the first place. I agree that it’s a nothingness debate. Quite clearly the brain is not a blank at birth.

https://cosmosmagazine.com/biology/seeing-the-adult-in-the-infant?utm_source=Cosmos+-+M...

"Researchers found that toddlers who displayed behavioural inhibition – cautious and fearful behaviours when exposed to unfamiliar people, objects and situations – became more reserved, introverted and less socially active as adults.

"And as teens, those that showed more intense brain activity after making mistakes in a computer task were more likely to develop symptoms of anxiety and depression, reports the study published in the journal Proceedings of the National Academy of Sciences.

“'Children show different behavioural styles very early in development,” explains lead author Alva Tang from the University of Maryland in the US.

***

"The finding that behaviourally inhibited infants became more reserved, introverted adults with lower social functioning extends other studies that tested children from three to six years of age.

"Various theories propose this occurs due to interactions between infant temperament and the environment.

“'As people age, personality might become increasingly stable due to the accumulation of and reinforcement from consistent experiences selected or created by the individuals,” the authors write.

"As an example, they suggest parents of behaviourally inhibited children might be overprotective, thus reinforcing the child’s temperament and social interactions.

"Children who are fearful of new social situations may avoid them and thus prevent opportunities for social learning and friendship building.

"Intriguingly, early inhibition was not related to career and education or romantic relationship outcomes, adding to other inconclusive findings in these regards.

"Tang suggests several possible reasons for this, including methodological or generational differences.

“'Alternatively,” she says, “it could mean that even though behaviourally inhibited infants have worse social functioning in some domains, they are by and large able to function effectively in society.”

"By revealing neural activity associated with anxiety disorders in adulthood, the study also gives insights into risk versus resilience, providing an opportunity to intervene.

“'These findings highlight the enduring nature of early temperament, which shapes long-term personality and wellbeing,” Tang says, “and suggests that neurophysiological markers could help identify individuals who are most at risk for internalising psychopathology in adulthood.'”

Comment: The objections to some of the studies' findings are valid, but miss the fact that adult personality is many faceted, and the study covers one small aspect. Autobiographical note: as a young teenager I remember being tentative about trying new things, yet I have had a very successful life, top of the class grades, career, and two marriages.

https://medicalxpress.com/news/2020-04-human-language-pathway-brain-million.html

"Scientists have discovered an earlier origin to the human language pathway in the brain, pushing back its evolutionary origin by at least 20 million years.

***

"They discovered a segment of this language pathway in the human brain that interconnects the auditory cortex with frontal lobe regions, important for processing speech and language. Although speech and language are unique to humans, the link via the auditory pathway in other primates suggests an evolutionary basis in auditory cognition and vocal communication.

"Professor Petkov added: "We predicted but could not know for sure whether the human language pathway may have had an evolutionary basis in the auditory system of nonhuman primates. I admit we were astounded to see a similar pathway hiding in plain sight within the auditory system of nonhuman primates."

"The study also illuminates the remarkable transformation of the human language pathway. A key human unique difference was found: the human left side of this brain pathway was stronger and the right side appears to have diverged from the auditory evolutionary prototype to involve non-auditory parts of the brain.

The actual abstract:

"Abstract
The human arcuate fasciculus pathway is crucial for language, interconnecting posterior temporal and inferior frontal areas. Whether a monkey homolog exists is controversial and the nature of human-specific specialization unclear. Using monkey, ape and human auditory functional fields and diffusion-weighted MRI, we identified homologous pathways originating from the auditory cortex. This discovery establishes a primate auditory prototype for the arcuate fasciculus, reveals an earlier phylogenetic origin and illuminates its remarkable transformation."

Comment: As usual I view it as God's preplanning evolution. It is simple to conclude God knew where He was headed.

https://medicalxpress.com/news/2020-04-infant-temperament-personality-years.html

"Temperament refers to biologically based individual differences in the way people emotionally and behaviorally respond to the world. During infancy, temperament serves as the foundation of later personality. One specific type of temperament, called behavioral inhibition (BI), is characterized by cautious, fearful, and avoidant behavior toward unfamiliar people, objects, and situations. BI has been found to be relatively stable across toddlerhood and childhood, and children with BI have been found to be at greater risk for developing social withdrawal and anxiety disorders than children without BI.

***

"The researchers assessed the infants for BI at 14 months of age. At age 15, these participants returned to the lab to provide neurophysiological data. These neurophysiological measures were used to assess error-related negativity (ERN), which is a negative dip in the electrical signal recorded from the brain that occurs following incorrect responses on computerized tasks. Error-related negativity reflects the degree to which people are sensitive to errors. A larger error-related negativity signal has been associated with internalizing conditions such as anxiety, and a smaller error-related negativity has been associated with externalizing conditions such as impulsivity and substance use. The participants returned at age 26 for assessments of psychopathology, personality, social functioning, and education and employment outcomes.

***

"The researchers found that BI at 14 months of age predicted, at age 26, a more reserved personality, fewer romantic relationships in the past 10 years, and lower social functioning with friends and family. BI at 14 months also predicted higher levels of internalizing psychopathology in adulthood, but only for those who also displayed larger error-related negativity signals at age 15. BI was not associated with externalizing general psychopathology or with education and employment outcomes.

"This study highlights the enduring nature of early temperament on adult outcomes and suggests that neurophysiological markers such as error-related negativity may help identify individuals most at risk for developing internalizing psychopathology in adulthood.

"'We have studied the biology of behavioral inhibition over time and it is clear that it has a profound effect influencing developmental outcome," concluded Dr. Fox."

Comment: A clear cut result.

dhw: My point was that if learning changes the structure of the brain, clearly the learning precedes the changes, which is why I suggest that the whole history of brain structure, including expansion, just like that of other organs, has come about through the cells’ responses to new situations, conditions etc. This proposal is in contrast to Darwin’s random mutations and to your own theory that your God made all the changes (either by preprogramming or by dabbling) before the new situations etc. arose.

DAVID: The changes we know in Indian illiterates and London cabbies alters an existing brain but does not create a species with a new brain size and capacity. I think your theory is a real stretch.

dhw: If you accept common descent, you will have to accept that the new brain size and capacity were the result of changes to existing brains. Since we know that learning changes the structure of the brain, it is not unreasonable to suggest that once an existing brain had reached the limits of its ability to cope with new situations (learning always involves something new to the learner), it had to increase its capacity. This too means a structural change – more cells, more connections, and an expansion of the container to house the new cells. I can’t see that this is more of a “stretch” than random mutations, or your God popping in to do a dabble before there is any need for expansion (just as you think he popped in to change the pre-whale’s legs into flippers before it entered the water). It seems perfectly logical to me that if something new causes existing structures to change now, it may have done the same throughout evolution.

I understand your problem in not accepting my approach. I do accept God as being in charge of creation and necessarily through the process of evolution. It is the only way I can explain the stepwise enlargement of the human brain.

DAVID: The changes we know in Indian illiterates and London cabbies alters an existing brain but does not create a species with a new brain size and capacity. I think your theory is a real stretch.

If you accept common descent, you will have to accept that the new brain size and capacity were the result of changes to existing brains. Since we know that learning changes the structure of the brain, it is not unreasonable to suggest that once an existing brain had reached the limits of its ability to cope with new situations (learning always involves something new to the learner), it had to increase its capacity. This too means a structural change – more cells, more connections, and an expansion of the container to house the new cells. I can’t see that this is more of a “stretch” than random mutations, or your God popping in to do a dabble before there is any need for expansion (just as you think he popped in to change the pre-whale’s legs into flippers before it entered the water). It seems perfectly logical to me that if something new causes existing structures to change now, it may have done the same throughout evolution.

dhw: Although I can’t follow all the scientific stuff on this particularly thread, I’m very interested in the “hint at how brain cells change structure when they learn something”. This is a known fact (we had various examples earlier of the illiterate women learning to read, and of taxi drivers’ and musicians’ brains undergoing such changes). The obvious implication is that the brain does not change before the arrival of new activities but in response to them. Thus one can well imagine that the first pre-humans to leave the trees (for whatever reason) and the first pre-whales to enter the water would not only have adapted their bodies to the new environment but would also have undergone brain change as a result of these new conditions and the need to adjust their behaviour. In the case of pre-humans, so great was the number of new things to be learned that the existing capacity would not have been large enough to cope – hence expansion of the brain: not the result of random mutations or of divine dabbling, but of the brain cell communities responding to new requirements. Just a hypothesis, of course.

DAVID: Of course current brain cells have a great deal of plasticity, but that capacity had to have been designed into the current brain by some process. For me only a designing mind fits.

dhw: I don’t have a problem with that argument. My point was that if learning changes the structure of the brain, clearly the learning precedes the changes, which is why I suggest that the whole history of brain structure, including expansion, just like that of other organs, has come about through the cells’ responses to new situations, conditions etc. This proposal is in contrast to Darwin’s random mutations and to your own theory that your God made all the changes (either by preprogramming or by dabbling) before the new situations etc. arose.

The changes we know in Indian illiterates and London cabbies alters an existing brain but does not create a species with a new brain size and capacity. I think your theory is a real stretch.