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Beyond Nature vs. Nurture

Researchers studying differences in how individuals respond to stress are finding that genes are malleable and environments can be deterministic.

By | October 1, 2011

VINTAGE, AUGUST 2011

A journalist once asked the behavioral psychologist Donald Hebb whether a person’s genes or environment mattered most to the development of personality. Hebb replied that the question was akin to asking which feature of a rectangle—length or width—made the most important contribution to its area.

The “nature vs. nurture” conundrum was reinvigorated when genes were identified as the units of heredity, containing information that directs and influences development. When the human genome was sequenced in 2001, the hope was that all such questions would be answered. In the intervening decade, it has become apparent that there are many more questions than before.

We’ve reached a point where most people are savvy enough to know that the correct response isn’t “nature” or “nurture,” but some combination of the two. Yet scientists and laymen alike still spend too much time and effort trying to quantify the relative importance of nature and nurture.

Recent advances in neuroscience make a compelling case for finally abandoning the nature vs. nurture debate to focus on understanding the mechanisms through which genes and environments are perpetually entwined throughout an individual’s lifetime. As neurobiologists who study stress, we believe that research in this area will help reframe the study of human nature.

Researchers have historically approached the study of stress from two perspectives: 1) a physiological account of the stress response, which consists of tracking the stress hormone cortisol and its effects on metabolism, immune function, and neural processes; and 2) a psychological/cognitive focus on how the perception and experience of a stressor influences the stress response. These approaches align with the nature vs. nurture debate, pitting nature, represented by the biology of cortisol responses, against nurture, in the form of external experience influencing cognitive processing. Academic researchers typically study stress by adopting one of these perspectives. However, anyone who’s been stuck in rush hour traffic or faced a looming deadline knows that the causes and consequences of stressful experiences do not adhere to these academic divides.

Scientists and laymen alike still spend too much time and effort trying to quantify the relative importance of nature and nurture.

In the past decade, researchers have made great strides in understanding the cellular, molecular, genetic, and epigenetic processes involved in the regulation of the stress response. Surprisingly, as stress research elucidated this molecular dimension, it shed light on the powerful role of environment and experience in remodeling our molecular makeup. It became clear that the environmental effects (nurture) are modulated by genetic polymorphism and epigenetic programming of gene expression (nature) to shape development. So, as the molecular underpinnings are elucidated, the need to study the interaction between environment and our genome is highlighted, and the divide seems less relevant.

Recent advances in stress research (focused on genetic, epigenetic, and molecular events) are inverting implicit assumptions about gene/environment relationships and the nature/nurture divide. The most current data indicate that environments can be as deterministic as we once believed only genes could be, and that the genome can be as malleable as we once believed only environments could be. For example, increased expression of the glucocorticoid receptor gene in particular brain regions improves the ability to regulate a stress response. In the lab we’ve demonstrated that enhanced maternal care provided to young rats serves to permanently increase expression of this gene in brain regions that ultimately influence how the animals respond to stress. Early nurturing regulates the expression of a gene that is crucial to modulating the stress response.

The mind/body divide is disappearing, too, as we discover that mental phenomena have physical correlates, an understanding of which can help us develop new approaches for research, teaching, and policy related to stress and health. While this integrative view of stress probably seems obvious to the average thinking person, it’s taken basic scientists fifty years to reach the same conclusion. The false dichotomy of nature vs. nurture is quickly eroding, and the modern era of stress research makes a compelling case for the study of the dynamic interplay between our genomes and our experiences.

This month’s Reading Frames articles are penned by contributors to Future Science: Essays From the Cutting Edge, a compilation of writings from leading young scientists pushing the boundaries of their respective fields.

Darlene Francis is an assistant professor in the University of California, Berkeley, School of Public Health–Division of Community Health and Human Development. Daniela Kaufer is an associate professor in the Department of Integrative Biology and the Helen Wills Neuroscience Institute at UC Berkeley. They collaborate on studying how stress in early life can alter neurodevelopment. You can read Francis's and Kaufer's essay from Future Science.

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Anonymous

October 21, 2011

Plasticity currently is gaining in popularity, and that is refreshing. 

In reading this article I was reminded, if only peripherally, of Thomas Kuhn's description, in his first essay, of how various branches of the sciences historically have been first scattered  prior to sort of coalescing into a somewhat unified or standardized into a paradigmatic unity.  (The terms "scattered," "coalescing," "unity" here are my best effort to cited his gist, rather than his terms of choice.)  I recall his saying that Isaac Newton first brought physics out of such a "scattered" state, Franklin brought the study of electricity out of its, etc.  One by one, various branchings and sub-branchings of sciences have come in out of this "scattered" state of having many different scholars working from many different approaches. 

The general field of biology, as the study of living things, has always impressed me as being enormously broad in scope, and various sub-branchings of it have become so unique, so specialized, so demanding of expertise to work at their frontiers (it seems to me) that trying to hold all of them in a single conceptual compartment of mind is beginning even to strain the imagination.  Simply to group them all by the commonality of being in regard to "living things" is to take an enormous number of disparate things under an umbrella.  It seems (to me at least) that it would be comparable to including under a single umbrella, say, things that participate in change and motion.

Some branchings of the general study of biological issues, so to speak, are so vastly distinct from others that those in one branch of study and research have little time for another.  At the same time, some specialized areas of study can, at some point, suddenly highly inter-interested. 

And in this round about way, my interest in the concept of "evolutionary adaptation," comes into play.  This is more than any simplistic, or dogma-based issue for me.  I genuinely am curious as to how a species can, over successive generations, few or many, rapidly or slowly, adapt to anything.  It has never, never ever struck me as feasible to say that random mutations come along and provide an advantage to some individuals in a species, which fortuitously enable the species, over multiple generations, to adapt in such a way as to increase fitness.

I harp on this.  My mind is open on it.  Nothing inclines me to be critical of any rationale whereby species may "adapt" to specific environmental changes, such as upon migrating into an area having different weather conditions, or into higher elevations, or when a portion of a species remains in a given area and the ecology in that area changes.  How, my curiosity demands me to ask, does a fortuitous mutation, or set of mutations, or series of mutations in just the right order... come along when it is needed.

It seems to me that Darwin's finches carry genes that are not new mutations, but have been present for a long, long time, whereby those with one capability (genetically constrained, or epigenetically constrained, as the case may be) tends to make the one ESTABLISHED PROPENSITY more favored for a time, and then when some of those finches become separated, and food conditions are different, or begin to change, EITHER epigenetic determinants may prefer the one or the other characteristic of beak formation OR genetically favored determinants may become favored (for a while).

What totally does NOT makes any sense to me is that Darwin's finches should be cited as EXAMPLES of evolution by way of current mutations.  The same applies to citing changes of moth coloration from darker to lighter, or lighter to darker, in adapting to changes in their environment.  This kind of "adaptation," it seems very reasonable to me is already established in said finches and in said moths.  And these changes are, as it were, "already wired in" as alternatives. 

Polar bears may have some "already wired-in" capability of changing (it will have to be FAST) to adapt, in some manner, to the currently ongoing melt-down in antartica.  Elephants may have some "already wired-in" capacity to adapt to the removal or sequestration beyond their access, of areas they are allowed to feed in.  Somehow I doubt these species will remain very far into the future, outside human intervention, which, itself, may become increasingly untenable for humans to keep up.
 
Never have I read or heard of any mechanism (as opposed to a historical acknowledgement and description of evidence of the fact of certain changes) that would account for testable hypotheses regarding same can be assigned to the so-called "Cambrian explosion," or to any other period of rapid change in the process of punctuated equilibrium could have occurred.  Of course, the first step, before hypothesizing about such a mechanism, would be to segregate  "already wired-in" adaptive capabilities from new random mutations (or a mechanism for interactive mutations appropriate to specific environmental stimuli, such as loss of ice flows, or desertification, or long term alternations from drought periods with rainy periods.

Random mutations might be increased by any stress upon gametes, perhaps.  For example, marginal starvation, or excess heat might physically influence them. For much too long a time, the "science" by which answers to such questions was sought was genetics.  Now, epigenetics becomes a more recognized area for thought in its regard.  But my curiosity continues,and grows, as to whether, and if so how, somatic cell experience, epigenetic experience, might signal to gametes:  "Hey guys, how about coming up with a mutation or something, that might help us adapt to this new situation we are having to deal with out here in our daily lives.  I mean, we need to CHANGE in some appropriate way if we are going to prevail, dudes!"                 

Avatar of: Guest

Anonymous

October 21, 2011

Regarding the somatic cells saying to the gametes: 

"Hey guys, how about coming up with a mutation or something, that might
help us adapt to this new situation we are having to deal with out here
in our daily lives.  I mean, we need to CHANGE in some appropriate way
if we are going to prevail, dudes!"

Here's a post script:

"This already wired-in stuff ain't cuttin' it.  You gotta give us some NEW mutation.  And, while you're at it, come up with something appropriate.  We don't need a change of eye-color, or spotted coats, or any cancers, or extra legs, please.  That's not what we NEED.  So, hurry up.  Time's running out?"

Avatar of:

Posts: 0

October 21, 2011

Plasticity currently is gaining in popularity, and that is refreshing. 

In reading this article I was reminded, if only peripherally, of Thomas Kuhn's description, in his first essay, of how various branches of the sciences historically have been first scattered  prior to sort of coalescing into a somewhat unified or standardized into a paradigmatic unity.  (The terms "scattered," "coalescing," "unity" here are my best effort to cited his gist, rather than his terms of choice.)  I recall his saying that Isaac Newton first brought physics out of such a "scattered" state, Franklin brought the study of electricity out of its, etc.  One by one, various branchings and sub-branchings of sciences have come in out of this "scattered" state of having many different scholars working from many different approaches. 

The general field of biology, as the study of living things, has always impressed me as being enormously broad in scope, and various sub-branchings of it have become so unique, so specialized, so demanding of expertise to work at their frontiers (it seems to me) that trying to hold all of them in a single conceptual compartment of mind is beginning even to strain the imagination.  Simply to group them all by the commonality of being in regard to "living things" is to take an enormous number of disparate things under an umbrella.  It seems (to me at least) that it would be comparable to including under a single umbrella, say, things that participate in change and motion.

Some branchings of the general study of biological issues, so to speak, are so vastly distinct from others that those in one branch of study and research have little time for another.  At the same time, some specialized areas of study can, at some point, suddenly highly inter-interested. 

And in this round about way, my interest in the concept of "evolutionary adaptation," comes into play.  This is more than any simplistic, or dogma-based issue for me.  I genuinely am curious as to how a species can, over successive generations, few or many, rapidly or slowly, adapt to anything.  It has never, never ever struck me as feasible to say that random mutations come along and provide an advantage to some individuals in a species, which fortuitously enable the species, over multiple generations, to adapt in such a way as to increase fitness.

I harp on this.  My mind is open on it.  Nothing inclines me to be critical of any rationale whereby species may "adapt" to specific environmental changes, such as upon migrating into an area having different weather conditions, or into higher elevations, or when a portion of a species remains in a given area and the ecology in that area changes.  How, my curiosity demands me to ask, does a fortuitous mutation, or set of mutations, or series of mutations in just the right order... come along when it is needed.

It seems to me that Darwin's finches carry genes that are not new mutations, but have been present for a long, long time, whereby those with one capability (genetically constrained, or epigenetically constrained, as the case may be) tends to make the one ESTABLISHED PROPENSITY more favored for a time, and then when some of those finches become separated, and food conditions are different, or begin to change, EITHER epigenetic determinants may prefer the one or the other characteristic of beak formation OR genetically favored determinants may become favored (for a while).

What totally does NOT makes any sense to me is that Darwin's finches should be cited as EXAMPLES of evolution by way of current mutations.  The same applies to citing changes of moth coloration from darker to lighter, or lighter to darker, in adapting to changes in their environment.  This kind of "adaptation," it seems very reasonable to me is already established in said finches and in said moths.  And these changes are, as it were, "already wired in" as alternatives. 

Polar bears may have some "already wired-in" capability of changing (it will have to be FAST) to adapt, in some manner, to the currently ongoing melt-down in antartica.  Elephants may have some "already wired-in" capacity to adapt to the removal or sequestration beyond their access, of areas they are allowed to feed in.  Somehow I doubt these species will remain very far into the future, outside human intervention, which, itself, may become increasingly untenable for humans to keep up.
 
Never have I read or heard of any mechanism (as opposed to a historical acknowledgement and description of evidence of the fact of certain changes) that would account for testable hypotheses regarding same can be assigned to the so-called "Cambrian explosion," or to any other period of rapid change in the process of punctuated equilibrium could have occurred.  Of course, the first step, before hypothesizing about such a mechanism, would be to segregate  "already wired-in" adaptive capabilities from new random mutations (or a mechanism for interactive mutations appropriate to specific environmental stimuli, such as loss of ice flows, or desertification, or long term alternations from drought periods with rainy periods.

Random mutations might be increased by any stress upon gametes, perhaps.  For example, marginal starvation, or excess heat might physically influence them. For much too long a time, the "science" by which answers to such questions was sought was genetics.  Now, epigenetics becomes a more recognized area for thought in its regard.  But my curiosity continues,and grows, as to whether, and if so how, somatic cell experience, epigenetic experience, might signal to gametes:  "Hey guys, how about coming up with a mutation or something, that might help us adapt to this new situation we are having to deal with out here in our daily lives.  I mean, we need to CHANGE in some appropriate way if we are going to prevail, dudes!"                 

Avatar of:

Posts: 0

October 21, 2011

Regarding the somatic cells saying to the gametes: 

"Hey guys, how about coming up with a mutation or something, that might
help us adapt to this new situation we are having to deal with out here
in our daily lives.  I mean, we need to CHANGE in some appropriate way
if we are going to prevail, dudes!"

Here's a post script:

"This already wired-in stuff ain't cuttin' it.  You gotta give us some NEW mutation.  And, while you're at it, come up with something appropriate.  We don't need a change of eye-color, or spotted coats, or any cancers, or extra legs, please.  That's not what we NEED.  So, hurry up.  Time's running out?"

Avatar of:

Posts: 0

October 21, 2011

Plasticity currently is gaining in popularity, and that is refreshing. 

In reading this article I was reminded, if only peripherally, of Thomas Kuhn's description, in his first essay, of how various branches of the sciences historically have been first scattered  prior to sort of coalescing into a somewhat unified or standardized into a paradigmatic unity.  (The terms "scattered," "coalescing," "unity" here are my best effort to cited his gist, rather than his terms of choice.)  I recall his saying that Isaac Newton first brought physics out of such a "scattered" state, Franklin brought the study of electricity out of its, etc.  One by one, various branchings and sub-branchings of sciences have come in out of this "scattered" state of having many different scholars working from many different approaches. 

The general field of biology, as the study of living things, has always impressed me as being enormously broad in scope, and various sub-branchings of it have become so unique, so specialized, so demanding of expertise to work at their frontiers (it seems to me) that trying to hold all of them in a single conceptual compartment of mind is beginning even to strain the imagination.  Simply to group them all by the commonality of being in regard to "living things" is to take an enormous number of disparate things under an umbrella.  It seems (to me at least) that it would be comparable to including under a single umbrella, say, things that participate in change and motion.

Some branchings of the general study of biological issues, so to speak, are so vastly distinct from others that those in one branch of study and research have little time for another.  At the same time, some specialized areas of study can, at some point, suddenly highly inter-interested. 

And in this round about way, my interest in the concept of "evolutionary adaptation," comes into play.  This is more than any simplistic, or dogma-based issue for me.  I genuinely am curious as to how a species can, over successive generations, few or many, rapidly or slowly, adapt to anything.  It has never, never ever struck me as feasible to say that random mutations come along and provide an advantage to some individuals in a species, which fortuitously enable the species, over multiple generations, to adapt in such a way as to increase fitness.

I harp on this.  My mind is open on it.  Nothing inclines me to be critical of any rationale whereby species may "adapt" to specific environmental changes, such as upon migrating into an area having different weather conditions, or into higher elevations, or when a portion of a species remains in a given area and the ecology in that area changes.  How, my curiosity demands me to ask, does a fortuitous mutation, or set of mutations, or series of mutations in just the right order... come along when it is needed.

It seems to me that Darwin's finches carry genes that are not new mutations, but have been present for a long, long time, whereby those with one capability (genetically constrained, or epigenetically constrained, as the case may be) tends to make the one ESTABLISHED PROPENSITY more favored for a time, and then when some of those finches become separated, and food conditions are different, or begin to change, EITHER epigenetic determinants may prefer the one or the other characteristic of beak formation OR genetically favored determinants may become favored (for a while).

What totally does NOT makes any sense to me is that Darwin's finches should be cited as EXAMPLES of evolution by way of current mutations.  The same applies to citing changes of moth coloration from darker to lighter, or lighter to darker, in adapting to changes in their environment.  This kind of "adaptation," it seems very reasonable to me is already established in said finches and in said moths.  And these changes are, as it were, "already wired in" as alternatives. 

Polar bears may have some "already wired-in" capability of changing (it will have to be FAST) to adapt, in some manner, to the currently ongoing melt-down in antartica.  Elephants may have some "already wired-in" capacity to adapt to the removal or sequestration beyond their access, of areas they are allowed to feed in.  Somehow I doubt these species will remain very far into the future, outside human intervention, which, itself, may become increasingly untenable for humans to keep up.
 
Never have I read or heard of any mechanism (as opposed to a historical acknowledgement and description of evidence of the fact of certain changes) that would account for testable hypotheses regarding same can be assigned to the so-called "Cambrian explosion," or to any other period of rapid change in the process of punctuated equilibrium could have occurred.  Of course, the first step, before hypothesizing about such a mechanism, would be to segregate  "already wired-in" adaptive capabilities from new random mutations (or a mechanism for interactive mutations appropriate to specific environmental stimuli, such as loss of ice flows, or desertification, or long term alternations from drought periods with rainy periods.

Random mutations might be increased by any stress upon gametes, perhaps.  For example, marginal starvation, or excess heat might physically influence them. For much too long a time, the "science" by which answers to such questions was sought was genetics.  Now, epigenetics becomes a more recognized area for thought in its regard.  But my curiosity continues,and grows, as to whether, and if so how, somatic cell experience, epigenetic experience, might signal to gametes:  "Hey guys, how about coming up with a mutation or something, that might help us adapt to this new situation we are having to deal with out here in our daily lives.  I mean, we need to CHANGE in some appropriate way if we are going to prevail, dudes!"                 

Avatar of:

Posts: 0

October 21, 2011

Regarding the somatic cells saying to the gametes: 

"Hey guys, how about coming up with a mutation or something, that might
help us adapt to this new situation we are having to deal with out here
in our daily lives.  I mean, we need to CHANGE in some appropriate way
if we are going to prevail, dudes!"

Here's a post script:

"This already wired-in stuff ain't cuttin' it.  You gotta give us some NEW mutation.  And, while you're at it, come up with something appropriate.  We don't need a change of eye-color, or spotted coats, or any cancers, or extra legs, please.  That's not what we NEED.  So, hurry up.  Time's running out?"

Avatar of:

Posts: 0

October 23, 2011

Expression of genes is affected by the enviroment (nurture).Only presence of gene for a particular trait can not be the reality of the trait,more significant is whether the expresses or not

Avatar of:

Posts: 0

October 23, 2011

Expression of genes is affected by the enviroment (nurture).Only presence of gene for a particular trait can not be the reality of the trait,more significant is whether the expresses or not

Avatar of: Dr. Ichha Purak

Dr. Ichha Purak

Posts: 1457

October 23, 2011

Expression of genes is affected by the enviroment (nurture).Only presence of gene for a particular trait can not be the reality of the trait,more significant is whether the expresses or not

Avatar of: keepitgoing

keepitgoing

Posts: 1

November 26, 2011

Perfect! The answer my friend is blowin in the wind...

Avatar of:

Posts: 0

November 26, 2011

Perfect! The answer my friend is blowin in the wind...

Avatar of:

Posts: 0

November 26, 2011

Perfect! The answer my friend is blowin in the wind...

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