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The trouble with trusting complex science (pg. 12)
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| Meat187 |
| quote: | Originally posted by woscar
What is your field of study? Using tunneling electron microscopes to analyze Slylee's posts does not count. :p |
Electrical Engineering, specialized in Bioengineering and Medical Life Science. After Lira's post 7 pages (with my awesome setting, shut up!) emerged and I can't believe the cor stayed on topic that long. :p |
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| Moral Hazard |
| quote: | Originally posted by Meat187
After Lira's post 7 pages (with my awesome setting, shut up!) emerged and I can't believe the cor stayed on topic that long. :p |
In all fairness, we totally got off topic. |
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| woscar |
| quote: | Originally posted by Chimney
Which is yours? |
I'm not a scientist, although my field (work, study, etc) when I graduate will be Engineering in Telecommunications.
Edit: that might seem contradictory, but what I meant is that I don't consider myself to be a scientist yet, just on a career to becoming one even though I do exercise a scientific approach and way of thinking in my day to day life. :p |
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| PETRAN |
| quote: | Originally posted by Chimney
Think you get a little ahead of yourself here. You work in the field of genetics? If not, I'd like to see some sources on this (books, sites et cetera).
There are plenty of traits that can change within ourselves from things we do daily. |
What i posted was partly a result of some relatively recent findings and some speculation (e.g. on the inherited psychological trauma which was just an idea) just for the purposes of firing imagination and creativity processes heh. My field is not genetics, i have a degree in psychology (with a cognitive/biological focus)and i came accross epigenetics through the work of a research psychopharmacologist called arturas petronis
http://www.pharmtox.utoronto.ca/fac...ry/petronis.htm
The fact that up to 35% of homozygotic genome can change was demonstrated in studies by this spanish research group
http://www.pnas.org/content/102/30/10604.full
The discussion section
Although genomic information is uniform among the different cells of a complex organism, the epigenome varies from tissue to tissue, controlling the differential expression of genes and providing specific identity to each cell type. DNA methylation and histone modifications store epigenetic information that mainly controls heritable states of gene expression (12, 13), and it is now well established that both epigenetic layers are mechanistically linked (12, 13).
Our study reveals that the patterns of epigenetic modifications in MZ twin pairs diverge as they become older. Differences in epigenetic patterns in genetically identical individuals could be explained by the influence of both external and internal factors. Smoking habits, physical activity, or diet, among others, are external factors that have been proposed to have a long-term influence on epigenetic modifications (12, 13). However, it is possible that small defects in transmitting epigenetic information through successive cell divisions, or maintaining it in differentiated cells, accumulate in a process that could be considered as an “epigenetic drift” associated with the aging process (14, 15). Identification of proteins that mediate these effects has provided an insightful view into this complex process and in the diseases that occur when it is perturbed (12, 13). Accumulation of epigenetic defects would probably occur at a faster rate than that corresponding to genetic mutations because their consequences in survival are probably less dramatic and cells have not developed a comparable amount of mechanisms to correct them.
MZ twins constitute an excellent example of how genetically identical individuals can exhibit differences and therefore provide a unique model to study the contribution/role of epigenetic modifications in the establishment of the phenotype (2, 16–18). What does make MZ twins differ? By using whole-genome and locus-specific approaches, we found that approximately one-third of MZ twins harbored epigenetic differences in DNA methylation and histone modification. These differential markers between twins are distributed throughout their genomes, affecting repeat DNA sequences and single-copy genes, and have an important impact on gene expression. We also established that these epigenetic markers were more distinct in MZ twins who were older, had different lifestyles, and had spent less of their lives together, underlining the significant role of environmental factors in translating a common genotype into a different phenotype. Our findings also support the role of epigenetic differences in the discordant frequency/onset of diseases in MZ twins (2, 16–18).
Other evidence indicates that relatively small differences in epigenetic patterns can have a large impact in phenotype, for instance in cloned animals (4), with MZ twins representing natural human clones. Another powerful example is provided by the agouti mouse (19). In this model, diet affects the methylation status of an inserted intracisternal A particle element that changes the animal's coat color: an environmental factor interacting with a single genotype, mediated by an epigenetic change, to produce a different phenotype. In humans, the investigation of how assisted reproductive technology that uses media with undisclosed concentrations of methyl-donors associates with epigenetic errors such as imprinting defects and cancer has been proposed (20). Our comparison of MZ twins suggests that external and/or internal factors can have an impact in the phenotype by altering the pattern of epigenetic modifications and thus modulating the genetic information. Future studies should now address the specific mechanisms responsible for the observed epigenetic drift of MZ twins
An exciting study made in 2009 linking neuro-behavioural and hereditary processes is mentioned in this article
http://www.technologyreview.com/biomedicine/22061/
In Feig's study, mice genetically engineered to have memory problems were raised in an enriched environment--given toys, exercise, and social interaction--for two weeks during adolescence. The animals' memory improved--an unsurprising finding, given that enrichment has been previously shown to boost brain function. The mice were then returned to normal conditions, where they grew up and had offspring. This next generation of mice also had better memory, despite having the genetic defect and never having been exposed to the enriched environment.
The researchers also looked at a molecular correlate of memory called long-term potentiation, or LTP, a mechanism that strengthens connections between neurons. Environmental enrichment fixed faulty LTP in mice with the genetic defect; the fixed LTP was then passed on to their offspring. The findings held true even when pups were raised by memory-deficient mice that had never had the benefits of toys and social interaction. "When you look at offspring, they still have the defect in the protein, but they also have normal LTP," says Feig. The findings were published today in the Journal of Neuroscience
A brief note of the epigenetic influence on evolution can be found in the quite-good IMO wikipedia article on epigenetics
http://en.wikipedia.org/wiki/Epigenetics
Evolution
Although epigenetics in multicellular organisms is generally thought to be a mechanism involved in differentiation, with epigenetic patterns "reset" when organisms reproduce, there have been some observations of transgenerational epigenetic inheritance (e.g., the phenomenon of paramutation observed in maize). Although most of these multigenerational epigenetic traits are gradually lost over several generations, the possibility remains that multigenerational epigenetics could be another aspect to evolution and adaptation. These effects may require enhancements to the standard conceptual framework of the modern evolutionary synthesis.[32][33]
Epigenetic features may play a role in short-term adaptation of species by allowing for reversible phenotype variability. The modification of epigenetic features associated with a region of DNA allows organisms, on a multigenerational time scale, to switch between phenotypes that express and repress that particular gene.[34] When the DNA sequence of the region is not mutated, this change is reversible. It has also been speculated that organisms may take advantage of differential mutation rates associated with epigenetic features to control the mutation rates of particular genes.[34]
Epigenetic changes have also been observed to occur in response to environmental exposure—for example, mice given some dietary supplements have epigenetic changes affecting expression of the agouti gene, which affects their fur color, weight, and propensity to develop cancer.
The importance of epigenetics can be found in the work of Eva Jablonka which performs groundbreaking work in all genetic, epi-genetic and non-genetic aspects of evolution. There is a groundbreaking book called "Evolution in Four Dimensions" which Jablonka states that traditional genetic inheritance, epigenetic changes, behavioural learning and symbolic (memetic) inheritance (the last one only found in humans) can contribute to evolution.
http://en.wikipedia.org/wiki/Eva_Jablonka
It seems that epigenetic contributions are very important in the development of the individual. The question is how important these changes are in regard to evolution and newer studies suggest that it is more important than previously thought. I don't know if all these could lead to a soft neo-lamarckist contribution to evolution but science would have the last word. |
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| woscar |
| And I just found out that my university opened a new faculty which will be offering a one year program on Basic Astrophysics which I will take next year. :) |
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| MrJiveBoJingles |
| quote: | Originally posted by PETRAN
Yep, thats the case. Although there is a new tendency which questions if this is the whole story. There are new findings that prove an important epigenetic influence leading to some very important ideas. Epigenetic findings suggest that DNA can change (through processes such as methylation or through proteomic mechanisms through histones) throughout the lifetime of the individual and the important fact is that, that some of these changes could pass to the offspring. |
I know. This is exactly why I wrote "usually." ;) |
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| Fledz |
It's great to see discussion on mutations in here. It stimulates my brain and takes me back to a couple of years ago while doing Molecular Biology and studying Immunology :D
| quote: | Originally posted by Moral Hazard
I think the trouble with the US polling results may be in the way the questions were asked. I would suspect that anyone who held a belief in any deity would be reluctant to agree that said deity had "no part in this process." Myself for instance; I am inclined to believe that if there is a deity then that deity is responsible for at very least laying the groundwork upon which the universe is built; subsequently, I could not agree that if there is a deity that deity had "no part" in evolution even though I fully accept evolution as the most probable explenation for the development of all life on earth without any direct guidence from said deity. I would imagine that if one were to re-word the questions slightly they would get drastically different results. |
I completely agree with you here mate. I definitely think there is room for the possibility of a higher being within the scope of science, though more on a philosophical plain rather than a fact based one. |
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| woscar |
| quote: | Originally posted by Moral Hazard
I think the trouble with the US polling results may be in the way the questions were asked. I would suspect that anyone who held a belief in any deity would be reluctant to agree that said deity had "no part in this process." Myself for instance; I am inclined to believe that if there is a deity then that deity is responsible for at very least laying the groundwork upon which the universe is built; subsequently, I could not agree that if there is a deity that deity had "no part" in evolution even though I fully accept evolution as the most probable explenation for the development of all life on earth without any direct guidence from said deity. I would imagine that if one were to re-word the questions slightly they would get drastically different results. |
Completely genuine question here, not intended to start any ...
If this is really what you believe, then it's pretty much textbook Deism. Why do you still follow the Roman Catholic religion? |
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| Fledz |
| quote: | Originally posted by woscar
Completely genuine question here, not intended to start any ...
If this is really what you believe, then it's pretty much textbook Deism. Why do you still follow the Roman Catholic religion? |
Not really. Deists are fairly certain that a "supreme being" exists, which is a big difference to believing in the possibility of a higher power but also being content with there not being one. It's more of an agnostic view.
The Catholic church is also to a degree somewhat open to agnostic viewpoints, hence the ability for people to refer to themselves as both Agnostic and Roman Catholic.
EDIT - Though they do push the creationism views which makes them out of touch. |
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| woscar |
| quote: | Originally posted by Fledz
Not really. Deists are fairly certain that a "supreme being" exists, which is a big difference to believing in the possibility of a higher power but also being content with there not being one. It's more of an agnostic view.
The Catholic church is also to a degree somewhat open to agnostic viewpoints, hence the ability for people to refer to themselves as both Agnostic and Roman Catholic.
EDIT - Though they do push the creationism views which makes them out of touch. |
Everything you said is highly contradicting. Just because people are able to "refer to themselves as both Agnostic and Roman Catholic" it doesn't mean that the Catholic Church is open to that view. Any Catholic is free to say what they want, that doesn't mean that their church supports it. Everything that their religion is built upon rejects that possibility. In the same way that Judaism and Islam do.
If you define yourself as an agnostic that acknowledges that in the possibility that a god exists, then that god must be the god of the Bible and that the way to know him is through the Roman Catholic Church, then you are really nothing more than a Catholic doubting your own beliefs.
Your definition of Deism is also wrong. Deists are not "fairly certain that a supreme being exists". They are only open to the possibility, but don't take the extra step into saying that if it exists then it is knowable, interferes in the lives of people, and is concerned with their morality, their sexual lives, their dietary habits, etc. They think that in the event that a supreme being exists, his involvement started and ended with creating the universe. |
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| Fledz |
| quote: | Originally posted by woscar
Your definition of Deism is also wrong. Deists are not "fairly certain that a supreme being exists". They are only open to the possibility, but don't take the extra step into saying that if it exists then it is knowable, interferes in the lives of people, and is concerned with their morality, their sexual lives, their dietary habits, etc. They think that in the event that a supreme being exists, his involvement started and ended with creating the universe. |
No, that would be an Agnostic. A Deist is much more forthright in saying that a higher being exists. I think you have your definitions mixed up.
As for the Catholic Church, what I meant was that certain aspects of the Agnostic view are acceptable to the church but only to a degree and you are right, the church is still very pro-creationism. |
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