Can you answer this question?

[monkeycousin]

If I understand the basic premise of the theory of Evolution, it is clear enough to me how over thousands of generations a species will produce millions of variations in the individuals. A long period of time, perhaps 10's of thousands of generations, will yield billions of individuals, each with slight variations. So it is logical and natural to conclude that a particular habitat may favor the survival (to reproduction at least) of those species with variations that best suit their environment. So, again over thousands of generation, it is easy to see that the individuals least suited to the environment may not survive to the reproductive age. The characteristics of the survivors will be the only ones possible to replicate.

 

I don't think anyone, no matter what philosophical opinion they may have toward the "theory" of Evolution can deny the idea of natural selection, or even "survival of the fittest" if you want to use the hot button term. If you admit that the individuals vary, sometimes drastically, from others of the same species, then it is only a matter of imagination and logic to realize that even after a few generations, many individuals will survive with characteristics in common enough to identify a "new' species. Darwin noticed this with the finch population on various islands in the Galapagos.

 

But here is the question I would like answered. Can evolution be affected by a mutation of a gene after the species reaches the reproductive age? In other word, can radiation or diet or calamity, or therapy alter a gene after the species is an adult, and if so, can that mutated gene be passed on to another generation and all subsequent generations? Is there proof that it has happened in the past? If so, was the change significant?

Edited August 2, 2011 by monkeycousin

[Ringer]

It would only if the mutation affected the gamete that would fertilize or be fertilized for a sexual reproducing species. If it affected, say, the arm of the animal and nothing else it shouldn't have an effect of the offspring.

[Essay]

But here is the question I would like answered. Can evolution be affected by a mutation of a gene after the species reaches the reproductive age? In other word, can radiation or diet or calamity, or therapy alter a gene after the species is an adult, and if so, can that mutated gene be passed on to another generation and all subsequent generations? Is there proof that it has happened in the past? If so, was the change significant?

 

Check into epigenetics. For instance, google: SNP agouti grandparents

i.e. http://www.ajcn.org/content/86/3/542.full

 

Science is beginning to understand how genetic variation and epigenetic events alter requirements for, and responses to, nutrients (nutrigenomics). At the same time, methods for profiling almost all of the products of metabolism in a single sample of blood or urine are being developed (metabolomics). Relations between diet and nutrigenomic and metabolomic profiles and between those profiles and health have become important components of research that could change clinical practice in nutrition. Most nutrition studies assume that all persons have average dietary requirements, and the studies often do not plan for a large subset of subjects who differ in requirements for a nutrient. Large variances in responses that occur when such a population exists can result in statistical analyses that argue for a null effect. If nutrition studies could better identify responders and differentiate them from nonresponders on the basis of nutrigenomic or metabolomic profiles, the sensitivity to detect differences between groups could be greatly increased, and the resulting dietary recommendations could be appropriately targeted. It is not certain that nutrition will be the clinical specialty primarily responsible for nutrigenomics or metabolomics, because other disciplines currently dominate the development of portions of these fields. However, nutrition scientists' depth of understanding of human metabolism can be used to establish a role in the research and clinical programs that will arise from nutrigenomic and metabolomic profiling. Investments made today in training programs and in research methods could ensure a new foundation for clinical nutrition in the future.

 

Key Words: Nutrigenomics • epigenetics • metabolomics • single-nucleotide polymorphism • clinical nutrition

 

But it would be helpful to also realize that most mutations (that lead to new species and niches being filled) are the result of mutations in the architecture of the genome, and not from mutations of a single gene.

 

~Cheers!

 

search: epigenetics agouti INDELs

i.e. http://www.ncbi.nlm....les/PMC2989988/

"Transgenerational epigenetic inheritance: More questions than answers"

This phenomenon is referred to as transgenerational epigenetic inheritance. Moreover, recent evidence shows that the environment can stably influence the establishment of the epigenome. Together, these findings suggest that an environmental event in one generation could affect the phenotype in subsequent generations, and these somewhat Lamarckian ideas are stimulating interest from a broad spectrum of biologists, from ecologists to health workers.

 

search: epigenetics Copy Number Polymorphisms INDELs "novel architecture"

i.e. http://www.scribd.co...-Dynamic-Genome

[very large and slow]

 

search: CNV Indels architecture

i.e. http://www.plosgenet...al.pgen.1000734

"There is a growing appreciation for the role of genome structural variation in creating phenotypic variation within a species. .... This genome content variation leads to differences in transcript content between inbred lines and likely contributes to phenotypic diversity and heterosis in maize."

 

or: http://www.ncbi.nlm....les/PMC2917707/

"Copy number variants and indels in 251 families with evidence of X-linked intellectual disability (XLID) were investigated.... Breakpoints of pathogenic variants were characterized to provide insight into the underlying mutational mechanisms and indicated a predominance of mitotic rather than meiotic events. By effectively bridging the gap between karyotype-level investigations and X chromosome exon resequencing, this study informs discussion of alternative mutational mechanisms, such as noncoding variants and non-X-linked disease, which might explain the shortfall of mutation yield in the well-characterized International Genetics of Learning Disability (IGOLD) cohort, where currently disease remains unexplained in two-thirds of families."

[monkeycousin]

Essay,

 

I think you may be talking a little over my head. I'm looking for documented evidence that a 1. A gene or group of genes has been shown to have been modified by environmental stress in a mature adult species and 2. that those altered genes were subsequently passed on to the offspring, and 3. that thereafter the altered gene continued to replicate in all subsequent offspring. If it happened millions of years ago, how would we know the difference between natural selection and this kind of environmental mutation?

 

I am just trying to understand Evolution outside of natural selection if it exist. Since "gene therapy" is apparently a valid medical tool, I assume science must be capable of "unnatural" selection.

[Essay]

If it happened millions of years ago, how would we know the difference between natural selection and this kind of environmental mutation?

 

I am just trying to understand Evolution outside of natural selection if it exist. Since "gene therapy" is apparently a valid medical tool, I assume science must be capable of "unnatural" selection.

 

I think those links cover your first three points. But now you're confusing selection with mutation.

 

Selective breeding of animals has been described since biblical times, and agriculture itself is a good example of "unnatural" selection; so what are you trying to get at?

===

 

Regardless of the mechanisms for mutation, whether random, or designed, or somatic, or environmental...

 

Selection Happens!

 

~

[Ophiolite]

It is irrelevant whether or not the mutation in the gamete occured when it was produced or after it was produced. There is no practical way to distinguish between these two events. We know that mutations can and do occur in both instances. We would fully expect that some beneficial mutations that are subsequently selected for are generated in one way and some are generated in the other way.

 

The environmental factor that caused the mutation in the gamete is highly unlikely (verging on impossible) to be one that protects the organism from that aspect of the environment.

 

To put it another way, your question does not seem to be relevant to the character of evolution, so like Essay I am not sure what you are trying to get at. Perhaps you can clarify.