Hi Louis,

"What is the difference between evolutionary change and evolutionary novelty?"

My intention was to separate due the following criteria:

Evolutionary novelty, are characteristics that are new to a given organism/population, therefore, never existed before in then.

Evolutionary change, are the changes in frequencies of the already existing characteristics of a population.

They are complementary, but different kind of evolutionary process.

Daniel,

What is the difference between evolutionary change and evolutionary novelty?

Perhaps the first list can be seen as factors which generate new variation in genetic and cultural information, and the second list as factors which affect the frequency and spread of said genetic and cultural information? Both of those being complementary facets of the evolutionary process.

Hi Louis,

"What is the difference between evolutionary change and evolutionary novelty?"

My intention was to separate due the following criteria:

Evolutionary novelty, are characteristics that are new to a given organism/population, therefore, never existed before in then.

Evolutionary change, are the changes in frequencies of the already existing characteristics of a population.

They are complementary, but different kind of evolutionary process.

I think you will find that "evolutionary change" is often, if not mostly, used as a more general term synonymous to "evolution" or "evolutionary process", i.e. talking about "evolutionary change" people do not explicitely rule out that it may yield some new quality (novelty) from time to time.

Michael, I agree with you. This dichotomy that I made may reflect a conventional way of delimitate something that in nature is not so well delimitated. Evolution presupposes change in frequencies of heritable variations. And new heritable variations presuppose origin of novelty. But changes in frequencies can influence also on probabilities of novelty arrival in a population.

Some biologists and philosophers of biology prefer not to separate those mechanisms (Developmental Systems Theory, Holists). Others, including me, seem this differentiation is sometimes, but not always, useful to understand causality relations.

In human culture, when a novelty/invention/design/new style is created, it will not have any impacts on society if it is not broadcast/propagate to a significant portion of the population. If it succeeded to be propagated like a movie with a multi billion dollar commercial campaign then it may flop it is not good. So novelty has to be propagated and then it has to be selected by a large part of the population and then if it succeeded culturaly other creators will be influenced in the same creative direction.

I think you will find that evolutionary change is mostly a biological adaptation with environmental influences. Where evolutionary novelty is the adaptation of the neural processes within a culture. In humans the search for novelty began as a mechanism for environmental adaptation and morphed into mental adaption to cultural influences. It is not been determined exactingly when this change took place but it can be that it is in full effect today. Recent studies has placed the search for novelty in the amygdala. Perhaps we need to seek better definitions of novelty.

@ Daniel: But if you consider "evolutionary novelty" as the biological version of "emergence" (spontanous formation of new qualities in any kind of natural system) it might be too simplistic to think that processes which create new genetic variants are more important than those which play around with them. Suppose you have got old variants lying around in the pool for millions of years and from time to time some of your "evolutionary change" type processes happen and eventually (BANG!) lead to a new quality.

Hi Michael,

I agree with you and that’s what I wish to express in saying: "…changes in frequencies can influence also on probabilities of novelty arrival in a population."

Emergent properties are in this sense novelties. My main point was not to make an unquestionable distinction, because this is not factual indeed.

I came with the idea of this distinction, in response to some RG members that think that because we are discovering and studying new forms of heredity and origin of novelty, natural selection are unnecessary in the Theory of Evolution, which is not even a little close to the reality. As you corrected pointed, natural selection (or drift) can also be seen as mechanisms that are related to origin of novelties as well. But if we take only the mechanisms that I proposed as origin of novelties, the amazing adaptations between the biota and environment that we see wouldn’t exist.

But that’s not for you; I see that you already appreciate that.

My perspective is rather that of a palaeontologist: If you see a time discrepancy between the origination of a new genetic variant (inferred from molecular data) and the occurrence of a morphological innovation controlled by that variant (inferred from morphological data, including fossils), the conclusion could be that a genetic potential for a novelty is usually not immediately realized.

Among palaentontologists Neil Shubin discussed that matter, see here:

http://genepath.med.harvard.edu/~tabin/Pdfs/Shubin.pdf

Or here:

http://www.allmanlab.caltech.edu/biCNS158/PDFs/Shubin2009.pdf

There are evolutionary forces that introduce new variability into populations: mutation and gene flow, and there are evolutionary forces that eliminate variability from populations: genetic drift and natural selection. If you consider fixation of a new allele to be "evolutionary change" then the latter two processes are responsible for that, while the former are responsible for evolutionary variability.

Michael ,

Thanks for the papers. They are very good. Co-option is a good example of an origin of novelty that is totally dependent of changes in frequencies, and is a case that there’s no use of making a strong distinction indeed.

Vrba and Gould's paper, where they introduced the exaptation term deals with that subject very well too.

http://www2.hawaii.edu/~khayes/Journal_Club/fall2006/Gould_&_Vrb_1982_Paleobio.pdf

Thanks for the comment Maggie,

I intented to embrace those environmental influences on "epigenetic changes".

Maggie

"Two individuals with identical genomes and epigenomes can exhibit very different phenotypes if exposed to different environments."

Yes, I surelly agree with that. But if I'm correct, are the epigenetic (broadly defined as any change in gene expression that affect phenotypes, even transient ones) changes that allows different responses to different environments right? I mean, when you expose an organism during ontogeny to a new environment, and this changes the resulting phenotype, some change has to happens on gene regulation/expression due some change of molecular gradients, and that would be an epigenetic change sensu Eva Jablonka.

I listed plasticity as a mechanism of change, since it can bias the way novelties persist on the biological system. But it could be as well, and maybe better suited as a mechanism of novelties origin.

And maybe I should have made more clear that this epigenetic change can or cannot be environmentally induced. Like mutation can or cannot be environmentally affect.

Best,

Daniel

Some epigenetic change e.g. due food ingestion can alter the parental phenotype and be inherited at least some generations. This creates a possibility that some beneficial novelty be subject to selection and to be genetically assimilated, the following paper is a review on evidence of trangenerational epigenetic inheritance, and have some candidates of adaptative traits.

http://ts-si.org/files/JablonkaQtrRevBio2009.pdf

The problem is to diagnosis if this is not an already evolved developmental response or a new induction that could be assimilated...

Others cases, If we consider learning as a kind of plasticity, adults can "acquire " new behavioral traits, that can be adaptative and inherited through social context.