After 50 years Neo Darwinian Phenotypic Plasticity falls to Lamarckian Epigenetics

Phenotypic plasticity (PP) refers to changes in an organism's behavior, morphology, and physiology in response to a unique environment. 

It's been known since the beginning of mankind that plants would act differently depending on where you place them.

 But how does this fit in with the modern theory of evolution i.e. neo-Darwinism?

Under neo-Darwinism there must first be a mutation that changes the genotype which then is naturally selected to form a new phenotype.

Phenotypic plasticity occurs almost immediately. How can this be accounted for by gradual mutations with natural selection?

I decided to do a journal search on phenotypic plasticity starting in the last century and moving up to the current date.

As you'll notice as time goes on scientists drop neo-Darwinism as an explanation of phenotypic plasticity to the new field of epigenetics.

The man that first discusses phenotypic plasticity was A.D. Bradshaw in 1965.

He says:

"Phenotypic plasticity is under genetic control..and able to be radically altered by selection.'

He points out that phenotypic plasticity is under genetic control and is associated with extreme natural selection. What is that? He sees a need for natural selection on steroids as there is such little time to act.

The next paper says:

1989

"Fisher once said to me, it is not surprising that such elaborate machinery should sometimes go wrong.

Botanists were carefully avoiding any mention of plasticity; environmental effects in experiments were considered" only an embarrassment.

The plastic phenotype, stigmatized by poorly understood environmental influences and the ghost of Lamarck, has sometimes been lost from view as the focus of selection."

Fisher was one of the evolutionary giants in the first part of the last century and he's shaped intimately the formation of Neo Darwinism. Holding onto neo-Darwinism he posits that sometimes the genotype is just "broken" to explain PP.

Also botanist we're diving for cover rather than discussing phenotypic plasticity.

The author stumbled upon the truth when she noted that phenotypic plasticity is haunted by the ghost of Lamarck. Recall that 50 years before Darwin Lamarck successfully described the environmental effects on individual organisms.

It fits epigenetics to a tee. 

The next paper goes on:

1993

"Genetically, plasticity is 'likely" due both to differences in allelic expression across environments."

Alleles are the same things as genes and are used by populational genetics to study evolution. This paper is asserting that the genes or alleles are the methods by which phenotypic plasticity occurs AKA NeoDarwinism.

Moving forward:

1995

"Understanding the evolution of adaptive phenotypic plasticity has been hampered by dissenting opinions on the merits of different methods of description, on the underlying genetic mechanisms, and on the way that plasticity is affected by natural selection in a heterogeneous environment."

In other words neo-Darwinism does not explain this feature and they're almost coming to blows over it.

Moving on:

2003

"Models of population divergence and speciation are often based on the assumption that differences between populations are due to genetic factors, and that phenotypic change is due to natural selection."

Again they're doubling down to say natural selection is causing this as they give a one paragraph description of what natural selection is.

Next:

2009

"Plasticity is important because it is an encompassing model to understand life on earth."

This is a statement that almost doubles down on the need to explain PP in order to understand evolution. If it can't it would be a shortcoming thereof.

Note in 2010 the encode project came out. They discovered  that junk DNA or non-coding DNA is 80% functional. Everything changes despite much consternation in the evolutionary field.

THEN:

2013

"Heritable variation in plant phenotypes, and thus the potential for evolutionary change, can in principle not only be caused by variation in DNA sequence, but also by underlying epigenetic variation."

Heritable variation is a code word for phenotypic plasticity.

Next:

2014

"Phenotypic plasticity or >>epigenetic modification<<

We point to promising avenues of research, identifying systems that can best be used to address the role of plasticity in evolution, as well as the need to apply our expanding knowledge of..epigenetic mechanisms."

They went ahead and said that the phenotypic plasticity IS epigenetic modification. Right at 50 years since Bradshaw first discussed it. Neo Darwinism apparently blinded them to certain results that they expected. There were notable exceptions to Neo Darwinism but no one really wanted to pay attention to them.

And finally:

2021

"Epigenetic mechanisms are central to gene regulation and phenotypic plasticity."

In the movie Patton a German Colonel was burning their plans as they were losing  the war in part due to Patton. He said "das ist das ende, das ist das ende." This is the end, this is the end.

And so goes NeoDarwinism as it haunts us all, "how could we have missed so bad for so many years?"