Saturday, May 20, 2017

Denis Noble writes about junk DNA

I have read Dance to the Tune of Life. It's a very confusing book for several reasons. Denis Noble has a very different perspective on evolution and what evolutionary theory needs to accomplish. He thinks that life is characterized by something he calls "Biological Relativity." I don't disagree. He also thinks that evolutionary theory needs to incorporate everything that has ever happened in the history of life. That's where we part company.

I'm working slowly on a book about genomes and junk DNA so I was anxious to see how Noble deals with that subject. I tend to judge the quality of books and articles by the way they interpret the controversy over junk DNA. Here's the first mention of junk DNA from page 89. He begins by saying that it's difficult to explain development and the diversity of tissues in multicellular organisms. He continues with,

Thursday, May 18, 2017

Jonathan Wells illustrates zombie science by revisiting junk DNA

Jonathan Wells has written a new book (2017) called Zombie Science: More Icons of Evolution. He revisits his famous Icons of Evolution from 2000 and tries to show that nothing has changed in 17 years.

I wrote a book in 2000 about ten images images, ten "icons of evolution," that did not fit the evidence and were empirically dead. They should have been buried, but they are still with us, haunting our science classrooms and stalking our children. They are part of what I call zombie science.
I won't bore you with the details. The icons fall into two categories: (1) those that were meaningless and/or trivial in 2000 and remain so today, and (2) those that Wells misunderstood in 2000 and are still misunderstood by creationists today.

Tuesday, May 16, 2017

"The Perils of Public Outreach"

Julia Shaw is a forensic psychologist. She is currently a senior lecturer in criminology at the London South Bank University (London, UK). Shaw is concerned that we are creating a culture where public outreach is being unfairly attacked. Read her Scientific American post at: The Perils of Public Outreach.

Shaw's point is rather interesting. She believes that scientists who participate in public outreach are being unfairly criticized. Let's look closely at her argument.
What scientists write in academic publications is generally intended for a scientific community, full of nuance and precise language. Instead, what scientists say and write in public forums is intended for lay audiences, almost invariably losing nuance but gaining impact and social relevance. This makes statements made in public forums particularly ripe for attack.

Wednesday, May 10, 2017

Debating philosophers: Pierrick Bourrat responds to my criticism of his paper

I recently criticized a paper by Lu and Bourrat on the extended evolutionary synthesis [Debating philosophers: The Lu and Bourrat paper]. Pierrick Bourrat responds in this guest post.


by Pierrick Bourrat
Research Fellow, Department of Philosophy
Macquarie University
Sydney, Australia

Both Qiaoying Lu and I are grateful to Professor Moran for the copious attention he has bestowed on our paper. We are early career researchers and didn’t expect our paper to receive so much attention from a senior academic in a public forum. Moran claims that our work is out of touch with science (and more generally works in philosophy of biology), that the paper is weakly argued and that some of what we write is false. But in the end, he puts forward a similar position to ours.

Saturday, May 06, 2017

Debating philosophers: Epigenetics

Qiaoying Lu and Pierrick Bourrat are philosophers in Australia.1 Their research interests include evolutionary theory and they have taken an interest in the current debate over extending evolutionary theory. That debate has been promoted by a small group of scientists who, by and large, are not experts in evolution. They claim that current evolutionary theory—which they define incorrectly as the 1960s version of the Modern Synthesis—needs to be overthrown or extended by including things like epigenetics, niche construction, developmental biology, and plasticity [New Trends in Evolutionary Biology: The Program].

Lu and Bourrat have focused on epigenetics in their recent paper [Debating philosophers: The Lu and Bourrat paper]. They hope to reach an accommodation by re-defining the evolutionary gene as: "any physical structure that causes a heritable variation." Then they go on to say that, "we define the phenotype of an evolutionary gene as everything that the gene makes a difference to when compared to another gene."

By doing this, they claim that epigenetic changes (e.g. transient methylation) fall with the new definition. Therefore, epigenetics doesn't really represent a challenge to evolutionary theory. They explain it like this ....

Thursday, May 04, 2017

Debating philosophers: The molecular gene

This is my fifth post on the Lu and Bourrat paper [Debating philosophers: The Lu and Bourrat paper]. The authors are attempting to justify the inclusion of epigenetics into current evolutionary theory by re-defining the concept of "gene," specifically the evolutionary gene concept. So far, I've discussed their understanding of current evolutionary theory and why I think it is flawed [Debating philosophers: The Modern Synthesis]. I described their view of "genes" and pointed out the confusion between "genes" and "alleles" and why I think "alleles" is the better term [Debating philosophers: The difference between genes and alleles]. In my last post I discussed their definition of the evolutionary gene and why it is too adaptationist to serve a useful function [Debating philosophers: The evolutionary gene].

Wednesday, May 03, 2017

Debating philosophers: The evolutionary gene

This is the forth post on the Lu and Bourrat paper [Debating philosophers: The Lu and Bourrat paper]. The philosophers are attempting to redefine the word "gene" in order to make epigenetics compatible with current evolutionary theory.

I define a gene in the following way: "A gene is a DNA sequence that is transcribed to produce a functional product" [What Is a Gene?]. This is a biochemical/molecular definition and it's not the same as the definition used in traditional evolution.

Lu and Bourrat discuss the history of the evolutionary gene and conclude,

Debating philosophers: The difference between genes and alleles

This is my third post on the Lu and Bourrat (2017) paper [Debating philosophers: The Lu and Bourrat paper]. Part of their argument is to establish that modern evolutionary theory is a gene-centric theory. They need to make this connection because they are about to re-define the word "gene" in order to accommodate epigenetics.

In my last post I referred to their defense of the Modern Synthesis and quoted them as saying that the major tenets of the Modern Synthesis (MS) are still the basis of modern evolutionary theory. They go on to say,

Tuesday, May 02, 2017

Debating philosophers: The Modern Synthesis

I'm discussing a paper by Lu and Bourrat (2017) [Debating philosophers: The Lu and Bourrat paper]. They begin by describing current evolutionary theory, known (to them) as the Modern Synthesis. The paper is about challenges to current evolutionary theory from those who advocate an extended evolutionary synthesis or from those who would replace, rather than extend, current evolutionary theory. It is reasonable to begin with a description of the theory that's being challenged.

Here's what Lu & Bourrat say,

Debating philosophers: The Lu and Bourrat paper

John Wilkins posted a link on Facebook to a recent paper by his colleagues in Australia. The authors are Qiaoying Lu of the Department of Philosophy at Macquarie University in Sidney Australia and Pierrick Bourat of the Department of Philosophy at The University of Sydney in Sidney Australia.

Lu, Q., and Bourrat, P. (2017) The evolutionary gene and the extended evolutionary synthesis. The British Journal for the Philosophy of Science, (advanced article) April 20, 2017. [doi: 10.1093/bjps/axw035] [PhilSci Archive]

Abstract: Advocates of an ‘extended evolutionary synthesis’ have claimed that standard evolutionary theory fails to accommodate epigenetic inheritance. The opponents of the extended synthesis argue that the evidence for epigenetic inheritance causing adaptive evolution in nature is insufficient. We suggest that the ambiguity surrounding the conception of the gene represents a background semantic issue in the debate. Starting from Haig’s gene-selectionist framework and Griffiths and Neumann-Held’s notion of the evolutionary gene, we define senses of ‘gene’, ‘environment’, and ‘phenotype’ in a way that makes them consistent with gene-centric evolutionary theory. We argue that the evolutionary gene, when being materialized, need not be restricted to nucleic acids but can encompass other heritable units such as epialleles. If the evolutionary gene is understood more broadly, and the notions of environment and phenotype are defined accordingly, current evolutionary theory does not require a major conceptual change in order to incorporate the mechanisms of epigenetic inheritance.

1 Introduction
2 The Gene-centric Evolutionary Theory and the ‘Evolutionary Gene’
      2.1 The evolutionary gene
      2.2 Genes, phenotypes, and environments
3 Epigenetic Inheritance and the Gene-Centred Framework
      3.1 Treating the gene as the sole heritable material?
      3.2 Epigenetics and phenotypic plasticity
4 Conclusion

The selfish gene vs the lucky allele

The Selfish Gene was published forty-one years ago (1976) and last year there was a bit of a celebration. I think we can all appreciate the impact that the book had at the time but I'm not sure it's as profound and lasting as most people believe ["The Selfish Gene" turns 40] [The "selfish gene" is not a good metaphor to describe evolution] [Die, selfish gene, die!].

The main criticisms fall into two categories: (1) the primary unit of selection is the individual organism, not the gene, and (2) the book placed too much emphasis on adaptation (Darwinism). I think modern evolutionary theory is based on 21st century population genetics and that view puts a great deal of emphasis on the power of random genetic drift. The evolution of a population involves the survival of individuals within the population and that, in turn, depends on the variation that exists in the population. Thus, evolution is characterized by changes in the frequencies of alleles in a population.