What Can't You Do in the House of Commons?

 
Almost anything goes in Ontario's House of Commons and debates can be rather lively. However, tradition (and House rules) state that you cannot accuse someone of lying. Here's what happens if you break that rule.



Ted Chudleigh is the Conservative MPP for Halton—a district that includes Oakville and Milton. He's ranting about a proposal to harmonize the GST and PST taxes.

Jennifer Smith lives in Milton and she's on the case. A little digging led her to this quotation from a speech by Ted Chudleigh in the House of Commons only 14 months ago [Ted Chudleigh on the HST: What a Difference a Year Makes].

Taxing businesses for their input costs is also a negative thing to do in an economy. It would be far better if we could find a way to harmonize the PST with the GST." (October 2, 2008 - Legislative Assembly Hansard)

Oh, dear. Is it possible that Mr. Chudleigh is a liar? Or is he just a hypocrite?

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A Critique of the Adaptationist Programme

The Royal Society of Britain has opened access to a number of classic papers that have been published in Proceedings of the Royal Society. One of them is ...

Gould, S. J. and Lewontin, R.C. (1979) The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme. Proc. R. Soc. Lond. B 205:581-598. [doi: 10.1098/rspb.1979.0086]

Abstract: An adaptationist programme has dominated evolutionary thought in England and the United States during the past 40 years. It is based on faith in the power of natural selection as an optimizing agent. It proceeds by breaking an organism into unitary 'traits' and proposing an adaptive story for each considered separately. Trade-offs among competing selective demands exert the only brake upon perfection; non-optimality is thereby rendered as a result of adaptation as well. We criticize this approach and attempt to reassert a competing notion (long popular in continental Europe) that organisms must be analysed as integrated wholes, with Bauplane so constrained by phyletic heritage, pathways of development and general architecture that the constraints themselves become more interesting and more important in delimiting pathways of change than the selective force that may mediate change when it occurs. We fault the adaptationist programme for its failure to distinguish current utility from reasons for origin (male tyrannosaurs may have used their diminutive front legs to titillate female partners, but this will not explain why they got so small); for its unwillingness to consider alternatives to adaptive stories; for its reliance upon plausibility alone as a criterion for accepting speculative tales; and for its failure to consider adequately such competing themes as random fixation of alleles, production of non-adaptive structures by developmental correlation with selected features (allometry, pleiotropy, material compensation, mechanically forced correlation), the separability of adaptation and selection, multiple adaptive peaks, and current utility as an epiphenomenon of non-adaptive structures. We support Darwin's own pluralistic approach to identifying the agents of evolutionary change.

If you haven't read this paper by now then download it and read it carefully. It's the most important paper to read if you are interested in evolution.

Jerry Coyne agrees, "Read the rest; it’s certainly one of the most important papers in modern evolutionary biology." [It’s a spandrel (sort of . . .)!].

He also says,

This paper is famous because the authors were famous, because it’s very well written, but most of all because it posed a direct attack on the “Panglossian paradigm”: the view that sociobiology wants to explain all traits, particularly human behaviors, as the direct products of selection. This paper has been the subject of furious discussion and at least one book. In my view, the paper made some valid points but went overboard in its criticism of the adaptationist program, which, after all, has produced lots of insights about evolution. I knew Gould, who was on my thesis committee, and it always seemed like pulling teeth to get him to admit that natural selection was even a relatively important force in evolution. If pressed, he would, but Gould always preferred (perhaps for political reasons) to emphasize the limitations of selection. Lewontin was not nearly so extreme.

It's true that the adaptationists have produced some valuable insights when the problem they are examining is actually an adaptation. However, this isn't as significant as you might imagine. Think of it like this. Everything looks like a nail when you have a large hammer in your hand. The fact that some things actually turn out to be nails is no excuse for blindly whacking at everything that sticks up.

Gould and Lewontin advocated a pluralist position where many different kinds of explanations should be considered. They note that Darwin himself was not committed to natural selection as the only possible mechanism of evolution.

Since Darwin has attained sainthood (if not divinity) among evolutionary biologists, and since all sides invoke God's allegiance, Darwin has often been depicted as a radical selectionist at heart who invoked other mechanisms only in retreat, and only as a result of his age's own lamented ignorance about the mechanisms of heredity. This view is false. Although Darwin regarded selection as the most important of evolutionary mechanisms (as do we), no argument from opponents angered him more than the common attempt to caricature and trivialize his theory by stating that it relied exclusively upon natural selection. In the last edition of the Origin, he wrote (1872, p. 395):

"As my conclusions have lately been much misrepresented, and it has been stated that I attribute the modification of species exclusively to natural selection, I may be permitted to remark that in the first edition of this work, and subsequently, I placed in a most conspicuous position-namely at the close of the introduction-the following words: "I am convinced that natural selection has been the main, but not the exclusive means of modification." This has been of no avail. Great is the power of steady misinterpretation."

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[Hat Tip: Pharyngula: Oldie moldies that are pretty darned fascinating]

On Determining the Structure of a Protein

Michael Clarkson is a biotech postdoc who blogs at Discount Thoughts. One of his recent thoughts is Don't look for "the" structure. He is referring to the fact that the crystal structure of a protein doesn't actually represent the only structure that the protein can adopt.

The figure shown here illustrates one of the problems with referring to the structure of a protein. This is a representation of an NMR structure of bovine ribonuclease A. It shows that various parts of the protein exist in several different conformations. The actual protein structure is a composite of all these structures in equilibrium with each other.

These conformation could be considered "breathing" and you may think they're not important. However, there are many cases where the conformations of a protein are quite different. We are familiar with allostery, where the conformation of a protein changes when it's bound to a ligand, but the are also examples where two very different structures exist in equilibrium in the absence of ligand.

Read his blog posting and keep in mind that proteins are dynamic structures and not static rigid crystals.

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FOX News Pie Chart

 
One of Ms. Sandwalk's ancestors was William Playfair who invented the pie chart [Bar Graphs, Pie Charts, and Darwin]. That was in 1786.

FOX News has heard of the concept but they don't quite seem to have mastered the technique.

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[Hat Tip: GrrlScientist]

The Cutest of all Invertebrates

Catalogue of Organisms features these cute little animals on "Taxon of the Week."

If you follow the link on that blog to a more detailed overview of the taxon you get a bonus—a description of why Christopher Taylor didn't make it to the International Conference of Arachnology in Brazil.

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Origin of Species at 150: Day Three

Tuesday November 24, 2009

08:00-09:00 Breakfast

09:00-11:00
Symposium V: Taxonomy
Chair: TBA

09:00-09:40
Mary Winsor (University of Toronto)
"Classification is a Census:" Huxley's Private Quarrel
with Darwin and its Public Consequences

09:40-10:20
Kevin Padian (University of California, Berkeley)
What is "Evidence for Evolution" to an Evolutionist?

10:20-11:00
Richard A. Richards (University of Alabama)
Context and Evidence in the History of Science

11:15-12:45
Session 4.i: Ancient Debates, Ancient Roots
Chair: Charissa Varma

11:15-11:45
P. William Hughes (Carleton University)
Aristotle contra Democritus: Anticipation of the Neutralist-Selectionist
Debate and a Haphazard Route Back to Darwin

11:45-12:15
Andreas Avgousti (Columbia University)
Pre-modern, Modern and Natural Understandings of Man:
Plato, Hobbes, and Evolutionary Theory

12:15-12:45
Robin Zebrowski (Beloit College)
The Evolution of Experience and the Experience of Evolution:
Revisiting Dewey's Analysis of the Influence of Darwin on Philosophy

11:15-12:45
Session 4.ii: The Devil’s Chaplain
Chair: David Smillie

11:15-11:45
Peter Sachs Collopy (University of Pennsylvania)
Naturalizing Calvinism: The Darwinism and Anti-Evolutionism
of George Frederick Wright

11:45-12:15
Stephen D. Snobelen (University of King’s College)
Theological Themes in Darwin's Origin of Species (1859)

12:15-12:45
Christopher diCarlo (University of Ontario Institute of Technology)
The Zing of Perceived Control: Memetic Equilibrium
and the Evolution of Religion

11:15-12:45
Session 4.iii: Laws of Evolutionary Economics
Chair: Mike Thicke

11:15-11:45
André Ariew (University of Missouri-Columbia)
Darwin’s Invisible Hand?

11:45-12:15
Eugene Earnshaw-Whyte (University of Toronto)
Breaking the Bonds of Biology: Natural Selection
in Nelson and Winter's Evolutionary Economics

12:15-12:45
Chris Haufe (Virginia Polytechnic Institute and State University)
Darwin’s “Laws”

12:45-13:30 Lunch Break

13:40-15:40
Symposium VI: Evolution and Development
Chair: Jean-Bernard Caron

13:40-14:20
Manfred Laubichler (Arizona State University)
From Boveri to Davidson and Back

14:20-15:00
Jane Maienschein (Arizona State University)
From Epigenesis to Epigenetics and Back

15:00-15:40
Michael Dietrich (Dartmouth College)
From Goldschmidt to Gould and Back

15:50-17:20 Session 5.i: It's All in the Mind
Chair: Eugene Earnshaw-Whyte

15:50-16:20
Byron Kaldis (The Hellenic Open University)
Species-Qua-Individuals and the Modularity of the Mind: The Saving Grace for Humans

16:20-16:50
Alain Ducharme & Sheldon Chow (The University of Western Ontario
Keeping Darwin in Mind

16:50-17:20
Steve DiPaola (Simon Fraser University)
Darwin, Creativity, and Evoluionary Programming

15:50-17:20
Session 5.ii: International Receptions
Chair: Ari Gross

15:50-16:20
Paranbes Nath (Calcutta University)
Darwin and India

16:20-16:50
Alex Levine & Adriana Nova (University of South Florida)
The Fate of Darwinian Analogies in Latin America:
The Reception of Darwinism in 19th Century Argentina

16:50-17:20
Nolan Heie (Queen’s University)
Albert Kalthoff, Entwicklung and the "World View of Modern Man"

15:50-16:50
Session 5.iii: Fitness
Chair: Ellie Louson

15:50-16:20
Marshall Abrams (University of Alabama at Birmingham)
Individuals have no Fitnesses if Fitness Differences Cause Evolution

16:20-16:50
Kent A. Peacock (University of Lethbridge)
The Three Faces of Fitness

15:50-16:50
Session 5.iv: Language and Logic
Chair: S.J. Patterson

15:50-16:20
Alexander G. Yushchenko (Kharkov State Polytechnic University)
Logics & Ethics of Evolution from the Point of View of Evolutionary Theology

16:20-16:50
Justin Humphreys (New School for Social Research)
Darwin on Language

17:20-18:20
Keynote Address: Brian K. Hall (Dalhousie University)
Charles Darwin, Evolutionary Embryology and Evo-Devo


18:20-19:00 Break

19:00-19:45
Keynote Address: Spencer Barrett (University of Toronto)
Charles Darwin and Current Perspectives on the Evolution and Function of Plant Sexual Diversity

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Origin of Species at 150: Day Two

Monday November 23, 2009

09:00-11:00Symposium III: Theistic Evolution
Chair: Michael Bourgeois

09:00-09:40
Bernard Lightman (York University)
Christian Evolutionists in the U.S., 1860-1900

09:40-10:20
Michael Ruse (Florida State University)
Are Science and Religion Compatible and If So, Why?

10:20-11:00
Denis O. Lamoureux (University of Alberta)
Darwinian Theological Insights: Toward an Intellectually Fulfilled Theism

11:15-12:45
Session 2.i: Acceptances and Denials
Chair: David Smillie

11:15-11:45
Fermin Fulda (University of Toronto)
Against Fodor Against Darwinism

11:45-12:15
Stefaan Blanke (Ghent University)
"A million guesses strung together:" Creationist Denial of the Science Behind Evolutionary Theory

12:15-12:45
Daniel A. Newman (University of Toronto)
The Rhetoric of Probability: How Darwin Overcame the Argument from Design

11:15-12:45
Session 2.ii: Historical Receptions
Chair: Jaipreet Virdi

11:15-11:45
John Court (University of Toronto)
Darwinian Evolution's First Fifty Years of Impact
on Botany at the University of Toronto. 1859 to 1909

11:45-12:15
David M. Steffes (Arizona State University)
Population Ecology and Evolution: Darwin's Origin and the
Modern Synthesis of the 1940s and 50s

12:15-12:45
Kevin Pent (York University)
Julian Huxley's 'Apogee of Species': Darwin's 'Man' Comes of Age

11:15-12:45
Session 2.iii: A Brave New Darwin
Chair: Chris Belanger

11:15-11:45
Peter Fedor (Comenius University)
Advances in Artificial Intelligence in Species Identification

11:45-12:15
Wybo Houkes (Edinhoven University of Technology)
Hypothesis Testing in Artefact Evolution

12:15-12:45
Laura Landen (Queen's University)
Natural Selection, The Intentional Stance, and Mirror Neuron Research

12:45-13:30 Lunch Break

13:40-15:40
Symposium IV: Species
Chair: Ronald de Sousa

13:40-1420
John Beatty (University of British Columbia)
Darwin on Species

14:20-15:00
Kevin de Queiroz (Natural Museum of National History; Smithsonian)
Charles Darwin and the Evolution of the Species Concept

15:00-15:40
Marc Ereshefsky (University of Calgary)
Mystery of Mysteries: Darwin and the Species Problem

15:45-16:45
Keynote Address: Michael Ruse (Florida State University)
Is Darwinism Past its “Sell-By” Date?

16:45-18:15
Session 3.i: Naturalism
Chair: Curtis Forbes

16:45-17:15
Jason Marsh (University of Western Ontario)
Darwinism and Divine Hiddenness

17:15-17:45
Khaldoun Sweis (Olive-Harvey College)
Philosophical Paradoxs of Darwin Evolutionary Naturalism

17:45-18:15
Maarten Boudry (Ghent University)
Methodological Naturalism as an Intrinsic Property of Science:
A Grist to the Mill of Intelligent Design Theory

16:45-18:15
Session 3.ii: Reconstructing Darwinism
Chair: Erich Weidenhammer

16:45-17:15
Peter Gildenhuys (Lafayette College)
Putting the Struggle for Existence to Work

17:15-17:45
Katharine Browne (University of Toronto)
A Darwinian theory of Games

17:45-18:15
Sarah Winter (University of Connecticut Storrs)
Species as Value: Biosemiotics in Darwin's Origin and Saussurian Linguistics

16:45-18:15
Session 3.iii: Applying Darwinism
Chair: Mike Stuart

16:45-17:15
Marion Blute (University of Toronto at Mississauga)
Darwinism in the Social Sciences Today

17:15-17:45
Howard M. Huynh (Acadia University)
In the Footsteps of Darwin: The Value of Scientific Collecting in
Biodiversity Research and Conservation

17:45-18:15
Joel Velasco (Stanford University)
The Tree of Life: From Darwin to Today

18:15-19:15
Keynote Address: Evelyn Fox Keller
(Massachusetts Institute of Technology)
Darwin as the Newton of a Blade of Grass

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Origin of Species at 150: Day One

The conference on Origin of Species at 150 was sponsored by The Institute for the History & Philosophy of Science & Technology, The Department of Ecology and Evolutionary Biology, and The Department of Philosophy at the University of Toronto.

Here's the schedule for the first day.

Sunday November 22, 2009

08:00-09:00 Breakfast

09:00-10:00
Keynote Address: Alison Pearn (Darwin Correspondence Project)
Cast of Thousands: Charles Darwin's Life in Letters

10:00-12:00
Symposium I: Gender, Evolution, and Sexual Selection
Chair: Joan Steigerwald

10:00-10:40
Lisa Lloyd (Indiana University)
Bias in Evolutionary Explanations of the Female Orgasm

10:40-11:20
Marlene Zuk (University of California, Riverside)
Sex and the Scala Naturae

11:20-12:00
Erika Milam (University of Maryland, College Park)
Negotiating Choice: Animal Minds and Human Instincts
in the History of Sexual Selection

12:00-12:30 Lunch Break

12:45-13:45
Session 1.i: Reassessing Themes and Sources
Chair: Michael Cournoyea

12:45-13:15
Scott Sinclair (St. Louis University)
Three American Philosophers’ Response to Darwin

13:15-13:45
Fred Wilson (University of Toronto)
Replacing an Old Paradigm: Intelligent Design and Natural Selection; Hume, Mill, and Darwin

12:45-14:15
Session 1.ii: Social Perceptions
Chair: Jaipreet Virdi

12:45-13:15
Eleanor Louson (University of Toronto)
Nature, Projected: Evolutionary Theory in Wildlife Documentaries

13:15-13:45
David Smillie (University of Toronto)
Evolution and Popular Culture: Darwin on the Box

13:45-14:15
Ian Hesketh (Queen’s University)
Of Apes and Ancestors: Myth and the Cultural Memory of the Oxford Debate of 1860

12:45-14:15
Session 1.iii: Species and Sexuality
Chair: Sebastián Gil-Riaño

12:45-13:15
Masoud Hassanpour Golakani (Macquarie University)
The Spiral Valve Intestine of the Australian Lungfish, a Primitive Characteristic

13:15-13:45
Eugene S. Morton (Hemlock Hill Field Station)
Sexual Conflict and Brood Desertion in Blue-Headed Vireos: How Females Won

13:45-14:15
Jerome Goldsten (San Francisco Clinical Research Center)
The Neurobiology of Sexual Orientation: A Tribute to Charles Darwin

14:30-16:30
Symposium II: Ecology
Chair: Richard Landon
(Coffee/Tea Service Provided)

14:30-15:10
Joan Roughgarden (Stanford University)
Darwin and Ecology

15:10-15:50
Gene Cittadino (New York University)
Reflections on Darwin and Ecology: The History of a Tenuous Relationship

15:50-16:30
Gregory Cooper (Washington and Lee University)
The Darwinian Character of Evolutionary Ecology

16:40-17:40
Keynote Address: James Moore (University of Cambridge)
Darwin’s Progress and the Problem of Slavery

18:00-19:30
Special Presentation
Re: Design: A Dramatisation of the Correspondence between Charles Darwin and Asa Gray (Produced by the Menagerie Theatre Company)

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150 Years Ago

On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life was published 150 years ago on November 24, 1859. The publisher, John Murray, had already taken orders for 1,500 copies so the initial printing of 1,250 copies was sold out immediately.

Although much remains obscure, and will long remain obscure, I can entertain no doubt, after the most deliberate study and dispassionate judgment of which I am capable, that the view which most naturalists entertain, and which I formerly entertained—namely, that each species is independently created—is erroneous. I am fully convinced that species are not immutable; but that those belonging to what are called the same genera are lineal descendants of some other and generally extinct species, in the same manner as the acknowledged varieties of any one species are descendants of that species. Furthermore, I am convinced that Natural Selection has been the main but not the exclusive means of modification.

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One More Reason to Visit Canada

 
I stole this from Bayblab It shows why Canadians like global warming.

Canadian Tourism Federation Welcome Video from Canadian Tourism Federation on Vimeo.

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Monday's Molecule #144: Winner?

 
The creature is the spirochete, Treponema pallidum. This bacteria causes syphilis. The Nobel Laureate is Julius Wagner-Jauregg who discovered a way to treat the lethal form of dementia that develops in the late stages of the disease.

There were only three people who got the right answer. All of them were ineligible. There is no winner this week!

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This is another one of those times when there's no "molecule" that provides a clue to a Nobel Laureate.

Your task is to identify this creature and the reason why it's important. There are three Nobel Laureates who might be associated with the creature but two of them have already been covered. The last name of the this week's Nobel Laureate does not begin with the letters "E" or "D". Who is it?

The first person to identify the "molecule" and name the Nobel Laureate(s) wins a free lunch. Previous winners are ineligible for six weeks from the time they first won the prize.

There are seven ineligible candidates for this week's reward: Markus-Frederik Bohn of the Lehrstuhl für Biotechnik in Erlangen, Germany, Jason Oakley a biochemistry student at the University of Toronto, Dima Klenchin of the University of Wisconsin, Madison, Alex Ling of the University of Toronto, Bill Chaney of the University of Nebraska, Linda Zhang, a former student at the University of Toronto who will soon be on her way to graduate school at the University of Hong Kong and Kirill Zaslavsky, a Neuroscience student at the University of Toronto.

Dima, and Bill have agreed to donate their free lunch to an undergraduate. Consequently, I have two extra free lunches for deserving undergraduates. I'm going to award an additional prize to the first undergraduate student who can accept it. Please indicate in your email message whether you are an undergraduate and whether you can make it for lunch. If you can't make it for lunch then please consider donating it to someone who can in the next round.

THEME:

Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) bioinfo.med.utoronto.ca) and I'll pick the first email message that correctly identifies the molecule(s) and names the Nobel Laureate(s). Note that I'm not going to repeat Nobel Prizes so you might want to check the list of previous Sandwalk postings by clicking on the link in the theme box.

Correct responses will be posted tomorrow.

Comments will be blocked for 24 hours. Comments are now open.

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Should Intelligent Design Creationism Be Taught in Schools?

 
PZ Myers and someone named Jerry Bergman debated the question; "Should Intelligent Design be Taught in The Schools?." Bergman said "yes" and PZ said "no."

You can read summaries of the debate on Greg Laden's Blog [Bergman vs. Myers Debate: Should Intelligent Design be Taught in The Schools?] and on Kittywhumpus [I thought it went really well, until he brought up Hitler]. PZ has posted a summary on Pharyngula [That Bergman-Myers debate].

By all accounts it was a rout. PZ won the day for keeping Intelligent Design Creationism out of the classroom. It was like shooting fish in a barrel.

I'd like to debate PZ on this topic. I think Intelligent Design Creationism has to be brought up in the classroom. It's the major misconception that students have and to ignore it is stupid. You have to address the issues that students are confused about or you aren't educating. It's one thing to say that Intelligent Design Creationism isn't science when you are outside of the classroom but unless the students hear it in the classroom you are wasting your time.

We are never going to make progress against scientific illiteracy unless we recognize the elephant in the room and deal with it. Study after study has shown that the misconceptions of students aren't changed when you just present them with facts. They will readily incorporate those facts into their distorted worldview and that's exactly what happens when we teach evolution to creationists.

They need to be shown why their worldview is wrong and this means bringing up in class all the problems with Intelligent Design Creationism. Like it or not, that means teaching Intelligent Design Creationism in the science classroom even if the goal is to refute it.

Astrology is a good analogy. One way to teach critical thinking is to have a lesson on astrology where you explain what's wrong with it and why it doesn't work. You don't ban it from the classroom because it's bad science—you bring it into the classroom because it's bad science and students need to hear why.

If you don't do that, many students will continue to think that astrology is real and before you know it you've created another generation of citizens who don't understand science.

The thing that Intelligent Design Creationists should fear the most is that we actually will confront it in the classroom and expose it for the nonsense it is. They're safe as long as we tip-toe around it. That leaves them free to teach their nonsense in Sunday school without fear of ever being contradicted.

(I'm well aware of the Constitutional arguments in America. If someone like PZ wants to argue that Intelligent Design Creationism should be taught in US schools but the Constitution forbids it, then I'm prepared to agree with him. The debate I want is whether it should be taught in schools that don't have such a silly law. Should it be taught in Canadian schools? I say yes.)

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Genetic Load, Neutral Theory, and Junk DNA

The average human newborn has about 130 new mutations that were not found in either parent [Mutation Rates]. These mutations accumulate as a natural result of errors in DNA replication between the time that the zygote is first formed and the time that the sperm and egg cells are produced for the next generation.

A species cannot afford to accumulate deleterious mutations in the genomes of its individuals. Eventually the number of "bad" mutations will reach a level where most genes have multiple "bad" alleles and it becomes impossible to produce offspring.

This phenomenon is referred to as genetic load. It means that species can only survive if the genetic load is below some minimum value. A good rule of thumb is that there can't be more than 0.1 deleterious mutations per individual per generation but in actual populations this value can be a bit higher. [UPDATE: This should be one (1) deleterious mutation per generation.]

How do you reconcile this with the known mutation rate in humans? If there are, on average, 130 mutations per individual per generation, then hardly any of these can be deleterious if the species is to survive.

This is one of the arguments in favor of Neutral Theory. Most mutations are neither deleterious nor beneficial. They are simply neutral with respect to natural selection.

Let's think about a typical protein-encoding gene.¹ The coding region is about 2,000 base pairs in length and consist of 666 codons. More than half these codons can be mutated to a new codon encoding a different amino acid without severe effects on the function of the protein.² These are called amino acid substitutions. Of the "essential" codons, many can tolerate mutations that create synonymous codons. Putting these facts together suggests that only about 20% of mutations to protein encoding regions are detrimental. The rest are effectively neutral.

This partially explains why we can tolerate 130 mutations per individual per generation. If only 20% were detrimental then the genetic load is reduced to about 26 mutations per generation.

That's still unacceptably high. It leads to the idea that a large percentage of our genome must be unaffected by mutations. In other words, genes represent only a small percentage of our genome and mutations can freely accumulate in the rest without detrimental consequences.

In order to bring the genetic load down to acceptable levels, the number of genes has to be less than 40,000 according to the arguments made in the 1960s. We now know that we have only 20,000 genes. Most of them encode proteins and the coding regions of those genes make up about 40,000,000 bp or about 1.3% of our genome [Junk in Your Genome: Protein-Encoding Genes].

Recall that only 20% of mutations in coding regions are likely to be detrimental. That means that the effective target size for detrimental mutations is about 20% x 1.3% = 0.26% of our genome. Out of 130 mutations, only 0.3 per individual per generation will be detrimental.³

Since we are diploid organisms, the 130 mutations in the zygote are spread out over two copies of our genome but almost all of them will be in the chromosomes coming from the father. Every zygote inherits one complete set of chromosomes with hardly any mutations while the other set has less than one detrimental mutation.

Because a large percentage of gene mutations are neutral, and because most of our genome is junk, we can easily tolerate 130 mutations per individual per generation without going extinct.

Creationists will never understand this because: (a) they believe that modern evolutionary theory is all about "Darwinism" and Darwinian evolution doesn't recognize neutral mutations and random genetic drift, and (b) they can't admit to junk DNA because that's the opposite of what intelligent design would look like.

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1. Similar arguments apply to genes that make functional RNAs and not proteins.

2. Over the course of several billion years of evolution it is unusual to see more than 30% sequence similarity between homologous genes. I realize that this is a somewhat circular argument but it's still a good one.

3. There are lots of other regions of the genome where mutations can be detrimental. I don't mean to imply that only protein encoding regions can be affected by mutations. Collectively, these other regions don't make up more than a few percent of our genome and they can tolerate many mutations [Genomes & Junk DNA]

Genetic Load

 
If the average rate of deleterious mutations is about 1 per individual per generation then the species can't survive. It means that most offspring will carry a mutation. This is an intolerable genetic load for a species.

In fact it's worse than that. Simple calculations suggest than even a rate of 0.1 deleterious mutations per individual will spell doom for the species. This is a well-known limitation and it was widely used in developing several key components of evolutionary theory and in explaining the size and composition of eukaryotic genomes.

The average total mutation rate in humans is about 130 mutations per genome per generation. Scordova concludes that this proves Intelligent Design Creationism [Nachman’s Paradox Defeats Darwinism and Dawkins’ Weasel]. It does no such thing. It proves once again that a little knowledge is a dangerous thing—especially in the mind of an IDiot.

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Monday's Molecule #144

 
This is another one of those times when there's no "molecule" that provides a clue to a Nobel Laureate.

Your task is to identify this creature and the reason why it's important. There are three Nobel Laureates who might be associated with the creature but two of them have already been covered. The last name of the this week's Nobel Laureate does not begin with the letters "E" or "D". Who is it?

The first person to identify the "molecule" and name the Nobel Laureate(s) wins a free lunch. Previous winners are ineligible for six weeks from the time they first won the prize.

There are seven ineligible candidates for this week's reward: Markus-Frederik Bohn of the Lehrstuhl für Biotechnik in Erlangen, Germany, Jason Oakley a biochemistry student at the University of Toronto, Dima Klenchin of the University of Wisconsin, Madison, Alex Ling of the University of Toronto, Bill Chaney of the University of Nebraska, Linda Zhang, a former student at the University of Toronto who will soon be on her way to graduate school at the University of Hong Kong and Kirill Zaslavsky, a Neuroscience student at the University of Toronto.

Dima, and Bill have agreed to donate their free lunch to an undergraduate. Consequently, I have two extra free lunches for deserving undergraduates. I'm going to award an additional prize to the first undergraduate student who can accept it. Please indicate in your email message whether you are an undergraduate and whether you can make it for lunch. If you can't make it for lunch then please consider donating it to someone who can in the next round.

THEME:

Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) bioinfo.med.utoronto.ca) and I'll pick the first email message that correctly identifies the molecule(s) and names the Nobel Laureate(s). Note that I'm not going to repeat Nobel Prizes so you might want to check the list of previous Sandwalk postings by clicking on the link in the theme box.

Correct responses will be posted tomorrow.

Comments will be blocked for 24 hours. Comments are now open.

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