We were discussing the field of evolutionary psychology at our local cafe scientific meeting last week. The discussion was prompted by watching a video of Steven Pinker in conversation with Stephen Fry. I pointed out that the field of evolutionary psychology is a mess and many scientists and philosophers think it is fundamentally flawed. The purpose of this post is to provide links to back up my claim.
The Dunning-Kruger Effect was first proposed in a classic 1999 paper (Kruger and Dunning, 1999).1 People suffering from this effect show one of two characteristics. If they are not knowledgeable about a subject they tend to overestimate their ability. If they are experts in a subject they tend to underestimate their ability (see figure).
The phenomenon is more significant in people who overestimate their ability because it includes a large number of people who are making decisions on subjects that they know little about. Because of the Dunning-Kruger effect, they are confident that their decisions are based on facts and evidence. That's bad enough, but there's another aspect to this problem—why do these people seem to be incapable of recognizing that they are suffering from the Dunning-Kruger effect? Here's how Kruger and Dunning explain this ...
Selfish DNA is a term that became popular with the publication of a series of papers in Nature in 1980. The authors were referring to viruses and transposons that insert themselves into a genome where they exist solely for the purposes of propagating themselves. These selfish DNA sequences are often thought, incorrectly, to be the same as the Selfish Genes of Richard Dawkins1 [Selfish genes and transposons]. In fact, "selfish genes" refers to the idea that some DNAs enhance fitness and the frequency of these genes will increase in a population through their effect on the vehicle that carries them. It's an adaptationist view of evolution. The selfish DNA of transposons and viruses is quite different. These sequences only propagate themselves—the fitness of the organism is largely irrelevant. These elements do not contribute directly to the adaptive evolution of the species.
Transposons and integrated viruses are subjected to mutation just like the rest of the genome. Deleterious mutations cannot be purged by natural selection because inactivating a transposon has no effect on the fitness of the organism.2 As a result, large genomes are littered with defective transposons and bits and pieces of dead transposons. This is not selfish DNA by any definition. It is junk DNA [What's in Your Genome?].I'm trying to read all the recent books on the human genome and anything related. There are a lot of them. Here's a list with some brief comments. You should buy some of these books. There are others you should not buy under any circumstances.
The irony meter was a running joke on the newsgroup talk.origins back in the last century. Our irony meters were supposed to protect us from the craziness of creationists but as soon as we built a really good irony meter a new bit of creationist crazy came along and fried it. Apparently Jesus and Mo have the same problem.
You probably know that climate change is real and humans are a major cause of global warming. You probably know that life has evolved and the Biblical story of creation is false. Scientists have been actively promoting these ideas for decades and they've been relatively successful in most countries. What you may not know is that these are just two of the many controversial claims that scientists are fighting. You may even have been tricked into believing some of the other pseudoscientific claims that are out there.
Did you know that the dirt in your local park is full of bacteria? Each scoop of soil contains millions of bacteria. And it's not just in your local park, soil bacteria are everywhere. This is part of the reason why the total mass of bacteria on the planet outweighs all of the eukayotes combined, including elephants and whales.
There are hundreds of different species of bacteria in your local dirt. They are as different from each other as moose and mushrooms.Together, our results suggest that soil bacterial communities, like plant communities, are typically dominated by a relatively small subset of phylotypes.
Image Credit: Bacillus Sp. soil bacteria from The ecology of soil-borne human diseases
Delgado-Baquerizo, M., Oliverio, A.M., Brewer, T.E., Benavent-González, A., Eldridge, D.J., Bardgett, R.D., Maestre, F.T., Singh, B.K., and Fierer, N. (2018) A global atlas of the dominant bacteria found in soil. Science, 359(6373), 320-325. doi: doi: 10.1126/science.aap9516
Charles Darwin, the greatest scientist who ever lived, was born on this day in 1809 [Darwin still spurs tributes, debates] [Happy Darwin Day!] [Darwin Day 2017]. Darwin is mostly famous for two things: (1) he described and documented the evidence for evolution and common descent and (2) he provided a plausible scientific explanation of evolution—the theory of natural selection. He put all this in a book, The Origin of Species by Means of Natural Selection published in 1859—a book that spurred a revolution in our understanding of the natural world.
Modern evolutionary theory has advanced well beyond Darwin's theory but he still deserves to be honored for being the first to explain evolution and promote it in a way that convinced others. Here's one passage from the introduction to Origin of Species.
Although much remains obscure, and will long remain obscure, I can entertain no doubt, after the most deliberate and dispassionate study of which I am capable, that the view which most naturalists entertain, and which I formerly entertained—namely, that each species has been 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 the descendants of that species. Furthermore, I am convinced that Natural Selection has been the main but not exclusive means of modification.
Random genetic drift is the process whereby some allele frequencies change in a population by chance alone. The alleles are not being fixed or eliminated by natural selection. Most of the alleles affected by drift are neutral or nearly neutral with respect to selection. Some are deleterious, in which case they may be accidentally fixed in spite of being selected against. Modern evolutionary theory incorporates random genetic drift as part of population genetics and modern textbooks contain extensive discussions of drift and the influence of population size. The scientific literature has focused recently on the Drift-Barrier Hypothesis, which emphasizes random genetic drift [Learning about modern evolutionary theory: the drift-barrier hypothesis].
Most of the alleles that become fixed in a population are fixed by random genetic drift and not by natural selection. Thus, in a very real sense, drift is the dominant mechanism of evolution. This is especially true in species with large genomes full of junk DNA (like humans) since the majority of alleles occur in junk DNA where they are, by definition, neutral.1 All of the data documenting drift and confirming its importance was discovered by scientists. All of the hypotheses and theories of modern evolution were, and are, developed by scientists.Next to last, comes an attitude that seeks to deploy science to answer questions beyond its scope. It seems to me that it is exceedingly easy to come up with questions that either science is wholly unequipped to answer, or for which it can at best provide a (welcome!) degree of relevant background knowledge. I will leave it to colleagues in other disciplines to arrive at their own list, but as far as philosophy is concerned, the following list is just a start:Before getting to random genetic drift, I'll just note that my main problem with Pigliucci's argument is that there are other definitions of science that render his discussion meaningless. For example, I prefer the broad definition of science—the one that encompasses several of the Pigliucci's questions [Alan Sokal explains the scientific worldview][Territorial demarcation and the meaning of science]. The second point is that no matter how you define knowledge, philosophers haven't been very successful at adding to our knowledge base. They're good at questions (see above) but not so good at answers. Thus, it's reasonable to claim that science (broad definition) is the only proven method of acquiring knowledge. If that's scientism then I think it's a good working hypothesis.
[my emphasis LAM]
- In metaphysics: what is a cause?
- In logic: is modus ponens a type of valid inference?
- In epistemology: is knowledge “justified true belief”?
- In ethics: is abortion permissible once the fetus begins to feel pain?
- In aesthetics: is there a meaningful difference between Mill’s “low” and “high” pleasures?
- In philosophy of science: what role does genetic drift play in the logical structure of evolutionary theory?
- In philosophy of mathematics: what is the ontological status of mathematical objects, such as numbers?
The scientific literature on all the above is basically non-existent, while the philosophical one is huge. None of the above questions admits of answers arising from systematic observations or experiments. While empirical notions may be relevant to some of them (e.g., the one on abortion), it is philosophical arguments that provide the suitable approach.I hardly know what to say.
1. There are some very rare exceptions where a mutation in junk DNA may have detrimental effects.
I'm sad because we now have almost a whole generation of young people who know very little about Stephen Jay Gould. (He died of cancer in 2002.) I was thinking of this yesterday as I was preparing a post on bacteria. Gould's 1996 book, Full House, is about fundamental misconceptions of evolution and progress and it contains the following passage (p. 176) ...
We live now in the "Age of Bacteria." Our planet has always been in the "Age of Bacteria," ever since the first fossils—bacteria, of course—were entombed in rocks more than three and a half billion years ago.Listen to him make this point twenty years ago ...
On any possible, reasonable, or fair criterion, bacteria are—and always have been—the dominant forms of life on earth.
A recent letter in Nature draws attention to a serious (?) problem in modern society; namely, the persecution of junior scientists by older scientists who ask them tough questions. Anand Kumar Sharma warns us: "Don’t belittle junior researchers in meetings". Here's what he says, ...
The most interesting part of a scientific seminar, colloquium or conference for me is the question and answer session. However, I find it upsetting to witness the unnecessarily hard time that is increasingly given to junior presenters at such meetings. As inquisitive scientists, we do not have the right to undermine or denigrate the efforts of fellow researchers — even when their reply is unconvincing.
It is our responsibility to nurture upcoming researchers. Firing at a speaker from the front row is unlikely to enhance discussions. In my experience, it is more productive to offer positive queries and suggestions, and save negative feedback for more-private settings.
This is a post about alternative splicing. I've avoided using that term in the title because it's very misleading. Alternative splicing produces a number of different products (RNA or protein) from a single intron-containing gene. The phenomenon has been known for 35 years and there are quite a few very well-studied examples, including several where all of the splice regulatory factors have been characterized.
Sixty evolutionary biologists are going to meet next July in Salzburg (Austria)to discuss "a new paradigmatic understanding of genetic novelty" [Evolution – Genetic Novelty/Genomic Variations by RNA Networks and Viruses]. You probably didn't know that a new paradigm is necessary. That's because you didn't know that the old paradigm of random mutations can't explain genetic diversity. (Not!) Here's how the symposium organizers explain it on their website ...
There's solid evidence that 90% of your genome is junk. Most of it is transcribed at some time but the transcripts are transient and usually confined to the nucleus. They are junk RNA [Functional RNAs?]. This is the view held by many experts but you wouldn't know that from reading the scientific literature and the popular press. The opposition to junk DNA gets much more attention in both venues.
There are prominent voices expressing the view that most of the genome is devoted to producing functional RNAs required for regulating gene expression [John Mattick still claims that most lncRNAs are functional]. Most of these RNAs are long noncoding RNAs known as lncRNAs. Although most of them fail all reasonable criteria for function there are still those who maintain that tens of thousands of them are functional [How many lncRNAs are functional: can sequence comparisons tell us the answer?].I realize that most of you are tired of seeing criticisms of ENCODE but it's important to realize that most scientists fell hook-line-and-sinker for the ENCODE publicity campaign and they still don't know that most of the claims were ridiculous.
I was reminded of this when I re-read Brendan Maher's summary of the ENCODE results that were published in Nature on Sept. 6, 2012 (Maher, 2012). Maher's article appeared in the front section of the ENCODE issue.1 With respect to regulatory sequences he said ...The consortium has assigned some sort of function to roughly 80% of the genome, including more than 70,000 ‘promoter’ regions — the sites, just upstream of genes, where proteins bind to control gene expression — and nearly 400,000 ‘enhancer’ regions that regulate expression of distant genes ... But the job is far from done, says [Ewan] Birney, a computational biologist at the European Molecular Biology Laboratory’s European Bioinformatics Institute in Hinxton, UK, who coordinated the data analysis for ENCODE. He says that some of the mapping efforts are about halfway to completion, and that deeper characterization of everything the genome is doing is probably only 10% finished.
