Biological SciencesBlogger

Quintessence of Dust

Quintessence of Dust explores science, society, and human nature, focusing on genetics, development, evolution, neuroscience, systems biology, and topics related to scientific literacy. I occasionally discuss intelligent design, creationism, science denial, and other political/social influences on scientific literacy. Additional topics: philosophy, baseball, scientific culture, and Shakespeare. My main theme is scientific explanation.
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Author Stephen Matheson

There are some truly vexing and annoying myths of evolution. They are almost exclusively recited and embellished by religious propagandists, some of whom actually know what they're doing. Rarely but notably, there are myths that are gleefully repeated by creationists while being amplified by scientists who should know better.

Published
Author Stephen Matheson

Human evolution has been in the news quite a lot recently. New genetic data suggest that ancient humans included both Neanderthals and Denisovans, which colonized different parts of the world but subsequently interbred with so-called modern humans and left telltale traces of this history in the genomes of living humans.

Published
Author Stephen Matheson

Titktaalik roseae. Image from https://tiktaalik.uchicago.edu/index.html The second post in my series on limb evolution is now up at the BioLogos site. This installment reviews the fossil evidence on fin-to-limb evolution, introducing the famous Tiktaalik . Next up: evidence from developmental biology. The first post at BioLogos outlined limb structure and some historical background.

Published
Author Stephen Matheson

Last month, I started a series on the topic of limb evolution, here at Quintessence of Dust. That series has been transformed (through a series of intermediates) into a series of posts* at the BioLogos site. The first installment is now up, and it provides an expanded introduction to the topic and a little historical context.

Published
Author Stephen Matheson

In the cartoon version of evolution that is often employed by critics of the theory, a new protein (B) can arise from an ancestral version (A) by stepwise evolution only if each of the intermediates between A and B are functional in some way (or at least not harmful). This sounds reasonable enough, and it's a good starting point for basic evolutionary reasoning.

Published
Author Stephen Matheson

Last month I had an interesting conversation with Casey Luskin of the Discovery Institute (DI), at Evolution News and Views (ENV), a DI blog/site that recently opened some articles to comments. The topic of the original post was common ancestry in humans and other primates, but Casey and I discussed various aspects of design thought. One subject that came up was the falsifiability of design.

Published
Author Stephen Matheson

One of the goals of the intelligent design (ID) movement is to show that evolution cannot be random and/or unguided, and one way to demonstrate this is to show that an evolutionary transition is impossibly unlikely without guidance or intervention. Michael Behe has attempted to do this, without success. And Doug Axe, the director of Biologic Institute, is working on a similar problem.

Published
Author Stephen Matheson

Given that disputes over the existence and meaning of the phylotypic stage and the hourglass model have simmered in various forms for a century and a half, the remarkable correspondence between the hourglass model and gene expression divergence discovered by Kalinka and Varga and colleagues would be big news all by itself. But amazingly, that issue of Nature included two distinct reports on the underpinnings of the phylotypic stage.

Published
Author Stephen Matheson

The controversy about the existence of the phylotypic stage is more than some bickering about whether one blobby, slimy fish-thing looks more like a Roswell alien than another one does. It's about whether the phylotypic stage means something, whether it tells us something important about development and how developmental changes contribute to evolution.