Bryan Gitschlag

Oh I’m excited to dig into this! I especially love that figure with the environment & behavioral variables mapped onto the phylogeny! In my grad work, I found that nutrient stress intensifies selection against a selfish mtDNA… can’t help but wonder if it was a molecular case of a similar phenomenon.

Highlighted excerpt from Darwin's book On the Origin of Species, which reads: "The offspring from the first cross between two pure breeds is tolerably and sometimes (as I have found with pigeons) extremely uniform, and everything seems simple enough; but when these mongrels are crossed one with another for several generations, hardly two of them will be alike,..."

Highlighted excerpt from Darwin's book On the Origin of Species, which reads: "Thus I believe it has been with social insects: a slight modification of structure, or instinct, correlated with the sterile condition of certain members of the community, has been advantageous to the community: consequently the fertile males and females of the same community flourished, and transmitted to their fertile offspring a tendency to produce sterile members having the same modification."

Some favorite Darwin facts from "On the Origin of Species"…

1. He came this close 🤏 to figuring out Mendelian genetics (if only he had put numbers on those observations!)

2. Proposed the basic idea of Inclusive Fitness Theory, a leading explanation for evolution of animal altruism.

#DarwinDay

Faith healers remind me of how martial arts masters are often perceived (by their students) to have superhuman abilities.

Martial arts master George Dillman once famously explained to a Nat Geo filmcrew that his “no touch” knockout didn’t work on a skeptic because the guy was “a total nonbeliever.”

I'm sorry to hear about your loss. Sending you virtual hugs. Do you have any particularly favorite memories of him, or your time with him, that you'd be willing to share?

Really cool study by @evokait.bsky.social et al.

In a simple three-species food web, presence of an apex predator (nematode) promotes aggregative multicellularity in the predatory bacterium Myxococcus xanthus.

www.biorxiv.org/content/10.1...

Oh this ought to be a great talk!

Is there a link to attend? I'm not seeing any way to see the talk on the event webpage.

Buddhism?

Also, to be fair, I think you just described a lot of mainline/liberal Protestantism.

I doubt that's news but I think it underscores how we're talking about fringe views (which seem to get a disproportionate amount of exposure on social media, unfortunately) rather than something that represents the field as a whole. Evolutionary biologists know sex is complex & can't be pigeonholed.

Hi, evolutionary biologist here. To add to what others have said, I just wanna mention that since transphobia & trans-exclusionary views on sex have no basis in evolutionary theory, one possibility is they're just invoking credentials to give the appearance of legitimacy to their prejudices.

a man in a tuxedo sits in a chair in front of a staircase with people walking down it Alt: A man in a tuxedo and top hat sits in a chair in the grand staircase on the titanic watching in horror as the water approaches his feet. People around him are fleeing the rising water.

👀

Not only that, but the insinuation that someone shouldn’t receive care for a medical emergency, unless they have a visa or green card, seems kinda sociopathic.

Another idea: it’s difficult to get their gene products back into the mitochondria if encoded in the nucleus. The remaining mtDNA proteins are largely hydrophobic, and they can reportedly be mis-targeted to the endoplasmic reticulum when expressed in the nucleus.

(Not an exhaustive list!)

6/6

Why are some genes being left behind in the mitochondria? One proposed idea is that it’s easier to couple their expression to energetic feedbacks in a fine-tuned way, if they’re in close physical proximity to the ETC. The proteins encoded in animal mtDNA are considered core ETC components.

5/6

And there appear to be mechanisms for such mt-to-nuc migration. Some studies have reported mtDNA sequences that integrated in the nuclear genome, as real-time (e.g. due to aberrant repair of double-strand breaks, either in cancer or as a consequence of attempts to induce breaks for DNA editing)

4/6

One idea I speculated about in my thesis (not aware of data to support it, but makes sense in principle) is that if an mtDNA gene is copied to the nucleus, a mutant mtDNA with a deletion of that gene can ‘selfishly’ rise to high frequency without harming the host, thanks to the nuclear copy.

3/6

There are benefits to having mitochondrial genes migrate to the nucleus. For example it puts distance from the source of mutagenic byproducts of OXPHOS. It also makes their inheritance more regulated (mtDNA inheritance is more stochastic & non-Mendelian, prone to selfish genetic elements).

2/6

Awesome questions! I was asked some of these in my qualifying exam 😅

To your first question, it’s often more the former, especially for Electron Transport Chain components (some proteins that localize to mitochondria, involving immunity for example, likely had a nuclear origin to my knowledge)

1/6

Oh dear. That’s like, “oh you’re a barista? Make me a coffee, hehe.”

I do appreciate the question for the opportunity to clarify some misconceptions about how evolution of biological complexity works, but the question is almost never in good faith. Usually more of a ‘gotcha.’

Evolutionary biologist. “How do you explain [complex thing]?”

Let me know if you start seeing shiny things like buttons and coins lying around your property. :)

What about moderately communist?

Evolution 😅

Dr. Knurick seems to be most active in the video-based social media platforms like іnstа.

Their bsky info…
@drjessicaknurick.bsky.social
@amylnon.bsky.social

I would also look at Amy Non's work. She's an anthropologist who studies social inequalities in health outcomes (and the biological/molecular basis of such inequalities). Not sure how much public science communication she does, though, but definitely a researcher in this area.

I know that Jessica Knurick has spoken on such issues before. She's a dietician and nutritionist with a large social media footprint, who does a lot of pseudoscience-debunking online (e.g. responding to bad health info by discussing systemic issues that impede people's access to healthy lifestyles)

We jointly analyzed datasets of adaptive change (e.g. drug-resistance mutations) and independent measurements of mutation rates, across a number of species, and show that species-specific tendencies in adaptive evolution respond (statistically) to species-specific mutational tendencies.

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Mutation bias and the predictability of evolution | Philosophical Transactions of the Royal Society B: Biological Sciences Predicting evolutionary outcomes is an important research goal in a diversity of contexts. The focus of evolutionary forecasting is usually on adaptive processes, and efforts to improve prediction typ...

It has become increasingly clear in recent years that the outcomes of adaptive evolution are statistically enriched for not only beneficial mutations but also high-probability mutations; see our review of the literature: royalsocietypublishing.org/doi/full/10....

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Graph showing a positive correlation between "bias in adaptive outcome" on the vertical axis and "mutation bias" on the horizontal axis, with 14 data points representing 14 respective species, with a line of best fit equal to a slope of 0.82 on the log-scale axes. Each data point contains horizontal and vertical error bars to illustrate the uncertainty in both the mutational and adaptive data. The 95% confidence interval of the slope is shown in parentheses (0.44 to 1.24), based on 10,000 simulated data sets, where the simulated data sets are based on statistical resampling of the empirical data (i.e. "bootstrap" data sets). Regression lines based on these bootstrap data sets are shown as light gray lines. The type of bias reported here refers to the ratio of transitions versus transversions, where transitions are a DNA mutation that preserves the basic structure of the DNA base (i.e. a purine-to-purine or pyrimidine-to-pyrimidine mutation), and transversions are mutations that alter the structure of the DNA base at a particular site (i.e. replacing a purine with a pyrimidine or vice versa). In other words, this graph shows that transitions contribute more toward adaptive evolution in species where transitions arise at a higher rate.

NEW PAPER! Some kinds of genetic mutations are more likely to arise than others. Such "biases" in mutation vary between species.

Analyzing data from 14 species, we show that this variation explains species differences in the genetics of adaptation!

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www.biorxiv.org/content/10.1...