Fungi are weird

I think about the evolution of multicellularity a lot, and I talk about it with colleagues. One of the things we talk about is what general principles we can infer from the many independent origins of multicellularity, for example in land plants, animals, red algae, brown algae, green algae, and fungi. Those are the groups that have evolved what we might call complex multicellularity, and one of the things we notice is that they all develop clonally; that is, they start out as a single cell, and when that cell divides, the daughter cells stick together. We notice that complex multicellularity has never evolved in species with aggregative development, when free-living cells come together to form a multicellular body, as they do in cellular slime molds and myxobacteria. Some aggregative developers have evolved a couple of different cell types, but all of the groups that have reached higher degrees of complexity develop by cell division and the products of cell division staying together. All, that is, except for fungi. Fungi are weird.

Fungi don’t really develop clonally in the way I’ve described, but they don’t really not develop clonally either. That’s because their cells don’t divide in the way we’re used to thinking about, through repeated rounds of mitosis. In mitosis, duplication of the genome is coupled to cell division: the chromosomes duplicate, they move to either end of the cell, then the cell divides. The chromosomes double, then they halve, so the daughter cells end up with the same number as the mother cell. That’s not how it works in fungi. Instead, they form filaments called hyphae (singular hypha) that grow at the tip. In some cases, partitions called septa (singular septum) form behind the growing tip, dividing the hyphae into individual cells. In some cases, no septa form, and each hypha is effectively one long, skinny cell with lots of nuclei (this is called a coenocyte).

So fungi don’t really develop by repeated rounds of cell division in the same sense that animals, plants, etc. do. Hyphae just grow, and they are divided into cells as sort of an afterthought, if they are divided into cells at all. Fungi with coenocytic (or aseptate) hyphae aren’t really even multicellular in the same sense as plants and animals are. Different people have different qualifications for what counts as multicellular, but it’s a stretch to call something multicellular that doesn’t have multiple cells. Fungi are weird.

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Reminder: early bird registration for Volvox 2019 ends soon

Volvox 2019 logo

If you’re planning to go to the Fifth International Volvox Conference, it’s time to get a move on. Early bird registration and, more importantly, abstract submission end Saturday. Registration is open (at a slightly higher rate) until July 13, but if you want to present a poster or talk, the June 1 deadline applies.

The meeting is July 26-28 in Tokyo and includes a July 29 excursion to the NIES microbial culture collection and the National Museum of Nature and Science.

The next bestseller: my autobiography

The genesis of the next bestseller:

Dear Dr. Matthew D Herron,

I am Luis, Editorial assistant from Oasis Publishing Group Ltd. contacting you with the reference from our editorial department. Basing on your outstanding contribution to the scientific community, we would like to write your autobiography.

Researchers like you are adding so much value to the scientific community, yet you are not getting enough exposure. No matter how many papers you publish in famous journals, you will be still unknown to common people. To solve this problem, we came up with this unique solution.

With our autobiography service, we will write your autobiography along with your research contributions in common man’s language. We will also include all your published papers into this book in a way that a common man can understand it. And then, we will publish your book with our publishing group. Before, publication, we will send the draft to you for scientific accuracy, once you approve our draft, we then proceed for publication. You will get all the rights of your book, and all the sales generated from your book, will be credited to you.

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Michael Egnor doesn’t understand free speech

Censorship

Persecution complex? Image from an Evolution News & Views post on the Discovery Institute’s exclusion from the United Methodist Church’s General Conference in 2016.

In a previous post, I brought up Michael Egnor’s criticism of a blog post by Jerry Coyne. The post in question was criticizing the laughably bad argument by John Staddon that secular humanism is a religion. Tellingly, Dr. Egnor’s post does not address the substance of Dr. Coyne’s criticism at all. Seriously, not one word of Egnor’s response answers a single one of Coyne’s arguments.

The one and only portion of Coyne’s post that Egnor responds to is this:

[T]he editors screwed up by accepting a piece that makes very little sense, and arrives at its conclusion by some risibly tortuous logic… Why did the editors of Quillette publish this odiferous serving of tripe?

Egnor characterizes this as “seeth[ing]”, “rant[ing]”, “hate[ful]”, and “malic[ious]”. I won’t pass judgement on that characterization. The piece does make very little sense, and it does use some risibly tortuous logic, as I’ve previously pointed out. “Odiferous serving of tripe?” I guess you could call that seething and ranting, but it is a few words out of a much longer, mostly impassive post. Anyway, Dr. Egnor is entitled to his opinion, and that’s not what I’m here to talk about.

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Up is down. Black is white. Atheism is religion.

Humpty Dumpty

If you can’t beat ’em, define ’em out of existence!

Some members of the intelligent design community seem to have a genuinely hard time understanding that non-religious people actually exist. They don’t have convincing arguments for their religion, so they attempt an end run around reason by simply declaring that everyone is religious.

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A stuck mensch

    Journey into bullshitJourney into bullshit

I have never blocked a comment on this site that wasn’t straight-up spam. This should not be construed as a promise that I never will; it’s my site, and I reserve the right to block anything for any reason. So far, I just haven’t seen the need.

Not that I haven’t had some pushback in the comments, but I generally prefer to let the criticism stand. Sometimes I answer it. Sometimes the arguments are so inane that I think they have the opposite of their intended effect. And sometimes they’re so gloriously bad that I want to make sure my readers see them. This one falls into the third category.

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Betteridge’s law of headlines, part 2

No.

Still no.

Do religious people realize how obvious their insecurities become when they try to define everything they don’t like as religion? I’ve previously written about one example here (“Evolution is religion; intelligent design is science“), and John Staddon, James B. Duke Professor of Psychology and Professor of Biology, Emeritus, at Duke University, has provided another.

As I wrote in part 1, Dr. Staddon is oblivious to the fact that his own argument refutes his central thesis, that secular humanism is a religion:

All religions have three elements. Secular humanism lacks one of those elements. This is the point at which an intellectually honest writer who was not committed to his thesis would reconsider his position. Dr. Staddon chooses another route: ignore the contradiction and stay the course.

I also said that Dr. Staddon’s article was “a hot mess of unsupported assertions, innuendos, and self-contradictions,” but I didn’t go into detail. This post is to give examples of what I meant.

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A clever little two-step

Baym et al. 2016 Fig. 1B

Figure 1B from Baym et al. 2016. Experimental evolution of antibiotic resistance in E. coli bacteria. Bacteria were inoculated at both ends of the plate and evolved to tolerate the initially deadly concentration of antibiotic in the middle.

It’s possible for something to be both true and misleading. Here’s a great example. Frank Sherwin, a Research Associate at the Institute for Creation Research, recently wrote,

Evolutionists list antibiotic resistance as evidence of evolution, but in reality it has nothing to do with the origin of antibiotic resistance genes—let alone novel bacterial species.

Each of those things is true, but the sentence still manages to be misleading. Evolutionary biologists do regard antibiotic resistance as evidence of evolution. Real-time observations of the evolution of antibiotic resistance, like those in Michael Baym’s experiment, demonstrate evolution in action. Those experiments do have nothing to do with the origin of novel genes or of speciation. I’ve just admitted that both parts of the sentence are true, so what’s the problem?

It’s the but.

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