The Panda’s Thumb

Araneus diadematus

2026-06-08T11:00:00-07:00

Photograph by Joel Eissenberg.

Photography Contest, Honorable Mention.

Araneus diadematus – orb spider, September, 2024. Mr. Eissenberg notes, "This spider spun a web on the outside of our dining tent on our back patio here in Rumford, Rhode Island."

Ark Park Attendance Drops Steadily: Righting America

2026-05-26T13:25:00-07:00

Credit: Northern Kentucky Tribune, CC BY-NC-ND 4.0.

The fifth anniversary of the Ark Park came up in July, 2021, and the Northern Kentucky Tribune announced in a headline, Ark Encounter marks fifth anniversary with record crowds, announcement of new attractions to come. The claim was not exactly true then – attendance actually began to fall in the fourth year – and William Trollinger, writing this week on the Righting America blog, proclaims in a headline, Sinking Further and Further Below Their Projections: The Facts of Ark Encounter Attendance. Using data provided by the “indefatigable” Dan Phelps, Dr. Trollinger shows that, relative to initial projections, Ark Park attendance has dropped monotonically from 50 % in the first full year of operation to 26 % in the most recent.

As Dr. Trollinger dryly remarks, Williamstown “has not enjoyed the economic benefits that it hoped would come from subsidizing the Ark.”

Zalophus californianus

2026-05-25T11:00:00-07:00

Photograph by David Young.

Zalophus californianus – California sea lion, San Diego, California, March, 2026.

Sphodros atlanticus

2026-05-11T11:00:00-07:00

Photograph by Al Denelsbeck.

Photography Contest, Honorable Mention.

Sphodros atlanticus – purseweb spider. Mr. Denelsbeck writes, "The business end of a male purseweb spider. While noticeable from above and seeming to take up far more of the spider's body mass than should be necessary, the chelicerae are most impressive from underneath, with very large fangs and serrated edges for gripping prey. Despite that, these are not large spiders – my specimen here is only 10-12 mm in body length. The females are almost never seen, generally remaining inside the lair that provides their name, usually looking like a small twig against a treetrunk (I've searched, but found nothing of the sort so far). Canon 7D, Canon 18-135 STM at 64 mm and 36 mm extension tube, ISO 200, F/13, 1/200 s with custom softbox flash unit."

Evolution revised, by A.I.

2026-05-07T15:00:01-07:00

A robot made by Toyota blows its own horn.
Image from Wikimedia.

I happened to type “evolution revised” into my Safari browser, and A.I. kicked in. I try to turn off A.I. as much as I can, but this slipped past me. Here’s what it said:

AI Overview

Evolutionary theory is currently being updated from the traditional gene-centric Modern Synthesis to an “Extended Evolutionary Synthesis” (EES). This revised framework incorporates new research, acknowledging that evolution is driven not just by random genetic mutations and natural selection, but also by epigenetic, behavioral, and environmental factors, alongside rapid, often developmental, adaptation.

Key Aspects of Revised Evolutionary Theory

Four Dimensions of Heredity: Beyond genetics, inheritance includes epigenetic (cellular modifications), behavioral (habits and cultural transmission), and symbolic (language) systems.

Extended Evolutionary Synthesis (EES): Proposes a more comprehensive framework than the Modern Synthesis, integrating developments in evolutionary developmental biology (evo-devo), epigenetics, and phenotypic plasticity.

Role of Plasticity and Environment: Organisms can modify their environment (niche construction) and transmit those changes. Acquired traits can be passed down via non-genetic mechanisms.

Faster, Recent Evolution: Recent studies, such as the analysis of 16,000 ancient genomes, reveal that natural selection has accelerated in some populations over the last 10,000 years, affecting hundreds of genes.

Regressive Evolution: Recognized as a common process where organisms lose complex traits to adapt (e.g., loss of eyes in cave-dwelling fish) to conserve energy in specific environments.

Key texts reflecting these changes include Evolution in Four Dimensions, Revised Edition by Jablonka and Lamb and The Princeton Guide to Evolution.

Any thoughts?

To display comments, click on the title of this post

Craig Venter dies

2026-04-30T16:48:00-07:00

The late Craig Venter. Photograph by Michael Janich. CC BY-SA 3.0.

We received an e-mail just now from Joel Eissenberg, Emeritus Professor of Biochemistry & Molecular Biology, Saint Louis University School of Medicine, saying,

As you may have seen, Craig Venter died yesterday. He played an important catalytic role in accelerating genome sequencing, both for humans and for my favorite model organism, D. melanogaster. His work obviously impacted comparative genomics.

Prof Eissenberg’s post at The Angry Bear is reproduced, with permission, below the fold:

Craig Venter died yesterday at the age of 79.

As a grad student, I wondered whether it would be possible to sequence the human genome. As a postdoc, I did both Maxam and Gilbert sequencing and Sanger sequencing (first with E. coli Klenow fragment, then reverse transcriptase) a couple hundred nucleotides per reaction, each reaction taking up to a week. For the first decade that I had my own lab, we did our own sequencing, but eventually it became cheaper and faster to send the template out to be sequenced by a company.

Venter drove the progress of DNA sequencing with his own company, then allied with the NIH to complete the first draft of the human genome. Genomic sequencing has transformed medicine, as well as evolutionary biology and taxonomy.

In the last five years that I had my own lab, genome sequencing was so cheap that I had a local company sequence the entire genome of a mutant fly line I’d created in order to define the sequence at one gene. And around that time, I also got my own genome sequenced for $199.

I’m sure we would have gotten here without Craig Venter, but I’m also sure it wouldn’t have happened as quickly. I’m glad I got to see it and benefit from it.

Chrysemys picta

2026-04-27T11:00:00-07:00

Chrysemys picta – painted turtle, Sawhill Ponds, Boulder, Colorado, April, 2026.

As I was preparing this post, I noticed that I had earlier posted two other pictures of painted turtles. In 2015, I displayed a handful sunbathing on a log. The 2010 picture of the underside of the turtle, which shows why they are called “painted,” must have disappeared during the Great Server Crash. I allowed someone to post it in Wikipedia, and you can see it here if you are so inclined.

Worldwide Pinhole Camera Day

2026-04-26T03:00:00-07:00

A rural scene in upstate New York taken with a pinhole camera. The photograph was exposed in about 1972 using a Praktiflex FX with a set of extension tubes and Kodak Tri-X film. The depth of field is virtually infinite, which is to say equally poor at all object distances.

Today is World Pinhole Camera Day, a fact I just learned on NPR yesterday morning. Which is somewhat surprising, because years ago I did some original research on the pinhole camera. Below the fold,…

… the cover of the issue of The Physics Teacher in which I published an article on pinhole optics. (The picture seems sharper than the picture above, possibly because I used a longer focal length, but such data are largely lost to antiquity.)

Resolution limit of the pinhole camera as a function of image distance, using normalized variables. s is the radius of the pinhole.

You may also see a pared down version of my research in the Wikipedia article on the pinhole camera. The heart of the paper is the figure, below left, showing in normalized variables the resolution limit of the pinhole camera as a function of image distance (colloquially but incorrectly called focal length in the paper). The pinhole camera is best focused when the pinhole is, in effect, a Fresnel zone plate with a single zone.

Since this is primarily a biology blog, I will mention that the nautilus has a pinhole eye.

Ramosomyia violiceps Calypte anna

2026-04-13T11:00:00-07:00

Photograph by Pierce Dayton.

Calypte anna – Anna's hummingbird, dining on aloe flowers. Pierce Dayton is the grandson of Vivian Dullien, whose photographs we posted here and here. He took the picture with his cell phone. More below the fold. (Added 4/17/26: Apparently it is an Allen's hummingbird; see the comments by John Harshman and others.)

According to this source, a hummingbird might flap its wings with a frequency of 50-90 Hz, though less when it is hovering. Mr. Dayton, who apparently knows his stuff, set his camera for F/2.8 and ISO 50, and achieved a shutter speed of approximately 1/3300 s, or 3300 Hz, which ought to be fast enough to stop the motion of the wings (according to the metadata associated with the photograph I received). Below, I will post another of his pictures, which shows the coloration of the bird somewhat better. I will confess that I cropped both pictures and adjusted the exposure ever so slightly.

Debates between different perspectives at DI site

2026-04-01T07:00:01-07:00

Finally, we will get to hear how and why these folks' views
differ from each other, and whether they can all be right.
Photos all from Wikimedia. I would be happy to add photos of the other 6 folks if they give permission.

Today, April 1, the Discovery Institute’s “Science and Culture Today” site will host a number of debates between leading figures in the Intelligent Design movement, highlighting their diverse perspectives, filling in the missing steps in their previous arguments, and giving an opportunity for readers of that site to leave comments on those posts, comments that will be as lively, instructive and stimulating as comments there usually are:

William Dembski, Winston Ewert, Robert Marks, and George Montañez will explain how having a large value of their Algorithmically Specified Complexity measure cannot have happened by natural selection making the value gradually larger. And why high functional information requires that the “description” of the phenotype (or is it genotype?) needs to be short.
Eric Hedin and Granville Sewell will explain what law of physics prevents any favorable mutation that improves functional information from increasing in frequency in any population.
Casey Luskin and Michael Behe will debate whether or not there is good evidence for common ancestry of primates, common ancestry of cercopithecoid monkeys, and common ancestry of apes (including humans).
John West and David Klinghoffer will explain why any scientific result that seems to them to make organisms behave immorally must therefore be scientifically invalid.

These discussions will be accompanied, as usual, by comments supplied by the enthusiastic and knowledgable S&CT readers, who appreciate the lively, honest and informative back-and-forth that signals the intellectual vitality of the “cdesign proponensist” movement.

Explanation here: