Hi I'm Nick Matzke. I dig evolution. Find Evolution of: biogeography, complex adaptations (carnivorous plants, flagella), evolutionary thought, R packages, texts, & creationist/ID silliness on The Panda’s Thumb.
Photograph by Paul Burnett.
Photography Contest, Honorable Mention.
Butorides virescens – green heron. Mr. Burnett writes, "This is in the same pond as my turtle pictures a few [as of 2016] years ago. There's a pair of them living around the pond, but they're so shy I haven't found a nest yet."
The number of entrants in the photography contest, but by no means the quality of the photography, has been decreasing more or less monotonically with time. But it has not hit 0 – so we thought we would announce the 11th annual contest, with entries accepted between June 14 and June 24, which gives you 2 weekends to polish your lenses or perfect your digital techniques. The rules will be the same as last year’s, except, obviously, that the dates will change. We will post a formal announcement at noon, MDT, June 14, and begin accepting entries immediately thereafter. We will choose a number of finalists and open voting for the winner at noon, June 28. The winner and the runner-up will receive a book courtesy of the National Center for Science Education.
These rats, probably Norway rats (see link), are active during the day, unlike most rats, which are nocturnal. The rat that interested me was the rat with the white blotch. Domesticated animals such as horses, cows, dogs, and now foxes often show blotchy coats, whereas, as far as I know, wild animals do not. The blotched rat, then, is probably a feral rat or a descendant of a feral rat that bred with a wild rat. Is that right? Did someone irresponsibly release a domesticated rat into the neighborhood?
United States District Court, Eastern District of Kentucky
Is God wroth with the Ark Encounter? We cannot know for sure, but it is entirely possible that he or she visited an admittedly minor act of God upon Ark Encounter LLC. The insurers of Ark Encounter LLC, all six of them, may or may not have thought so, but they refused to pay for a landslide along a road leading directly to the "Ark." Ark Encounter, in its turn, prayed for relief, not to God, but to the United States District Court (see the link in the caption).
Dan Phelps, a nearby Kentucky geologist, notes, "Any competent geologist would have told them that landslides are a consequence of building on the shales of the Kope Formation," and expresses surprise that they did not have access to one. He further explains that the photograph, which we got from the text of the lawsuit, "is a textbook example of a landslide occurring in the Late Ordovician Kope Formation of northern Kentucky. The Kope is typically more than 50% shale. If the Kope gets wet and is on a steep slope, it is very much vulnerable to landslides."
It seems likely that Ark Encounter's geologists are no better than their staff astrophysicists, though their failure is perhaps more obvious and more meaningful.
http://chandra.harvard.edu/photo/2014/eso137/. Photo credits (it is a composite): X-ray: NASA/CXC/UAH/M.Sun et al; Optical: NASA, ESA, & the Hubble Heritage Team (STScI/AURA).
Our occasional contributor (and my sometime pen pal) David MacMillan has written a splendid article detailing his “conversion” from young-earth creationist to rational scientist. I will not give the story away, but Mr. MacMillan seeks answers from distinguished “creation scientists” and accepts complex rationalizations, until he sees an event that obviously took much, much longer than 6000 years to unfold.
Eye of Diretmus argenteus – silver spiny fish. Modified Figure S9 of Supplementary Materials for "Vision using multiple distinct rod opsins in deep-sea fishes".
The figure represents the eye of the silver spiny fish, Diretmus argenteus. Elizabeth Pennisi reports in Science magazine that this fish lives in the very deep ocean, where there is no ambient light from the sun. Unlike many other creatures, such as blind cave fish, that lose their sight when deprived of light, these fish have evolved an eye that detects the faint glow of bioluminescence.
And what an eye it is! It consists of a cornea, a ball lens, an iris that is probably fixed and functions only as an aperture stop, and a variety of rods that apparently can distinguish color. Layers of rods are piled on top of each other. In the upper part of the drawing, the long rods are 95 μm long, and the short rods in the stack are each 15 μm long. The lower part of the drawing shows a layer of ultra-long rods 525 μm long and a stack of short rods 27.5 μm long. The rods contain different photopigments, or opsins, and span the range of bioluminescence wavelengths. Presumably the lengths of the rods also have something to do with color sensitivity. There is also a layer of cones, but I will hazard the guess that they are nonfunctional, since cones are generally used in bright, or photopic, illumination. It is unusual that the rods, which are used in dim, or scotopic, illumination have evolved to distinguish colors. I do not know what the honeycombed area represents, but it is probably various retinal layers that are not light-sensitive.
The optics of the eye is also interesting. The bulk of the receptors appear in the upper and lower parts of the picture, not along what you might think of as the axis, so the fish sees primarily above and below. I will hazard another guess, that the index of refraction of the liquid inside the eye is close to that of water, so the cornea is weak, and most of the power is due to the ball lens. I do not know whether the lens actually projects an image or merely acts as a condenser; see the Appendix.
The original paper is Vision using multiple distinct rod opsins in deep-sea fishes, by Zuzana Musilova and 17 others. The paper is concerned primarily with the evolution of the opsins, not the structure of the eye.
Appendix. The focal length f' of a ball lens is given by
f' = nD/(4(n – 1)),
where D is the diameter of the lens and n is the index of refraction. f' is (in this case) measured from the center of the sphere. Very roughly, if the drawing is at all to scale, the focal length would have to be about equal to the diameter in order to project an image onto the receptors at the very top or the very bottom of the drawing. If the index of refraction of the lens is 1.8, then we use n = 1.8/1.33, because the lens is surrounded by water, and we find that the focal length is roughly equal to the diameter of the lens. If that is so, then the system operates at a relative aperture of f/1. The lens in the human eye has an index of refraction around 1.4, and most common solids and liquids display indexes below 1.6, so an index of refraction of 1.8 seems high to me. On the other hand, if the cornea has power, as possibly evidenced by the location of the aperture stop, then the index of the lens may be lower than 1.8.
On the thread about Eric Holloway's dismissal of criticisms of ID, a commenter, "camsail", asks whether people have a response to
an article in the conservative online magazine Claremont Review of Books by Yale University computer scientist
and contrarian David Gelernter. This thread is intended to allow discussion of that article without disrupting the Eric Holloway
thread. Let's take a look ...
This supportive review of pro-ID books appears in CRB this month. Given the review author is well respected... I would
love to see a comprehensive refutation in response as I really think it will be trumpeted by the ID publicity
machine. Sorry for posting it in this thread but I have no other way I'm aware of to
communicate. Feel free to delete as off topic. Here's the link to the review:
(I recommend that people save the PDF when they look at the article, as going back too to read it too many times will lead CRB to
demand a subscription).
Here is my own reaction to the article:
I read Gelernter's article. Although he is a very competent computer scientist, he mostly just buys into the arguments
Stephen Meyer makes in Signature In the Cell and in Darwin's Doubt, plus adding in Doug Axe's recent arguments. He
attempts no evaluation of the mathematical arguments people like Dembski and Marks have made. His statements about
the Cambrian Explosion seem to be made without taking into account the Small Shelly Fauna, or the fact that
extant forms descended from that Explosion show up related to Cnidarians and Ctenophores in evolutionary trees. In
short, nothing much new. We've discussed these arguments before. CRB is a conservative publication. Although it has the
name "Claremont Review of Books" it seems not to be affiliated with the Claremont Colleges.
I need to correct one statement there -- Gelernter's article refers to one of those books by Meyer, Darwin's Doubt, and does not mention
the other, Signature in the Cell.
Anyway, on-topic discussion is welcome. I will, as usual pa-troll against off-topic trolling and also responses to that trolling.
Commenter "ds" made a couple of responses in the other thread, and is welcome to copy that text into comments here.
These seem to be a pair of scaups, but I have not the foggiest idea whether lesser scaup,
Aythya affinis, or greater scaup, A. marila, Wonderland Lake, Boulder, Colorado, April 6, 2019.
To my eye the markings are the same, right down to the black mark on the nose. Hard to tell their size, but probably smaller than mallards. Boulder is on the edge of both their ranges. I am curious why 2 species would be so nearly identical – is there significant interbreeding, or did they simply bifurcate very recently?