Recently in Evolution Category
Photograph by Marilyn Susek.
Photography contest, Honorable Mention.
Aeshna cyanea – southern hawker.
Beginning this week, we will run photographs every other Monday, so no picture next week; we no longer have enough honorable mentions and other miscellaneous photographs to continue posting a photograph every week. But polish your lenses (very carefully) and keep an eye out for the contest in the summer.
Larus delawarensis – ring-billed gull, Boulder, Colorado. There is right now a fairly large flock at Walden Ponds east of Boulder. They are too far away to get a picture, unless you like snapshots of an array of gray-and-white ellipses. But this one very kindly landed in a parking lot and posed long enough to enable this portrait.
On August 14, William Dembski spoke at the Computations in Science Seminar at the University of Chicago. Was this a sign that Dembski’s arguments for intelligent design were being taken seriously by computational scientists? Did he present new evidence? There was no new evidence, and the invitation seems to have come from Dembski’s Ph.D. advisor Leo Kadanoff. I wasn’t present, and you probably weren’t either, but fortunately we can all view the seminar, as a video of it has been posted here on Youtube.
It turns out that Dembski’s current argument is based on two of his previous papers with Robert Marks (available here and here) so the arguments are not new. They involve considering a simple model of evolution in which we have all possible genotypes, each of which has a fitness. It’s a simple model of evolution moving uphill on a fitness surface. Dembski and Marks argue that substantial evolutionary progress can only be made if the fitness surface is smooth enough, and that setting up a smooth enough fitness surface requires a Designer.
Briefly, here’s why I find their argument unconvincing:
- They conside all possible ways that the set of fitnesses can be assigned to the set of genotypes. Almost all of these look like random assigments of fitnesses to genotypes.
- Given that there is a random association of genotypes and fitnesses, Dembski is right to assert that it is very hard to make much progress in evolution. The fitness surface is a “white noise” surface that has a vast number of very sharp peaks. Evolution will make progress only until it climbs the nearest peak, and then it will stall. But …
- That is a very bad model for real biology, because in that case one mutation is as bad for you as changing all sites in your genome at the same time!
- Also, in such a model all parts of the genome interact extremely strongly, much more than they do in real organisms.
- Dembski and Marks acknowledge that if the fitness surface is smoother than that, progress can be made.
- They then argue that choosing a smooth enough fitness surface out of all possible ways of associating the fitnesses with the genotypes requires a Designer.
- But I argue that the ordinary laws of physics actually imply a surface a lot smoother than a random map of sequences to fitnesses. In particular if gene expression is separated in time and space, the genes are much less likely to interact strongly, and the fitness surface will be much smoother than the “white noise” surface.
- Dembski and Marks implicitly acknowledge, though perhaps just for the sake of argument, that natural selection can create adaptation. Their argument does not require design to occur once the fitness surface is chosen. It is thus a Theistic Evolution argument rather than one that argues for Design Intervention.
That’s a lot of argument to bite off in one chew. Let’s go into more detail below the fold …
Photograph by Kari Tikkanen.
Photography contest, Honorable Mention.
Noctilucent clouds. Mr Tikkanen writes that these “are bluish clouds located in the mesosphere at altitudes of around 80 kilometers. Relative recent appearance and their gradual increase may be linked to climate change.”
Alluvial fan created by the torrential rainfall 1 year ago, as seen from the Visitor Center, Trail Ridge Road, Rocky Mountain National Park, Colorado, September, 2014. The meander at the bottom of the screen passes through the bed of Fan Lake, which was formed in 1982 when the Lawn Lake Dam burst and inundated the City of Estes Park.
Honeysuckle, by Richard Meiss.
Photography contest, Finalist.
Lonicera X bella – Asian bush honeysuckle. Mr. Meiss writes, “This photo shows the coexisting ripe berries and new flowers of the Asian bush honeysuckle, an invasive species in the American midwest. This ‘second flowering’ in mid-September was induced by the very hot and dry summer of 2012. The phenomenon, an adaptation to environmental stress, was also widely noted in the British Isles; its prevalence is likely related to global warming. In this case, it may give a ‘leg up’ to an already-troublesome invasive species.”
Photograph by Keith Barkley.
Photography contest, Finalist.
Solar eclipse, May 20, 2012. Mr. Barkley writes, “I lucked out that the eclipse was still going on during local sunset. One of the few eclipse images you will see that was taken without a sun-viewing filter on the lens.”
A blogger in the Daily Kos reports that Neil deGrasse Tyson thinks people should “chill out” regarding genetically modified food. Tyson argues, as I have for years, that all our food is genetically modified, but it took on the order of 10,000 years to get where we are now.
The pseudonymous blogger, SkepticalRaptor, notes that GM foods are to many on the left as global warming is to many on the right: It is an article of faith that genetic modification is bad, and no amount of evidence can be adduced to change that opinion.
I would add, though, that there are valid reasons to oppose at least some genetic modifications, such as corn that is immune to glyphosate (Roundup) or plants laced with insecticide (Bt). Additionally, you could reasonably argue (as does SkepticalRaptor) that, whereas it may be legal to sell seeds that cannot reproduce themselves, it is certainly immoral to sell them to farmers in developing countries. Finally, I seem to recall that there have been occasional problems introducing, say, fish genes into tomatoes. None of these problems speaks against genetically modified food in general, though they surely militate in favor of considerable caution.
SkepticalRaptor concludes with the observation that Tyson is correct in following the evidence to its conclusion rather than denying the evidence in order to support a preordained conclusion. I could not agree more.
Jean-Baptiste Pierre Antoine de Monet was born on 1 August 1744 in Bazentin-le-Petit, Picardy, France. He was from a family of impoverished nobility, so he came to have the title Chevalier de Lamarck. He died at the age of 85 on 18 December 1829.
He was probably the greatest invertebrate biologist, clarifying the classification of invertebrates greatly. For that matter he is the one who coined the terms “invertebrate” and “biology”. He also was the first major evolutionary biologist, arguing that species had evolved from common ancestors and putting forward his own theory of the mechanisms – an inherent complexifying force combined with inherited effects of use and disuse of organs. One thing he did not do was introduce the notion of inheritance of acquired characters. Everyone already believed it; he just made use of it. So it should not be called “Lamarckian inheritance”.
Happy birthday to Lamarck, not a crackpot, not a quack, but a great evolutionary biologist.
Photograph by Dan Moore.
Photography contest, Second Place.
Phalacrocorax harrisi – flightless Galápagos cormorant. Mr. Moore writes, “Having made its way to a small set of islands we now call the Galápagos and given sufficient food and no predators, the cormorant had no need to fly, so over the years lost its full-feathered wings. Its bright-orange companion is Grapsus grapsus – the Sally Lightfoot crab.”
A big story in the press today. Scientists – mechanical engineers and physicists, one working for Boeing with his office only a few miles from my home – show that the evolution of airplanes works the same way as the evolution of organisms:
The evolution of airplanes
A. Bejan, J. D. Charles and S. Lorente
J. Appl. Phys. 116, 044901 (2014);
(fortunately this paper can be downloaded for free).
They make allometric plots of features of new airplane models, log-log plots over many orders of magnitude. The airplanes show allometry: did you know that a 20-foot-long airplane won’t have 100-foot-long wings? That you need more fuel to carry a bigger load?
But permit me a curmudgeonly point: This paper would have been rejected in any evolutionary biology journal. Most of its central citations to biological allometry are to 1980s papers on allometry that failed to take the the phylogeny of the organisms into account. The points plotted in those old papers are thus not independently sampled, a requirement of the statistics used. (More precisely, their error residuals are correlated). Furthermore, cultural artifacts such as airplanes do not necessarily have a phylogeny, as they can borrow features from each other in massive “horizontal meme transfer”. In either case, phylogeny or genealogical network, statistical analysis requires us to understand whether the points plotted are independent.
The paper has impressive graphs that seem to show trends. But looking more closely we notice that neither axis is actually time. If I interpreted the graphs as trends, I would conclude that birds are getting bigger and bigger, and that nobody is introducing new models of small airplanes.
At least we may rejoice that the authors are not overly shy. They make dramatic statements on the implications for biology:
The engine mass is proportional to the body size: this scaling is analogous to animal design, where the mass of the motive organs (muscle, heart, lung) is proportional to the body size. Large or small, airplanes exhibit a proportionality between wing span and fuselage length, and between fuel load and body size. The animal-design counterparts of these features are evident. The view that emerges is that the evolution phenomenon is broader than biological evolution. The evolution of technology, river basins, and animal design is one phenomenon, and it belongs in physics.
Evolution means a flow organization (design) that changes over time.
Thanks, now I finally know what evolution is. And that biologists should go home and leave its study to the physicists and engineers.
[Note: I will pa-troll the comments as aggressively as I can and send trolling and troll-chasing to the Bathroom Wall.]
Contrails, in the general direction of Denver International Airport, as seen from Boulder, Colorado, August, 2011. Jeff Mitton, Professor of Ecology and Evolutionary Biology at the University of Colorado, in an article in the Boulder Daily Camera, reminds us that contrails reduce diurnal temperature fluctuations and may have a significant effect on climate.
By David MacMillan.
8. New perspective. I think there are several different varieties of creationism activists. Some are obsessed with the presumed negative effects of evolution and secular humanism. Some are driven by suspicion for science and the certainty that a conspiracy must be afoot. Some use creationist apologetics to make themselves feel smarter and better-informed than the general public. Some are genuinely interested in science and want to know the truth.
I’d be lying if I said my motivations for arguing creationism were firmly in the last camp. I wasn’t much of a conspiracy theorist, but I certainly believed that there were inevitable negative consequences from the acceptance of evolution. I was definitely stuck-up about my “special” expertise. But deep down, I really did want to know the truth about the world. I loved being right, but I loved learning new things more.