Nazi racial ideology was religious, creationist, and opposed to Darwinism

Anyway, it seems Coyne may have taken one small step away from absolute adaptationism in his post “Redundant parts“. (I have to admit, the question he posed about “superfluous” veins, “Maybe we can live without them, but couldn’t they have evolved as ‘backups’—in case something went wrong with a partner vessel?” is the kind of thing I would expect one of my introductory evolution students to ask at the beginning of the course).

Evolution: Education and Outreach

Volume 3, Number 4 / December 2010

• 489-490

  Editorial

  Niles Eldredge and Greg Eldredge

• 491-494

  How Systematics Became “Phylogenetic”

  Niles Eldredge

• 495-498

  Introduction to the Special Issue

  Sagas of the Children of Time: The Importance of Phylogenetic Teaching in Biology

  Daniel R. Brooks

• 499-505

  Why Trees Are Important

  Edward O. Wiley

• 506-519

  How to Read a Phylogenetic Tree

  Deborah A. McLennan

• 520-525

  The Gummy Tree Challenge—Building Connections One Treat at a Time

  Marcus Kumala

• 526-531

  The Neverending Story—Using the Narrative as a Fundamental Approach to Teaching Biology and Beyond

  Marcus Kumala

• 532-538

  A Natural History of You

  Marcus Kumala

• 539-547

  Characters Are Key: The Effect of Synapomorphies on Cladogram Comprehension

  Laura R. Novick, Kefyn M. Catley and Daniel J. Funk

• 548-557

  Sociobiology and the Comparative Approach: One Way to Study Ourselves

  Deborah Ann McLennan

• 558-562

  The Biodiversity Crisis: Lessons from Phylogenetic Sagas

  Daniel R. Brooks and Deborah A. McLennan

• 563-572

  Evolutionary Trees from the Tabloids and BeyondAnastasia Thanukos

• 573-575

  Why Are There Still Monkeys?

  William Eric Meikle and Eugenie C. Scott

• 576-584

  Brocchi, Darwin, and Transmutation: Phylogenetics and Paleontology at the Dawn of Evolutionary Biology

  Stefano Dominici and Niles Eldredge

• 585-594

  Brocchi’s Subapennine Fossil Conchology

  Stefano Dominici

• 595-604

  College Students’ Perceptions of Intelligent Design

  Craig Tollini and Jess White

• 605-613

  “Force-Talk” in Evolutionary Explanation: Metaphors and Misconceptions

  Ross H. Nehm, Meghan A. Rector and Minsu Ha

• 614-620

  Creationism and the Teaching of Evolution in PolandBartosz Borczyk

• 621-628

  Teaching Tree-Thinking to Undergraduate Biology Students

  Richard P. Meisel

• 629-632

  Do Americans Believe Modern Earth Science?

  Allan Mazur

• 633-640

  Considering Adaptation and the “Function” of Traits in the Classroom, Using Wiki Tools

  Sean A. Rands

• 641-660

  Scientific Authority in the Creation–Evolution Debates

  Finn R. Pond and Jean L. Pond

• 661-667

  Should the Teaching of Biological Evolution Include the Origin of Life?

  Antonio Lazcano and Juli Peretó

• 668-674

  Exploring Phylogeny at the Tree of Life Web Project

  Adam M. Goldstein

• 675-676

  Book Review

  A Specialized Reference and Then Some: Chronology of the Evolution-Creationism Controversy
  Chronology of the Evolution-Creationism Controversy, by Randy Moore, Mark Decker, and Sehoya Cotner. Santa Barbara, CA: Greenwood Press, 2010. pp. xx+455. H/b $85.00.

  Lawrence S. Lerner

• 677-678

  Book Review

  God Versus the Human Genome
  Inside the Human Genome: A Case for Non-Intelligent Design, by John C. Avise. Oxford: Oxford University Press, 2010. Pp. xi + 222. H/b $19.95.

  Adam M. Goldstein

• 679-686

  Other Media Reviews

  Paleontology and Evolution in the News

  Sidney Horenstein

• The Curious Disconnect: Introduction (March 19, 2010).
• The Mutationism Myth 1. The Monk’s Lost Code and the Great Confusion (March 29, 2010) describes how the mutationism story is told in books and articles.
• Theory₁ vs Theory₂ (April 13, 2010) explores a hidden distinction that will prove very useful later.
• The Mutationism Myth, 2. Revolution (April 30, 2010) will show you how to think about evolution the way Darwin did.
• The Mutationism Myth, 3. Foundations of Evolutionary Genetics (May 19, 2010) shows some of the synthetic thinking of the Mendelians.
• The Mutationism Myth, 4. Mendelian Heterodoxies (May 25, 2010) explains their views of mutation as a source of initiative, discontinuity, creativity and direction.
• The Mutationism Myth, 5.  The Restoration (June 14, 2010) tells how the Modern Synthesis restored “Darwinism”, at least in name.
• The Mutationism Myth, 6. Back to the Future (August 31, 2010) wrap ups the Mutationism Myth series and sets the stage for the future by locating the primary weakness of the 20th century neo-Darwinian consensus in its theory of variation.

Arlin is contemplating starting a new blog where this kind of topic could be explored and discussed, so stay tuned.

I appreciate comments and ideas from everyone, but I am especially interested in hearing from science writers as they are the intended users.

Segmentation Is the Secret Behind the Extraordinary Diversification of Animals

ScienceDaily (July 27, 2010) — Segmentation, the repetition of identical anatomical units, seems to be the secret behind the diversity and longevity of the largest and most common animal groups on Earth. Researchers from CNRS and Université Paris Diderot have shown that this characteristic was inherited from a common segmented ancestor thought to have lived 600 million years ago and whose presence “changed the face of the world.”

…

[Arthropods, vertebrates, and annelids] are not closely related to one another. So, where does their segmentation come from? Is it possible that they all inherited this feature from a very distant common ancestor that lived 600 million years ago, before the Cambrian explosion, which produced most of the large animal groups that exist today? Or has segmentation occurred several times during the history of evolution? This is the question addressed by the researchers of CNRS and Université Paris Diderot at the Institut Jacques Monod, because segments seem to offer a significant advantage to the groups that have them, in terms of diversity, longevity and overall evolutionary success.

…

The researchers found that the genes controlling segment formation during embryo development are almost the same in drosophila (an arthropod) and in annelid marine worms, on which they concentrated their studies. These similarities led them to conclude that the genes had been inherited from a common ancestor, which was itself segmented. It also appears that vertebrates inherited this characteristic from an ancestor they share with the arthopods and the annelids. This is what the researchers are now seeking to confirm.

Arthropods are segmented and very diverse. Nothing newsworthy there. But wait, what’s that? The second largest phylum is molluscs, which aren’t segmented? And what else? Nematodes, which are undoubtedly hyperdiverse, aren’t segmented either? Early-branching animals like sponges, cnidarians, and ctenophores aren’t segmented either, you say? Only three phyla are segmented, two of which (Chordata and Annelida) are not as large as Mollusca and Nematoda? Hmmm.

Anyway, the story (which is bad, even by press release standards) suggests that finding a common gene involved in segmentation in three distantly related phyla implies that their common ancestor had the gene and therefore was segmented as well. We’ve been through this whole “shared regulatory gene equals homology of morphological trait” issue with the eye. The alternative interpretation is that the same genes were co-opted for similar functions independently. The authors of the original paper dismiss this possibility in one sentence:

“Because they are not known to be part of a conserved core regulatory network or “kernel” that might have been coopted en bloc, each gene would have been recruited independently, which seems unlikely.”

Let’s think about this for a minute. Yes, it seems “unlikely” that the same genes would be co-opted three times for similar functions. But the hypothesis that the ancestor was segmented requires another major assumption.

Here is a very basic phylogeny from an introductory textbook.

For the ancestor of chordates, annelids, and arthropods to have been segmented, this means that segmentation must have been lost in molluscs, nematodes, echinoderms, brachiopods, rotifers, flatworms, and various smaller phyla. Moreover, several of these phyla that lost segmentation subsequently became more diverse than chordates and annelids.

Another example of misunderstanding phylogenetics.

An example:

This is the duck-billed platypus, Ornithorhynchus anatinus. It is a mammal, but as a monotreme it also lays eggs. It has fur and produces milk, but it does not have nipples. Because of these features, it is often considered a “primitive” species and people often compare features of the platypus to those of placental mammals in order to draw conclusions about the evolution of “modern” placental mammals.

It’s true that platypuses lay eggs and lack nipples. They also have a bill, can sense electric currents in the water, and (in males) have a spur that delivers venom. Does this mean that the ancestor of platypuses and placental mammals had bills and venom? No, it doesn’t. That’s because these are derived traits that evolved in the platypus lineage after the monotreme and placental mammal lineages diverged from a common ancestor.

There is no such thing as a primitive species, only primitive or derived traits. The platypus, like every species, is a mixture of the two. As such, comparing it with other living species of mammals does not automatically tell you anything about what the ancestral mammal was like.

What about the claim that the monotremes are an “older” group of mammals? It’s possible that, as a recognizable group, monotremes appeared before placentals. However, the lineage of which the modern platypus is a representative and the lineage of which humans are a representative have been evolving for exactly the same amount of time. This is simply a result of the fact that they share a common ancestor at some point in the past. The two lineages diverged from this ancestor and then began evolving separately. Some traits found in the ancestor were maintained in the platypus lineage, others in the human lineage, and in both cases there were new features that evolved that were not found in the common ancestor.

The take-home message is this. You can’t consider one species “primitive” and another “derived” and assume that any given feature in the former was found in the ancestor of the two. You need more information before you can interpret the evolutionary history of a particular characteristic.

Anyway, New Scientist seems to have fallen for this in their interpretation of a recent paper.

Bellyflopping frogs shed light on evolution

Playing leapfrog would be tricky for the most primitive living frogs: those from the Leiopelmatidae family crash-land rather than touch down gracefully after leaping. The finding may reveal how frog jumping evolved.

Richard Essner of Southern Illinois University in Edwardsville suspected unusual jumping behaviours in leiopelmatids because they are known to swim differently from other frogs, using a “trotting” movement rather than a synchronous double kick.

Essner’s team used high-speed video to compare jumping in three leiopelmatid species with two more-evolved species. Whereas the more advanced species begin to fold up their hind-limbs in mid-air to prepare for landing and their next leap, “Leiopelmatid frogs don’t fold up their legs until after they’ve hit the ground,” he says.

Ascaphus montanus, the most primitive species, kept its legs splayed as it landed in a belly flop or nosedive, then skidded to a halt on its belly. Perhaps it’s no surprise that frogs evolved to jump before they could master landing.

The authors of the paper state several times that these frogs retain the ancestral swimming style. Presumably this is backed up with clear evidence in the fossil record, and not just position on the reconstructed phylogeny. Otherwise, there is an obvious alternative interpretation: the swimming mode in leiopelmatids is derived and results in a reduced leaping ability. Given that they are mostly aquatic and have other derived adaptations to life in fast-running streams, this is not at all implausible. Again, these are all modern species that have been evolving for exactly the same amount of time since their split from a common ancestor.

UPDATE: Evolutionary concepts are often superficially simple but in fact very difficult to grasp correctly. This story shows how this extends to both researchers and science writers and, presumably, their readers. New Scientist, Scientific American, Discoblog (Discover), Ed Yong (Discover), the journal (Naturwissenschaften), and the study authors all appear to be confused to some extent about what “primitive” means and how one establishes ancestral vs. derived characteristics.

Here’s an example from my paper on evolutionary trees. Which is more “primitive”, “early branching”, “least evolved”, or what have you? Can you conclude anything about the ancestor of echinoderms and chordates by comparing modern humans vs. modern echinoderms and assuming the early branching lineage is primitive?

I have tried to tackle these in my previous series of reviews in the journal Evolution: Education and Outreach. Sadly, despite some moves in the right direction, these are still not freely available from Springer.  (You may recall that I resigned as associate editor over the lack of access).

However, if you want to send a PDF to someone who is confused about these topics, you can get the papers at the links below.

Gregory, T.R. (2009).  Understanding natural selection: essential concepts and common misconceptions.  Evolution: Education and Outreach 2: 156-175.

Gregory, T.R. (2008). The evolution of complex organs.  Evolution: Education and Outreach 1: 358-389.

Gregory, T.R. (2008). Understanding evolutionary trees.  Evolution: Education and Outreach 1: 121-137.

Gregory, T.R. (2008).  Evolution as fact, theory, and path.  Evolution: Education and Outreach 1: 46-52.

Bacteria Expect the Unexpected
Organisms ensure the survival of their species by genetically adapting to the environment. If environmental conditions change too rapidly, the extinction of a species may be the consequence. A strategy to successfully cope with such a challenge is the generation of variable offspring that can survive in different environments. Even though a portion of the offspring may have a decreased chance to survive, the survival of the species as a whole is guaranteed. For the first time scientists have now observed the evolution of such a strategy under lab conditions in an experiment with the bacterial species Pseudomonas fluorescens: A bacterial strain exposed to rapidly changing environmental conditions developed the ability to generate variable offspring without additional mutations. This new strategy ensured the survival of the bacterial strain. The results were published in NATURE. (05.11.2009).