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Posts Tagged ‘evolution’

Deck the ‘Nets With PeerJ Papers— please sing along!

♬Deck the ‘nets with PeerJ papers,
Fa la la la la, la la la la.
‘Tis the day to show our labours,
Fa la la la la, la la la la.

Downloads free; CC-BY license,
Fa la la, la la la, la la la.
Read the extant ratite science,
Fa la la la la, la la la la.

See the emu legs before you
Fa la la la la, la la la la.
Muscles allometric’ly grew.
Fa la la la la, la la la la.

Follow the evolvin’ kneecaps
Fa la la la la, la la la la.
While we dish out ratite recaps 
Fa la la la la, la la la la.

Soon ostrich patellar printing
Fa la la la la, la la la la.
Hail anat’my, don’t be squinting
Fa la la la la, la la la la.

Dissections done all together
Fa la la la la, la la la la.
Heedless of the flying feathers,
Fa la la la la, la la la la♪

(alternate rockin’ instrumental version)

Stomach-Churning Rating: 5/10: cheesy songs vs. fatty chunks of tissue; there are no better Crimbo treats!

Today is a special day for palaeognath publications, principally pertaining to the plethora of published PeerJ papers (well, three of them anyway) released today, featuring my team’s research! An early Crimbo comes this year in the form of three related studies of hind limb anatomy, development, evolution and biomechanics in those flightless feathered freaks of evolutionary whimsy, the ratites! And since the papers are all published online in PeerJ (gold open access), they are free for anyone with internet access to download and use with due credit. These papers include some stunning images of morphology and histology, evolutionary diagrams, and a special treat to be revealed below. Here I’ll summarize the papers we have written together (with thanks to Leverhulme Trust funding!):

1) Lamas, L., Main, R.P., Hutchinson, J.R. 2014. Ontogenetic scaling patterns and functional anatomy of the pelvic limb musculature in emus (Dromaius novaehollandiae). PeerJ 2:e716 http://dx.doi.org/10.7717/peerj.716 

My final year PhD student and “emu whisperer” Luis Lamas has published his first paper with co-supervisor Russ Main and I. Our paper beautifully illustrates the gross anatomy of the leg muscles of emus, and then uses exhaustive measurements (about 6524 of them, all done manually!) of muscle architecture (masses, lengths, etc.) to show how each of the 34 muscles and their tendons grew across a more than tenfold range of body mass (from 6 weeks to 18 months of age). We learned that these muscles get relatively, not just absolutely, larger as emus grow, and their force-generating ability increases almost as strongly, whereas their tendons tend to grow less quickly. As a result, baby emus have only about 22% of their body mass as leg muscles, vs. about 30% in adults. However, baby emus still are extremely athletic, more so than adults and perhaps even “overbuilt” in some ways.

This pattern of rapidly growing, enlarged leg muscles seems to be a general, ancestral pattern for living bird species, reflecting the precocial (more independent, less nest-bound), cursorial (long-legged, running-adapted) natural history and anatomy, considering other studies of ostriches, rheas, chickens and other species close to the root of the avian family tree. But because emus, like other ratites, invest more of their body mass into leg muscles, they can carry out this precocial growth strategy to a greater extreme than flying birds, trading flight prowess away for enhanced running ability. This paper adds another important dataset to the oft-neglected area of “ontogenetic scaling” of the musculoskeletal system, or how the locomotor apparatus adapts to size-/age-related functional/developmental demands as it grows. Luis did a huge amount of work for this paper, leading arduous dissections and analysis of a complex dataset.

Superficial layer of leg muscles in an emu, in right side view.

Superficial layer of leg muscles in an emu, in right side view. Click any image here to emu-biggen. The ILPO and IC are like human rectus femoris (“quads”); ILFB like our biceps femoris (“hams”); FL, GM and GL much like our fibularis longus and gastrocnemius (calf) muscles, but much much bigger! Or, perhaps FL stands for fa la la la la?

Data for an extra set of emus studied by coauthor Russ Main in the USA, which grew their muscles similarly to our UK group. The exponents (y-axis) show how much more strongly the muscles grown than isometry (maintaining the same relative size), which is the dotted line at 1.0.

Data for an extra set of emus studied by coauthor Russ Main in the USA, which grew their muscles similarly to our UK group. The exponents (y-axis) show how much more strongly the muscles grew than isometry (maintaining the same relative size), which is the dotted line at 1. The numbers above each data point are the # of individuals measured. Muscle names are partly above; the rest are in the paper. If you want to know them, we might have been separated at birth!

2) Regnault, S., Pitsillides, A.A., Hutchinson, J.R. 2014. Structure, ontogeny and evolution of the patellar tendon in emus (Dromaius novaehollandiae) and other palaeognath birds. PeerJ 2:e711 http://dx.doi.org/10.7717/peerj.711

My second year PhD student Sophie Regnault (guest-blogger here before with her rhino feet post) has released her first PhD paper, on the evolution of kneecaps (patellae) in birds, with a focus on the strangeness of the region that should contain the patella in emus. This is a great new collaboration combining her expertise in all aspects of the research with coauthor Prof. Andy Pitsillides‘s on tissue histology and mine on evolution and morphology. This work stems from my own research fellowship on the evolution of the patella in birds, but Sophie has taken it in a bold new direction. First, we realized that emus don’t have a patella– they just keep that region of the knee extensor (~human quadriceps muscle) tendon as a fatty, fibrous tissue throughout growth, showing no signs of forming a bony patella like other birds do. This still blows my mind! Why they do this, we can only speculate meekly about so far. Then, we surveyed other ratites and related birds to see just how unusual the condition in emus was. We discovered, by mapping the form of the patella across an avian family tree, that this fatty tendon seems to be a thing that some ratites (emus, cassowaries and probably the extinct giant moas) do, whereas ostriches go the opposite direction and develop a giant double-boned kneecap in each knee (see below), whereas some other relatives like tinamous and kiwis develop a more “normal”, simple flake-like bit of bone, which is likely the state that the most recent common ancestor of all living birds had.

There’s a lot in this paper for anatomists, biomechanists, palaeontologists, ornithologists, evo-devo folks and more… plenty of food for thought. The paper hearkens back to my 2002 study of the evolution of leg tendons in tetrapods on the lineage that led to birds. In that study I sort of punted on the question of how a patella evolved in birds, because I didn’t quite understand that wonderful little sesamoid bone. And now, 12 years later, we do understand it, at least within the deepest branches of living birds. What happened further up the tree, in later branches, remains a big open subject. It’s clear there were some remarkable changes, such as enormous patellae in diving birds (which the Cretaceous Hesperornis did to an extreme) or losses in other birds (e.g., by some accounts, puffins… I am skeptical)– but curiously, patellae that are not lost in some other birds that you might expect (e.g., the very non-leggy hummingbirds).

Fatty knee extensor tendon of emus, lacking a patella. The fatty tissue is split into superficial (Sup) and deep regions, with a pad corresponding to the fat pad in other birds continuous with it and the knee joint meniscus (cushioning pad). The triceps femoris (knee extensor) muscle group inserts right into the fatty tendon, continuing over it. A is a schematic; B is a dissection.

Fatty knee extensor tendon of an emu, showing the absence of a patella. The fatty tissue is split into superficial (Sup) and deep regions, with a pad corresponding to the fat pad in other birds continuous with it and the knee joint meniscus (cushioning pad). The triceps femoris (knee extensor) muscle group inserts right into the fatty tendon, continuing on over it. A is a schematic; B is a dissection.

Sectioning of a Southern Cassowary's knee extensor tendon, showing: A Similar section  as in the emu image above. revealing similar regions and fibrous tissue (arrow), with no patella, just fat; and B, with collagen fibre bundles (col), fat cells (a), and cartilage-like tissue (open arrows) labelled.

Sectioning of a Southern Cassowary’s knee extensor tendon, showing: A, Similar section as in the emu image above. revealing similar regions and fibrous tissue (arrow), with no patella, just fat; and B, With collagen fibre bundles (col), fat cells (a), and cartilage-like tissue (open arrows) labelled.

Evolution of patellar form in birds. White branches indicate no patella, blue is a small flake of bone for a patella, green is something bigger, yellow is a double-patella in ostriches, and grey is uncertain. Note the uncertainty and convergent evolution of the patella in ratite birds, which is remarkable but fits well with their likely convergent evolution of flightlessness and running adaptations.

Evolution of patellar form in birds. White branches indicate no patella, blue is a small flake of bone for a patella, green is something bigger, yellow is a double-patella in ostriches, black is a gigantic spar of bone in extinct Hesperornis and relatives, and grey is uncertain. Note the uncertainty and convergent evolution of the patella in ratite birds (Struthio down to Apteryx), which is remarkable but fits well with their likely convergent evolution of flightlessness and running adaptations.

3) Chadwick, K.P., Regnault, S., Allen, V., Hutchinson, J.R. 2014. Three-dimensional anatomy of the ostrich (Struthio camelus) knee joint. PeerJ 2:e706 http://dx.doi.org/10.7717/peerj.706

Finally, Kyle Chadwick came from the USA to do a technician post and also part-time Masters degree with me on our sesamoid grant, and proved himself so apt at research that he published a paper just ~3 months into that work! Vivian Allen (now a postdoc on our sesamoid bone grant) joined us in this work, along with Sophie Regnault. We conceived of this paper as fulfilling a need to explain how the major tissues of the knee joint in ostriches, which surround the double-patella noted above, all relate to each other and especially to the patellae. We CT and MRI scanned several ostrich knees and Kyle made a 3D model of a representative subject’s anatomy, which agrees well with the scattered reports of ostrich knee/patellar morphology in the literature but clarifies the complex relationships of all the key organs for the first time.

This ostrich knee model also takes Kyle on an important first step in his Masters research, which is analyzing how this morphology would interact with the potential loads on the patellae. Sesamoid bones like the patella are famously responsive to mechanical loads, so by studying this interaction in ostrich knees, along with other studies of various species with and without patellae, we hope to use to understand why some species evolved patellae (some birds, mammals and lizards; multiple times) and why some never did (most other species, including amphibians, turtles, crocodiles and dinosaurs). And, excitingly for those of you paying attention, this paper includes links to STL format 3D graphics so you can print your own ostrich knees, and a 3D pdf so you can interactively inspect the anatomy yourself!

(A) X-ray of an ostrich knee in side view, and (B) labelled schematic of the same.

Ostrich knee in side view: A, X-ray, and (B) labelled schematic.

3D model of an ostrich knee, showing: A, view looking down onto the top of the tibia (shank), with the major collateral ligaments (CL), and B, view looking straight at the front of the knee joint, with major organs of interest near the patella, sans muscles.

3D model of an ostrich knee, showing: A, View looking down onto the top of the tibia (shank), with the major collateral ligaments (CL), and B, View looking straight at the front of the knee joint, with major organs of interest near the patella, sans muscles.

You can view all the peer review history of the papers if you want, and that prompts me to comment that, as usual at PeerJ (full disclosure: I’m an associate editor but that brings me £0 conflict of interest), the peer review quality was as rigorous at a typical specialist journal, and faster reviewing+editing+production than any other journal I’ve experienced. Publishing there truly is fun!

Merry Christmas and Happy Holidays — and good Ratite-tidings to all!

And stay tuned- the New Year will bring at least three more papers from us on this subject of ratite locomotion and musculoskeletal anatomy!

♬Should auld palaeognathans be forgot, 
And never brought for scans? 
Should publications be soon sought, 
For auld ratite fans!♪

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Let's play find-the-spandrel!

Let’s play find-the-spandrel!

We just passed the 35th anniversary of the publication of Gould and Lewontin’s classic, highly cited, highly controversial essay (diatribe?), “The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme.” The 21st of September 1979 was the fateful date. Every PhD student in biology should read it (you can find pdfs here— this post assumes some familiarity with it!) and wrestle with it and either love it or hate it- THERE CAN BE NO MIDDLE GROUND! With some 5405 citations according to Google Scholar, it has generated some discussion, to put it lightly. Evolutionary physiologists and behaviourists who were working at the time it came out have told me stories of how it sent (and continues to send) shockwaves through the community. Shockwaves of “oh crap I should have known better” and “Hell yeah man” and “F@$£ you Steve,” more or less.

I am among those who love “The Spandrels Paper“. I love it despite its many flaws that people have pointed out to seemingly no end- the inaccurate architectural spandrel analogy, the Gouldian discursive (overly parenthetical [I’m a recovering victim of reading too much Gould as an undergrad]) writing style, the perhaps excessive usage of “Look at some classic non-scientific literature I can quote”, the straw men and so on. I won’t belabour those; again your favourite literature search engine can be your guide through that dense bibliography of critiques. I love it because it is so daringly iconoclastic, and because I think it is still an accurate criticism of what a LOT of scientists who do research overlapping with evolutionary biology (that is, much of biology itself) do.

The aspects of The Spandrels Paper that I still think about the most are:

(1) scientists seldom test hypotheses of adaptation; they are quick to label something that is useful to an animal as an adaptation and then move on after rhapsodizing about how cool of an adaptation it is; and

(2) thus alternatives to adaptation, which might be very exciting topics to study in their own right, get less attention or none.

True for #2, evo-devo has flourished by raising the flag of constraint (genetic/developmental/other factors that prevent evolution from going in a certain direction, or even accelerate it in less random directions). That’s good, and there are other examples (genetic drift, we’ve heard about that sometimes), but option #1 still often tends to be the course researchers take. To some degree, labelling something as an adaptation is used as hype, to make it more exciting, I think, in plenty of instances.

Truth be told, much as Gould and Lewontin admitted in their 1979 paper and later ones, natural selection surely forges lineages that have loads of adaptations (even in the strictest sense of the word), and a lot of useful traits of organisms are thus indeed adaptations by any stripe. But the tendency seems to be to assume that this presumptive commonality of adaptations means that we are justified to quickly label traits as adaptations.

Or maybe some researchers just don’t care about rigorous tests of adaptation as they’re keen to do other things. Standards vary. What I wanted to raise in this post is how I tend to think about adaptation:

I think adaptations are totally cool products of evolution that we should be joyous to imagine, document, test and discover. But that means they should be Special. Precious. A cause for celebration, to carefully document by scientific criteria that something is an adaptation in the strictest sense, and not a plesiomorphy/exaptation (i.e. an adaptation at a different level in the evolutionary hierarchy; or an old one put to new uses), spandrel/byproduct, or other alternatives to adaptation-for-current-biological-role.

But that special-ness means testing a hypothesis of adaptation is hard. As many authors waving the flag of The Modern Comparative Method (TMCM) have contended, sciencing truth-to-adaptationist-power by the rules of TMCM takes a lot of work! George Lauder’s 1996 commentary in the great Adaptation book (pdf of the chapter here) outlined a lengthy procedure of  “The Argument from Design“; i.e., testing adaptation hypotheses. At its strictest implementation it could take a career (biomechanics experiments, field studies, fitness measurements, heritability studies, etc.) to test for one adaptation.

Who has time for all that?

The latter question seems maladaptive, placing cart and horse bass-ackwards. If one agrees that adaptations are Special, then one should be patient in testing them. Within the constraints of the practical, to some degree, and different fields would be forced to have different comfort levels of hypothesis testing (e.g. with fossils you can’t ever measure fitness or other components of adaptation directly; that does not mean that we cannot indirectly test for adaptations– with the vast time spans available, one would expect palaeo could do a very good job of it, actually!).

I find that, in my spheres of research, biomechanists in particular tend to be fast to call things they study adaptations, and plenty of palaeontologists do too. I feel like over-usage of the label “adaptation” cheapens the concept, making the discovery of one of the most revered and crucial concepts in all of evolutionary biology seem cheapened and trite. Things that are so easy to discover don’t seem as precious. When everything is awesome, nothing is…

I’ve always hesitated, thanks in part to The Spandrels Paper’s indoctrination, from calling features of animals adaptations, especially in my main research. I nominally do study major ?adaptations? such as terrestrial locomotion at giant body sizes, or the evolution of dinosaurian bipedalism. I searched through my ~80 serious scientific papers lately and found about 50 mentions of “adapt” in an adaptationist, evolutionary context. That’s not much considering how vital the concept is (or I think it is) to my research, but it’s still some mentions that slipped through, most of them cautiously considered– but plenty more times I very deliberately avoided using the term. So I’m no model of best practice, and perhaps I’m too wedded to semantics and pedantry on this issue, but I still find it interesting to think about, and I’ve gradually been headed in the direction of aspect #2 (above in bold) in my research, looking more and more for alternative hypotheses to adaptation that can be tested.

I like talking about The Spandrels Paper and I like some of the criticism of it- that’s healthy. It’s a fun paper to argue about and maybe we should move on, but I still come back to it and wonder how much of the resistance to its core points is truly scientific. I’m entering into teaching time, and I always teach my undergrads a few nuggets of The Spandrels Paper to get them thinking about what lies beyond adaptation in organismal design.

 What do other scientists think? What does adaptation mean (in terms of standards required to test it) to you? I’m curious how much personal/disciplinary standards vary. How much should they?

For the non-scientists, try this on for size: when our beloved Sir David Attenborough (or any science communicator) speaks in a nature documentary about how the otter is “perfectly adapted” to swim after prey underwater, do you buy into that or question it? Should you? (I get documentaries pushing me *all the time* to make statements like this, with a nudge and a wink when I resist) Aren’t scientists funny creatures anyway?

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[This is the original, unedited text of my shorter, tighter (and I think actually better) News & Views piece for Nature, on the paper described below)

Ambitious experimental and morphological studies of a modern fish show how a flexible phenotype may have helped early “fishapods” to make the long transition from finned aquatic animals into tetrapods able to walk on land.

Stomach-Churning Rating: 1/10. Cute fish. Good science. Happy stomachs!

Photo by Antoine Morin, showing Polypterus on land.

Photo by Antoine Morin, showing Polypterus on land.

Napoleon Bonaparte’s military excursions into Egypt in 1798-1799 led a young French naturalist, Ètienne Geoffroy Saint-Hilaire, to cross paths with a strange fish that had paired lungs and could “walk” across land on its stubby, lobelike fins. In 1802, he dubbed this fish “Polyptère bichir”1, today known as the Nile bichir, Polypterus bichir La Cepède 1803. The bichir’s mélange of primitive and advanced traits helped to catapult Geoffroy into scholarly conflict with the reigning naturalist Georges Cuvier back in France and to establish Ètienne as a leading anatomist, embryologist and early evolutionary researcher of repute even today2. Now, on their own excursion under the very “evo-devo” flag that the discoverer of Polypterus helped raise, Canadian scientists Standen et al.3 suggest how the remarkable plasticity of the skeleton of Polypterus (the smaller west African relative of P. bichir, P. senegalus or “Cuvier’s bichir”) reveals a key part of the mechanism that might have facilitated the gradual transition from water to land and thus from “fishapods” to tetrapods (four-limbed vertebrates).

In a bold experiment, the authors raised 149 young bichirs on land and in water for eight months, then studied how they moved on land vs. in water, and also how the ultimate shape of the skeletal elements of the paired front fin bases differed between the land- and water-raised bichirs. Standen et al.3 discovered that both the form and function of the fins’ foundations transformed to better satisfy the constraints of moving on land. Land-acclimated bichirs took faster steps on land, their fins slipped across the substrate less, they held their fins closer to their body, their noses stayed more aloft and their tails undulated less, with less variable motions overall—behaviours that the authors had predicted should appear to enhance walking abilities on land. In turn, the bones of the neck and shoulder region altered their shape to produce a more mobile fin base with greater independence of fin from neck motion, along with improved bracing of the ventral “collarbone” region. These environmentally-induced traits should have fostered the locomotor changes observed in “terrestrialized” fish and aided the animals in resisting gravity, and they represent a common biological phenomenon termed developmental plasticity4,5. Interestingly, the land-reared fish could still swim about as well as the wholly aquatic cohort, so there was not a clear trade-off between being a good swimmer and a good walker, which is surprising.

Considered alone, the developmental plasticity of bichir form and function shows how impressive these amphibious fish are. But Standen et al.’s study3  ventured further, to apply the lessons learned from bichir ontogeny to a phylogenetic context and macroevolutionary question. The phenotypic plasticity during bichir development, they infer, could have been harnessed during the evolutionary transformation of fins for swimming into limbs for walking, in the “fishapod” ancestors of tetrapods. Indeed, bichirs are close to the base of the family tree of fishes6, and other living relatives of tetrapods have reduced or lost their fins (lungfishes) or adapted to strange deep-sea swimming lifestyles, never walking on land (coelacanths). Thus perhaps bichirs and the “fishapod” lineage share what Geoffroy would have called “unity of type”, today termed homology, of their developmental plasticity in response to a land environment. Surveying the fossil record of early “fishapods” and tetrapods, Standen et al.3 found that the macroevolutionary changes of neck and shoulder anatomy in these gradually more land-adapted animals parallel those they observed in terrestrialized Polypterus, providing ancillary support for their hypothesis.

A further test of the application of Polypterus’s plasticity to fossil tetrapods is naturally difficult. However, the “fishapod” lineage has some exceptional examples of fossil preservation. With sufficient sample sizes (e.g. fossil beds that reveal growth series, such as the Late Devonian Miguasha site in Canada7) and palaeoenvironmental gradients in fish or tetrapods, one could imagine performing a rigorous indirect test. Even small samples could be helpful– for example, the early tetrapod Ichthyostega exhibits some developmental changes in its forelimb suggesting that it became more terrestrial as it grew, whereas the related Acanthostega does not evidence such changes8— this hints at some developmental plasticity in the former animal.

During the Devonian period (~360-420 million years ago), were the “fishapod” ancestors of tetrapods floundering about on land now and then, gradually shifting from anatomy and behaviours that were more developmentally plastic (as in bichirs) to ones that were more canalized into the terrestrialized forms and functions that more land-adapted tetrapods retained? An attractive possibility is that the developmental plasticity could have led to fixation (reduction of plasticity), an evolutionary phenomenon called genetic assimilation, which another intellectual descendant of Geoffroy, Conrad Hal Waddington, promoted from the 1950s onwards9, a concept that now enjoys numerous cases of empirical support10 that this one may eventually join.

The nature of the genetic and developmental mechanism that bichirs use to achieve the observed developmental plasticity is still unclear. If it has a high enough degree of heritability, then it could be selected for in cross-generational experiments with bichirs. With sufficient time and luck raising these unusual fish, the hypothesis that their plastic response to a terrestrial environment can become genetically assimilated could be directly tested. This study could thus become an epic exemplar of how genetic assimilation can contribute not only to microevolutionary change but also to major macroevolutionary events, as was presciently suggested in a seminal review of developmental plasticity4.

This genetic assimilation is the Polypterus study’s reasonable speculation, and one that Geoffroy likely would have applauded, all the more for involving his beloved bichirs. Much as Napoleon’s landfall in Egypt was not a lasting success, bichirs never left wholly terrestrial descendants despite their malleable locomotor system. But the same type of plastic developmental mechanism that bichirs use today to make tentative, floppy incursions of the terrestrial realm might have been harnessed by our own “fishapod” forebears, leaving a far more revolutionary dynasty upon the Earth.

 

References

  1.  Geoffroy, E. (1802). Histoire naturelle et description anatomique d’un nouveau genre de poisson du Nil, nommé polyptère. Annales du Muséum d’Histoire Naturelle 1:57-68.
  2. Le Guyader, H., & Grene, M. (2004) Geoffroy Saint-Hilaire: A Visionary Naturalist. Univ. Chicago Press.
  3. Standen, E. M., Du, T. Y., & Larsson, H. C. E. (2014). Developmental plasticity and the origin of tetrapods. Nature, published online.
  4. West-Eberhard, M. J. (1989). Phenotypic plasticity and the origins of diversity. Annual Review of Ecology and Systematics 20:249-278.
  5. Pigliucci, M., Murren, C. J., & Schlichting, C. D. (2006). Phenotypic plasticity and evolution by genetic assimilation. Journal of Experimental Biology 209(12):2362-2367.
  6. Near, T. J., Dornburg, A., Tokita, M., Suzuki, D., Brandley, M. C., & Friedman, M. (2014). Boom and bust: ancient and recent diversification in bichirs (Polypteridae: Actinopterygii), a relictual lineage of ray‐finned fishes. Evolution 68:1014-1026.
  7. Cloutier, R. (2013). Great Canadian Lagerstätten 4. The Devonian Miguasha Biota (Québec): UNESCO World Heritage Site and a Time Capsule in the Early History of Vertebrates.Geoscience Canada40:149-163.
  8. Callier, V., Clack, J. A., & Ahlberg, P. E. (2009). Contrasting developmental trajectories in the earliest known tetrapod forelimbs.Science324:364-367.
  9. Waddington, C. H. (1953). Genetic assimilation of an acquired character. Evolution 7:118-126.
  10. Crispo, E. (2007). The Baldwin effect and genetic assimilation: revisiting two mechanisms of evolutionary change mediated by phenotypic plasticity. Evolution 61:2469-2479.

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Construction of the Phyletisches Museum in Jena, Germany began on Goethe’s birthday on August 28, 1907. The Art Nouveau-styled museum was devised by the great evolutionary biologist, embryologist and artist/howthefuckdoyousummarizehowcoolhewas Ernst Haeckel, who by that time had earned fame in many areas of research (and art), including coining the terms ontogeny (the pattern of development of an organism during its lifetime) and phylogeny (the pattern of evolution of lineages of organisms through time) which feature prominently in the building’s design and exhibits (notice them intertwined in the tree motif below, on the front of the museum). Ontogeny and phylogeny, and the flamboyant artistic sensibility that Haeckel’s work exuded, persist as themes in the museum exhibits themselves. Haeckel also came up with other popular words such as Darwinism and ecology, stem cell, and so on… yeah the dude kept busy.

Cavorting frogs from Haeckel's masterpiece Kunstformen der Natur (1904).

Cavorting frogs from Haeckel’s masterpiece Kunstformen der Natur (1904).

I first visited the Phyletisches Museum about 10 years ago, then again this August. Here are the sights from my latest visit: a whirlwind ~20 minute tour of the museum before we had to drive off to far-flung Wetzlar. All images are click-tastic for embiggenness.

Stomach-Churning Rating: 3/10 for some preserved specimens. And art nouveau.

Willkommen!

Willkommen!

Frog ontogeny, illustrated with gorgeous handmade ?resin? models.

Frog ontogeny, illustrated with gorgeous handmade ?resin? models.

Fish phylogeny, illustrated with lovely artistry.

Phylogeny of Deuterostomia (various wormy things, echinoderms, fish and us), illustrated with lovely artistry.

Phylogeny of fish and tetrapods.

Phylogeny of fish and tetrapods.

Slice of fossil fish diversity.

Slice of fossil fish diversity.

Plenty of chondryichthyan jaws and bodies.

Plenty of chondrichthyan jaws/chondrocrania, teeth and bodies.

Awesome model of a Gulper eel (Saccopharyngiformes).

Awesome model of a Gulper Eel — or, evocatively, “Sackmaul” auf Deutsch (Saccopharyngiformes).

Lobe-finned fishes (Sarcopterygii)- great assortment.

Lobe-finned fishes (Sarcopterygii)- great assortment including a fossil coelacanth.

Lungfish body/model and skeleton.

Lungfish body and skeleton.

Coelacanth!

Coelacanth!

Coelacanth staredown!

Coelacanth staredown!

Fire salamander! We love em, and the museum had several on display- given that we were studying them with x-rays, seeing the skeleton and body together here in this nice display was a pleasant surprise.

On into tetrapods– a Fire Salamander (Salamandra salamandra)! We love ’em, and the museum had several on display- given that we were studying them with x-rays, seeing the skeleton and body together here in this nice display was a pleasant surprise.

A tortoise shell and skeleton, with a goofball inspecting it.

A tortoise shell and skeleton, with a goofball inspecting it.

In a subtle nod to recurrent themes in evolution, the streamlined bodies of an ichthyosaur and cetacean shown in the main stairwell of the museum, illustrating convergent evolution to swimming locomotor adaptations.

In a subtle nod to recurrent themes in evolution, the streamlined bodies of an ichthyosaur and cetacean shown in the main stairwell of the museum, illustrating convergent evolution to swimming adaptations.

Phylogeny of reptiles, including archosaurs (crocs+birds).

Phylogeny of reptiles, including archosaurs (crocs+birds).

Gnarly model of an Archaeopteryx looks over a cast of the Berlin specimen, and a fellow archosaur (crocodile).

Gnarly model of an Archaeopteryx looks over a cast of the Berlin specimen, and a fellow archosaur (crocodile). The only extinct dinosaur on exhibit!

Kiwi considers the differences in modern bird palates: palaeognathous like it and fellow ratites/tinamous (left), and neognathous like most living birds.

Kiwi considers the differences in modern bird palates: palaeognathous like it and fellow ratites/tinamous (left), and neognathous like most living birds.

Echidna skeleton. I can't get enough of these!

Echidna skeleton. I can’t get enough of these!

Skulls of dugong (above) and manatee (below).

Skulls of dugong (above) and manatee (below), Sirenia (seacows) closely related to elephants.

Fetal manatee. Awww.

Fetal manatee. Awww.

Adult Caribbean manatee, showing thoracic dissection.

Adult Caribbean manatee, showing thoracic dissection.

Hyraxes, which Prof. Martin Fischer, longtime curator of the Phyletisches Museum, has studied for many years.  Rodent-like elephant relatives.

Hyraxes, which Prof. Martin Fischer, longtime curator of the Phyletisches Museum, has studied for many years. Rodent-like elephant cousins.

Old exhibit at the Phyletisches Museum, now gone: Forelimbs of an elephant posed in the same postures actually measured in African elephants, for the instant of foot touchdown (left pic) and liftoff (right pic). Involving data that we published in 2008!

Old exhibit at the Phyletisches Museum, now gone: Forelimbs of an elephant posed in the same postures actually measured in African elephants, for the instant of foot touchdown (left pic) and liftoff (right pic). Involving data that we published in 2008!

Gorilla see, gorilla do. Notice "bent hip, bent knee" vs. "upright modern human" hindlimb postures in the two non-skeletal hominids.

Eek, primates! Gorilla see, gorilla do. Notice the primitive “bent hip, bent knee” vs. the advanced “upright modern human” hindlimb postures in the two non-skeletal hominids.

Phylogeny of select mammals, including the hippo-whale clade.

Phylogeny of artiodactyl (even-toed) mammals, including the hippo-whale clade.

Hand (manus) of the early stem-whale Ambulocetus.

Hand (manus) of the early stem-whale Ambulocetus.

Carved shoulderblade (scapula) of a bowhead whale (Balaena mysticetus), which apparently Goethe owned. Quite a relic!

Carved shoulderblade (scapula) of a bowhead whale (Balaena mysticetus), which apparently Goethe owned (click to emwhalen and read the fine print). Quite a relic!

One of Haeckel's residences. There is also a well-preserved house of his that one can visit, but I didn't make it there.

One of Haeckel’s residences, across the street from the museum. There is also a well-preserved house of his that one can visit, but I didn’t make it there. I heard it’s pretty cool.

Jena is tucked away in a valley in former East Germany, with no local airport for easy access- but get to Leipzig and take a 1.25 hour train ride and you’re there. Worth a trip! This is where not just ontogeny and phylogeny were “born”, but also morphology as a modern, rigorous discipline. Huge respect is due to Jena, and to Haeckel, whose quotable quotes and influential research still resonate today, in science as well as in art.

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This is the mammoth image I remember, from a 1971 book, with no artist credited. It's actually not as good as I remember, by modern standards at least.

This is the mammoth image I remember, from a 1971 book, with no artist credited. It’s actually not as good as I remember, by modern standards at least.

Mammoths and I go way back, not quite to the Ice Age but at least to the late 1970s with my family’s visits to the University of Wisconsin Geology Museum, and Milwaukee Public Museum, to name two prominent places that inspired me. And one of my favourite science books had a colourful mammoth painting on the cover (above), an image that has stayed with me as awesomely evocative.

Stomach-Churning Rating: 3/10. But there’s a butt below, but that’s too late for you now. And there’s poo and other scatological (attempts at) humour. Otherwise, bones and a baby mammothsicle.

Fast forward to the 2000’s and I’m studying mammoths, along with their other kin amongst the Proboscidea (elephants and relatives). I even bumped into a frozen mammoth in Sapporo, Japan, nine years ago–

Yep. That's what it looks like. Nope, not the front end. That orifice is not the mouth. This is the XXXXX mammoth.

Yep. That’s what it looks like. Nope, not the front end. That dark orifice is not the mouth. This is a mammoth that was found on Bolshoi Lyakhovsky island, in the east Siberian arctic (New Siberian Islands archipelago), in 2003. Just think of finding this and being all excited then realizing, “Jackpot! Wait… Oh man, I just found the ass. I’ve discovered a mammoth bunghole, dammit.” Still, it’s pretty damn amazing, as frozen Ice Age buttocks go. I’d love to find one. I would not be bummed.

found on Bolshoi Lyakhovskiy island in 2003

What I know now that I didn’t realize as a kid, is that a mammoth is an elephant in all but name. Mammoths are more closely related to Asian elephants than either is to African elephants, and all of these elephants are members of the group Elephantidae. If we saw a smallish Columbian mammoth, we’d probably mostly look upon it as similar to a slightly hairy Asian elephant (but a scientist would be able to spot the distinctive traits that each has). Only woolly mammoths adopted the uber-hirsute state that we tend to think of as a “mammoth” trait. Think about it: a big animal would benefit most from a thick hairy insulation in an extremely cold habitat, and Columbian mammoths ranged further south than Woolly ones. No mammoths were radically different from living elephants, unless you count the dwarf ones. But as a kid, like most people do, I saw them as something else: an exotic monster of the past, eerily unlike anything today, and bigger too. And mammoths have the added mystique of the extinct.

Now I see mammoths as neither exotic nor that far in the past. Giant ground sloths, now those are still alien and exotic to me. I don’t get them. I know elephants pretty well, and I can understand mammoths in their light and in light of mammoth fossils. Various mammoth species persisted as late as maybe 10,000 (for the Woolly and Columbian species; the latter seeming to vanish earlier) to <4000 (for isolated Siberian forms) years ago, into quasi-historic times. And only some mammoths got larger than African elephants (Loxodonta) do, such as Columbian mammoths (~10,000 kg or more maximal body mass; Loxodonta is closer to 7-10 tonnes at best).

Lately, coincidence has brought me new knowledge of – and even greater interest in – mammoths.

First, a fortunate last-minute visit to Waco, Texas’s “Mammoth Site” (see my Flickr photo tour here) two weeks ago during a short visit to give a talk in that fine central Texan city.

Second, the subject of today’s post: the Natural History Museum’s new special exhibit “Mammoths: Ice Age Giants“, which is open until 7 September. The exhibit was created by the Field Museum in Chicago, but the NHM has given it a special upgrade under the expert guidance of mammoth guru Prof. Adrian Lister of the NHM, who was very kind to give me a tour of the exhibit.

What follows is primarily a photo-blog post and review of the exhibit, but with some thoughts and facts and anecdotes woven through it. Dark setting, glass cases, caffeination, crowds, and mobile phone camera rather than nice SLR in hand means that the quality isn’t great in my images– but all the more reason to go see the exhibit yourself! All images can be clicked to em-mammoth them.

On entry, one views a mammoth skeleton with a timelapse video backdrop that shows how the landscape (somewhere in USA) has changed since ~10,000 BCE.

On entry, one views a mammoth skeleton with a timelapse video backdrop that shows how the landscape (somewhere in USA) has changed since ~10,000 BCE.

The first part of the exhibit does a nice job of introducing key species of Proboscidea (elephants and their closest extinct relatives), with a phylogeny and timescale to put them into context, starting with the earliest forms:

The first part of the exhibit does a nice job of introducing key species of Proboscidea: from early species like Moeritherium...

from species like the tapir-sized Moeritherium

Skull of Moeritherium, reconstructed. Not that different from an early sirenian (seacow) in some ways, and general shape.

Skull of Moeritherium, reconstructed. Not that different from an early sirenian (seacow) in some ways, and general shape, whereas still quite a long way from a modern elephant in form– but the hints of tusks and trunk are already there.

...To the early elephantiform Phiomia, here shown as a small animal but I'm told it actually got quite large. And continuing with giant terrestrial taxa...

…To the early elephantiform Phiomia, here shown as a smallish animal but I’m told it actually got quite large. And continuing with giant terrestrial taxa…

I was awed by this reconstruction of the giant early elephantiform relative Deinotherium, with the short, swollen trunk and downturned tusks-- so bizarre!

I was awed by this reconstruction of the huge early elephantiform-relative Deinotherium, with the short, swollen trunk and downturned tusks– so bizarre!

Looking down onto the roof of the mouth of a NHM specimen of Deinotherium.

Looking down onto the roof of the mouth of an NHM specimen of Deinotherium. Big, sharper-edged, almost rhino-like teeth; far from the single mega-molars of modern elephants.

The lower jaw (top) and fairly straight tusk (bottom) of the widespread, early elephantiform Gomphotherium.

The lower jaw (top) and fairly straight tusk (bottom) of the widespread, early elephantiform Gomphotherium.

The big "shovel-tusker" elephantiform Amebelodon. This was one of the earliest stem elephants I learned of as a kid; the odd tusks still give me a sense of wonder.

The big “shovel-tusked” elephantiform Amebelodon. This was one of the earliest stem elephants I learned of as a kid; the odd tusks still stir wonder in me.

Amebelodon lower jaw, sans shovel tusks.

Amebelodon lower jaw, sans shovel tusks. Extended chin looks like some sort of childrens’ fun-slide. To me, anyway.

Next, there are some fun interactive displays of elephant biomechanics!

How would a mammoth hold up its head? This lever demonstration shows how a nuchal ligament helps.

How would a mammoth hold up its head? This lever demonstration shows how a nuchal ligament helps. Tension on the nuchal ligament is a force that acts with a large lever (represented by the big neural spines on the vertebrae around the shoulders, forming the mammoths’ “hump” there), creating a large moment (i.e. torque; rotational force) that holds the head aloft.

I love this robotic elephant trunk demonstration. It captures some of the weirdness of having a muscular hydrostat attached to your lip.

I love this robotic elephant trunk demonstration. It captures some of the weirdness of having a muscular hydrostat attached to your lip and nostrils. Not so easy for a human to control!

But forget the myths about elephants having 40,000 to 150,000 muscles in their trunk. They have three muscle layers: a circumferential one, an oblique one and a longitudinal one. Like any muscles, especially ones this large, the layers each consist of many muscle fibres. That’s where the 40-150k myth comes from, but muscle fibres (cells) are at a more microscopic level than whole muscles (organs). Elephants do have excellent control of their trunks, but it’s not magical. It’s just different.

Then we come to the centrepiece of the exhibit, the ~42,000 year old Woolly mammoth (Mammuthus primigenius) baby “Lyuba“, which the NHM added to the original exhibit in this new version, as a star attraction — and a big win. Adrian Lister related to me how he’d never seen Lyuba in person before (access to it was tightly guarded for years). So when the NHM received the crate and held a press event to open it and reveal Lyuba, a journalist asked Adrian to act excited, to which he responded something like, “I don’t need to act! I’m very excited!” I would be, too! Full story on Lyuba’s arrival, by NHM site here. A key paper on Lyuba by Fisher et al. is here.

Studies of tooth growth in Lyuba reveal her gestation period (like living elephants, around 22 months), season of birth (early spring), and age at death (1 month), among other information.

Studies of tooth growth in Lyuba reveal her gestation period (like living elephants, ~22 months), season of birth (early spring), and age at death (~1 month), among other information.

Here we can see the right ear, which was gnawed off along with the tail by dogs of the reindeer herders that found and retrieved Lyuba. Regardless, there's loads of anatomy preserved! A hump of juvenile "brown fat" atop the head, very strange flanges on the trunk (also visible in 1 other frozen mammoth specimen, but here preserved very clearly!), and more visible postcranially...

Here we can see the right ear, which was gnawed off along with the tail by dogs of the reindeer herders that found and retrieved Lyuba in 2006. Regardless, there’s loads of anatomy preserved!

A hump of juvenile “brown fat” sits atop the head and neck of Lyuba. This probably was  metabolized during growth to warm the baby; brown fat is packed with mitochondria and thereby conducts what is called “non-shivering thermogenesis”. Furthermore, Lyuba has very strange flanges on the trunk (also visible in 1 other frozen mammoth specimen, but here preserved very clearly! What were they used for?). More details are visible postcranially…

The body was naturally “freeze-dried”, with the addition of later rounds of soaking in formalin and ethanol, leaving the body dessicated and stiff, permanently stuck in a lifelike pose as seen below:

Whole view from an exhibit panel (you cannot photograph the specimen but these are fair game!). Here we see hair on the right forearm and remnant of the ear, and the labia and nipples showing it is a female mammoth are also preserved. The head-hump is lost during growth, and the shoulder changes to change the Asian elephant-like convex curvature of the back into the characteristic humped-shoulder form of a mammoth. But ontogeny still reveals the evolutionary connection of Elephas and Mammuthus.

Whole view from an exhibit panel (you cannot photograph the specimen but these are fair game!). Here we see hair on the right forearm and remnant of the ear, and the labia and nipples showing it is a female mammoth are also preserved. The head-hump is lost during growth, and the shoulder changes to change the Asian elephant-like convex curvature of the back into the characteristic humped-shoulder form of a mammoth. But ontogeny still reveals the evolutionary connection of Elephas and Mammuthus.

Lyuba and scientists studying her, which also shows how rigid the carcass is.

Lyuba and scientists studying her, which also shows how rigid the carcass is; one can almost stand it up. Inside the digestive tract, researchers found chewed up plant material that was probably dung eaten by the baby to gain vital bacterial digestive flora, and Lyuba had plenty of body fat and ingested milk, indicating that she did not starve to death. Rather, vivianite in the respiratory tract indicates drowning as the cause of her demise. Perfusion of the body by these vivianites may have helped to preserve the body.

Answering an question the public may be wondering about: is the hype about cloning a mammoth very soon true? Nope. Well addressed, including what to me is the urgent question: would cloning a mammoth be ethical?

Answering a question the public may be wondering about: is the hype about cloning a mammoth very soon true? Nope. Well addressed, including what to me is the urgent question: would cloning a mammoth be ethical?

The fourth part of the exhibit takes on a largely North American focus to first illustrate what mammoths were like biologically, and second to wow the visitor with some huge beasts in full body, full scale glory, as we shall see!

Mammoth hair! These samples and recent molecular studies show that mammoths were not ginger-coloured as we long thought, but rather the ginger color comes as the dark grey-brown-black colour fades postmortem, as a preservational artefact. I didn't know that; cool.

Mammoth hair! These samples and recent molecular studies show that mammoths were not ginger-coloured as we long thought, but rather the ginger color comes as the dark grey-brown-black colour fades postmortem, as a preservational artefact (story here). I didn’t know that; cool.

Mammoth chow!

Mammoth chow! I liked this addition to the exhibit. This brought mammoth ecology closer to home for me.

Mammoth poop!

Mammoth poop!

After the biology explanations, let there be megafauna!

Mammoth skull! A nice one, too.

Mammoth skull! A nice one, too.

Top predators of Ice Age North America: Arctodus (short-faced bear) and Homotherium (sabre-toothed cat).

Top predators of Ice Age North America: Arctodus (short-faced bear– does the short face mean they were happy, unlike a long face? Sorry but they never are shown as very happy, unless it is the joy of whupass) and Homotherium (the other sabre-toothed cat; not the longer-toothed Smilodon).

Skulls of North American megafauna: left to right, top to bottom: horse, short-faced bear, giant sloth, then camel, sabretooth,  rabbit, direwolf (viva Ned Stark!), and pronghorn antelope.

Skulls of North American (mega)fauna: left to right, top to bottom: horse, short-faced bear, giant ground sloth, then camel, sabretooth cat, rabbit, direwolf (viva Ned Stark!), and pronghorn antelope.

Mastodon skeleton!

Mastodon (Mammut americanum) skeleton!

Mammoths seem to have been wiped out by a combination of climate change and habitat fragmentation, combined with what this item symbolizes: human hunting. This beautiful piece is the main part of an atlatl, or javelin-hurling lever. It would give Ice Age hunters the extra power they'd need to penetrate mammoth hide and cause mortal injuries.

Mammoths (and perhaps mastodons, etc.) seem to have been wiped out by a combination of climate change and habitat fragmentation, combined with what this item symbolizes: human hunting. This beautiful piece is the main part of an atlatl, or javelin-hurling lever. It would have given Ice Age hunters the extra power they’d need to penetrate mammoth hide and cause mortal injuries. It is also a great tie-in to my recent post on the British Museum’s odd-animals-in-art.

Finally, the exhibit surveys the kinds of mammoths that existed- there is a huge reconstruction of a Columbian mammoth near the mastodon (above), then smaller kinds and discussions of dwarfism, which is another strength of NHM mammoth research:

Woolly mammoth lower jaw (right) and its likely descendant, the pygmy mammoth of the Californian coastline, Mammuthus exilis.

Woolly mammoth lower jaw (right) and its likely descendant, the pygmy mammoth of the Californian coastline, Mammuthus exilis.

The world's smallest mammoth (left), molar tooth compared with that of its much larger ancestor Palaeoloxodon. The status of Mammuthus creticus as a dwarf mammoth from Crete was cemented by Victoria Herridge and colleagues, including Adrian Lister at the NHM.

The world’s smallest mammoth (left), molar tooth compared with that of its much larger ancestor Palaeoloxodon. The status of Mammuthus creticus as a dwarf mammoth from Crete was cemented by Victoria Herridge and colleagues, including Adrian Lister at the NHM.

Pygmy mammoth reconstruction. Shorter than me. I want one!

Pygmy mammoth reconstruction. Shorter than me. I want one!

In the end, from all that proboscidean diversity we were left with just 2 or 3 species (depending on your species concepts; it's probably worth calling the African forest elephant its own species, Loxodonta cyclotis). The exhibit closes with a consideration of their conservation and fate. Ironically, this elephant skull could not be mounted with its tusks on display, because that would be commercializing ivory usage-- even though the whole point of the exhibit's denouement is to explain why elephants need protection!

In the end, from all that glorious proboscidean diversity we were left with just 2 or 3 species of elephantids today (depending on your species concepts; it’s probably worth calling the African forest elephant its own species, Loxodonta cyclotis). The exhibit closes with a consideration of their conservation and fate. Ironically, this elephant skull could not be mounted with its tusks on display, because that would be commercializing ivory usage– even though the whole point of the exhibit’s denouement is to explain why elephants need protection!

Reactions to the exhibit: the photos tell the tale. It’s undeniably great, in terms of showing off the coolness of mammoths, other proboscideans and Ice Age beasties, to the general public. I felt like the factual content and learning potential was good. It didn’t feel at all like pandering to the lowest common denominator like some other exhibits I’ve seen (cough, Dino Jaws, cough). I loved the reconstructions, which were top quality in my opinion. I could have done with some more real skeletons, yet more realistically the exhibit hall was already large and full of cool stuff. But give me a break: Lyuba. This trumps everything. Going to see a real friggin’ frozen mammoth baby buries the needle of the awesomeness meter on the far right. That’s pretty much all I need to say. The spectacle was a spectacle.

This exhibit shows a lot of work, a lot of thought, and a personalized NHM touch that reflects the actual research (even very recent work!) that NHM staff like Prof. Lister are doing with collaborators around the globe. What more could we want, a herd of cloned mammoth babies frolicking around and tickling guests with their flanged trunks? Don’t hold your breath.

You’ve got just over 2 months to see the exhibit. Don’t come complaining on September 8 “BBBBBbbbut I didn’t know, I didn’t think it would be that cool! I just thought there’d be a guy in a Snuffleupagus suit signing autographs!” You have a duty as a Freezerino to go bask in the frozen glory of these Ice Age critters. There may be an exam at the end. :)

Is the exhibit kid-friendly? More or less. The text is more targeted at teenager-level or so, but the visual impact is powerful without it. I’d warn a sensitive child about the withered baby mammoth body before showing it to them, so they aren’t caught off guard and scarred by the experience. I saw plenty of kids in the exhibit and they all seemed happy. Parents may want to linger longer and absorb all the interesting information, whereas kids may blitz through or goof around, so plan accordingly if you’re inbound with sprogs.

You know what I was eyeing up in the gift shop...

You know what I was eyeing up in the gift shop…

Aside: The frozen mammoths get me wondering- what else does the Siberian (or extreme northern Canadian/Scandinavian) permafrost conceal? There are a lot of awesome Ice Age megafauna I’d cut my left XXXXX off to study quasi-intact… think about how amazing it would be to find a giant ground sloth (not bloody likely), sabretooth cat, or other species. There’s a lot of north up north. A lot of space and ice. A lot could happen. And climate change will make discoveries like this more likely, while the melting (and humanity) lasts…

Wool we ever find the Lyuba of woolly rhinos? It could happen.

Wool we ever find the Lyuba of woolly rhinos (Coelodonta)? Cast of a mummified woolly rhino from the NHM’s entry hall. More of these finds are likely, I’d say.

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A very short post here to plug BBC Radio 4’s excellent second series of “Just So Science”. These are 15 minute stories involving a reading of parts of Rudyard Kipling’s great British/natural history stories, and then examining how the science of today informs us about the real lives of animals, without resorting to just-so stories a la Kipling (co-opted as a term in evolutionary biology, too!). I was featured last year on rhinos.

I’m featured this year on kangaroos (now available online) and elephants (also available online now). I just listened to the kangaroo episode and it was good fun. I’ve studied the biomechanics of kangaroos a bit, in as-yet unpublished work featured here in a BBC News story (video from that work is below), and we’ve done other work on their bone morphology and how it relates to body size that is sure to come out in not too long.

Don’t blink! Or, for your enjoyment, a looping GIF:

kangaroo hop

My freezers feature heavily in one bit, in which you can hear me vent my frustrations about an unlabelled bag and stacks of specimens– where is the wallaby? And what’s that crinkling noise?

Best beloved, it is the sound of science. Just so. Enjoy!

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Less words, more pictures in this post, and I’ll get the one lame cake joke out of the way early. I’ve nearly finished my research blitz through the postcranial material of the NHM-Tring’s osteological collection and have made some pit-stops for cake skulls now and then when I see one that pleases me. Now I shall present a survey of some of the species I’ve examined. I’ll proceed up from the base of the crown clade of living birds (Neornithes/Aves; the most recent common ancestor of living birds and all its descendants) and first take a tour of Palaeognathae; the ratites and kin; then move another step up into the Neognathae, first featuring the lineage featuring the ground fowl (Galliformes) and then the waterfowl (Anseriformes). If all this taxonomy and phylogeny is a bit much, check out this page for a brush-up on the bushy branches of bird biodiversity.

First, lots of bones of our cast of currasows, chachalacas, cassowaries and other kooky characters. And then, perhaps, a stop to the excessive alliteration. Finally, I will finish with some examples of species oddity (hat tip to Chris Hadfield).

Stomach-Churning Rating: 2/10- some bony pathologies but still just dry bones. Minimal cake jokes, and no filthy swearing this time.


BRING ON THE BONES:

My photographs are shown with kind permission from the Natural History Museum, London.

Exploded skull of an ostrich/ This takes skill.

Exploded skull of an ostrich, Struthio camelus. This kind of careful preparation takes crazy skill, and creates a thing of rare beauty.

Neat skull of a cassowary, Casuarius casuarius.

Imposing skull of a cassowary, Casuarius casuarius, with a rather worn head casque.

Mummified Owen's Little Spotted kiwi, Apteryx owenii.

Mummified Owen’s Little Spotted Kiwi, Apteryx owenii. The feathers were still soft and fluffy, but I would not call this specimen cuddly.

Dorsal view of the back/hips of the Great Spotted kiwi, Apteryx haasti.

Dorsal view of the back/hips of the Great Spotted Kiwi, Apteryx haasti. I like this photo and am not sure why. The symmetry and shading pleases me, I guess.

Front view of the back/hips of the Great Spotted kiwi, Apteryx haasti.

Front view of the back/hips of the Great Spotted Kiwi, Apteryx haasti, watching over my laptop and watching me while I write this blog on my laptop… so meta(ornithine)!

Wing of a kiwi, showing the fragile bones and feather attachments.

Wing of a kiwi, showing the fragile bones and feather attachments. “Apteryx” = “no wings”… well not quite. Click to emkiwi(?) so you can identify the individual bones, from the humerus right down to the fingers! I love this specimen.

The left leg (in front view) of the elephant-bird, Aepyornis maximus, from Madagascar, with a small moa nearby in left side view.

The titanic left leg (in front view) of the Elephant Bird, Aepyornis maximus, from Madagascar, with a small moa nearby in left side view. There’s so much awesomeness about elephant birds I don’t know where to start, but this is one good place to do so.

Mummified Unulated tinamou, Crypturellus undulatus.

The smaller end of the palaeognath scale: a mummified Undulated Tinamou, Crypturellus undulatus. Somehow the head got stuck into the abdominal cavity underneath the sternum, so this tinamou almost had its head up its arse. A tinamou with head in its proper position looks and sounds like this (video).

And now we take a left turn into the Galloanseres, most basal branch of the neognath birds, to see some of the neglected, strange early branches off from the “main line” that led to the modern diversity of ducks, geeses and swans (Anatinae, Anserinae).

Screamers (Anhimidae) are to Anseriformes as megapodes (see below; brush turkeys) are to Galliformes. By that I mean that both screamers and megapodes are very early branches off the main line of their respective lineages’ evolution, and both are quite strange when seen in that context… an unfair one, frankly; over-focused on the most familiar, “modern” or most speciose group. More about this issue further below.

This was my first hands-on experience with screamer anatomy; I was familiar from reading Tetrapod Zoology and other material about them. Check out the sound that gives them their name here! I’m now a big fan- they have so many strange features: oddly chunky but often very light bones, big feet with long toes, and then these switchblade-wrists, which would make Batman jealous:

Crested screamer, Chauna torquata, showing the wicked spur on the carpometacarpus.

Crested Screamer, Chauna torquata, showing the wicked spur (and smaller one) on the carpometacarpus.

Horned screamer, Anhima cornuta; similar carpometacarpal spur as in Chauna.

Horned Screamer, Anhima cornuta; similar carpometacarpal spurs as in Chauna.

Torso of a screamer seen in top view. Nice narrow body.

Torso of a screamer seen in top view. Nice narrow body, and no uncinate processes (spur-like bony struts that cross the ribs and act as levers for the muscles that move the ribcage during breathing)

The long, gracile, clawed toes of a screamer.

The long, gracile, clawed toes of a screamer. Those toes, especially as they belong to an animal called a screamer, are spooky for me. Note also: very little toe-webbing for a “waterfowl.”

Not to be outdone, on the Galliformes side of Galloanserae, we have some funky headgear in the Maleo (a megapode bird/Megapodiidae; a very basal branch of “brush turkeys” and kin) and curassows (part of the Cracidae; odd South American birds whose males make booming sounds, presumably using their head-casques as resonating chambers?):

Skull of a male maleo, Macrocephalon maleo.

Skull of a male Maleo, Macrocephalon maleo. AR Wallace famously pursued it, and here is its funky call.

Australian brush-turkeys, Alectura lathami i, at the Alma Park Zoo near Brisbane, Australia; they run wild there. Here they are doing what they are best known for: making a mound-like nest.

Australian brush-turkeys, Alectura lathami, at the Alma Park Zoo near Brisbane, Australia; they run wild there. Here they are doing what they are best known for: making a mound-like nest. We were doing kangaroo biomechanics experiments and they were everywhere. I was in awe to see such exotic (to me) birds; locals seemed not so enthused (the birds are loud and make a lot of mess).

Skull of Helmeted curassow, Crax/Pauxi pauxi.

Skull of Helmeted Curassow, Crax/Pauxi pauxi,  showing that resonating chamber. Along with this boom-boom-room, the male uses a piece of food that he holds to draw in the female; if she takes it, then it’s sexy time.

Foot of a Russian Black Grouse, Tetrao tetrix (nothing to do with a certain videogame), with and without flesh.

Foot of a Siberian Black Grouse, Tetrao tetrix (nothing to do with a certain videogame), with and without flesh. Regard the broad, feathered feet, well insulated and with plenty of surface area for prancing around in the snow or moorlands. Tetrao engage in a cool display pattern called lekking, in which the males group together and show off to watching females.

A theme in the section above that is not to be missed is that there is some amazing disparity of anatomical forms in these basal lineages of poultry-relatives. Don’t dismiss the Galloanserae as just boring food-birds! Heaps of not-so-well-studied species exist here, surely with a treasure trove of cool neontological and evolutionary questions waiting for the right person to ask! Darwin’s chickens may get their share of neglect, but that pales in comparison to how little we understand about many basal Galloanserae.

What a lot of people think of as a “ground fowl” or galliform way of life is more of a way of life somewhat typical of the Phasanidae- chickens, pheasants and their familiar kin. Megapodes, curassows, guans, grouse and other Galliformes do not necessarily do things in the “typical” ground fowl way, much as the earlier branches of the Anseriformes don’t always look/act like “proper water fowl” (i.e. Anatidae). The phenomenon at play here is one of the great bugaboos in biology: essentialism— the often implicit misconception that variation away from some abstract ideal is negligible, uninteresting or just not conceivable due to mental blinders. When we say something like “the chicken is a fascinating species” we are sliding down the essentialistic slope. There is no “the chicken.” Not really. Oh dear, speaking of slippery slopes, I’d best stop here before I start talking about species concepts. And no one wants that to happen! Anyway, essentialism still pervades a lot of modern scientific thinking, and has its place as a conceptual crutch sometimes. But in biology, essentialism can be very insidious and misleading. It burrows in deep into the scientific mind and can be hard to root out. Unfortunately, it is entrenched in a lot of science education, as it makes things easier to teach if you sweep aside the exceptions to the essentialist “rules” in biology. I catch myself thinking in static, essentialist ways sometimes. The punishment is no cake for a week; so awful. :)

And speaking of “normal” or “typical,” morphology is of course often not that way even within a species, age class or gender. Pathology is a great example; by definition it is abnormal. It is a shattering of the “essence” of animals, brought on by some malady.

Next I’ve highlighted some of the amazing pathologies I’ve seen in the Tring skeletons. There have been so many I’ve been unable to keep track of them– some of these birds had the stuffing beaten out of them, and I’m not talking about Thanksgiving turkeys. Some were captive animals, in which the pathology might be blamed on living an inappropriate environment, but some were wild-caught — given the extreme pathologies, it’s a wonder those even survived to be found, but perhaps less a surprise that they were caught.


BONES GONE BONKERS:

View of left knee of a specimen of the Highland guan, Penelopina nigra, showing some nasty osteoarthritis around the whole joint.

View of left knee of a specimen of the Highland Guan, Penelopina nigra, showing some nasty osteoarthritis around the whole joint. Eew.  A happier Guan sounds like this.

Femora and tibiae of the Blue-throated Piping Guan, Aburria cumanensis. Amazing pathology involving the left femur (broken, rehealed) and tibiotarsus (secondary infection?).

Femora and tibiotarsi of the Blue-throated Piping Guan, Aburria cumanensis. Amazing pathology involving the left femur (broken, rehealed) and tibiotarsus (secondary infection?). Interestingly, the non-fractured limb also showed some pathology, perhaps indicating general infection and/or arthritis in reaction to the severe damage to the other leg, or just increased load-bearing on that leg.

Little Chachalaca, Ortalis motmot, showing a broken and rehealed right femur and the tibiotarsus.

Little Chachalaca, Ortalis motmot, showing a broken and rehealed right femur and the tibiotarsus. As in the guan above, this animal was not walking for many weeks; its femur had snapped in two, but somehow melted back together. The tibiotarsus didn’t look too great, either; lumpy and bendy. In better times, the Chachalaca does the cha-cha like this.

These two specimens blew my mind. On the right is a normal Tetrao tetrix (Black grouse); on the left is one hybridized with another (unknown) species.

These two specimens blew my mind. On the left is a normal Tetrao tetrix (Black Grouse); on the right is one hybridized with another (unknown) species.

In the picture above, what amazed me first was the very unusual flattened pelvis/synsacrum of Tetrao, which characteristically is light and wide. But in the hybrid this morphology was completely gone; the pelvis had a more standard “galliform” (read: Phasianid)-like shape, deeper and narrower and more solid in build. I am guessing that the hybrid was a cross with a pheasant like Phasianus itself, whose anatomy would be more like this. Somewhere in here there is a fantastic evo-devo/morphometrics project waiting to happen.

That’s my quick specimen-based tour of “basal birds”. Beyond these two clades of Palaeognathae and Galloanseres, there lies the forebidding territory of Neoaves: much of living avian diversity, and extremely contentious in its phylogenetic relationships. I’m tackling them next for my research on the evolution of the patella/kneecap. But first, I’ll be at the NHM-Tring today for a whirlwind tour through the respectably speciose “normal” Galloanseres clades of Phasianidae and Anserinae+Anatidae, so off I go! (It’s my wife’s birthday celebration, so cake may have to wait for later this time)

So what do you think? What’s your favourite neglected “primitive” bird group (more apropos: early branching avian lineage that may still be very specialized, rare and poorly understood), or cool factoid about palaeognaths and basal neognaths?

No quaggas were harmed during the writing of this post.

No quaggas were harmed during the writing of this post. Polly wanna quagga?

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