Science Literature

Sinosauropteryx holds a special place in evolutionary studies, partly because of exquisite preservation and partly because it displays integumental structures (described as proto-feathers by many). Alternative hypotheses about these structures were considered in a previous blog, showing that there is compelling evidence contrary to the protofeather hypothesis. However, it remains to be established what the integumental structures of Sinosauropteryx actually are and how they became fossilised. This is the theme of this blog. The relevant research is again that of Professor Lingham-Soliar from South Africa. He has presented new data allowing two alternative hypotheses to be tested.

"A sound understanding of the externally preserved fossilized tissue of Sinosauropteryx is crucial to resolving the differences in interpretation. If the tissue represents protofeathers, then it should comprise independent, freestanding filaments. Alternatively, if it represents structural fibres (excluding spines and bristles), then it should form part of a more inclusive structure, such as the dermis or a crest or frill." (p.700)

Sinosauropteryx reconstructed (erroneously) with dino-fuzz (source here)

Lingham-Soliar is surely correct when he states: "Little is known of the taphonomy of Sinosauropteryx NIGP 127587, which probably provides the best examples of preserved soft tissue known in the species." (p.70) To address this gap in knowledge, decomposition experiments were conducted on two animals with characteristics considered to be illustrative of decay processes in Sinosauropteryx. These were Genetta genetta (the greater spotted genet) and Naja mossambica (the Mozambique spitting cobra). The decay processes are animated here.

"The fresh cadavers of G. genetta and N. mossambica were placed in a nature conservancy area in as near to natural conditions as possible. The area is populated by a number of small mammals and reptiles, e.g. monkeys, mongoose, genets, cane rats, feral cats, varanids, agamids, snakes (e.g. black mambas and spitting cobras), and birds (including hawks, kites and other birds of prey and carrion). For consistency the progress of the cadaver through the sigmoidal decomposition pattern are referred to in six stages-fresh, bloated, active decay, advanced decay, dry, remains." (p.701-702)

These decomposition studies informed a re-examination of the fossil Sinosauropteryx: the purge fluids, the filamentous tissues and the death pose. It is probable that the timescale before rapid fossilisation was in the range 2-3 days, that insects were primarily responsible for the observed decay, and that the opisthotonic posture was produced by muscle spasms associated with death. This forensic approach has led to the falsification of one of the two hypotheses regarding the filamentous tissues.

"Quite extraordinarily, Currie and Chen (2001) describe only the filamentous tissue in NIGP 127587 (as protofeathers) despite the fact that the dermal tissue distal to and overlying it comprises the greater part of the external tissue, extending as a continuous band from the head to the tail. This is quite unmistakable. The description presented here shows that the filamentous structures were internal support fibres that together with the overlying dermal tissue comprised a composite structure, i.e. an external frill or crest (compare Jesus lizard, Basiliscus plumifrons, and frilled lizard, Chlamydosaurus kingii), comprehensively refuting the notion of free filaments, i.e. protofeathers in Sinosauropteryx." (p.707-708)

Is this issue only of interest to evolutionary biologists and palaeontologists? Why is it considered in this blog as relevant to Intelligent Design? There are several reasons - as discussed below.

First, the 'theropod dinosaur to bird' evolutionary thesis has attained the status of 'consensus science'. This means that it gets favoured treatment in the media, by the editors of scientific journals and by funding bodies. Whilst this is partly because of weight of numbers, there are other significant factors in operation. There is an unfortunate tendency for 'consensus scientists' to treat dissidents as irrelevant to their discipline and as having nothing useful to contribute. Lingham-Soliar and other colleagues (notably Alan Feduccia) represent the minority view that Birds Are Not Dinosaurs (BAND) but evolved from archosaurian stock. It is not difficult to find disparaging words on internet forums about the quality of their research. They are described, for example, as having views that are "deeply flawed", guilty of "special pleading" and irresponsible (see here).

Yet, it is apparent to me that Lingham-Soliar is providing a great service to science in proposing and testing alternative hypotheses, doing important groundwork on the decomposition of animals, reworking scientific data to check their repeatability, and assessing the robustness of the conclusions of others. On the basis of this case, we ought to find ways of encouraging dissident scientists and to protect them from every sign of closed minds exhibited by 'consensus' trolls.

There is another lesson to learn here. Consensus-science is sleep-inducing (see here) and it leads to scholarship that fails to challenge its own cherished assumptions. It leads to undue credence being given to false positives (see here). The goal of research changes in a subtle way: instead of a search for truth, effort is directed towards strengthening the paradigm. This is especially apparent in evolutionary biology, as almost every research finding is hailed as confirmation of the theory of evolution. (If anyone needs to reflect on why this is adversely affecting science, all you need to do is look at the hype associated with almost every discovery of hominid remains). What that Lingham-Soliar has done is to show that the 'birds are dinosaurs' researchers have been blind to evidences available to them - overlooking relevant data; failing to formulate and test alternative hypotheses; and focusing their efforts on very narrow objectives (such as proving the reality of proto-feathers). By contrast, whilst dissenting scientists can also display stubbornness in the face of contradictory evidence, they have also demonstrated an agility of mind in their willingness to consider alternative explanations. As an example, consider Lingham-Soliar's comments on the proposed "crest" explanation for the structural filaments:

"Interestingly, the area between the crest and spine (caudal vertebrae 1–12) shows traces of anal purge fluids (and decay; compare G. genetta, ESM Table 1) that had apparently seeped under the tail. The implication is that the crest here decayed at its base very soon after death (perhaps within hours) and sprung upward as a consequence of the stored tensile forces in the stiffened, semi-flexible crest." (p.709)
"Finally, it is bewildering that in a lacustrine environment, a crest-like structure on the tail or body or both, useful in swimming, is generally not even contemplated in dinosaurs such as Psittacosaurus, Sinosauropteryx, Tianyalong, and Beipiaosaurus." (p.710)

The reason why the controversy over protofeathers is relevant to ID is that it provides us with a case study of the human face of science, of the power of paradigms in controlling the minds of scholars, and the tensions that arise between orthodoxy and dissent. The ID distinctive is, of course, more radical in that it postulates that intelligent causation is detectable within science. ID advocates argue that chance, necessity and intelligent agency are necessary causes to explain both the animate and inanimate aspects of the universe. We are confronted by 'consensus' scientists who insist that science has to be based exclusively on chance and necessity (i.e. natural causation) and they exclude intelligent agency as a matter of principle. They are not prepared to acknowledge that ID represents a different paradigm (despite it being owned by all the leading lights of the Scientific Revolution), nor that ID research can ever bring contributions to knowledge. Happily, philosophical arguments based on a commitment to naturalism are weak (see here and here). The debate needs to move on: engaging with the issues and addressing the evidence base on which design inferences are made.

The evolution of the feather: Sinosauropteryx, life, death, and preservation of an alleged feathered dinosaur
Theagarten Lingham-Soliar
Journal of Ornithology, 153(3), (July 2012), 699-711 | DOI 10.1007/s10336-011-0787-x.

Abstract: Among the spectacular dinosaur fossils reported from the Jehol Group of northeastern China is the most celebrated, Sinosauropteryx, which continues to excite interest in questions concerning feather origins - most recently with alleged identifications of melanosomes and colour in its integumental structures, which proved unfounded. The crucial significance of Sinosauropteryx is undoubtedly the focus on its basal theropod status and potentially pivotal position in informing models of the early evolutionary origin of modern feathers. On the basis of new evidence in Sinosauropteryx NIGP 127587 and GMV 2124, it is shown here that the alleged protofeathers were not free filaments but part of a composite tissue. It is shown that the tail terminates in a unique, smoothly edged, spatula-shaped structure. The dinosaurs died in the vicinity of a lake. For the first time, the taphonomy of Sinosauropteryx is investigated on the basis of aboveground decomposition experiments on living animals so as to get a better understanding of conditions preceding the death of the animal, its death, decomposition and finally preservation of soft tissue as manifested in the fossil. The signs point strongly to invertebrate colonization of the carcass of Sinosauropteryx rather than vertebrate predation or scavenging, with moderate decay associated with the purge fluids while major decay was forestalled by burial, at most a few days after death. Lastly, a theory that the opisthotonic posture of fossils such as Sinosauropteryx NIGP 127587 occurred perimortem as a consequence of neural spasms provides the basis for a forensic reconstruction of the stages leading to the dinosaur's death and the final preserved position of the external, dorsally preserved soft tissue, which proves to be more consistent with a uniform crest than individual, free protofeathers.

See also:

Sarewitz, D. The voice of science: let's agree to disagree, Nature, 478, 7 (5 October 2011) | doi:10.1038/478007a