28 August 2008

Beide Seiten.

In Louisiana wurde vor kurzem eine neues Gesetz (Science Education Act) beschlossen, das die Einführung evolutionskritischen Materials in die Schulen erlaubt. Carl Zimmer hat das in einem Post so zusammengefasst:

A couple weeks ago Louisiana passed a new science education act that promotes “critical thinking skills, logical analysis, and open and objective discussion of scientific theories being studied including, but not limited to, evolution, the origins of life, global warming, and human cloning.” Along with the regular textbook, the law states, teachers “may use supplemental textbooks and other instructional materials to help students understand, analyze, critique, and review scientific theories in an objective manner.” The law “shall not be construed to promote any religious doctrine, promote discrimination for or against a particular set of religious beliefs, or promote discrimination for or against religion or nonreligion.”
What the law does not make clear, however, is how schools will determine whether the extra instructional material is good science or nonsense. There is nothing in the law that would keep a teacher from introducing a bogus non-argument about gravity and the revolution of the planets.
Auch interessant dieser Artikel, 'Eroding Evolution: Religious Right Forces In Louisiana Try New Tactic To Smuggle Religion Into Public School Science Classrooms', der die ganze Geschichte noch einmal aktuell zusammenfasst. Über Thoughts in a Haystack, wo ich auch den Link zu diesem Artikel gefunden habe, bin ich auf die Seite des Louisiana Family Forums gestoßen, die eine der treibenden Kräfte hinter der Verabschiedung des neuen Gesetzes waren. Diese stellen für eine ganze Reihe von Biologie-Textbüchern Ergänzungen bereit, die angeblich eine kritische Analyse der Evolutionstheorie ermöglichen sollen.

Ich hab nur in eine der Ergänzungen [.pdf] kurz reingeschaut und bin gleich am ersten Absatz hängengeblieben:
On the basis that micro evolution was true he hypothesized that "macro” evolution or "molecules to man” evolution was also true. The textbook defines macro-evolution as “large scale evolutionary patterns and processes that occur over long periods time.” (Page 435) Macro-evolution could be said to occur if a dog became a cat or a dinosaur became a bird. It occurs at the genus or higher level (see text page 450) and implies that all life on Earth descended from a few types of cells that somehow came into being in the past. The diagram below should help you understand the differences in the two terms

MACRO-EVOLUTION can be considered to be VERTICAL (Has no proven examples.)

<- MICRO-EVOLUTION can be considered to be HORIZONTAL ->

It is a change or adaptation at the species level. (Examples are the number of different types of: cats, dogs, cattle, birds, fish, etc.).

Based upon these definitions it is easy to see that micro-evolution is true but the truth of macroevolution has not been established since it has not been observed directly. Using the term "evolution" without specifying which type is being discussed is misleading and unfortunate and has caused much misunderstanding among scientists and the public. The term “macro” (molecules to man) evolution should be used in order to clarify the problem.
Das ist auf so vielen Ebenen falsch, es ist erschütternd.

Die Literatur, die sie als Referenz verwenden, ist im Schnitt von 1970-80 (dabei wurde u. a. damit argumentiert, das Gesetz sollte es den Lehrern ermöglichen, auch neueres, aktuelleres Material in den Unterricht zu bringen) und solche Behauptungen wie die obige sind natürlich überhaupt nicht belegt.

Als zweiten Auszug noch ihr "Addendum" zur Evolution des Menschen:
Even the 5% difference amounts to a staggering amount of information in the DNA. If the human and chimpanzee genomes are considered to have the same number of base pairs, (3,200,000,000) in spite of the chimp having 2 more chromosomes than the human and 10% more DNA, the 5% amounts to 150,000,000 bases. This is the amount of information contained in a book whose thickness is equivalent to about 30 books such as this textbook if it contained nothing but full pages of print from cover to cover. If this much information difference exists in the DNA between the chimpanzee and the human the difference between man’s ancestor and man must be much larger. It is completely inconceivable that this much coherent information could have been accidentally changed in the DNA of a member of the ape family to get man when the mutational problems discussed earlier are considered. If the transition from ape to man is to be accomplished by mutations, it is apparent that there should be plenty of fossil evidence. Where is the fossil evidence?

Think Critically: If the chimp has 10% more DNA than a human how can it be said that there is only a 5% difference? Which of the differences given above is the most reasonable?

There is much disagreement over whether or not “Lucy” is in the ancestral lineage of man. Many reputable paleontologists maintain that she is only a pygmy chimpanzee similar to ones alive today. Paleontologist Adrienne Zihlman, University of California at Santa Cruz says, "Lucy's fossil remains match remarkably well with the bones of a pygmy chimp." Evolutionists such as Charles Oxnard, Sir Solly Zuckerman, William L. Jungers, Jack T. Stern, Jr and Randall L. Susman all concur.
Hier wollen die Autoren den Unterschied zwischen Menschen und Schimpansen möglichst groß erscheinen lassen, daher sprechen sie von 2 Chromosomen, ohne zu erwähnen, dass das für den *diploiden* Chromosomensatz gilt (wir haben 23 verschiedene Chromosomen, der diploide Chromosomensatz umfasst also 46 Chromosomen; Schimpansen haben 24 verschiedenen Chromosomen, also 48 diploid) und natürlich ohne zu erwähnen, dass das zusätzliche Chromosom der Schimpansen einem Abschnitt auf einem unserer Chromosomen entspricht.
Das menschliche Chromosom 2 ist aus einer Verschmelzung zweier Chromosomen entstanden, wie man beispielsweise an den Resten von Telomeren (normalerweise "Endstücke" von Chromosomen) innerhalb des Chromosoms erkennen kann. Der eine Teil des menschlichen Chromosoms 2 ist nahezu identisch mit Chromosom 2a von Schimpansen, der andere Teil ist nahezu identisch mit Chromosom 2b von Schimpansen.

Dann der Vollschwachsinn, der Unterschied zwischen unseren Vorfahren und uns müsse größer sein als der Unterschied zwischen Schimpansen und uns. Warum um alles in der Welt? Wenn nach der Aufspaltung der Linien, die zu den Schimpansen und den Menschen führen, in der "Schimpansen-Linie" X Veränderungen aufgetreten sind und in der "Menschen-Linie" Y Veränderungen, dann unterscheiden sich Schimpansen und Menschen durch X + Y Veränderungen. Der Unterschied zwischen Menschen und Schimpansen (X + Y) kann NIE kleiner sein, als der Unterschied zwischen Schimpansen und dem letzten gemeinsamen Vorfahren (X) oder der Unterschied zwischen uns und unserem letzten gemeinsamen Vorfahren mit den Schimpansen (Y).

Aber sie wollen logisches und kritisches Denken fördern, gute Güte.

Und als letztes Schmankerl bringen sie noch das uralte Kreationistenargument, Lucy wäre nur ein kleiner Schimpanse gewesen. Bei Talk.Origins gibt es eine längere Widerlegung, daraus:
Solly Zuckerman attempted to prove with biometrical studies (based on measurements) that the australopithecines were apes. Zuckerman lost this debate in the 1950's, and his position was abandoned by everyone else (Johanson and Edey 1981). Creationists like to quote his opinions as if they were still a scientifically acceptable viewpoint.

Charles Oxnard (1975), in a paper that is widely cited by creationists, claimed, based on his multivariate analyses, that australopithecines are no more closely related, or more similar, to humans than modern apes are. Howell et al.(1978) criticized this conclusion on a number of grounds. Oxnard's results were based on measurements of a few skeletal bones which were usually fragmentary and often poorly preserved. The measurements did not describe the complex shape of some bones, and did not distinguish between aspects which are important for understanding locomotion from those which were not. Finally, there is "an overwhelming body of evidence", based on the work of nearly 30 scientists, which contradicts Oxnard's work. These studies used a variety of techniques, including those used by Oxnard, and were based on many different body parts and joint complexes. They overwhelmingly indicate that australopithecines resemble humans more closely than the living apes.
Und weiter unten:
Creationists are generally reluctant to accept that australopithecines, including Lucy, were bipedal. A statement by Weaver (1985) that "Australopithecus afarensis ... demonstrates virtually complete adaptation to upright walking" is dismissed by Willis (1987) as "a preposterous claim". Willis adds: "Many competent anthropologists have carefully examined these and other "Australopithicine" [sic] remains and concluded that Lucy could not walk upright."

Willis' evidence for this consists of a statement by Solly Zuckerman made in 1970; a 1971 statement from Richard Leakey that australopithecines "may have been knuckle-walkers", and a quote from Charles Oxnard about the relationship between humans, australopithecines and the apes. In fact, none of these quotes refer to Lucy. Two of them were made before Lucy, and A. afarensis, was even discovered (and the third was made very soon afterwards, before Lucy had been studied). [Anm.: Lucy wurde 1974 gefunden.]

Even in 1970, Zuckerman's views had long since been largely abandoned. In what is obviously a fabrication, Willis says that Leakey "referred to Lucy as an ape who did not walk upright", three years before Lucy was discovered. Leakey was merely making a suggestion (about robust australopithecines) which he soon retracted, not stating a firm opinion, and he has since stated (1994) that Lucy "undoubtedly was a biped". Oxnard (1975; 1987) has some unorthodox opinions about the australopithecines, but the Oxnard quote supplied by Willis discusses neither bipedality nor A. afarensis. Elsewhere in the same paper that Willis refers to, Oxnard (1975) repeatedly mentions that australopithecines may have been bipedal, and he has since stated (1987) that the australopithecines, including Lucy, were bipedal.

Die beiden Referenzen, die hier für Zuckermann und Oxnard angegeben werden, sind exakt dieselben, die auch in der Textbuch-Ergänzung verwendet werden. Keine einzige ihrer Referenzen zu Lucy ist jünger als 1984.

Fassen wir also zusammen:
Zuckerman (1970): Bevor Lucy gefunden wurde. Nicht peer-reviewed.

Oxnard (1974): Im gleichen Jahr, in dem Lucy gefunden wurde, ohne Lucy untersucht zu haben. Nicht peer-reviewed.

Und der Rest der angegebenen Referenzen?

Zihlman (1984): Aus einem Artikel im New Scientist! Nicht peer-reviewed.
Kann leider das Originalzitat nicht überprüfen, aber ich gehe mal schwer davon aus, dass es sich um quote mining handelt. Es gibt nämlich sogar einen Nature-Artikel von Zihlman zu dem Thema: Pygmy chimpanzee as a possible prototype for the common ancestor of humans, chimpanzees and gorillas [Nature 275, 744 - 746 (26 October 1978)]. Aus dem haben sie aber verständlicherweise auch nicht zitiert, denn der belegt keineswegs, was sie behaupten.
Das Abstract:
A CONVINCING theory of human origins must clarify man's relationships with living primates and with the ancestral forms known only through fossils. Phylogenetic relationships have previously been determined mainly by anatomical similarities, but now, biochemical similarities provide independent criteria for evolutionary relationships. Albumin and transferrin immunology, immunodifrusion, DNA annealing and amino acid analysis all indicate that chimpanzees, gorillas and humans share a substantial common ancestry, and that the Asiatic apes (gibbons and orangutans) diverged earlier from this lineage. These findings directly conflict with the more widely held view that all the great apes diverged from a common ancestor long after the 'Origin' of the evolutionary line leading to modern humans4. The molecular data consistently suggest a much more recent origin of the man–chimpanzee–gorilla separation than was previously imagined, namely, in the range of 4–6 M yr ago. These data show that, although the two chimpanzee species (Pan paniscus and P. troglodytes) are biochemically distinct, they are more closely related to each other than either is to humans or gorillas. The chimpanzees speciated, then, after the initial three-way split. We therefore, here contend that, among living species, the pygmy chimpanzee (P. paniscus) offers us the best prototype of the prehominid ancestor. Biochemical, morphological, behavioural and palaeontological data support this proposition and argue for a relatively recent and accelerated divergence of the hominid from the pongid line.
Junger (1982): Das Abstract des als Referenz angegebenen Artikels, in dem Lucy keineswegs als "pygmy chimp" bezeichnet wird:
Precise information about the bodily proportions of early hominids is crucial for accurate functional and phylogenetic interpretations of early human evolution. The partial skeleton of Australopithecus afarensis (AL 288-1; 'Lucy') recovered in 1974 from the Hadar area of Ethiopia9 permits the first direct assessment of body size, limb proportions and skeletal allometry in ancestral hominids that pre-date 3 Myr. Using allometric relationships for limb lengths in non-human catarrhine primates (as a whole and for African apes alone) as empirical base lines for comparison, I show here that the limb proportions of A. afarensis are clearly unique among hominoids. The data indicate that A. afarensis had already attained forelimb proportions similar to those of modern humans but possessed hindlimbs that were relatively much shorter; hence the 'intermediate' humerofemoral index of AL 288-1 (85.1) compared with Homo sapiens and great apes. It follows that relative and absolute elongation of the hindlimbs represents one of the major evolutionary changes in later human evolution. The bodily proportions of Lucy are not incompatible with some form of bipedal locomotion, but kinematic identity and functional equivalence with the bipedal gait of modern humans seem highly improbable. Reduced relative stride length in AL 288-1 probably implies both greater relative energy cost and relatively lower peak velocities of bipedal locomotion in A. afarensis.
Stern und Susman (1983): Leider habe ich keinen Zugriff auf den Volltext, den Abstract gibts hier. Daraus:
It is demonstrated that A. afarensis possessed anatomic characteristics that indicate a significant adaptation for movement in the trees. Other structural features point to a mode of terrestrial bipedality that involved less extension at the hip and knee than occurs in modern humans, and only limited transfer of weight onto the medial part of the ball of the foot, but such conclusions remain more tentative than that asserting substantive arboreality. A comparison of the specimens representing smaller individuals, presumably female, to those of larger individuals, presumably male, suggests sexual differences in locomotor behavior linked to marked size dimorphism. The males were probably less arboreal and engaged more frequently in terrestrial bipedalism. In our opinion, A. afarensis from Hadar [Anm.: aka Lucy] is very close to what can be called a "missing link." We speculate that earlier representatives of the A. afarensis lineage will present not a combination of arboreal and bipedal traits, but rather the anatomy of a generalized ape.
In diesem kleinen Ausschnitt, den ich mir angeschaut habe, werden Fakten verdreht oder verschwiegen (und man muss nicht die Evolutionstheorie anerkennen, um z. B. Telomerreste innerhalb eines Chromosoms zu entdecken; das gehört allerdings zu den Fakten, die eine Theorie erklären können muss), es werden grobe logische Fehler begangen und es wird gequotemined, was das Zeug hält.
Den Rest dieses Ergänzungsmaterials habe ich mir gar nicht erst angeschaut, aber ich bezweifle keine Sekunde lang, dass auch die anderen Abschnitte so voller logischer und faktischer Fehler sind wie dieser.

Und das ist, was als Resultat eines Gesetzes, welches "critical thinking skills, logical analysis, and open and objective discussion of scientific theories" fördern soll, höchstwahrscheinlich auf die Schüler losgelassen wird.

So lange ich mich mit dieser ganzen Kreationismus-Geschichte schon befasse, bin ich doch immer wieder aufs Neue überrascht, wie abgrundtief schlecht ihre Argumente sind - man muss doch aktiv verhindern, dass Schüler tatsächlich einen kritischen Umgang mit vorgeblich wissenschaftlichen Texten erlernen, wenn man ihnen solch grottiges "Lehrmaterial" vorsetzen und nicht Gefahr laufen möchte, ausgelacht zu werden.


[Bild-Quelle oben: PTET; unten: verändert von mir, ursprünglich Indexed]

0 Kommentare: