|Evolution in the News - June 2006|
|by Do-While Jones|
In “mammal-like-reptiles” evolutionists see evidence that jaws evolved into ears. But when it comes to fish, the story is that the nose evolved into an ear.
Believe it or not, this appeared in last month’s Discover magazine.
Our earliest ancestors may have breathed through their ears, say paleontologists Martin Brazeau and Per Ahlberg of Uppsala University in Sweden. The tubes that form the middle-ear canal in humans probably evolved from a pair of gill-like holes that allowed primeval sea creatures to breathe from the back of their heads, the researchers find.
Brazeau and Ahlberg deduced this transformation from studies of the 370-million-year-old Panderichthys, an intermediate species between fish and the first four-limbed animals to crawl onto land. 1
We sometimes get email from people asking us how we can make fun of the theory of evolution. The real question is, “How can we not make fun of it when evolutionists say things like this?”
There weren’t any references in the Discover article, so we looked around to see what this could possibly be based upon. It turned out that Ahlberg started pursuing this idea about six years ago.
Life started in the water, and between 380 million and 350 million years ago, scientists agree, some intrepid fish, probably seeking food, crept onto land. But just how they made the switch to being land dwellers has eluded researchers. There are no transitional fossils to link the latest four-limbed or tetrapod-like fish, known as Panderichthys, and the earliest tetrapods, which appeared millions of years later. But now two tiny fossil fragments may supply some missing evidence.
Earlier this month, paleontologist Per Ahlberg of the Natural History Museum in London unveiled two "new" fossils dug up from the drawers of museums in Latvia and Estonia. Both are fragments, several centimeters long, of fishlike lower jaws. They have several parallel rows of teeth unlike anything seen in the fossil record of either fish or tetrapods. 2
The obvious question is, “If these jaw fragments are unlike fish or tetrapod jaws, why would one think they are related to fish or tetrapods, especially if there are no transitional fossils?”
Several years went by, and then Ahlberg published this:
The Late Devonian genus Ichthyostega was for many decades the earliest known tetrapod, and the sole representative of a transitional form between a fish and a land vertebrate. However, despite being known since 1932 from a large collection of specimens, its morphology remained enigmatic and not what was expected of a very primitive tetrapod. Its apparent specializations led it to be considered as a "blind offshoot" or "sidebranch" off the tetrapod family tree, and recent cladistic analyses have disagreed about its exact phylogenetic position within the tetrapod stem group. In particular, its braincase and ear region defied interpretation, such that conventional anatomical terms seemed inapplicable. Using new material collected in 1998, preparation of earlier-collected material, and high-resolution computed tomography scanning, here we identify and interpret these problematic anatomical structures. They can now be seen to form part of a highly specialized ear, probably a hearing device for use in water. This represents a structurally and functionally unique modification of the tetrapod otic region, unlike anything seen in subsequent tetrapod evolution. The presence of deeply grooved gill bars as in its contemporary Acanthostega suggest that Ichthyostega may have been more aquatically adapted than previously believed. 3
This creature is so strange they really aren’t really sure how to classify it.
This structure is not that of a tympanic ear. The spiracular notch is in quite a different position from that in tetrapods with tympanic ears such as temnospondyls, the stapes is in an inappropriate position, is orientated away from the notch, and is quite different in shape from those of tympanic ears. As for the 'middle ear' (or spiracular tract) itself, it could in principle have been occupied by either water or air. The phylogenetic position of Ichthyostega within the lungfish-tetrapod clade suggests that it was at least a facultative air-breather, implying that the spiracular tract could easily have been air-filled even if the animal was essentially (and primitively) aquatic. Functionally, the most plausible interpretation of the ear seems to be that the chamber housed an enlarged air pocket. The stapes was not in contact with any hard-tissue structure except for its delicate articulation with the braincase. We believe it may have been embedded in a soft-tissue membrane forming the ventral wall of the otic chamber. 4
It is hard to believe that this is the argument in favor of nose-to-ear evolution, not an argument against it written by an opponent!
The choana, a unique 'internal nostril' opening from the nasal sac into the roof of the mouth, is a key part of the tetrapod (land vertebrate) respiratory system. It was the first component of the tetrapod body plan to evolve, well before the origin of limbs, and is therefore crucial to our understanding of the beginning of the fish-tetrapod transition. However, there is no consensus on the origin of the choana despite decades of heated debate; some have claimed that it represents a palatally displaced external nostril, but others have argued that this is implausible because it implies breaking and rejoining the maxillary-premaxillary dental arcade and the maxillary branch of nerve V. The fossil record has not resolved the dispute, because the choana is fully developed in known tetrapod stem-group members. 5
Last January, Ahlberg co-authored another article 6 in which he again tries to argue that Panderichthys had a really unusual ear that must have been a nostril evolving into an ear. It’s just wild speculation, but Discover reported as fact.
"We have long suspected that there was a connection between throat structures used for air breathing and middle-ear structures used for hearing," says Jennifer Clack of the University Museum of Zoology in Cambridge, England, who has studied related fossils. "Here is the concrete evidence." 7
We keep listening to what evolutionists tell us, but it sounds like nonsense to us. Maybe our noses just haven’t evolved enough to hear them properly.
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Minkel, Discover, May 2006, “Origin of the Ear”, page 16
2 Science, 21 April 2000, Vol. 288. “Random Samples”, p. 431 (Ev)
3 Clack, Ahlberg, et al., Nature 425, 4 September 2003, “A uniquely specialized ear in a very early tetrapod”, page 65 (Ev)
5 Zhul and Ahlberg, Nature 432, 4 November 2004, “The origin of the internal nostril of tetrapods”, page 94 (Ev)
6 Brazeau and. Ahlberg, Nature 439, 19 January 2006, “Tetrapod-like middle ear architecture in a Devonian fish” pages 318-321 (Ev)
7 Minkel, Discover, May 2006, “Origin of the Ear”, page 16 (Ev)