Scanned fossils confuse water-land transition, according to reports from Duke University News 17 April 2009, ScienceDaily 19 April 2009 and Science vol. 324, p341 & p364, 17 April 2009.
Researchers from Duke University found some fossils embedded in rocks from Greenland and rather than risk damaging them, they scanned them with a CT scanner and used computer imaging software to construct a three dimensional image of the fossils. The fossils were Acanthostega and Ichthyostega – extinct creatures commonly believed to be transitional forms in the evolution from fish to land creatures.
Acanthostega is believed to have been the first to show changes from fish fins to legs, with Ichthyostega being more advanced. The new fossils included the first juvenile Ichthyostega ever found, which enabled scientists to reconstruct changes that occurred in the creature’s bones as it grew and developed.
The researchers concentrated on the humerus – the bone that connects forelimb to shoulder. The researchers examined nine humeri of Ichthyostega from six individual animals, and four humeri from three Acanthostegaspecimens. The fossil did not show a neat progression from Acanthostega to Ichthyostega. According to Viviane Callier, one of the scientists who studied the fossils: “Although Acanthostega appears to be aquatically adapted throughout the recorded developmental span, its humerus exhibits subtle traits that make it more similar to the later, fully terrestrial tetrapods.”
Ichthyostega seemed to be “aquatically adapted” as a juvenile, but as it matured its humerus became more able to support “weight-bearing terrestrial locomotion.” Callier went on to suggest: “If Ichthyostega is actually more primitive than Acanthostega, then maybe animals evolved towards a terrestrial existence a lot earlier than originally believed. Maybe Acanthostega was actually derived from a terrestrial ancestor, and then, went back to an aquatic lifestyle.”
She went on to say: “It seems like there were different species evolving the same or similar traits independently – evidence of parallel evolution. The terrestrial environment posed new challenges like feeding and moving on land and breathing air, to which the first tetrapods had to evolve solutions. Sometimes different lineages stumbled upon similar solutions.”
These confusing results led Callier to conclude: “If there is one take-home message, it is that the evolutionary relationship between these early tetrapods is not well resolved.”
Editorial Comment: Creation Research predicts the evolutionary relationship between these creatures will never be resolved because it didn’t happen. There is no evidence for the story that water creatures turned into land creatures, and then somehow changed their minds and their bodies as they evolved back into water creatures.
These new fossils are clearly two separate living creatures, each with their own growth pattern and design suitable for the environment they lived in. The fact that they are both now extinct is a reminder that the world is degenerating, which sadly fits the Biblical description of the world of created perfection followed by degeneration.
Evidence News 8 July 2009
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