Claim CC371.1:
Soft, flexible tissue, complete blood vessels, and apparently intact cells
were found when a Tyrannosaurus bone was broken open (Schweitzer et
al. 2005). Such preservation indicates that the bones are only a few
thousand years old, not millions of years.
Source:
Response:
- The reports of the soft tissue, though remarkable, have been
sensationalized further. The tissues were not soft and pliable
originally. The tissues were rehydrated in the process of removing the
surrounding mineral components of the bone (Schweitzer et al. 2005).
Moreover, it is unknown whether the soft tissues are original tissues.
Fossil flexible tissues and nucleated cells have been found before in
which the original material was not preserved (Stokstad 2005).
- The age of fossils is not determined by how well they are preserved,
because preservation depends far more on factors other than age. The
age of this particular bone was determined from the age of the rocks it
was found in, namely, the Hell Creek Formation. This formation has
been reliably dated by several independent methods (Dalrymple 2000).
- DNA has never been recovered from any dinosaurs nor from anything as
old as them, and researchers do not expect to find DNA from these soft
tissues (though they can still hope). DNA has been recovered, however,
from samples much more than 10,000 years old (Poinar et al. 1998), even
more than 300,000 years old (Stokstad 2003; Willerslev et al. 2003).
If dinosaur fossils were as young as creationists claim, finding soft
tissues in them would not be news, and recovering DNA from them should
be easy enough that it would have been done by now.
Links:
Hurd, Gary S. 2005. Dino-blood redux.
http://www.talkreason.org/articles/DinoBlood.cfm
References:
- Dalrymple, G. Brent. 2000. Radiometeric dating does work!
Reports of the National Center for Science Education 20(3): 14-19.
http://www.ncseweb.org/resources/rncse_content/vol20/6061_radiometeric_dating_does_work_12_30_1899.asp
- Poinar, Hendrik N. 1998. Molecular coproscopy: Dung and diet of the
extinct ground sloth Nothrotheriops shastensis.
Science 281: 402-406.
- Schweitzer, M. H., J. L. Wittmeyer, J. R. Horner, and J. K. Toporski.
2005. Soft-tissue vessels and cellular preservation in Tyrannosaurus
rex. Science 307: 1952-1955.
- Stokstad, Erik. 2003. Ancient DNA pulled from soil. Science 300:
407.
- Stokstad, Erik. 2005. Tyrannosaurus rex soft tissue raises
tantalizing prospects. Science 307: 1852.
- Willerslev, E. et al. 2003. Diverse plant and animal genetic records
from Holocene and Pleistocene sediments. Science 300: 791-795.
Further Reading:
Skulan, Joe. 2005. Non-mineralized tissues in fossil T rex. Reports
of the National Center for Science Education
25(5-6): 35-39.
created 2005-4-22, modified 2006-6-28
