Even Parasite Genes Look Young

The parasite Trichinella spiralis is commonly dated as being around 20 million years old. A recent DNA study by U.S. Department of Agriculture (USDA) scientists, however, has yielded some surprising results.

T. spiralis causes trichinosis in humans when they eat undercooked pork that has juvenile forms of the worm encysted within the pig muscle. The USDA scientists collected and analyzed samples of Trichinella DNA from 28 countries. If the parasite is indeed millions of years old, then the different geographical locations should yield distinct groups that retain ancient familial mutations.

However, “the scientists were surprised to find that parasite samples from Europe, North Africa and the Americas had remarkably uniform DNAs. In fact, statistical analyses grouped all 44 samples from all evaluated regions into a single ‘Western’ group of T. spiralis, due to the high degree of genetic similarity.”1

In other words, instead of finding genetically and geographically identifiable groups, they found that all these worms were so similar as to still belong to just one group. The worms, sampled from around the world and yet without the evolutionarily predicted mutational differences, appear as though they have not evolved.

One good explanation for why they have accumulated so few mutations is that these worms, along with all other living things, have only been around for thousands, not millions of years. As previously reported, remarkable similarities between the raw sequences (like words in a book) as well as organizational structures (like book chapters) of human DNA demonstrate the youthfulness of humankind.2, 3, 4 The genetics of the lowly trichina worm is further support for the biblical model of a young earth.


  1. Perry, A. Humans Prompted New Paths for Parasites. U.S. Department of Agriculture press release, November 25, 2008.
  2. Thomas, B. Why Are Human Genes Still Linked? ICR News. Posted on icr.org August 6, 2008, accessed December 17, 2008.
  3. Criswell, D. 2008. ABO Blood and Human Origins. Acts & Facts. 37 (2): 10.
  4. Morris, J. 2006. How Old Is Life? Acts & Facts. 35 (6).

* Mr. Thomas is Science Writer.

Article posted on December 29, 2008.

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