By Dennis D. McDonald

During my morning news scan today I ran across an item in Science News titled An extinct rat shows CRISPR’s limits for resurrecting species. Researchers using CRISPR gene editing techniques attempted to recreate the extinct Christmas Island rat (pictured above, which disappeared around the early 1900s) by editing the genetic material of a modern Norway brown rat based on preserved DNA-bearing samples of the extinct rat.

The result was something that looked like the extinct Christmas Island rat but which differed in 5% of its genetic material. That 5% included genes important to smell and the immune system, genes that had been lost in the Norway rat since it evolutionarily diverged from the Christmas Island rat around 2.6 million years ago. That small difference could be important if one attempted to re-introduce the clone into an environment where that missing 5% might be important to survival.

What immediately comes to mind is the fanciful genetic engineering made popular by the movie Jurassic Park where the DNA from the blood contained in a preserved mosquito was used to resurrect beasts from the past. If the results of this rat experiment are any indication there’s no guarantee whether, say, a resurrected Velociraptor would look or behave identically to the original. Who knows, a pet-friendly Velociraptor?

For me, the real significance of this rat research is not limited to the resurrection of extinct species but to potential significance that even minor difference in genes can make between generations and even individuals. We are already seeing how our understanding of genetic science has altered old fashioned concepts of race. Already attempts are underway to manipulate genes in order to reduce susceptibility to certain genetically-related diseases.

Such sought-for manipulations, of course, presume an understanding of how unintended consequences can be controlled. This rat research is a reminder of how much we have left to learn.

Copyright (c) 2022 by Dennis D. McDonald