Lately, I’ve been thinking a lot about the Grinch. You know, the one who stole Christmas by taking away everything fun and good? (Shades of 2020, anyone?) The story goes that the Grinch’s heart grew three sizes when the inhabitants of Whoville showed him the true meaning of the holiday. (Hint: it is love for one another in the face of adversity.)
Although it didn’t happen in a matter of moments, humans and other large primates saw a similarly dramatic increase in heart size as they evolved from smaller primates. It’s thought that the increased blood pumping ability may have contributed to our relatively larger body size.
Now, Stanford Medicine pathology instructor Kitchener Wilson, PhD, together with cardiologist Joseph Wu, MD, PhD, graduate student Mohamed Ameen and instructor Hongchao Guo, PhD, have come up with a reason for this Grinch-like transformation. They recently published their findings in Developmental Cell.
Endogenous retroviruses
The culprit looks to be a remnant of an ancient viral infection in the form of a DNA sequence called BANCR that has piggybacked in our genomes for millions of years.