Death is more like the slow shutdown of a computer than the flipping off of a light switch, says a scientist, explaining a new study that shows genes in the body remain alive for about two days after the heart stops. In the study of mice and zebrafish, University of Washington researchers found that gene activity generally decreased after death, as would be expected, per New Scientist. But 548 zebrafish genes and 515 mouse genes showed peak levels of messenger RNA—which genes use to communicate with cells—up to 48 hours after death in what researchers termed the "twilight of death." In other words, "not all cells are 'dead' when an organism dies," study author Peter Noble tells Seeker. He believes the same thing occurs in humans, too.
The activated genes were associated with fetal development, stress, immunity, inflammation, and cancer, says Noble, who suggests the cells may be "attempting to repair themselves" just as if the body were alive. It's also possible that they're activated simply because the genes that normally suppress them do turn off after death. Researchers note that a similar activation of cancer genes may explain why organ transplant recipients are more prone to get cancer, though more research is needed to determine possible strategies to rectify this, per a release. Researchers say a measurement of mRNA in the body after death may also result in more precise times of death, possibly down to the minute. (Scientists are working to reverse death.)