Henrietta Lacks achieved a kind of immortality on February 9, 1951. On that day a sample of cancerous cells from her cervix was transferred to a culture dish, doused with nutrients, and left to grow. Lacks, a 30-year-old mother of four from Baltimore, had one of the most aggressive cervical cancers her doctors had ever seen, and the cells culled from her tumor grew avidly, doubling their number each day. Then they escaped. Small spills are always happening in laboratories; what distinguished Lacks’s cells was their ability to survive after they were somehow spilled. They were so hardy that if just one of them fell on a petri dish it would outgrow and overwhelm anything else living on that dish within a month.
Soon Henrietta Lacks’s cells were traveling from lab to lab, either deliberately sent--many cancer researchers had taken to using them in their experiments--or as an unseen contaminant tagging along in another cell line. Some researchers who thought they were looking at something completely different--a line of liver cells, say--ended up studying Henrietta Lacks’s cervical cells by accident. The cells even slipped through the iron curtain and into Russia.
Lacks died in October 1951, but her peripatetic cells lived on. Now some biologists are saying that those cells, called HeLa cells for short, have lost more than their connection to Henrietta Lacks. HeLa cells, these researchers claim, are no longer human at all: they are single-celled microbes--closely related to us, to be sure, but their own distinct species.
[...]
These little unicellular organisms have crossed oceans, spread their range, got into other cultures and outcompeted them, says Richard Strathmann, a marine biologist at the University of Washington’s Friday Harbor Laboratories who dabbles in evolutionary theory. They’re only different from other single-celled organisms in that a human being gave rise to them.