Recent legislation that permits mitochondrial genetic transplanting to embryos finally acknowledges that all chromosomal material in our bodies doesn’t come from our mother and father.

This is important because the human body is really one big family comprising parent organs, the offspring and visitors who come to stay and never leave.

But not every member of the family sports our own genetic double-stranded DNA.

Take E. Coli, for example. It helps us with our daily functioning; it helps degrade our waste products and it is a welcome visitor in our intestines – as long as it remains in the bottom end of our bowel. Similarly, Staph Albus is an important tenant of our integument keeping it reasonably well protected from the minor invaders that cause mild acne.

The symbiosis is only disrupted when our visitors pass into areas where they shouldn’t. For example when E Coli strays into the urinary tract and causes a bladder infection. Or, when Staph Albus’ ugly cousin, Staph Aureus, usurps its relative on the skin and forms an infected hair follicle or cellulitis.

But not all bodily visitors are welcome. Viruses can cause more harm than the original infection. For example when a virus changes the genetic makeup of a cell, as is the case with the Epstein-Barr virus (commonly associated with glandular fever) it can cause rare lymphomas and gastric cancers.

We don’t yet know if viruses will have an intergenerational effect and change the course of the human genome as the third mitochondrial gene.

Conversely, some people can live with viruses (HIV, Hep C) for years – unaffected and uninfective; the virus that causes Chicken Pox and can live dormant in our spinal column for years before emerging as Shingles.

Our understanding of the true integration of our genetic visitors is some way off. We don’t yet know if viruses will have an intergenerational effect and change the course of the human genome as the third mitochondrial gene. Animal studies, to date, have only revealed that most of the genetic material introduced by viruses is eliminated in the recipient species within a few generations.

Fortunately, genetic visitation is a growing area of research interest, especially in oncology. Viral vectors, for example, are in development for use in a variety of cancers from melanoma to liver cancer.

As research progresses into these new frontiers, legislative decisions that permit IVF babies to be created using biological material from three different people offer hope that scientific thinking will continue to inform and direct forward-looking thinking in government. It is time the ethicists of all spectra followed suit.