Feedback archive › Feedback 2006

Racial origins and bone marrow transplants

If we’re all related, why does ‘race’ make a difference in looking for donors
for bone marrow transplants?

J.R. had seen information that bone marrow donors are best accepted within the same ethnic groupings, and was puzzled as to why that would be so, given the close relatedness of all people groups, and presumably knowing what we had previously written about evolution and ‘race’. The following feedback came from J.R. of Canada who says:

Dr Carl Wieland replied:

These two Australians, featured in Creation magazine, are obviously not from the same ethnic group. But when the man on the right was dying of kidney failure, the most compatible organ that could be found was from his best friend at left. This should not surprise us given the genetic unity of humanity revealed from both the Bible and science. But nevertheless, on average, there would be a greater chance of high compatibility within one’s own ethnic group, simply because that reflects a greater degree of relatedness in an otherwise trivial sense, just as a first cousin is more closely related than a second cousin.

Thanks for your enquiry. To explain this matter, we first need to understand that the issue is bone marrow for transplantation. In that sense, one can view bone marrow as an ‘organ’. And with any organ transplantation, the chance of acceptance (non-rejection) is much greater if the tissue is as compatible (i.e. as genetically close) as possible.

If one were to receive one’s own tissue, that would obviously be 100% compatible. The next closest would be one’s identical twin (remember that identical twins have the same sequence of DNA ‘letters’, but there can be differences in the way in which certain of these genes are switched on or off, known as epigenetic differences).

The next best chance of finding someone as genetically close as possible would clearly be from within members of one’s own nuclear family than otherwise. However, since this involves different DNA combinations from the same parents, the tissue from one of one’s siblings may not be as compatible as that from another of one’s siblings.

If we go further ‘out’, to the extended family, one should have a greater chance of compatibility for organ transplantation than an individual chosen at random. BUT this is a statistical, an ‘on average’ thing; it could easily happen that an individual from the neighbourhood was more compatible than one’s cousin, for instance.

And so on to larger groups, all the way out. The principle is that statistically, the closer one is related, the better the chance of a compatible donor. In that sense, the members of an ethnic group can be seen as a larger extended family, since they have originally descended from a common gene pool, though with of course lots of genetic crossover since.

So once again, on average it would be more likely to have compatibility from within one’s own ethnic group than outside – BUT once again, it could easily happen, for the same reasons given earlier, that an individual from another ethnic group was more compatible than someone from one’s own, even more so than someone from one’s own extended family.

So this is perfectly compatible with the fact that we are all relatives, with the addendum that some of us are more closely related to each other than we are to others – which addendum is a fairly unremarkable statement when applied to one’s own family/extended family, for instance.

For example, I have a standard sort of Germanic ethnic background. So logically, although I am astonishingly closely related to everyone on earth, as modern genetics has revealed, I am more closely related to a Dutch, Swedish or German person than to a member of Nigeria’s Ibo tribe, or a native of Mongolia, or a Khoi San person from the Kalahari.

Thus, I will have a greater chance of having good compatibility from an individual within my own group of greatest relatedness (my own ‘tribe’, if you like – a biblical concept, unlike ‘race’). BUT, as stated earlier, I should not be at all surprised if I were to find that the best organ donor available from a group of options might happen to be an Ibo person, for instance, over against a native of Berlin, for instance. As was stated in Discover magazine not long ago,

‘This genetic unity [referring to the fact that genetics has revealed that there is only one human race] means, for instance, that white Americans, although ostensibly far removed from black Americans in phenotype, can sometimes be better matches for them than are other black Americans.’ Discover Nov. 1994, pp. 71–75.

I trust that this (admittedly simplified) explanation has been helpful.

Thanks also for your kind words about our ministry.

Yours in Christ,
Carl W.

Dr Carl Wieland
Managing Director,
Creation Ministries International (Australia)