Making Sense of Biology
Nothing in Biology Makes Sense Except in the Light of Evolution, Theodosius Dobzhansky (1973). The American Biology Teacher, 35(3), 125-129.
“Sometimes Even the President of the United States Must Stand Naked…”
…Or Be Racially Profiled. One would think that this should not happen to the President of the United States. However, the Associated Press recently reported that President Barack Obama’s early colon cancer screening was sometimes recommended for high-risk groups such as African Americans1. From this we can infer that the president’s doctors are counting Mr. Obama as an African American in the biomedical (and not cultural) sense of the word. Is this reasonable?
President Barack Obama is descended from a Kenyan father and a European American mother. Therefore he is does not share the same ancestry as most socially described African Americans who are descended from West and Central Africans with about 18.5% European ancestry2. When African Americans were examined using 1327 genetic markers compared to other world populations they were closer to Europeans than they were to Western Africans. The STRUCTURE analysis with 14 clusters showed Saharan Africa, Western Africa, Central Africa, Eastern Africa, Southern Africa, African Americans, Europe, Middle East, Central Asia, India, Eastern Asia, Oceania, and the Americas3. On the face of it, the position of African Americans along the genetic continuum of human diversity seems odd. After all, historical records indicate that the vast majority of African Americans are descended from Western and Central Africa. Few slave cargoes arrived in the Transatlantic route from Eastern Africa (certainly not Kenya.) The records of the slave trade are available in a searchable database entitled: The Transatlantic Slave Trade Database4. There are records of over 34,937 voyages between the years 1514 to 1866. In this database, the vast majority of slaves originated from West and Central Africa. There is a significant subset of slaves that originated in Southeastern Africa (today’s Tanzania and Malawi5.) It is possible that some of these slaves may have originated in Kenya; however these voyages ended in Brazil (where the vast majority of African slaves ended up.) Thus, it is highly unlikely that any slaves of Kenyan origin ended up in either the Caribbean or Southern American states. Thus it is likely that the admixture of European genes into African Americans explains how STRUCTURE places African Americans in a position closer to Europeans and past Eastern Africans on the genetic continuum of the human species. This also demonstrates that there really is not a great deal of genetic variation within the human species to begin with, since such a small amount of average admixture (18.5%) moves a population whose African ancestry is mainly western and central, past Eastern Africans towards Europeans.
This means that any African American is as likely to share genes in common with Barack Obama through his mother’s ancestry as they are to through the father’s Kenyan ancestry. What little information we have about colorectal cancer rates we have from Africa suggest that this disease is rare amongst Africans6. It could be rare because predisposing genetic elements do not give rise to cancer in African environments; or it could be rare there because Africans do not share the same colon cancer predisposing alleles with African Americans. Actually, the etiology of colon cancer strongly suggests that environmental factors are much more responsible for the patterns of incidence we observe than genetic ones. For example, exposure to heterocyclic amines and polycyclic aromatic hydrocarbons are known risk factors for colorectal cancer. The amount of exposure of these compounds an individual gets is related to the amount of red meat uptake in their diet. The relationship of exposure of these compounds to red meat uptake could explain why colorectal cancers are rare in African populations, who do not eat nearly as much red meat as Europeans or Americans. One study examined genetic polymorphisms at UGT1A1 and UGT1A9 to determine the degree to which these explain variations in colorectal cancer rates between African- and European-Americans. UGT1A1 and UGT1A9 detoxify heterocyclic amines and polycyclic aromatic hydrocarbons. The study found that when all individuals were examined that there was no significant difference between genetic variants and colorectal cancer incidence; however when stratified by self-identified race, intermediate and low activity genotypes were associated with an increased risk in European Americans, but not African Americans7. The racial profiling conclusion that one would draw from this, is that with regard to this locus, it would be President Obama’s European ancestry that would put him at risk, not his African ancestry. This is a conclusion rarely arrived at by racially profiling physicians!8
Another important environmental risk factor for colorectal cancer is the bacterium Helicobacter pylori. The role that this bacterium plays in producing disease is complex. It is an interaction between the bacterium, host, and environment9. There are specific genetic variants of H. pylori that are more likely to be associated with intestinal cancers and the frequency of these genetic variants is different around the world10. Finally, one might try to find a racially profiling mechanism in the relationship between vitamin D receptor variation and intestinal cancer risk. After all, we know that human populations show clinal variation in vitamin D receptor alleles, associated with solar intensity11. We also know that lifetime sunlight exposure and dietary history influence tumor incidence and that vitamin D plays an important role in mediating incidence and survival of cancer12. Again, when applied to Barack Obama this reasoning would not hold up. VDR frequencies are associated with latitude, not socially constructed racial groups. In his case, he has ancestry from Northern Europe and tropical Africa. Strictly speaking we would expect him to show heterozygote advantage with regard to VDR genotype. With respect to environment, especially dietary composition, President Obama’s education would indicate that he has maintained the sort of diet one would expect from an upper middle class European American. Thus, none of the features of the African American stereotype that are required for a racially profiled diagnosis to have any relevance to him would be in place.
Indeed, racially profiling really doesn’t work for anyone13. Yet despite the excellent scientific reasons to abandon this form of medical practice, it is still rampant. The fact that even the President of the United States experiences this, illustrates the nature of the problem we face to eliminate it.
But since my thought dreams have been seen, they’d scheduled my head for the guillotine…
It’s Alright, Ma (I’m Only Bleeding)
Darkness at the break of noon
Shadows even the silver spoon
The handmade blade, the child’s balloon
Eclipses both the sun and moon
To understand you know too soon
There is no sense in trying.
Pointed threats, they bluff with scorn
Suicide remarks are torn
From the fool’s gold mouthpiece the hollow horn
Plays wasted words, proves to warn
That he not busy being born is busy dying.
Temptation’s page flies out the door
You follow, find yourself at war
Watch waterfalls of pity roar
You feel to moan but unlike before
You discover that you’d just be one more
So don’t fear if you hear
A foreign sound to your ear
It’s alright, Ma, I’m only sighing.
As some warn victory, some downfall
Private reasons great or small
Can be seen in the eyes of those that call
To make all that should be killed to crawl
While others say don’t hate nothing at all
Disillusioned words like bullets bark
As human gods aim for their mark
Make everything from toy guns that spark
To flesh-colored Christs that glow in the dark
It’s easy to see without looking too far
That not much is really sacred.
While preachers preach of evil fates
Teachers teach that knowledge waits
Can lead to hundred-dollar plates
Goodness hides behind its gates
But even the president of the United States
Sometimes must have to stand naked.
An’ though the rules of the road have been lodged
It’s only people’s games that you got to dodge
And it’s alright, Ma, I can make it.
Advertising signs they con
You into thinking you’re the one
That can do what’s never been done
That can win what’s never been won
Meantime life outside goes on
All around you.
You lose yourself, you reappear
You suddenly find you got nothing to fear
Alone you stand with nobody near
When a trembling distant voice, unclear
Startles your sleeping ears to hear
That somebody thinks they really found you.
A question in your nerves is lit
Yet you know there is no answer fit
To satisfy, insure you not to quit
To keep it in your mind and not forget
That it is not he or she or them or it
That you belong to.
Although the masters make the rules
For the wise men and the fools
I got nothing, Ma, to live up to.
For them that must obey authority
That they do not respect in any degree
Who despise their jobs, their destinies
Speak jealously of them that are free
Cultivate their flowers to be
Nothing more than something they invest in.
While some on principles baptized
To strict party platform ties
Social clubs in drag disguise
Outsiders they can freely criticize
Tell nothing except who to idolize
And then say God bless him.
While one who sings with his tongue on fire
Gargles in the rat race choir
Bent out of shape from society’s pliers
Cares not to come up any higher
But rather get you down in the hole
That he’s in.
But I mean no harm nor put fault
On anyone that lives in a vault
But it’s alright, Ma, if I can’t please him.
Old lady judges watch people in pairs
Limited in sex, they dare
To push fake morals, insult and stare
While money doesn’t talk, it swears
Obscenity, who really cares
Propaganda, all is phony.
While them that defend what they cannot see
With a killer’s pride, security
It blows the minds most bitterly
For them that think death’s honesty
Won’t fall upon them naturally
Life sometimes must get lonely.
My eyes collide head-on with stuffed
Graveyards, false gods, I scuff
At pettiness which plays so rough
Walk upside-down inside handcuffs
Kick my legs to crash it off
Say okay, I have had enough
What else can you show me?
And if my thought-dreams could be seen
They’d probably put my head in a guillotine
But it’s alright, Ma, it’s life, and life only.
Copyright © 1965 by Warner Bros. Inc.; renewed 1993 by Special Rider Music
- Associated Press, Doctors overtesting, reports say, Greensboro News & Record, March 13, 2010.
- K. Bryc, A. Auton,M.R. Nelson, et al. (2010) Genome-wide patterns of population structure and admixture in West Africans and African Americans, Proc. Nat. Academy of Sciences, 107(2): 786-791. www.pnas.org/cgi/doi/10.1073/pnas.0909559107.
- S.A. Tishkoff, F.A. Reed, F.R. Friedlaender, et al., The genetic structure and history of Africans and African Americans, Science May 22, 324: 1035-1044 (2009).
- http://wilson.library.emory.edu:9090/tast/database/search.faces. T
- Hine, D, Hine W.C, and Harrold, S, African Americans: A Concise History, (New York, NY: Pearson), 2010; see map pg. 29.
- Saidi H, Nyaim EO, Githaiga JW, Karuri D, CRC surgery trends in Kenya, 1993-2005, World J Surg. 32(2):217-23, 2008.
- Girard, H et al, UGT1A1 and UGT1A9 functional variants, meat intake, and colon cancer, among Caucasians and African Americans, Mutation Research 644 (1-2): 56-63; 2008.
- Dorer, M.S, Talarico, S, and Salama, N.R, Helicobacter pylori’s unconventional role in health and disease, PLoS Pathogens 5(10): 1-6, 2009.
- Graves, J.L., Biological V. Social Definitions of Race: Implications for Modern Biomedical Research, Review of Black Political Economy, DOI: 10.1007/s12114-009-9053-3, 2009.
10. Wu, I et al, Association between Helicobacter pylori seropositivity and digestive tract cancers, World J. Gastroenterol 15(43): 5465-5471, 2009.
11. Roychoudhury, A and Nei, M, Human Polymorphic Genes: World Distribution, (New York, NY: Oxford University Press), 1988.’
12. Campbell, F.C. et al, The Yin and Yang of vitamin D receptor (VDR) signaling in neoplastic progression: Operational networks and tissue-specific growth control, Biochemical Pharmocology 79:1-9, 2010.
13. Graves, J.L. and Rose, M.R. (2006) Against Racial Medicine, Patterns of Prejudice vol. 40 (4-5): 481-493, Sander Gilman editor.