Malevolent Designer News - Is God a Racist?

Vitamin D - where we get it from and why we need it

Genetic variants for skin color in African Americans linked to vitamin D deficiency, City of Hope study finds

Here is a nice piece of science for people who have fallen for the Intelligent [sic] Design hoax to ponder on. It begs the question, Is God a malevolent Racist?

It is a paper by researchers at Beckman Research Institute of City of Hope, showing the link between skin colour in African Americans and the problems associated with the resultant vitamin D deficiency that 70% of them suffer from - an increased risk for cancers and cardiovascular diseases. African Americans have a 14% greater risk from cancers than do white Americans.

First, a little background information, from a blog post I wrote some years ago:

Human beings need vitamin D for normal bone development in childhood. We can get it from two sources: from our food or by making it ourselves in our skin. Our diet is normally deficient in it so we need to supplement this by manufacturing it in our skin. This process involves ultraviolet-B (UVB) from the sun which converts a cholesterol-like substance known as provitamin D3 to vitamin D3. This is then processed further by the liver and the kidneys to form vitamin D.

Deficiency in vitamin D in childhood leads to thin limb bones deficient in calcium phosphate which give the bones strength so the child may fail to grow to a normal height, may be susceptible to bone fractures and may well have deformed limbs, especially the lower leg bones which may be 'bowed'. Teeth may also fail to develop normally.

But, with UVB comes ultraviolet-A (UVA) and too much exposure to UVA can cause cells in the skin to mutate and become cancerous, giving rise to melanoma, an especially aggressive cancer. There are also a couple of other skin cancers caused by too much exposure to direct sunlight (or sunbeds).

One of the reasons humans evolved dark skin as we lost body hair may well have been selective pressure caused by melanomas, in conditions where the sun was strong enough to produce enough vitamin D despite it being filtered by protective melanin in the skin.

Melanoma

When the immediate ancestors of modern human migrated out of Africa one of the problems preventing them extending their range northwards may well have been the incidence of rickets caused by lack of sunlight on a dark skin evolved in a part of the world where the seasons are not so well differentiated and where the sun is always high in the sky. It used to be thought that Europeans and northern Asians evolved pale skin by this selective pressure alone but it might well be that we acquired it from our Neanderthal cousins with whom there is now known to have been limited interbreeding.

Neanderthals had been evolving in Euro-Asia for some 200,000-250,000 years before Homo sapiens arrived on the scene and so had probably 'solved' many of the problems of living in colder, cloudier and more seasonal climates. In effect, we may have short-circuited evolution and acquired in a few thousand years what it had taken Neanderthals and their ancestors 250,000 years to evolve. See, So What Did The Neanderthals Ever Do For Us?

The problem is that the solution to the lack of UVB on our skins created the problem of too much UVA and so an evolutionary balancing act was created with Europeans walking a tightrope between rickets and melanomas. We mostly avoid rickets, though not very well in some situations and we mostly avoid melanomas, though not very well in some situations. It might well be that Neanderthals had evolved a defence to melanoma which, for some reason, we didn't inherit from them. We inherited half the package which was enough to allow us to move north but the tradeoff was that we sometimes get melanoma and we sometimes have rickets.

Abstract

A recent genome-wide association study (GWAS) in African descent populations identified novel loci associated with skin pigmentation. However, how genomic variations affect skin pigmentation and how these skin pigmentation gene variants affect serum 25(OH) vitamin D variation has not been explored in African Americans (AAs). In order to further understand genetic factors that affect human skin pigmentation and serum 25(OH)D variation, we performed a GWAS for skin pigmentation with 395 AAs and a replication study with 681 AAs. Then, we tested if the identified variants are associated with serum 25(OH) D concentrations in a subset of AAs (n = 591). Skin pigmentation, Melanin Index (M-Index), was measured using a narrow-band reflectometer. Multiple regression analysis was performed to identify variants associated with M-Index and to assess their role in serum 25(OH)D variation adjusting for population stratification and relevant confounding variables. A variant near the SLC24A5 gene (rs2675345) showed the strongest signal of association with M-Index (P = 4.0 x 10−30 in the pooled dataset). Variants in SLC24A5, SLC45A2 and OCA2 together account for a large proportion of skin pigmentation variance (11%). The effects of these variants on M-Index was modified by sex (P for interaction = 0.009). However, West African Ancestry (WAA) also accounts for a large proportion of M-Index variance (23%). M-Index also varies among AAs with high WAA and high Genetic Score calculated from top variants associated with M-Index, suggesting that other unknown genomic factors related to WAA are likely contributing to skin pigmentation variation. M-Index was not associated with serum 25(OH)D concentrations, but the Genetic Score was significantly associated with vitamin D deficiency (serum 25(OH)D levels less than 12 ng/mL) (OR, 1.30; 95% CI, 1.04–1.64). The findings support the hypothesis suggesting that skin pigmentation evolved responding to increased demand for subcutaneous vitamin D synthesis in high latitude environments.

Author summary

Genome-wide association and replication study for skin pigmentation was performed in African Americans, and then the implication of the skin pigmentation genes in serum vitamin D variation was assessed. A variant, rs2675345, near SLC24A5 showed the strongest associations with skin pigmentation. A Genetic Score calculated using the top variants from 3 genomic regions, SLC24A5, SLC45A2 and OCA2, and West African genomic ancestry together account for a large proportion of skin pigmentation variation. The pattern of association between the Genetic Score and skin pigmentation was different between men and women suggesting an interaction between sex and genetic variation. The Genetic Score from the same 3 skin pigmentation gene variants was also associated with severe vitamin D deficiency, defined as serum 25(OH)D levels <12 ng/mL. However, skin pigmentation and vitamin D pathway gene variants account for a small but significant proportion of serum vitamin D variation. The results suggest that genomic variations strongly control skin pigmentation and also influence serum vitamin D levels.

Batai K, Cui Z, Arora A, Shah-Williams E, Hernandez W, Ruden M, et al. (2021)
Genetic loci associated with skin pigmentation in African Americans and their effects on vitamin D deficiency.
PLoS Genet 17(2): e1009319. doi: 10.1371/journal.pgen.1009319

Copyright: © 2021 The authors. Published by PLOS Genetics
Open access
Reprinted under a Creative Commons Attribution 4.0 International (CC BY 4.0)

Of course, that is the evolutionary explanation for the different skin colours; an Intelligent [sic] Design advocate must reject that in favour of all this being the intentional design of a magic deity, including melanomas and rickets!

Now we need to add an increased risk of prostate, colon, rectum or breast cancers and cardiovascular diseases as the supposedly intentional design of this magic deity too. And remember, evangelical Christian creationists will proclaim this putative intelligent [sic] designer to be one and the same as the reputedly all-loving god of the Bible!

As the news release from City of Hope explains:

“We should not shy from this new study looking at the genetics of skin color and its effects on vitamin D deficiency because being ‘colorblind’ is what has led to the widespread health disparities that we as a society are now trying to address,” said Rick Kittles, Ph.D., director of the Division of Health Equities at Beckman Research Institute of City of Hope, a world-renowned independent research and treatment center for cancer, diabetes and other life-threatening diseases.

“Skin color has strong social and biological significance — social because of race and racism and biological because over 70% of African Americans are vitamin D deficient, resulting in increased risk for cancer and cardiovascular disease,” Kittles added. Notably, the difference in cancer death rates^[PDF] between African Americans and whites is 14%.

Researchers in the City of Hope-led data study, published Feb. 18 in PLOS Genetics, conducted a genome-wide association study using the data of 1,076 African Americans to analyze the genetics of skin pigmentation in this group, replicate results and test if the identified genetic variants are linked to vitamin D deficiency in African Americans.

This was the first genome-wide association study of skin pigmentation in African Americans, Kittles said. Study participants self-identified as African American. Blood samples for DNA analysis and vitamin D levels were collected at recruitment, and scientists measured the sun-protected area of the skin in the inner upper arm of participants using a digital reflectometer.

Although skin pigmentation was measured in an area of the body unexposed to the sun, various factors such as aging, outdoor activities and consistent UV exposure over the years may influence skin pigmentation and the association between skin pigmentation and vitamin D levels. Understandably, researchers found that skin pigmentation gene variants, rather than skin pigmentation, measured using a reflectometer were associated with serum vitamin D levels.

Scientists found three regions (SLC24A5, SLC45A2 and OCA2) in the genes of African Americans with strong links to skin color and severe vitamin D deficiency. The genetic variant rs2675345, which is near a region in the gene called SLC24A5, showed the strongest association with skin pigmentation and vitamin D deficiency.

Studies have shown that individuals with darker skin pigmentation require longer or more intense ultraviolet radiation exposure to synthesize sufficient levels of vitamin D. In other words, if you have darker skin, you tend to make less vitamin D in the sun than people with lighter skin.

So, would an Intelligent [sic] Design advocate like to explain why we should not regard this increased risk from prostate, colon, rectum or breast cancers and cardiovascular diseases in African Americans, associated with skin pigmentation, as the intentional design of the god of the Bible, and why evolution by natural selection is the only explanation that doesn't leave this putative designer looking like a malevolent racist?

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