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Current North African skin tones are the result of various factors: geography, sexual selection, melanin production, multiple genes, polygenic inheritance, adaptation, human migrations, genetic continuity, shared ancestry, and genetic overlap. Today, I will explain all these factors.
Surprisingly, skin tones don’t depend solely on Y-dna, Mt-dna and autosomal dna genes.
Also, the changes in North African skin tone over time explains why these four statements are all correct and supported by evidence: More than 50 Greek authors identified ancient Egyptians as dark skinned (black); there is genetic continuity between the ancient Egyptian dna and modern Egyptian dna; the proportion of dark skinned North Africans have dropped over time; the answer isn’t invasion and replacement theory.
Geography: Certain latitudes result in a different level of ultraviolet light radiation intensity (UV B exposure). UV B can damage the skin if the body pigmentation isn’t brown at the highest UV B intensity latitudes such as the equator. However, UV B absorption can also help the body produce vitamin D which is essential for regulating the amount of calcium and phosphate in the body. These nutrients keep bones, teeth and muscles healthy. A body which doesn’t produce vitamin D well can lead to bone deformities such as rickets in children and bone pain from an adult condition called osteomalacia, which is just a modern Latin word for bone (osteo) prefixed to the Greek word for soft (malakos). The further away from the equator humans get, the more of a liability a dark skin is for having strong bones, since a lighter skin is better at absorbing UV B and producing vitamin D at lower intensity UV B latitudes. This led to “sexual selection”.
Sexual selection: Over time, human ancestors who were not scientists would have manifested “sexual selection” by through social control tools such as creating taboos against dark skinned people such as the curse of ham and racism to encourage the selection of light skinned sexual partners. This would have caused a skin tone shift over a period of 100-200 generations which equates to 2500-5000 years. This was discovered by studying the remains of humans that left Africa and went north. The opposite would have happened to light skinned people that migrated back to regions receiving higher levels of UV B exposure, resulting in re-pigmentation over 2500-5000 years. This was discovered from studying ancient Indian remains and the modern Indian population.
Y-dna, Mt-dna and autosomal dna: Y-DNA haplogroups are genetic markers that trace paternal lineage, passing exclusively from father to son. While they provide insights into human migration patterns and ancestry, they do not directly correlate with or provide information about individual traits like skin tone. Human pigmentation, including skin tone, is a complex trait influenced by multiple genetic and non-genetic factors. Scientists explain this by saying skin tone is “a polygenic trait influenced by multiple genes”, and it is not solely determined by Y-DNA haplogroups. This means that individuals living in regions with higher sun exposure tend to have darker skin tones, regardless of their Y-DNA haplogroup. Y-dna code associated with Europe therefore have been found in dark skinned humans such as R1b and E-M2. Likewise Y-dna associated with dark skinned populations have been found in Eurasian populations.
Melanin production: Melanin, a pigment produced by specialized cells called melanocytes, plays a central role in determining skin, hair, and eye color. The amount and type of melanin produced by an individual’s melanocytes largely influence their skin tone. Genetic factors regulating melanin production are not linked exclusively to Y-DNA haplogroups but involve various other genes.
Multiple genes involved: Pigmentation is influenced by multiple genes, including those located on non-sex chromosomes. Y-DNA haplogroups, which trace paternal lineage, do not account for the diversity of genes involved in determining pigmentation. Other genetic factors, such as those on autosomal chromosomes, also contribute significantly to skin tone.
Polygenic inheritance: Human pigmentation is a polygenic trait, meaning it is controlled by the interaction of multiple genes. Each gene may have small effects on pigmentation, and the combined effect of multiple genes determines the observed skin tone. Y-DNA haplogroups, focusing solely on paternal lineage, do not provide a comprehensive picture of the polygenic nature of pigmentation.
Evolutionary adaptation: Human populations have evolved diverse skin tones as adaptations to different environments and levels of UV radiation. Natural selection has favored different pigmentation traits in response to varying UV exposure levels across regions. These adaptations have occurred over thousands of years and are not solely determined by Y-DNA haplogroups.
Human migrations have played a significant role in shaping African skin tones. As populations migrated out of the continent, back to the continent, and across the continent, they encountered varying environmental conditions, such as UV radiation levels. Natural selection favored genetic variations that provided better protection against excessive UV radiation. This led to the development of diverse skin tones, with darker pigmentation prevailing closer to the equator where UV exposure is higher and lighter pigmentation in regions with less intense sunlight.
Genetic continuity has also influenced African skin tones. Despite migrations and the establishment of new settlements, there has been a continuity of genetic traits within African populations. This continuity is due to the intergenerational transmission of genes that determine skin pigmentation. As a result, certain variations associated with specific skin tones have been preserved over time, contributing to the diversity observed today.
Shared ancestry is another important factor. African populations share common ancestry, tracing back to a common origin in the continent, for all Africans. On this point scientists, Christians, and Muslims agree, although there are disagreements about many other things. Over thousands of years, populations intermixed, leading to genetic exchange and the spread of specific genetic traits related to skin pigmentation. This shared ancestry has contributed to the broad spectrum of skin tones found across different regions of Africa.
Implications:
• Some of the ancient Egyptians had dark skin tones. This is supported by evidence from ancient sculptures and paintings that depict individuals with darker skin.
• Some of the ancient Egyptians had light skin tones. Similarly, ancient artwork also portrays individuals with lighter skin tones, suggesting a range of skin colors within the ancient Egyptian population.
• Some of the ancient Egyptians had intermediate skin tones. The depictions of ancient Egyptians also include individuals with intermediate or varying skin tones, indicating a diversity of appearances within the population.
• It is incorrect to assume that the ancient Egyptians had 100% white skin tones. The ancient Egyptians were a diverse group with a complex genetic and cultural history. While individuals with lighter skin tones were present, it is incorrect to assume that all ancient Egyptians had exclusively white skin tones.
• It is incorrect to assume that the ancient Egyptians only had 100% black skin tones. Similarly, it is incorrect to claim that all ancient Egyptians had exclusively black skin tones. The population of ancient Egypt was diverse, and their genetic makeup included a mixture of different ancestral components.
• It is incorrect to assume that Y-DNA and mtDNA results can tell us anything about skin tones. Y-DNA and mtDNA are genetic markers that provide information about ancestry and lineage but do not directly reveal specific physical traits such as skin tone. Skin tone is influenced by a complex interplay of multiple genetic factors, and it cannot be accurately determined solely based on Y-DNA or mtDNA analysis.
• The Moors that invaded Europe as well as the Arabs have a diversity of skin tones.
Not everyone will understand this post. Not everyone will want to believe in the need for a complex answer. People may ignore this science-backed explanation due to cognitive dissonance, confirmation bias, emotional attachments, fear of change, social conformity, identity protection, selective exposure, lack of awareness, misinformation and disinformation, and cognitive biases. Experiences of racism may mean that some people prefer to believe alternative explanations.
