* Skin Tone is a Spectrum: Skin color isn't binary (light or dark). It exists on a continuous spectrum with many variations and shades.
* Subjective Classification: What one person considers "light" another might consider "medium." There's no universally agreed-upon definition.
* Complex Genetics: Skin pigmentation is determined by multiple genes, making it a complex trait.
* Data Collection Issues: Accurate global data on skin tone distribution is not systematically collected. Self-reported data can be unreliable due to subjective perception.
What We Can Say:
* Geographic Distribution: Generally, populations closer to the equator tend to have more melanin-rich skin (what might be considered "darker skin"), while populations further from the equator tend to have less melanin-rich skin (what might be considered "lighter skin"). This is due to adaptation to different levels of sunlight exposure.
* The Majority: The majority of the world's population has medium to darker skin tones.
In Conclusion: While we can talk about general trends and geographic correlations, there is no definitive answer to the question of how many people have "light skin" versus "dark skin."