Tag: Natural selection

The vitamin D folate hypothesis is a prominent evolutionary theory that explains the diversity of human skin pigmentation as an adaptation to different levels of ultraviolet (UV) radiation. It posits a delicate balancing act between synthesizing UV-beneficial vitamin D and protecting against UV-harmful folate photodegradation.

Over 80% of all living green plants are flowering plants, or angiosperms, and their evolutionary success is inextricably linked to the answer of how did fruits come into existence. This remarkable biological innovation fundamentally changed plant reproduction and colonization across the planet.

While all infant mammals, including humans, can produce the enzyme lactase to digest milk, most mammals stop producing it after infancy. This suggests that the ability for many adults to process lactose is a relatively recent evolutionary development, not an ancient trait shared by all humanity.

While it is a common misconception, Europeans are not the only population group with low rates of lactose intolerance; approximately 65% of the world's adult population cannot digest lactose efficiently. The ability to drink milk past infancy, known as lactase persistence, evolved independently in various populations around the world, not just Europe.

Approximately two-thirds of the world's adult population cannot properly digest fresh milk, making lactose intolerance the human default. The ability to become lactose tolerant is a recent and powerful genetic adaptation, driven by specific environmental and cultural factors in certain populations.

While roughly 65% of the world's adult population has a reduced ability to digest lactose, many Europeans, particularly those of northern European descent, do not face this issue. The answer to why do Europeans not have lactose intolerance lies in a rapid, relatively recent genetic mutation driven by natural selection.

While almost all mammals lose the ability to digest lactose after infancy, a significant portion of the human population, approximately 40%, has evolved a unique adaptation that allows them to continue consuming milk throughout their lives. This remarkable ability, known as lactase persistence, emerged relatively recently in human history and is a prime example of rapid evolution driven by cultural and environmental changes.

In the mid-19th century, Dutch men were among the shortest in Europe, but today, they are the world's tallest population. The question of what makes Dutch people so tall has intrigued scientists for decades, revealing a complex mix of evolutionary and environmental factors.

Over 60 million years ago, a single disabling genetic mutation occurred in the common ancestor of all anthropoid primates, rendering our lineage unable to produce its own vitamin C. This remarkable biological change explains why humans are among the few species that depend entirely on their diet to fulfill their vitamin C requirements.