Why Do We Have Fingernails: Uncovering Their Purpose and Function

This article explains how fingernails, primarily made of keratin, have evolved to aid survival, functionality, and serve as health indicators.

The Evolutionary Perspective of Fingernails

Fingernails have rich evolutionary significance, evidencing humanity’s adaptation for improved survival and functionality.

This section explores the structures of nails and their roles across different species, their adaptive purposes in survival, and the way they can signal health concerns.

Anatomy and Composition of Fingernails

Fingernails are composed primarily of keratin, a hard protein also found in animal horns, hooves, and claws.

Human nails have several components including the nail plate—the visible part; the nail bed—skin beneath the nail plate; and the nail matrix, where new cells push older ones forward, causing the nail to grow.

The lunula, visible part of the matrix, and the cuticle or eponychium that seals the space between the nail and the skin, are also integral to its structure.

Fingernails in the Animal Kingdom

In the animal kingdom, structures similar to human nails, such as claws and hooves, serve a variety of purposes.

Primates, including apes, monkeys, and lemurs, possess nails that support activities like climbing and branching.

Fingernails and their variants are essential for animals to effectively grip, defend, manipulate objects, and in some species, even for balance during movement.

Adaptation for Survival and Functionality

Throughout evolution, the transforming shape and function of nails played a vital role.

Early ancestors developed broad fingertips paired with nails to aid in precise gripping and dexterity, which allowed for the use of tools, crucial in human development.

The utilization of stone tools about 2.5 million years ago, is one example of this adaptation in action.

Health Indicators through Nail Conditions

Nails not only serve mechanical functions but also provide insights into an individual’s health.

Changes in nail growth or appearance can signal various health issues ranging from nail disorders like psoriasis and fungal infections to medical conditions such as diabetes and heart disease.

Subtle changes, such as nail clubbing, pitting, or brittleness can be early indicators of systemic diseases, including melanoma and other serious conditions.

The Biological Importance of Fingernails

A close-up of a small animal using its sharp fingernails to dig into the ground or climb a tree, showcasing the biological importance of fingernails

Fingernails serve various biological functions, from protection to enhancing sensation.

These mechanisms have a significant impact on daily activities and have evolved to suit intricate tasks.

Protective Function and Sensory Roles

Fingernails provide a protective layer for the delicate tips of fingers, safeguarding the sensitive nerves underneath from injuries.

This defensive function is especially important for tasks that could potentially cause harm to the fingertips.

Additionally, their hard surface adds strength, which assists in certain types of locomotion and gait.

For instance, primates, including humans, utilize their nails for climbing and gripping.

The sensitivity of fingertips is enhanced by the presence of nails as they act as a counterforce when objects are held between the finger and thumb, improving precision and sensation.

Cultural and Cosmetological Aspects

Beyond their protective and functional roles, fingernails have cultural significance.

They are often viewed as a canvas for self-expression through the use of nail varnish and nail art, which have become prevalent practices among various demographics, including American young adults.

Additionally, the condition of one’s nails can reflect grooming habits and general health.

Research and Study on Fingernails

The study of fingernails can provide a wealth of information in fields such as anthropology and medicine.

For instance, the growth rate of nails can reveal insights into an individual’s metabolic rate and health status.

Moreover, analysis of nail composition can help in identifying nutritional deficiencies or chronic conditions.

Fingernails have even been linked to our evolutionary history with researchers like John Hawks exploring how nails have evolved from claws in our primate ancestors as an adaptation for improved manipulative abilities and fine motor skills.