[Species Identification Based on Morphological Variability of Femur].

This study explored the morphological characteristics of the femur (the thigh bone) in humans and 11 different species of animals (cattle, horses, pigs, goats, sheep, dogs, cats, rabbits, geese, ducks, chickens) with the goal of establishing an effective method for identifying species based on these characteristics. Results showed distinct patterns in the bone structure across different species, allowing for the creation of mathematical models with a high success rate in correctly identifying the species.

Methodology

• The study focused on the 4 cm middle segment of the femur bone obtained from adult humans and eleven different adult animal species. In humans, the bone samples were taken from individuals over 20 years old who had undergone autopsy.
• After the bones were decalcified, they were sliced and examined using an optical microscope.
• Twenty-five distinct morphological indexes were selected and subjected to a stepwise discriminant analysis to identify differences between humans and mammals, humans and poultry, and humans and the 11 selected animal species.

Results

• The histological structure and bone mineral density of the femur revealed distinctive characteristics between species. Additionally, the osteon’s morphology (a central canal containing nerve fibres and blood vessels in bones) and count also implied significant variance hinting at biological evolution.
• Eleven unique indexes showed significant differences between humans and the 11 animal species, providing the data to create mathematical models to discriminate between species.
• The success rate of the discrimination models was 96.3% between humans and mammals, 100% between humans and poultry, and 89.4% among humans, mammals, and poultry.

Conclusion

• The study formed mathematical models with promising discriminant accuracy between humans and other animal species. This could be useful in practical species identification cases, such as forensic investigations.