专家影片：动物学家迈克 林利在皇家诺福克展会现场讲述不同类型的家养牛。

This lesson explores the fascinating diversity within animal species, highlighting how selective breeding creates animals with specific traits, such as cattle bred for milk or meat, and how environmental adaptation influences physical features like fur length. Discover how genetic variation and human intervention shape the appearance and purpose of animals across different regions and breeds.