In a short essay (100-150 words), describe darwin's view of how natural selection resulted in
both unity and diversity of life on earth. include in your discussion some of his evidence. (see
tips for writing good essays and a suggested granding rubic in the study area of
mastering biology under "writing tips and rubic".)

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]