Answer:
Organs are made of several tissues, each tissue consists of cells that differentiated into specific types with specific functions. Therefore, there is a “division of labor” so to speak.
Can you re-word better? i'm having a hard time reading this.
The study of artificial selection by Darwin helped him to establish his theory of evolution via natural selection. One of the animals Darwin examined in detail was the domestic rock pigeon. In the 1850s breeding of pigeons was an ancient past time, thus, Darwin decided to keep and breed the pigeons by himself.
While studying pigeons, Darwin established scrupulous determinations of their skeletons and wondered at the breeds' distinct colors, behaviors, and proportions. He also observed the patterns of inheritance of various features, and he demonstrated that birds of very distinct breeds can, however, generate fertile offspring. Thus, supporting the theory that they all originated from a single species.
B, the lowest layer is a dinosaur fossil, therefore the mammal fossil was after
