Answer: water, wind, volcanic rock, sand, and other stuff that can pile up basically.
D, the black squirrels have survived because black has provided them with an advantage in this environment.
Scar tissue is made of a protein called collagen
Hag Fish and Lamprey
Vertebrates are the organism which posses a vertibral column(aka the spine or back bone structure), while the earliest had a head they lacked a spine and jaw, these jawless vertebrae lived 500-600 million years ago. they are the ancestors of bony fish which in time became amphibians and other groups of animals
