1.The presence of valves 2.the milking action of skeletal muscles 3. the veins as the muscles contract
Answer: Human evolution, the process by which human beings developed on Earth from now-extinct primates. Viewed biologically, we humans are Hono Sapines, a culture-bearing upright-walking species that lives on the ground and very likely first evolved in Africa about 315,000 years ago.
Answer:
Water isn't wet by itself, but it makes other materials wet when it sticks to the surface of them.
PMAT (Prophase,Metaphase,Anaphase, Telophase)
C. punctuated equilibrium. Scientists believe in two evolutionary theories: gradualism and punctuated equilibrium. If punctuated equilibrium suggests species can rapidly evolve into a new species, gradualism suggests that these changes (selection and variation) happen more gradually.
