Which of the following was not an effect of the Great Oxidation Event?

What do animals wth echolocation have in common other than echolocation

What must be true for natural selection to heppen

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism