Made by looking at the result of a behavior or occurrence. a. indirect observations b. direct observations c. scientific laws d. scientific theories

Which of the following is one of the four conditions necessary for natural selection to occur in a population? fewer organisms are born than the habitat can support mutation does not occur organisms have identical characteristics variation is inherited

What was the land like over 500 million years ago? what was under the sea?

Nucleic acid certain protein cell membranes certain carbohydrates