How do scientists know that the first organisms were simple, unicellular organisms

Which of the following is an example of competition that could be found in a forest? question 14 options: deer eat berries and their droppings seed new areas creating more berry bushes two fox populations utilize the same rabbit population as their main food source two hawk populations utilize the same scorpion population as their main food source lack of sunlight due to changes in the seasons restricts the growth of certain plants