Native American cultures in the New World almost never had negative effects on their environments.

The centers of Maya cities usually included:

What subsistence technology helped Aztec people to flourish?

The most prevalent theory on the ‘Chaco phenomenon’ is that

According to your lectures, Uruk, located in Mesopotamia, was the very first city in the world. 

A preexisting civil war among the Inka made things much easier for the Spanish conquerors.

When societies collapse all the inhabitants die and that culture no longer exists.  

The idea that pre-contact groups in the New World did not change their environment is termed:

Scholars debate whether the Mayan site of Tikal qualifies as a real city because:

Jon Gibbs is a 28-year-old college student who has been reportedly healthy with the exception of recent fatigue and low energy.  School “has been stressful this year” but he says that he tries to exercise and eat as well as he can to stay healthy.   Mr. Gibbs faints in class and falls, hitting his head on a desk on the way to the floor.  911 is called and emergency personnel arrive!  Vital signs are 37.9 C, 112, 30, 200/104.  The cardiac monitor displays an irregular cardiac rhythm with premature ventricular contractions (PVCs).  A swollen, red area is noted on the back of his head from the fall.   Mr. Gibbs is subsequently admitted to the hospital.  You observe that he is alert, shaky with trembling hands, anxious, and weak.  Skin is dry and mucous membranes are moist.  He has bilateral edema of his feet and ankles.  A chest x-ray reveals myocardial hypertrophy, and a computerized tomography (CT) scan of the head is negative. Serum Electrolytes are assessed. Na 152 mEq/L                           Cl 104 mEq/L                          K 6.4 mEq/L BUN 42 mg/dl Creat. 3.4 mg/dl CO2 23 mmol/L Ca 7.2 mg/dl Mag 3.7 mEq/L Phos 5.6 mg/dl Glucose 132 mg/dl Albumin    4.4 g/dl   Lactic Acid 1.8 mEq/L