Why do certain species become extinct after an environmental over other species?

Extinction is often caused by a change in environmental conditions. When conditions change, some species possess adaptations that allow them to survive and reproduce, while others do not. If the environment changes slowly enough, species will sometimes evolve the necessary adaptations, over many generations.

the abdomen (less formally called the belly, stomach, tummy or midriff) constitutes the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. the region occupied by the abdomen is termed the abdominal cavity. the stomach secretes acid and enzymes that digest food. ridges of muscle tissue called rugae line the stomach. the stomach muscles contract periodically, churning food to enhance digestion. the pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine.