The fossil presence of anatomically modern humans in demonstrates that our ancestors were capable of substantial water crossings by 40,000 years ago.

The correct answer is - Africa.

Explanation:

Scientists found the fossils of modern humans called Mota an ancient man who lived around 40000 to 45000 years ago in Ethiopia. It was the first DNA isolated from Africa.

This DNA sample says that the Europeans have 6% of the DNA of this modern human, which suggests that there was substantial migration of people into Africa from Europe and the middle east by water crossings.

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.