Worldwide, too little iodine in the diet is the most common cause of hypothyroidism. In countries with enough iodine in the diet, the most common cause of hypothyroidism is the autoimmune condition Hashimoto's thyroiditis.
The pronghorn is the second fastest land mammal in the world, after the cheetah. It can attain speeds of over 53 miles (86 kilometers) per hour. Size relative to a 6-ft (2-m) man: Fleet-footed pronghorns are among the speediest animals in North America. They can run at more than 53 miles (86 kilometers) an hour, leaving pursuing coyotes and bobcats in the dust.
The fastest average speed records are: 1  Solo man: Christoph Strasser, 2014, who averaged 16.42 mph (26.425 km/h) riding 3,020 miles (4,860 km) in 7 days, 15 hours, and 56 minutes. 2  Solo woman: Seana Hogan, 1995, who averaged 13.23 mph (21.3 km/h) riding 2,912 miles (4,686 km) in 9 days, 4 hours, 2 minutes.