Myoglobin levels are higher in Tibetans and other ethnic groups that live at high altitudes. Explain the benefit of higher myoglobin levels for individuals living at high altitudes.

They are able to take up and store more oxygen in their muscles

Explanation:

According to Oxford dictionary, myoglobin is ''a red protein containing haem, which carries and stores oxygen in muscle cells. It is structurally similar to a subunit of haemoglobin.''

The fact that Tibetans have a high level of myoglobin implies that they are able to take up and store more oxygen in their muscles since myoglobin is involved in storage of oxygen in muscle cells. Hence elevated levels of myoglobins enables the muscle cells to work more effectively.

it will increase due to the time span

since there are no options posted i'll give you a few examples.

a dolphin's flipper, bird's wing, cat's leg.