A biologist hypothesizes that some lizards living at high altitudes have evolved blood that delivers oxygen more efficiently than that of their lowland relatives, rather than simply having larger lungs.
Which finding, if true, would most strongly support the biologist's hypothesis?
- Acheck_circle
High-altitude lizards' blood binds oxygen at significantly lower pressures than lowland relatives' blood, even though their lung size is similar.
- B
Lizards are ectothermic, regulating body temperature externally.
- C
High-altitude habitats are found on every inhabited continent.
- D
Some lizards can change color to absorb more sunlight.
Explanation
A reports the predicted blood-level adaptation while equating lung size, isolating blood as the locus of adaptation. B, C, and D are general or tangential.