The population in south africa is more prone to sickle cell anemia (genotype "ss"). people with genotype "ss" survive only up to 14-15 years of age. people with "ss" are prone to malaria because the parasite resides inside their rbcs. people with genotype "ss" are resistant to malaria because the parasite cannot reside inside their rbcs, and they can live a normal life (without sickle cell anemia).what kind of evolutionary force must be operative in south africa?

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phaneritic textures in which phaner means visible so phaneritic textures are standard of impertinent volcanic rocks. these rocks crystallized gradually under the surface of earth. when the magma cools deliberately then the ores have chance to develop and produce long crystals.

sorry, is there a picture? i do not see any arrows.

wut? unius0123 wut?