What are the three types of selection pressures that could act and eliminate organisms with undesirable traits

The three types of selection pressures are:

resource availability, environmental conditions, and biological factors

Explanation:

Selection pressures are those external factors which drives the process of natural selection; by influencing the organism's phenotype by eliminating undesirable traits, or by increasing the favorable traits, so as to increase its ability and adaptability to survive in its environment.

Selective pressures are broadly falls under biotic, abiotic, and neutral factors.

Various selective pressures include competition, predation, diseases and illnesses, sexual selection, pollutants, climate change, parasitism, sunlight, wind, land clearance etc.

These can be broadly classified as resource availability, environmental conditions, and biological factors.

Resource availability in form of food, shelter or habitat, mates etc., are the major selective pressures

Environmental factors like sunlight, wind, weather conditions, climate, pollution; all can influence natural selection

Biotic factors include predators, parasitism, diseases and illnesses etc.

The adaptation of giraffes with long neck and legs are due to selective pressures to reach for food present at higher levels of vegetation.