Charles Darwin Origin of Species 3. Discuss the difficulties with sterility of organisms under captivity. 4. Why do organisms that are closely related look different? 5. How important is the environment to growth of organisms? Solution 3). The animals under human care, otherwise known as organisms under captivity can be turned sterile if they are the hybrids containing two different sets of chromosomes. So, no breeding between the animals is possible and all the animals are produced mostly from one origin. This could contribute to the termination of that particular species and also alter the biodiversity..