Genus Essay Example | Topics and Well Written Essays - 750 words

Genus - Essay Example The workers keep busy in construction and provision of food. Being sterile, they do not have a direct offspring but work cooperatively together to look after the offspring of the queen. However, these workers are not â€Å"obligatory sterile† (Ciszek 2000:1), meaning that they are capable of reproducing but when they have to live in colonies, they are not supposed to breed. But, if they are separated from their colonies, then they are able to actively reproduce. Worker mole-rats are able to transmit their genes to the next generation if they are sterile through the concept of inclusive fitness (Hamilton 1964:1; Axelrod & Hamilton 1981:1390), according to which if the worker mole-rats share genes with their mother queen, then they are able to assist her in raising future queens, thus, enabling the workers to transmit their genes. This assistance is a special feature of eusociality. Hence, we see close inbreeding in these mole-rats since there is high genetic similarity (Faulkes , Abbott & Mellor, 1990). This close inbreeding eliminates the chances of out-breeding in mole-rats which increases their relatedness to the queen’s offspring. This close genetic relatedness maximizes the workers’ potential to do more work. ... The male members of these non-workers mate with the breeding female. Since most of these non-workers are sleeping most of the time, thus, the overall energy requirement for the colony is reduced. Their main role is the assistance in the brought up of the offspring. Female mole rats of all these categories are non-breeding, and will never reproduce. Although they are not sterile, yet their ovaries have been found to be inactive. Male mole-rats are able to inseminate; however, small mole-rats have difficulty mating with the bigger breeding female. As far as the breeding female is concerned, she belongs to the category of non-workers, and is of the same size as that of non-workers. She is identified through her prominent mammary glands. The offspring that is born is fed by the breeding female, and rests with the sleeping non-workers. If the nest is in some danger, both the sexes of the frequent and infrequent workers pick up the offspring, and take him out of the nest. When the danger i s over, all the members of all castes bring him back in. During weaning, he feeds on the food brought in by the frequent workers; and, when he is about 2 months old, he joins the army of frequent workers, and is about their size at one year. His joining the caste of frequent workers is an evidence of that the naked mole-rats share an extended family, which makes them eusocial. Hence, the naked mole-rats are a perfect example of eusociality. They resemble a lot with eusocial insects but differ in that mole-rats do not have a clearly defined breeding male. The breeding female is not easy to catch which shows that she does not reside at such a place that is frequently exposed to dangers like predators. This feature is also present in eusocial insects.