Apparent altruism in non-human animals Essays

Apparent altruism in non-human animals Essays Apparent altruism in non-human animals Essay Apparent altruism in non-human animals Essay Altruism can be described as an act or behavior in which is advantageous to another but at a cost to the organism carrying it out. Apparent altruism is the concept that although a behavior may seem to be fully altruistic or selfless, there is actually a benefit gained by the individual implementing the act. Charles Darwin, he who initially presented the Theory of Evolution in 1859, was bewildered about the reasons in why altruism occurs between animals. Part of his problem was that he did not have any knowledge concerning genetics. He believed that all characteristics in living organisms were solely passed on by a process of blending. He also believed that individuals lived to reproduce. Hence, if a parent, say a mother bear, were to protect her cubbased on his theory it would not benefit her in any way, as it would not increase her ability to reproduce later on. After Darwin passed away, however, many theories emerged and became the many explanations in why altruism takes place in n on-human animals. One of the great problems of Darwins theory of evolution was its incapability to justify the development of the queen bee and sterile worker bees. How could such a group evolve if its members could leave no offspring to breed the sterile worker traits? In 1963, Hamilton resolved Darwins paradox by presenting the Kin Selection Theory. His theory states that any individual that pass on genes to the future generations is performed, not only by means of their own reproductive success, but also by improving the reproductive potential of their relatives. Hamilton (1963) established the term inclusive fitness to describe the degree to which apparent altruism is shown depending on the genetic relatedness between individuals. The relatedness between a parent and a child is 1/2 (as the child will inherit half of each parents gene); siblings relatedness is 1/2, also regarded as offspring equivalents; a grandparent and a grandchild, 1/4, and so on. According to this theory, the closer the inclus ive fitness, the greater the cooperation and altruism. Kin Selection explains situations such as the reproductive altruism in social insects. Female worker bees forgo their reproduction ability to nurse queens young. By doing so, they increase their inclusive fitness by more than 1/4 (however always less than 1/2, as it would never reach to the mother-daughter point). This would seem more reasonable than if any female worker bees decided to leave the hive, reproduce on her own and in the end, losing all of her inclusive fitness to zero as a result of losing all protection, warmth and food from her hive. In 1981, Sherman observed Kin altruism between Beldings ground squirrels. It was such that close-related squirrels (such as mother-daughter, sister-sister relationships) did not show any aggressive behavior towards each other; it was even observed that they often helped each other in defending their young ones and sign alarm calls at the sight of predators, while unrelated females were observed to be highly aggressive. In North Mexico, female nurse prairie dogs feed offspring belonging to her siblings. The female prairie dogs give up resources belonging to them and provide it their siblings offspring because as they keep them fed and fit, she increases her inclusive fitness. The male prairie dogs, in the meanwhile, sit on the burrow rim and give warning barks to help others escape from predators. He, by giving these alarm signals, would not only increase his inclusive fitness (helping the females and offspring be alarmed and escape), but may also receive a reciprocal favor by others later in the future. This can be explained by another theory found by Trivers (1971) known as Reciprocal Altruism. Reciprocal altruism is the process by which an individual will perform an altruistic act towards another in exchange for the second individual returning the altruistic favor some time in the future. The end result of this exchange leaves both individuals with an increased personal fitness. Wilkinson (1984) observed altruism performed between Vampire bats. They regurgitated food for one another in hoping to build up a relationship based on mutual exchanges of favor. If ever a bat would not return a favor, the cost of being denied a meal having once cheated is very high. Trivers was aware of the possibilities, hence he indicated that reciprocal altruism would only evolve in species where individuals could recognize each other and apply punishments to those who refuse to reciprocate. The tit for tat strategy (Axelrod and Hamilton, 1981) works by each animal responding so that a cooperative behavior is followed by a cooperative behavior, and a defection is followed equally by mutual defection, as happens among bats. Sentry meerkats risks attack by giving alarm calls to others. This act will cost danger in his part, perhaps even death; however, it is assumed that the act will be reciprocated in the future. Young male baboons without mates will work together to steal a dominant males mate (Packer 1977): one baboon distracting the dominant male while the other mates. The cost to the baboon (the risk of being injured by the dominant male) is far outweighed by the genetic benefit gained by the baboon mating. However, later on, when the male, which carried out the previous altruistic act, is ready, the second baboon will return the favor by being the distraction. Mutualism, or return effects, occurs where individuals will cooperate and help one another because as a team, they can achieve more than working alone. Caraco and Wolf (1975) observed a mutual effect between lionesses; they hunt together to bring down wildebeests. Induced altruism- also referred to manipulation or social parasitism-is the act of asking for help from others and utilize it as a tactic aimed at cheating. Brood Parasitism, the laying of eggs in another birds nest, is an example of induced altruism performed by cuckoos and a number of other species (Davies and Brooke 1991). Beetle grub begs for food from the passing ant and then preys on them. Aspidontus, a fish whose appearance resembles the cleaner fish Labroides, instead of cleaning the host fish, approaches and bites into its flesh. Charles Darwin was aware that his theory of evolution contained flaws; he did not manage to understand the reasons why altruism occurred; why an individual would carry out a certain act or behavior to help others while, in the meantime, disadvantaging themselves. However, with the help from Hamilton, Trivers, Wilkinson and other researchers, we can now apply the knowledge of genetics that we possess today, and, to a certain extent, explain and justify the reasons of altruism. Research has indicated that for apparent altruism to occur, there must be something in return; compensations such as a genetic reward (increasing their inclusive fitness, key: Kin Altruism), or a long-term reward for the individual involved (personal fitness or self-interest, key: Reciprocal Altruism). But do animals always require something in return in order for them to act out a good deed? Well, there are instances in which true altruism occurs, but it is merely on a non-voluntary or mistaken basis due to som e kind of deception or manipulation (Induced Altruism) but other than that, we can pretty much assume that animals are down right selfish.