Biopark concept

This technique is beginning to attract interest. The basic idea is to create exhibits that explain, elucidate, and exemplify the interconnectedness of life. More specifically, it is the idea

In some cases, orphaned or abandoned animals are taken to and raised at zoos. (Photo by © Carl & Ann Purcell/Corbis. Reproduced by permission.)

biologically unstable and their long-term survival is unlikely if events occur at random. Genetically only one-half or 50% of a mammal's alleles are passed to its offspring. Alleles are mutable genes that are responsible for inheritable traits. Therefore, genetic diversity is reduced by 50% with each generation. In other words, the relatedness or mean-kinship of these individuals increases by 50% with each generation. This increase in relatedness also increases the chance that alleles that produce a fatal birth defect or reduced survivability will be expressed. These are often called lethal genes. Demographic factors also influence the long term survival of small populations. If an excessively disproportionate number of females or males occurs in a population, only a limited number of animals will be represented in the population. This will result in a reduction of genetic diversity and increased mean kinship. This may eventually cause a small population to crash without the addition of new founders (genetically unrepresented animals in the population). Therefore, a population with a sex ratio that is nearly equal has a better long-term chance for survival. Age distribution in a small population is also very important. If there is an excessively disproportionate number of older post-reproductive or younger pre-reproductive mammals in a population, reproduction will intensify in a single cycle and decline in a single cycle. Without the addition of new founders, this will also reduce genetic diversity and cause a small population to crash.

Frankham (1986) and Foose (1986) very eloquently document two extreme reasons for managing captive zoo populations. Individuals are either intentionally selected to be well adapted to captive environments, or they are managed to preserve genetic diversity.

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