Genetics -- an introduction:
Genetics is the science by which experts can trace the origins of an animal and the inherited characteristics of a group of organisms. Simply put, it is the science of plant and animal breeding.
Different members of the same species all have similar genes, however these are far from being the same in all cases. These genes determine things like your skin and eye colour, and whether your hair is curly or straight.
In the same way, all animals carry genes to determine their final appearance. White tigers, black leopards and jaguars, white lions; these have all had their pelage colours decided through a recessive gene carried by the parents.
Allele is the name given to one member of a pair or series of genes that occupy a specific position on a specific chromosome.
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Each person and animal has two sets of genes inherited from their mother and father. So you have two variations (alleles) for each kind of gene.
Individuals have a random mixture of homozygous and heterozygous genes. When a different allele for a particular gene comes from each parent it is said to be heterozygous for that gene. When the same allele for a particular gene comes from each parent it is said to be homozygous.
Chromosomes are the carriers of genes. The chromosomes of the tiger are arranged in 19 pairs giving a total of 38 chromosomes altogether.
Genetics in wildlife conservation:
Captive species make up a reservoir of animals to back up their wild cousins. If the wild group experiences a severe reduction in numbers the captive species can be used in one of two ways:
1. To repopulate the wild species through captive breeding and release. A prime example of this was the California condor which, by 1985, had reached the point that not one individual remained in the wild, and only handful were in captivity. The species bred quite well in zoo conditions and by the year 2000 thirty-six birds had been successfully released back into safer areas.
2. Some animals cannot yet be released back into the their natural surroundings. Their needs are such that release is not possible due to:
...and a myriad of other reasons. But though complete loss of an animal in the wild may be a distinct possibility, man can usually maintain a species in captivity with an eye towards releasing it in the future.
For various reasons the tiger is in the second non-release category:
The use of genetic typing can reveal much about an animal. For instance, testing all tigers could well prove there are less subspecies than originally thought. Many biologists have long been of the opinion that there are only three subspecies:
| Hearing & Ear Spots | Eyesight
| Smell | Teeth
| Communication | Flehman
| Genetics |
With Thanks To Hans Stenström (Photo 1)