The problem Inbreeding poses The genetic diversity of Siberian Tiger populations has been declining rapidly due to increased inbreeding between tigers which has occurred as a result of their dwindling numbers. This poses a very real and worrying problem as a low number of different alleles in a species’ gene pool undermine the ability of members of the species to evolve and adapt to changes in their environment. This in turn would put the tigers at a greater risk of extinction which would have the effect of permanently disrupting food chains- a problem which could cause even more species to become extinct. Not only do Tigers contribute to biodiversity but, “they prevent over-grazing by limiting herbivore numbers” . Tigers hunt herbivores which keep the number of herbivores grazing at a similar number and so the grass which they graze on can adapt and evolve in order to avoid extinction. Were this not the case then herbivores would eat more grass as there would be more available to feed on and so the selection pressure strength on the grass would be too strong and it may not be able to evolve an adaptation to this pressure hindering its ability to survive. This could ultimately have disastrous consequences on the diets of other organisms that depend on grass for food and shelter. “A broad genetic sampling of 95 wild Russian tigers found the population behaving as if it were just 27–35 individuals.” This means that Siberian Tigers have low genetic diversity because instead of having the diversity of 95 tigers, they have the diversity of 27-35. These tigers often mate with close relatives and so they carry many recessive alleles & have a very small gene pool. This has resulted in: 1. Tigers becoming susceptible to rare genetic disor... ... middle of paper ... ...rs the Tigers vulnerable to attack from new diseases and changes in their environment as it means that there is a smaller probability that Tigers in the population will have genes allowing them to adapt to their environment as so many tigers will have the same genes. However a population with high genetic diversity will have higher survival rates & be more likely to carry the gene of resistance to many diseases. They are also less probable to die from rare genetic disorders as they are ‘deleted’ by healthy genes. Works Cited 1. Yerevan Zoo. (Unknown). Siberian Tiger (Panthera Tigris longipilis). Available: http://www.yerevanzoo.am/index.php?id=83&L=0&tx_ttnews%5Btt_news%5D=236&cHash=d560037f214a0172422a228ce742c2ba. Last accessed 05/01/2014. 2. Wikipedia. (Unknown). Siberian tiger. Available: http://en.wikipedia.org/wiki/Siberian_tiger. Last accessed 05/01/2014.
The major threat to their survival is the restricted and degraded habitats (Wang and Garshelis). Their habitat is not just one big area of land. In actuality, the Giant Panda’s habitat is fragmented and separated into small patches, each supporting a small population of the pandas. This fragmentation in habitat was caused by logging, deforestation, mining, poaching and by lightning speed economic development (Threats). Logging had been found to separate the once well integrated Giant Panda habitat into many sub sections (Zhou and Pan 363) and their forest habitats became increasingly fragmented by roads and railroads (Threats). Clearing the land in Giant Panda habitats had been another reason for the fragmentation of the Giant Panda’s habitat (Wang and Garshelis). The animal had been pushed higher and higher into the mountains, as their lower and flatter habitats were seized for human for agricultural activity (Wang and Garshelis). The small population due to the fragmentation is also a factor in the decrease in the population size. Studies have shown that small populations lead to a loss of genetic diversity and can lead to problems of inbreeding (Zhou and Pan
Population bottleneck is an evolutionary event in which a large part of a population or species is died or otherwise cannot reproduce, which increases genetic drift that can cause big losses of genetic variation for small populations. However, the amount of drift is inversely proportional to the population size, population bottleneck result a smaller population with reduced genetic diversity. Dropped genetic variation implies that the population will most likely be unable to adjust to new selection pressures, such as a shift in available resources (food, shelter, etc.) or climatic change, because the genetic variation that selection would act on may have already drifted out of the population. This genetic drift can affect the proportionate distribution of an allele and even cause to fixation or damage of alleles. Also, population bottleneck increases inbreeding and genetic homogeneity as there are some animals left in the gene pool which lead to unfavorable alleles can accumulate. Due to the smaller population size after a bottleneck event. population bottlenecks inform us that intraspecies diversity is similarly very vital
Robert C.L., 1987. Loss of genetic diversity from managed population: Interacting effects of drift, mutation, immigration, selection, and population subdivision. Conservation Biology 2:143-158.
An estimated one hundred species go extinct each and every day, which means that approximately 36,500 species would go extinct every year (British Broadcasting Corporation, 2003). This extinction trend coul...
With the studies that Charles Darwin obtained he published his first work, “The Origin of Species.” In this book he explained how for millions of years animals, and plants have evolved to better help their existence. Darwin reasoned that these living things had gradually changed over time to help themselves. The changes that he found seemed to have been during the process of reproduction. The traits which would help them survive became a dominant trait, while the weaker traits became recessive. A good example of what Darwin was trying to explain is shown in giraffes. Long-necked giraffes could reach the food on the trees, while the short-necked giraffes couldn’t. Since long necks helped the giraffes eat, short-necked giraffes died off from hunger. Because of this long-necks became a dominant trait in giraffes. This is what Charles Darwin would later call natural selection.
According to Darwin and his theory on evolution, organisms are presented with nature’s challenge of environmental change. Those that possess the characteristics of adapting to such challenges are successful in leaving their genes behind and ensuring that their lineage will continue. It is natural selection, where nature can perform tiny to mass sporadic experiments on its organisms, and the results can be interesting from extinction to significant changes within a species.
The white tiger is one of the biggest in the cat family. The white tiger is long it can grow up to 3.3 meters long and weigh as much as 300 kilograms hard to carry. Subspecies of the white tiger like Sumatran Tiger, Amur(or Siberian) Tiger, Indian (or Bengal) tiger, south china tiger, malayan tiger,indo-chinese tiger,bali tiger,javan tiger,caspian tiger thats extinct theres nine subspecies of the white tiger.A lot of subspecies are endangered or extinct because people hunt them for their fur to make jackets or sweaters and destroying their habitat.Some tiger cubs don’t live to be an adult because around half of the cubs die around 2-3 years of age.The cubs leave their mother at around 2 years old they live a long time because their mom taught them what they would know from eating to hiding from people.A group of tigers is called ambush or streak because the group may be hunting.You probably thought these tigers can’t swim because they are in the cat family but if you do you are wrong because ...
Have you ever wondered what makes you unique? The reason you are unique is because of genetic variation. Genetic variation is what makes humans all look different than each other such as hair color, eye color and skin color . Variation in the same species is based on genetic and environmental factors. Species that are the same have very similar genes but are not exact. This has to do with sexual reproduction traits of parents and offspring, parents give half of each chromosome pair. It is uncommon for there to be variation that genes carry resulting in a mutation. Genes control the traits in an organism but the environment and DNA does change things like appearance, behavior and having an offspring.
Wild tigers live mainly in Asia. “The population is distributed over six countries: India, Bangladesh, Nepal, Bhutan, China, and Myanmar.” (Sinha 57). However, they can be found all around the world in captivity. There are eight different breeds of tiger; “they are the Siberian, Chinese, Indochinese, Sumatran, Javan, Balinese, Caspian, and Indian (also known as Bengal). Of these eight the Bali, Javan, and Caspian/Persian tigers are extinct” (Ives 139). This means there are only 5 breeds of tiger left, possibly less than that, and they are all in the endangered species category. “According to the law, endangered species are those that are in danger of extinction throughout all or a portion of their range” (Williamson and Henry 11). In other words, today’s tigers are disappearing fast and the question is, why?
Next there is the Sumatran Tiger, or Panthera Tigris Sumatrae. This subspecies is the rarest and smallest of all living tigers and faces a serious survival problem in their habitat. They are the sole surviving subspecies in the islands of south asia as there are two other subspecies that have gone extinct there which are talked about later. They are inhabitants of the island of Sumatra which is in Indonesia. They are also inhabitants to Bukit Barisan Selatan National Park where they are found in isolated patches of sea-level forests. They do have a preference for dense vegetation habitats in the center of forests and avoid any human occupied areas. They naturally are found at high-altitude zones that have vegetation at ground level. Their characteristics feature a thick orange coat of fur and have the densest fur and stripes compared to the other tigers and males have thick hair around the neck.
Hong Kong, Singapore, South Korea and Taiwan are known as Asian Tigers. The highly free developed
Degradation, destruction and fragmentation of natural habitat of many forest residing animals has resulted in the extinction of their natural territory. It has resulted in the complete destruction of biomes as a whole.
The Java tiger has short fur, darker orange fur, fewer stripes, and black spots in between the stripes.the Tigers also have sensitive behaviors about their habitats. They're very protective about their habitat and young. There also quick, quiet, and can jump 15ft in one leap. They don't climb trees, and there very good swimmers. Even though the tiger has many skills they still have to be prepared for the people and predators that are around.
Nowadays a lot of animals are being hunted. The organism that I have chosen is the national animal of India - The Bengal tiger (Panthera tigris). It has a lot of physical adaptations like striped fur to camouflage, soft pads which allows them to walk silently to their prey, this allows them to survive in its habitat. They are nocturnal animals.
The tiger is known for being a wild and dangerous animal, but also its beauty. In relations to India this could be a reference to the beautiful culture which enriches our experience of India, but also some of the downsides that it has like poverty and unemployment and other sociological factors which paint a grim picture of Indian life.