For species diversity means the variety of species in a region. Such diversity can be measured in many ways, and scientists have not agreed on what the best method. The number of species in a region-its “wealth” in kind “is a measure often used, but a more precise measurement,” taxonomic diversity takes into account the close relationship between one species and others.

For example: an island in which two species live birds and one species of lizard has greater taxonomic diversity than an island where there are three species of birds but no lizards. Therefore, even if there are more species of beetles on earth than all other species combined, they do not affect the species diversity because they are so closely related. Similarly, much larger number of species living on land that they live in the sea, but terrestrial species are more closely linked to ocean species, of which diversity is higher in marine ecosystems that suggesting a strict count of species.

How many species are there?

It is surprising that scientists know best how many stars are there in the galaxy than how many species on Earth. Estimates of species diversity in the world to between two million and 100 million species, with the most accurate estimate of around 10 million, of whom only 1.4 million have been named. The problems posed by the limits of current knowledge on species diversity are complicated by the lack of a database or a centralized list of the world’s species.

Continue to discover new species, including new birds and mammals. On average, each year about three discover new bird species, and in a year as recently as 1990 there was a new species of monkeys. Other groups of vertebrates are still far from having been fully described: it is estimated that 40% of freshwater fish from South America have not yet been classified.

Source: http://www.biotech.bioetica.org/clase3-8.htm
photo source: http://marinebio.org/

In any case, preservation outside the place of origin, ex situ obviously only possible for a small part, is extremely expensive and often involves a loss of genetic diversity by the high probability of inbreeding (founder effects; v. gr. a Venezuelan family of Lake Maracaibo, about three thousand people-is descended from a German sailor carrying the gene for chorea (Huntington), the incidence of this disease among existing members is 60%, so this factor effect is called the “founding member”).

Source: http://www.biotech.bioetica.org/clase3-7.htm

Wild:

Natural populations have a high degree of genetic diversity ensured by the condition of maturation of wild female and male individuals (eg in plants that maturation occurs with a day apart and the effect is bolstered addition, the presence of a self-incompatibility factor gene, all of which promotes cross-pollination or cross-pollinated). Also, the various wild species represent accumulated or ancestral gene pool with great diversity that is apparent eg peach palm cultivated in hybridization.

Cultivated:

Genetic diversity of cultured organisms although many generic should decrease by the selection of only a few individuals who display the characters “desired” in many cases is even greater than that of wild populations because it is the result of domestication enriching of different species and their hybrids (v.gr1, maize, potato, ajitomate in America, which was a product of pre-Columbian domestication and diversity sought as a weapon to combat pests and enrichment of the diet from a few species.)

But, generally, or in our day-breeding process creates uniform varieties with a range restricted. This reduction reaches its maximum when it is reproduced by cloning, which makes the crop more efficient producer, but more susceptible to health problems (loss of variability is loss of response alternatives). Planting / mixed breeding varieties reduces this potential problem.

It confirms what has been said about the importance of maintaining genetic diversity of the original or wild species, which breeds and varieties are obtained to ensure adequate performance of domestication, and the very existence of the species.

Until recently, measures of genetic diversity were applied mainly to domesticated species and populations held in zoos or botanical gardens, but the techniques are increasingly applied to wild species. Allowed within or outside the place of origin. Some integrated management programs have begun to merge these approaches essentially dissimilar.

Source: http://www.biotech.bioetica.org/clase3-7.htm

Genetic diversity represents the heritable variation within and between populations of organisms. Essentially, it depends on the variations in the sequence of the four key pairs are formed, so the genetic code, taking into account that, in advanced organisms, only a small fraction (often less than 1%) of genetic material is expressed outwardly in the form and functioning of the body.

The role of genetic diversity (= genetic load, expressed or not individuals of a species) is to maintain a reservoir of terms-of-variation response to the environment, that allows adaptation and survival. In response, the significance of any alteration in genetic diversity (reservoir) is uncertain.

Each of the different genes present in the biota of the world does not make an equal contribution to the total genetic diversity. In particular, genes that control fundamental biochemical processes are kept in differential rates and generally show little variation, although variation does exist that may exert a strong effect on the viability of the organism, the opposite is possible on other genes. Moreover, an astonishing level of molecular variation in the immune system of mammals, for example, is possible through a small number of genes inherited.

The new genetic variation come from gene mutations and chromosome in individuals, and agencies with the power of sexual reproduction can spread to the population through recombination. It has been estimated that in humans, as in flies, the number of possible combinations of different forms of each gene sequence exceeds the number of atoms in the universe.

The frequency of genes within the total population is the result of natural selection, and in turn, is the determinant of the evolution of the population. The importance of genetic variation is summarized by saying: allows evolutionary changes based on selective breeding.

Source: http://www.biotech.bioetica.org/clase3-7.htm
photo source: www.ri.net

Biodiversity is the variability among living organisms, terrestrial, marine and aquatic ecosystems and the ecological complexes of which they are part: this includes diversity within species, between species and within and between ecosystems.

Human cultural diversity could be considered as part of biodiversity. Because it has some attributes that could be considered solutions to problems of survival in particular environments (nomads, crop rotation). It also help people adapt to environmental change.

Cultural diversity is reflected in the diversity of language, religious beliefs, practices of land management, art, music, social structures, the selection of crops in the diet and all attribute of society.

Many of the least disturbed ecosystems in biodiversity across the planet are in Latin America (Patagonia, Amazon, tropical mountain forests, the concentrations of marine Atlantic or the South Pacific and the Tepuyes to them must also add the Antarctic).

Tropical forests are the key to store the world’s biological diversity. The same was developed by 100 million years of evolutionary activity (forming an irreplaceable gene bank). Occupy only 6% of land area, and live there for more than half of all species on earth.

The reduction of biodiversity is a direct consequence of human development, because many ecosystems have been converted into impoverished systems that are less productive, economically and biologically. You might say, inappropriate use of ecosystems and disrupt their operation also involves a cost.

The conservation of biodiversity is a change in attitude from a defensive posture (protection of nature against the impact of development) to active work that seeks to meet the needs of biological resources of the population while ensuring the sustainability over time of Earth’s biotic wealth.