Biodiversity

Biodiversity

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  • What is biodiversity?

The earth is populated by an incredible quantity of different living organism. The term used to define this set of organisms, that inhabit every corner of the planet and that adapted to the most extreme environments, is biodiversity or biological diversity.

The elements that make up biodiversity can be traced back to three different levels:

  • Genetic level
  • Spieces level
  • Ecosystem level

Genetic biodiversity 
Genetic diversity refers to differences in genetic heritage within a species.

An example is the morphological characteristics, that is, the visible traits of the organisms

Species biodiversity
When we talk about biodiversity, we generally refer to the spieces biodiversity,

to the diversity of the different species in a given environment, where by species is meant a group of organisms that can cross between them giving a fruitful offspring. Species biodiversity can be measured by the number of species in a given area (species richness), the number of individuals of each species in one place (abundance of one species) and by the evolutionary relationship between different species (taxonomic diversity).
Biodiversity of ecosystems

The variety of environments in a given natural area is the expression of biodiversity at the ecosystem level, it consider the differences between the various types of habitats.

  • What are the most biodiverse environments of our planet ?
  • Rain Forest

Here live about 750 species of trees , 400 species of birds and 125 of mammals , 100 species of reptiles and 60 of amphibians

It’s the largest forest in the world: it covers an area of 600 million square kilometers .

 

  • Barrier Reef

For the habitat “Barrier Reef” we can also include corals, animals (in addition to the fish)

The Barrier Reef has an almost infinite number of species.

  • Why biodiversity is so important?

Each species has a particular function in an ecosystem, from energy functions to those related to the protection of the pollution level . Obviously, all these important functions are essential for human survival . More an ecosystem is varied , that is, with greater biodiversity , the more is resistant to environmental stress. Biodiversity is important not only as a value in itself , but also because it contributes to human well-being : the vegetable components and forest wildlife are an important food source for many local populations, are a source of active ingredients ( 25 % medicines ) , contribute to increase the income and the freedom of choice of local populations and also they have an important effect on social relations and in the preservation of cultural heritage.

  • How many species are there on the Earth?

Today modern science cannot give an answer. It isn’t even known the exact number of known species, which are the ones which have been named, catalogued and registered, because there isn’t a specialized list recognized worldwide.           According to the best estimates, that number results to be around 1.8 millions.

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  • Where does this variability come from?

Mutation

Genetic mutation means every stable and inheritable change in the sequence of genetic material (both DNA and RNA) due to external agents or to the case but not to genetic recombination. So a mutation change the genotype of an individual and could eventually change the phenotype depending on its characteristics and its interactions with the environment.

Genetic recombination (meiosis )

For genetic recombination we mean any process by which , starting from a            genotype , are obtained new combinations of alleles compared to the initial ones . The most widespread recombination is that which happens in the course of meiosis and which gives birth to gametes with recombined genotypes ; the fulfillment of these processes is the reason why the offspring always differs from the parents

Natural selection

The natural selection, a concept introduced by Charles Darwin, is a mechanism by which species’ evolution happens and according to it a progressive increase of individuals’ frequency with ottimal features for the life ambient is had. The natural selection theory provides that inside of that variability, resulting by random genetic mutations, during the generations after the showing of the mutation, the mutations which bring the individuals to have more advantageous features in that ambiental conditions are favorite, determinating a better adaptation in terms of survival and riproduction.

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  • The importance of names

When we know an organism’s name, we have  the key for the access to an infinity of information about  that organism: we can discover if it’s edible or poisonous, if it has an economic value, if it has been introduced from other countries or if it is spontaneous, etc. We need the names also to deduct other information. For example, the presence of a particular specie may indicate the quality of the air or the water of the place where  it grows. A wrong name is misleading. Only with a correct name it’s possible to reach a correct information. For this reason the species’ names must be identified with precision. The names are like tags and the way in which we applicate them to the organisms is fundamental. Scientists must pay attention to very strict rules. Latin names are usually used intead of the ones of the different countries’ languages.

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Names are like labels, and the way we apply them to organisms is very important. For this reason scientists follow strict rules. Latin names are considered the “real” names to define them.

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