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In the light of current knowledge of evolutionary biology, the answer is clear. But Glimpse back to the sixth century. XIX, when the divine ip65 creation and the immutability of species began to be challenged to admit that they might have suffered changes over time. Two names appear closely linked to the concept of species evolution, Jean Baptiste ip65 de Monet, Knight Lamarck and Charles Darwin (*).
Lamarck and Darwin differed greatly in their explanations of the evolutionary ip65 process of species. For example, Lamarck held that species could change their characteristics throughout its life and then transmit this change to their offspring. Darwin, on the other hand, recognized the importance of variations in the characteristics that individuals of a given population and have argued that this variation should be related to the environment in which this population was. Thus, an individual who had characteristics that somehow benefited would be able to play more, passing these characteristics to their offspring. A process that Darwin called natural selection.
Today we know that these characteristics are the result of errors in copying DNA-the molecule that contains the information for the "construction and operation" of every living being that it gives the name of mutation. And the mutations occur spontaneously, with each cell division; some are immediately detected and 'corrected' but others escape this mechanism of control and become part of the genetic information of an individual. If a given feature in a given environment, confer some sort of advantage ip65 for the survival and reproduction of that individual, it will be the target of natural selection ip65 process. Ie, that individual is more likely to pass this trait to their offspring, leading to an increase in the number of individuals with that trait in the population.
Returning to the original question, we can assume that a giraffe have been born with a mutation that gave rise to the stretch of your neck, allowing him to feed the higher leaves. ip65 This advantage in power translated into better physical condition to survive and reproduce will be herself. Therefore, the mutation for the long neck have been transmitted to their offspring, which in turn, having the same kind of advantage, will also transmitted to their offspring. And so, as soon as the generations, the number of giraffes ip65 with long necks increased so that today only see giraffes with this feature.
(*) Actually there is a third name: Alfred Russel Wallace, a British naturalist who came to the same conclusion as Darwin on the role of natural selection in the evolution of species. The conclusions reached were both reported ip65 to the Linnean Society of London simultaneously. [This text has been adapted to answer the question 'Why do giraffes have great neck? 'Placed the disclosure project science Science 2.0. The new version can be read here.]
The competition 'A ip65 book on evolution' is intended to select a set of texts that integrate a book about evolution, ip65 editing in 2013.'s Book will be composed of selected works and supplementary texts written by faculty ip65 and visiting researchers.
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