The secret of finches that inspired Darwin – Hipertextual

K. Thalia Grant

The famous story of Darwin finches and is known around the globe. The naturalist traveling in the Galapagos, documenting the “scientific” in the same paragraph when he came upon some differences that made him reflect on an idea: and if nature promotes a range of features while detracts other ? What if there are advantages that make a species more successful? And if there is something called “natural selection”? Finches are the turning point in a reflection that changed biology forever. And a recent study has succeeded in demonstrating the genetic mechanism that exists behind this peculiarity.

Speaking of Darwin’s finches

Darwin himself not he realized their relationship until another colleague, Gould, an eminent ornithologist, explained his relationship Indeed, Darwin’s finches were not the decisive clue. In fact, Darwin himself was not aware of their relationship until another colleague, Gould, an eminent ornithologist, said his kinship. Darwin’s finches are fifteen different species of these birds very closely related . Yes, it was his physiognomic features, namely the shape and size of its beak, which represented the decisive detail that made Darwin, following the identification of Gould, noticing a crucial difference. And we all finches are very similar, the same color and size. But its beak is adapted to their primary food source. That fact fueled the idea that crystallize later in the theory of “natural selection”. But these differences have to have some basis. For example, genetic. Now, a recent study has managed to identify the database, allowing us to better understand how it happened and how evolution works.

Character Offset

In places where species like, as Darwin’s finches live together, their characteristics tend to differentiate more among them. This is due to the selective and ecological pressure, what promotes diversification of physiognomic features , such as size and shape of the peak, as required. For we understand it, is a way to specialize very similar species to obtain a particular type of resource, so that spread together, obtaining greater success by dedicating each to a particular resource. Character displacement is the way to name this selective phenomenon also seen particularly well in Darwin’s finches.

From finches, their genetic and drought

the recent study by Sangeet Lamichhaney and colleagues genetically sequenced six species of Darwin finches that differ in several features. By analyzing their “genetic map” they noticed a locus , ie, a particularly important genetic position: the HMGA2. This locus is associated, as shown by the study, with beak size and body . As shown by the analysis, the finches that were affected by drought that occurred between 2004 and 2005 were more or less success as the set of genes they had. Specifically, HMGA2. Thus, finches that had the variation is expressed with a small peak were much more successful than those with a larger peak.

K. Thalia Grant

This also demonstrated by statistical data. Specifically, finches with smaller peak constitute 61% of survivors, compared with grosbeak, which are only 37% of the variability among finches who resisted. Thus, we see that the drought in the Galapagos revealed the role of this locus in adapting the size of the peaks in situations of changing environmental conditions . This is because the situation makes the species have to compete for food differently, for example. The results show conclusively that there are adaptive and selective processes operating in nature, which otherwise had been difficult to prove (and is also a fairly misunderstanding done).

finches with smaller peak is 61% of survivors and grosbeak only 37% However, although we know that HMGA2 controls the expression of size, we do not know the exact mechanism of this control. However, for the evolutionary demonstrations, though necessary, is not required . And we already have strong evidence (a) that evolution works at various levels. Moreover, we face a clear mechanism of how natural selection and selective pressure works. And all again, thanks to the mythical Darwin’s finches. Who would have thought that these birds would give much to talk about?