Monday, 15 May 2017

First Arrival Hypothesis in Darwin’s Finches Gets Some Caveats

The finch species of the Galapagos Islands became the crowning testimonies of Darwin theory.
Already more than 200 years ago, many scholars had noticed that the living creatures are using all imaginable survival recipes - today one would say to fill all the biological niches - and that the multitude of species could not have all been fit for Noah's Ark. There must have been a development of the species.

In addition, it was already known at the time that innumerable species, which could be reconstructed from fossils, had to have perished. It could not be that the species were created and then not changed. Since skeletons of living beings were found in the fossil-bearing layers, which had to be clearly related to species living today, the idea that there must be a development of the species was obvious. In the sequence of the geological layers, it was also clear (mostly) that the fossils embedded in it were all the more primitive the older the layers were.

Thus, mammals have only existed since the Cretaceous, fish appear later than molluscs, etc. One could even use the fossils to define a sequence of the geological ages; one could use the fossils of a stratum to roughly estimate their age. The idea that first came to the fore was that the life is derived from simple monks who have split up into many species.

Suddenly, nature invented a multicellular organism, probably from a colony-forming single cell, and began the era of the multicellular. At first, "simple" animals such as jellyfish, hollow animals or worms emerged, later (next stage of development) animals with internal skeletal (skeletal) or external skeleton (arthropods) developed And birds, there is a similar sequence for the plants.

Anyone who has slipped over the Pacific waves of Santa Cruz to the neighboring island Isabela without help from the travel agent with the postboat of the Galapagos Islands feels like Darwin. You have finally solid ground under your feet, and the sea sickness leaves you a first time in peace.

The young British naturalist enters the firm's volcanic ground in September 1835, the year when the first railroad line is put into operation on the European mainland in Belgium, the printer Carl Bertelsmann founds a publishing company in Gutersloh, and the Bayerische Hypotheken- und Wechselbank in Munich And Hegel's "Lectures on Aesthetics" appear in book form. 1835 is, however, the year in which Charles Darwin collects those impressions, animal bellies and deeper insights that are decisive for Darwin theory of evolution.

This is what the legend says: On every island, the naturalist sees new species of animals which are very similar to those of the neighboring island. He concludes that these different species had a common ancestor, so that species are altered and not created by God, as the Bible says. Especially a group of animals is supposed to have given him this revolutionary insight when he made island hopping together with Captain Fitz-Roy: the finches living there with their different sized beaks.

The so-called "Darwin-Finches" today, together with illustrations, appear in every textbook, along with the explanation of how they came to their different beaks. On one of the young volcanic islands, which were still bird-free, there had once been a swastika of a mainland, almost a thousand miles distant. It. Their descendants colonize the island. And like the storm that once brought the Eve-Finkin over it, in the following millennia, the Founder-Finch also travels from there to the other islands. And depending on the food supply - insects, cacti, hard-shell fruits - the animals adapt themselves for generations, especially in the form of their beaks. They find their respective ecological niche.
This is Darwin theory of evolution - not in a nutshell, but in a few finches. How do species develop? Not by millions of creatures, but by other means. Why do they arise? Because, when the environmental conditions change, they also have to adapt. How does this adjustment come about? Through "natural selection". The individuals of a species differ slightly from one another, and the characteristics which are of advantage in the respective environment are determined by generations. Why are there so many species? Because of a kind of new species, for example by an "adaptive radiation", in which different ecological niches are occupied by the offspring. Just as the finches have done on Galapagos

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