It does not matter whether you live in the Czech Republic like Nebraska, Mongolia or like me or not. These places will be biologically poor and dull without the beneficial effects of the islands, away from the nearest sea. The immense biodiversity of this planet is fundamentally dependent on their existence. Without exaggeration, it can be said that island is a true cradle of development.
Let’s start our story on 16 September 1835, when HMS Beagle anchored near San Christobal’s Gallapagos Island (then called Chautham). The islands imprisoned a young 26 -year -old naturalist, then unidentified Charles Darwin. His sharp mind was designed for abnormal and mostly unique organisms and flora of the archipelago, with no equivalent only 1000 kilometers on the mainland. This wasland was life that gave Darwin the first indication to the principle of his development.
Among them, the blind striking Galapagos legendary turtles, marine iguana, and with a group of about 18 bird species, but with infallible plumage but attractive life history made their way into biology textbooks. These so -called Darwin’s finch later became a classic example of adaptive radiation, a evolutionary process, during which a leading species, after colonating the new area, is divided into several species. This usually occurs where many available and invited empty ecological niches occur.
But why is the islands so important for the emergence of new species? At this point, it is necessary to widen our common romantic perception of an island as a piece of land surrounded by water. For a biologist, an island is essentially isolated any area from its surroundings. This definition makes sense, because for development, it is necessary to separate a sub -grouper of a species. No interpreter is allowed between two separate population members, and distance islands are perfect for it.
However, in the case of the Galapagos Islands and the South American mainland, 1000 km between two population is not always necessary for the sea. Of course, for excessive mobile birds such as albatros, no island is sufficiently different. But even among the birds, the average and poor are also flying. Some forest species, after flying a few hundred meters on open water, fall from exhaustion and simply drown. Such species include South American Antbirds, Antitas and Tepaculos. For them an island may be within the vision of the mainland.
Emfibians can be close to their homeland and still separate from the point of view of development. Due to their sensitive skin, salt water is a fatal atmosphere. Even an island can serve as a solid barrier at just ten meters away, effectively separate the two frog populations.
From a biological perspective, an island can also be a high mountain surrounded by the Terai regions. For mountain species, it can be as irrelevant to the Terai as for the sea to the beach. The Colombian mountain range, Sierra Nevada de Santa Marta, is an ideal inland island. The slope of this 5, 685-meter high mountain range is houses for some 30 spatial bird species, for which there is nothing more than a blurred confusion in their ancestral home distance in the ends.
Some restless and talkative islands can also be your child’s head-for less than lice population, for which the hair covered with hair is a succulent pasture. However, the development of a new lice species often fails either due to some chemical treatment or due to its close contact with another “island”, either fails due to extinction that provides equally suitable living conditions. The limited lifetime of humans (and thus “island”) also determines a tight time limit for the development of a new species.
In short, the world is largely a mosaic of islands islands. The degree of isolation varies from species to species. What is a mellah for an eagle can be the Himalayas for an earthworm. What is a puddle for an albatros, the Pacific Ocean for a beetle can be the huge water.
So the important question is: How do the island and their separation contribute to the development of new species? Full books have been written on this subject, so in an attempt to answer it, I will essentially make things very simple.
Well, in addition to isolation, development also requires variability within a species. But what variability of what? Jean! These can be understood as the blueprint of their living carriers, in simple words. Genes are mutated from time to time and produce different types that can eventually lead to new species.
However, a large population spread over vast areas, even a very promising genetic innovation can disappear. The heavy dominance of genetic mainstream only dilutes and eliminates new mutations. And this is where the island comes! The islands allow species to take new Niches with novels and beneficial genetic mutations.
For example, say that a tropical storm blows a small herd of finch for a distant island. It may be that at the same time, some iguana or a fertilized female turtle flow in the same direction and logs (filled with tropical rivers). Their fleeting fleet, which was done by Humbolt current at a distance of about 20 kilometers per day, can reach Galapagos in two months. Will his passengers live till then? Will the fleet be washed, allowing the castway to reject? Probably not. But every time and for one time, these fearless courageous people win the lottery and survive.
And when the existing species reach their new house on such islands or other islands or other islands, the evolutionary mill begins to grind. Any genetic mutation that comes out of it, especially beneficial people have a great possibility of successfully spreading in a small population. Over time, it leads to gradual changes of the castway. When two population meets for some time in the future far away, they will probably no longer produce fertile children because their genes will no longer be compatible. A new species is born!
What can we conclude from all this? All these living things, including humans, are the products of “islands” development. For this reason, I was very freedom to choose images to portray this article.
In fact, one can say that I focus almost especially in my work on island species. Nevertheless, I was very selective in pictures of my choice. In this article, one thing is the same in all organisms: they are spatial species from Sri Lanka’s (real) island and (inland) island in Colombia, Sierra Nevada Dey (Inland) island of Santa Marta. Beyond the strict boundaries defined by these two foreign islands, they are not found anywhere else in the world.
