Serial bis
Significance of variation in biological evolution
....... However, some readers may already think, the only thing that happens if this is the breeding living organisms, NA me even after thousands of generations experience, ability to adapt to the strongest member of the eyes only the initial population as large as the largest eye . According to our observation of nature found in the human or animal eye size is greater than the generation of generation trend actually exists. The reason why this happens is because when the process of gene transfer to future generations, there will be a very small probability of error, so that the gene was minor changes. This is somewhat like the ancient Chinese game of whisper sent a message: in a team of people, one by one, put a message passed on; the first person against the second person's ear softly tells a story, and then the second man quietly this story spread to the third, and so on, until the last man and then heard the story out. Usually this will promise a lot of joke: the last person to speak out with the first story has been talked about is completely different. In fact, this type of error occurs when the actual transmission of information from one system to another system. Figure 3.2 an example of the picture is a surprising display. This is the result of the first test: The first person to draw a map of a bird (see top left corner) to the second person, who saw his second after a redraw to him the next person, so repeat until the last man drawn graphics will be significant 'alienation'. If you have a chance and more than a dozen friends gathered together, I recommend you to do something this small test, because the original picture seems to have so many incredible changes.
| Interesting facts |
图 3.2 信息移转的一个试验。 ( Thames 和 Hudson 提供的幻想图形 )
.......你可以说，图形或故事的情节在从一个人到另一个人的传递过程中，已经发生了变异 (或称突变，mutation ) ，同样的变异在生物繁衍过程中会在它们的基因中出现。发生变异的概率通常都很小，但经历大量世代之后变异就会显得很可观。一些变异对生物将是不利的 (这有最大的可能)，另一些则对生物的适应性可能没有任何影响，但也有一些则可能会给生物带来一些明显的利益，使它能超过与其同类的生物。在前面我们所讲的例子中，你看到的能使动物引起眼睛直径变大的基因突变就是一种有利的突变，它将使该动物与群体其余动物相比，就好像一个超级的时髦模特儿那样显得突出。这种使眼睛变得越来越大的趋势需要基因参与才能实现。当进化过程经历成千上万代之后，就会使动物长出一对如同盛菜的盘子那样大的眼睛！见图3.3。
图 3.3 一个 Adonis 的进化
.......进化机制除了能改进已具备的特征之外，也能产生各种各样全新特征。让我们再以眼睛的进化作为一个例子来说明吧。
.......可以设想，曾有一个时期动物就根本没有眼睛。那时，动物在它们的环境中航行完全是靠嗅觉和触觉来躲避掠食它们的动物。他们也 相当 擅长于这样做，因为他们靠这样已经历了成千上万个世代。在那个时候，鼻子大和手脚长的男性是受女孩子们欢迎的。然而，突然有一天，当两个动物配对时，一个基因突变发生在为皮肤细胞提供的蓝图上。这一突变使其后代在他们的头上发育出了一个具有相当光敏效应的细胞，使其后代能足够识别周围环境是亮的还是暗的。这样就给他带来了一个微小的优点，因为，如果一种食肉动物，比如一只鹰，来到了某个范围以内，则它将阻挡了光线，这时，该动物就会感觉得到，就可迅速跑到隐蔽的地方去躲藏起来。另外，这种皮肤细胞还能指示现在是晚上或白天，或告诉他现在是在地面之上或地面之下，这些信息在捕食和吸取营养时都能为它提供方便。你能看到这一新型皮肤细胞将使这一动物与群体中其余的动物相比，具备了稍多的优点，并因此也就有更多的生存和繁殖的机会。过了一段时间，由于进化机制的作用，许多动物的染色体中都会出现具有光敏皮肤细胞的基因。
....... Now, if you then make some extrapolation, imagine that the photosensitive cell gene mutation has been further advantageous, if you can see, after many, many generations, after the photosensitive cells to differentiate to form a region ; this area becomes larger and larger, resulting in a more certain number of characteristics, such as a crystal form, or produce a color vision can distinguish cells; also conceivable, a mutation changing an animal by the photosensitive area is a two photosensitive areas thus it is the animals that had stereoscopic vision. Stereo vision for a living is a huge step forward, because it can accurately tell him how far he had to leave the target. Of course, you can also have the adverse effect of a mutation into the eyes of those same genes. But the important point here is that future generations will not grow out of this as a success and cousins who already have improved the eye, they will eventually become extinct. Only successful gene will be inherited. Any features that exist in nature will be able to find you observe their evolution is the use of countless tiny mutation evolved, and they are beneficial to the owner. Incredible, right?
....... these restructuring and mutation mechanism explains how evolution is complete. I hope now you understand, is how organisms gradually form a variety of different types of features to help them achieve greater success in their living environment.
Reproduced in: https: //my.oschina.net/dake/blog/196724