Phylgengy - 高级

Can two different be related?
::两种不同可以互相关联吗?

Of course they can. For example, there are many different species of mammals , as there are also many different species of one type of mammal, such as mice. They are all related. Evolutionarily, what does it mean to be "related?" How close or how far apart did they separate from a common ancestor during evolution? Determining how different species are evolutionarily related can be a tremendous task.
::当然,它们可以。例如,有多种不同的哺乳动物物种,因为也有多种不同种类的哺乳动物,如小鼠。它们都是相互关联的。进化而言,它们意味着什么是“相关”?在进化过程中,它们与共同祖先的距离或距离有多大?确定不同的物种在进化过程中是如何相联的,可以是一项巨大的任务。

Phylogeny
::丙基苯基

In the century after Linnaeus published his system of , ideas about classifying organisms began to change. In 1859, published his major work on evolution, On the by . After that, there was more and more interest in classifying organisms by incorporating their evolutionary history, including the genetic relationships of organisms.
::在林瑙斯公布其生物分类体系的世纪里,关于生物分类的想法开始发生变化。 1859年,他发表了关于进化的主要著作《On the by ” 。 在那之后,人们越来越有兴趣通过吸收生物的进化历史(包括生物的遗传关系)来对生物进行分类。

The evolutionary history of a group of genetically related organisms is called a phylogeny . It includes ancestor species and descendant species. A phylogeny is usually represented by a tree diagram called a phylogenetic tree . An early example of a phylogenetic tree is Darwin’s “Tree of Life” ( Figure ). In this diagram, Darwin was trying to show how he thought evolution had occurred. The tree shows how species evolved through time, from the bottom of the tree to the top. As species evolved, they formed new branches on the tree of life. Some of these species eventually branched into additional descendant species. Others went extinct, without leaving any descendants.
::一组基因相关生物的进化史被称为“植物基因学 ” 。 它包括祖先物种和后代物种。 植物基因学通常以树形图为代表,叫作植物遗传树。 植物遗传学树的早期例子就是达尔文的“生命之树 ” ( 图 ) 。 在这个图中,达尔文试图说明他所认为的进化是如何发生的。 这棵树显示了物种从树底到树顶部的演化过程。随着物种的进化,它们在生命树上形成了新的树枝。其中一些物种最终会分化成更多的后代物种。 另一些物种灭绝了,没有留下任何后代。

Modern biologists still use phylogenetic trees to represent evolutionary histories. A simple phylogenetic tree is shown in the Figure  . The tips of the branches represent genetically related species. The branching points represent common ancestors. A common ancestor is the last ancestor species that two descendant species shared before they took different evolutionary paths. In the tree Figure  , species 1 and 2 shared a more recent common ancestor with each other than with species 3. Therefore, species 1 and 2 are more closely related to one another than either is to species 3.
::现代生物学家仍然使用植物基因树来代表进化史。图中显示的是简单的植物基因树。树枝的小点代表着基因相关物种。分支点代表着共同的祖先。共同的祖先是两个后代物种在走不同的进化道路之前共有的最后祖先物种。在树图中,第1和第2种与其他物种相比,彼此共有一个较新的共同祖先。因此,第1和第2种与第3种相比,彼此之间联系更为密切。因此,第3种与第3种相比,第1和第2种与第3种的关系更为密切。

Ancestor species are like your own ancestors. Your most recent common ancestor with any siblings you may have is a shared parent. Your most recent common ancestor with a first cousin is a shared grandparent. Your most recent common ancestor with a second cousin is a shared great-grandparent. In general, the more distant the relationship between you and relatives in your own generation, the farther in the past you shared a common ancestor. The same holds true for related species. The more distant the relationship between two related species, the farther back in time they shared a common ancestor.
::祖先的物种就像你的祖先一样。你最近与任何兄弟姐妹的祖先都是同父异母的。你最近与第一堂兄弟的共同祖先是同父异母的祖父母。你最近与第二堂兄弟的共同祖先是同父异母的祖先是同父异母的祖父母。一般而言,你与自己一代的亲戚的关系越遥远,过去你与同父异母的祖先的关系就越远。对相关物种来说也是如此。两个相关物种之间的关系越遥远,他们与同父异母的祖先的关系就越远。

Summary
::摘要

播放段落
• Phylogeny is the evolutionary history of a group of genetically related organisms. It is usually represented by a diagram called a phylogenetic tree.
  ::Phylgeny是一组与基因有关的生物体的进化历史,通常用一个称为植物基因树的图表来表示。

Review
::回顾

播放段落
1. What is a phylogeny?
   ::什么是血压?
播放段落
2. Describe Darwin's Tree of Life.
   ::描述达尔文的生命树