14.2 动物分类 -- -- 先进
Section outline
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Insect? Yes. But what type?
::昆虫,是的,但哪种类型的?This insect would be classified as a beetle. The order Coleoptera, otherwise known as the beetles, means “sheath wings ,” a reference to the hardened forewings which cover the insect’s body.
::这一昆虫将被归类为甲虫。 科洛佩拉(又称甲虫 ) , “ 甲虫 ” ( Coleoptera ) 的顺序是指“羊翅 ” , 指覆盖昆虫身体的硬化前缝。Classification of Animals
::动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类 动物分类Despite the general characteristics that have in common, they are an enormously diverse group of organisms . Animals exhibit great variation in structure and function. They include simple animals, such as , as well as highly complex animals, such as humans. The members of the animal are subdivided into more than 30 different groups called phyla. There are 7 major hierarchies, or ranks, in animal classification. Kingdom is the highest and most inclusive rank. Phylum is the rank below kingdom, and is the most fundamental rank. The hierarchy of the ranks is shown in Figure .
::动物在结构和功能上存在巨大差异,包括简单的动物,例如......,以及高度复杂的动物,例如人类。动物成员被细分为30多个不同的群体,称为植物类。在动物分类中,有7个主要的等级或等级。王国是最高和最包容的等级。Phylum是王国以下的等级,也是最基本的等级。等级的等级如下图所示。Major hierarchical rankings in animal classification. For more information, see the Classification concepts. The subdivision of the animal kingdom into different phyla is based on the evolutionary relationships within and between the species of each phylum. The organisms within a phylum are considered to be more closely related to each other than they are to organisms of other phyla. As was discussed in the Animals: Characteristics (Advanced) concept, the relatedness of two organisms has to do with how recently they diverged from a common ancestor . In the following sections we will look at two ways in which scientists determine how closely related two animal species are to each other, and then we will examine the major phyla that make up the animal kingdom. More on is discussed in the Concept Invertebrates (Advanced) chapter and the Concept Vertebrates (Advanced) chapter.
::动物王国分为不同的植物群,其基础是每个植物群物种内部和之间的进化关系。植物群中的有机体被认为比其他植物群中的有机体更密切地相互联系。正如动物群中所讨论的:特征(高级)概念,两个生物体的关联性与它们最近与共同祖先不同的程度有关。在以下各节中,我们将研究两种方法,即科学家如何确定两个动物种彼此之间的密切关系,然后我们将研究形成动物群的主要植物群。在“纵向概念(高级)”一章和“Vertebrates概念(高级)”一章中讨论的更多。Traditional versus Molecular Phylogeny
::传统对分子磷基Traditional phylogeny divides animals into hierarchical categories based on structural similarities. This assumes that these similarities reflect a shared evolutionary history. In other words, it is assumed that all animals having a particular trait, such as a segmented body plan, evolved that trait from the same recent common ancestor. The problem with this method is a process called convergent evolution . Convergent evolution is when organisms that are not closely related to each other independently develop the same trait over time. This can happen when two unrelated organisms have to adapt to similar environmental pressures. Molecular phylogeny can often resolve these classification problems. In molecular phylogeny, the evolutionary relatedness of two organisms is determined by comparing the molecules that make up their genetic material . It is changes in the of an organism that lead to the changes we observe in their outward appearance. However, not all changes in the genetic code lead to observable changes in the appearance of an organism. Therefore, molecular phylogenetics can detect relationships that are not reflected in shared, observable traits.
::传统植物基因根据结构相似性将动物分为等级类别。 这假定这些相似性反映了共同的进化历史。 换句话说, 假设所有具有特定特性的动物, 如分解体计划, 都会从最近相同的共同祖先进化。 这个方法的问题是所谓的趋同进化过程。 趋同的进化过程是当与彼此没有密切联系的有机体在一段时间内独立地发展同一特性的时候。 当两个互不相关的生物体必须适应类似的环境压力时, 就可能发生这种进化。 分子植物基因往往可以解决这些分类问题。 在分子的进化过程中, 两种生物的进化关联性是通过比较构成其遗传材料的分子来决定的。 生物体的变化导致我们观察到的外表变化。 然而, 基因编码的所有变化并不导致生物体外观的可见变化。 因此, 分子植物遗传学可以检测出没有反映在共同的、 可观测特性中的关系。Animal Phyla
::动物植物There is some controversy in the field of phylogenetics based on the conflicts between traditional and molecular phylogeny. This controversy can lead to different estimates of the number of animal phyla. Depending on the classification scheme, there are roughly 34 animal phyla. There are nine phyla that are considered the major phyla, and these are listed in the Major Phyla of the Animal Kingdom Table. This Table also includes a description of the major evolutionary changes that arose with these phyla and some of the members of each phylum. Each of these phyla contain at least 10,000 different species, with the phylum arthropoda containing over one million species.
::基于传统和分子的植物间冲突,在植物间存在一些争议。这种争议可能导致对动物性植物数目的不同估计。根据分类方法,大约有34种动物性植物。有9种植物被认为是主要的植物,这些植物列在动物王国的主要植物表。本表还列出了这些植物和每种植物的一些成员引起的重大进化变化。这些植物中,每种动物性植物都含有至少10,000种不同的物种,而植物节肢含有100多万种。Major Phyla of the Animal Kingdom Phylum Evolutionary Developments Porifera Multicellularity Cnidaria True tissue , radial symmetry Platyhelminthes Mesoderm , bilateral symmetry Nematoda Complete digestive system , pseudocoelom Arthropoda Segmented body Annelida Closed , segmented body Mollusca Highly developed brain in cephalopoda class Echinodermata Deuterostomes Chordata Notochord Summary
::摘要-
There are 7 major hierarchies, or ranks, in animal classification. Kingdom is the highest and most inclusive rank, and species is the most fundamental rank.
::在动物分类中,有7个主要的等级或等级。 王国是最高和最包容的等级,物种是最基本的等级。 -
The subdivision of the animal kingdom into different phyla is based on the evolutionary relationships within and between the species of each phylum.
::动物王国分为不同的植物群 以每种植物物种内部 和物种之间的进化关系为基础 -
Controversy between tradition and molecular phylogeny has lead to different estimates of the number of animal phyla.
::传统与分子血原体之间的争议导致对动物植物数量的不同估计。
Review
::回顾-
How many hierarchies are there for animal classification? What are they?
::动物分类有多少等级? -
How were animals originally classified? What are some problems with the older form of classification?
::动物最初是如何分类的?旧分类形式有什么问题? -
Why is there controversy over the number of phyla in the animal kingdom? Roughly how many are there?
::为什么动物王国的植物数量有争议?
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There are 7 major hierarchies, or ranks, in animal classification. Kingdom is the highest and most inclusive rank, and species is the most fundamental rank.
