相关实验视频
Updated: Mar 26, 2026

07:04
Genotyping of Sea Anemone during Early Development
Published on: May 13, 2019
6.2K
克塞纳科洛莫尔法是尼弗罗动物的姊妹群
Johanna Taylor Cannon1, Bruno Cossermelli Vellutini2, Julian Smith3
1Naturhistoriska Riksmuseet, PO Box 50007, SE-104 05 Stockholm, Sweden.
Nature
|February 5, 2016
概括
澄清了Xenacoelomorpha,缺乏关键双边特征的海洋的遗传位置. 我们的研究揭示了Xenacoelomorpha是所有其他双胞胎 (Nephrozoa) 的姐妹群, 重塑了我们对早期动物进化的理解.
科学领域:
- 动物学
- 进化生物学
- 遗传学
背景情况:
- 在动物族系中,Xenacoelomorpha (Acoela,Nemertodermatida,Xenoturbella) 的位置受到争议.
- 克塞纳科埃洛莫尔法缺乏像门和膜这样的共同双胞胎特征,导致两个假设:所有双胞胎的姐妹或Deuterostomia.
- 解决这个问题对于理解早期的双边进化或二次复杂性损失至关重要.
研究的目的:
- 确定Xenacoelomorpha在动物王国中的确切遗传位置.
- 提供强有力的证据来解决有关Xenacoelomorpha进化关系的相互矛盾的假设.
- 根据其遗传位置重建祖先的双边特征.
主要方法:
- 使用11个新的xenacoelomorph转录组进行了基因组学分析.
- 用各种进化模型应用最大概率和贝叶斯推理方法.
- 对25个数据集进行严格的测试, 以减轻长枝吸引,和和缺失数据等潜在偏差.
主要成果:
- 对于Xenacoelomorpha作为Nephrozoa (所有剩余的双胞胎) 的姐妹分类,发现了强大的基因组支持.
- 分析证实了不同模型之间的这种关系,并且对潜在的重建偏差具有弹性.
- 姐妹组关系始终得到恢复,反驳了其他假设.
结论:
- 克塞纳科埃洛莫尔法代表了尼弗罗动物的姐妹群,阐明了它在生命树上的地位.
- 这一发现暗示最后一个共同的双胞胎祖先是一个简单的,有毛的,虫.
- 关键的双边特征,如分泌器官和神经绳,在Xenacoelomorpha从Nephrozoa血统分离后演变.
相关概念视频
Diversity of Protists III
2.0K
Rhizaria are a diverse group of unicellular protists characterized by their threadlike cytoplasmic extensions known as pseudopodia. These structures aid in both locomotion and feeding, giving Rhizaria an amoeboid appearance. Their amoeboid morphology once led to taxonomic confusion, but molecular phylogenetics has clarified their evolutionary placement and emphasized their shared use of pseudopodia despite divergent lineages.This clade comprises diverse lineages such as Chlorarachniophyta,...
2.0K
Diversity of Protists I
2.2K
Excavata is a diverse group of protists that includes both chemoorganotrophic and phototrophic species, with some thriving in anaerobic environments. Among the key groups within Excavata are diplomonads and parabasalids, which are flagellated protists that lack mitochondria and chloroplasts. These microorganisms typically inhabit anoxic environments, such as the intestines of animals, where they exist either symbiotically or as parasites, relying on fermentation for energy production. Some...
2.2K
Diversity of Protists II
2.2K
Alveolates are a group of organisms recognized by the presence of alveoli, which are cytoplasmic sacs located beneath the cell membrane. While their function remains uncertain, alveoli may help regulate water balance by controlling how much water enters and leaves the cell. In dinoflagellates, these structures may serve as armor plates. There are three major types of alveolates: ciliates, which move using cilia; dinoflagellates, which use flagella for movement; and apicomplexans, which are...
2.2K
Diversity of Protists IV
2.1K
Amoebozoa represent a diverse group of terrestrial and aquatic protists that utilize lobe-shaped pseudopodia for locomotion and feeding. This characteristic differentiates them from the Rhizaria, which possess threadlike pseudopodia. The primary classifications within Amoebozoa include gymnamoebas, entamoebas, and the plasmodial and cellular slime molds. Phylogenetic evidence indicates that Amoebozoa diverged from a lineage that ultimately gave rise to fungi and animals.Gymnamoebas and...
2.1K
Phylogeny
64.5K
Phylogeny is concerned with the evolutionary diversification of organisms or groups of organisms. A group of organisms with a name is called a taxon (singular). Taxa (plural) can span different levels of the evolutionary hierarchy. For instance, the group containing all birds is a taxon (comprising the class Aves), and the group of all species of daisies (the genus Bellis) is a taxon. Phylogenies can likewise include just one genus (i.e., depict species relationships) or span an entire kingdom.
64.5K
Taxonomy
92.8K
Taxonomy is the science of defining and naming groups of biological organisms based on shared characteristics. It uses a hierarchy of increasingly inclusive categories with Latin names. The smallest units of taxonomy, species and genus, are used to assign a formal, taxonomic name to each species in a system. This classification system, referred to as binomial nomenclature, was formalized by Carolus Linnaeus in the 18th century.
Hierarchy of Taxonomy
The hierarchy that Carolus Linnaeus first...
Hierarchy of Taxonomy
The hierarchy that Carolus Linnaeus first...
92.8K

