哺乳动物的进化. 基底哺乳动物形式的进化发展,由一个docodontan揭示
Zhe-Xi Luo1, Qing-Jin Meng2, Qiang Ji3
1Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA. zxluo@uchicago.edu mengqingjin@bmnh.org.cn.
Science (New York, N.Y.)
|February 14, 2015
概括
一种新发现的罗纪晚期多科多坦哺乳动物表现出挖掘的适应性,反映了现代黄金. 这些古老的哺乳动物拥有专门的数字部分和肋骨结构,这表明了今天哺乳动物中发现的发育途径的早期演变.
科学领域:
- 古生物学的古生物学
- 发展生物学 发展生物学
- 进化生物学 进化生物学
背景情况:
- 多科多顿人代表了早期分离的哺乳动物血统.
- 地下生活方式在各种哺乳动物群体中独立演变.
- 了解早期哺乳动物进化需要检查它们独特的形态和发育过程.
研究的目的:
- 为了描述一个新的罗纪晚期的docodontan,适应了地下生活方式.
- 为了比较这个docodontan的骨专业化与现存的地下哺乳动物.
- 研究保存发育机制在早期哺乳动物形式多样化中的潜在作用.
主要方法:
- 化石挖掘和对一个新的docodontan标本的形态分析.
- 与现存哺乳动物的数字段和脊柱的比较解剖学.
- 对控制哺乳动物四肢和轴骨发育的遗传和发育途径的审查.
主要成果:
- 新的docodontan显示了减少的数字段,类似于现存的金色子.
- 观察到胸脊肋骨的位置转移,这是现代哺乳动物中发现的特征.
- 这些特征表明早期哺乳动物中发育机制的运作,如链融合和霍克斯基因调节.
结论:
- 早期的哺乳动物形式,包括docodontans,拥有与现代哺乳动物相似的发育机制.
- 这些保存的发育途径可能有助于早期哺乳动物进化过程中观察到的形态多样性.
- 该研究提供了关于哺乳动物骨发育和适应的深层进化根的见解.
相关概念视频
02:35What is Evolutionary History?
45.2K
Scientists record evolutionary history by analyzing fossil, morphological, and genetic data. The fossil record documents the history of life on Earth and provides evidence for evolution. However, both fossil and living organisms offer evidence that outlines Earth’s evolutionary history.
45.2K
01:54Convergent Evolution
34.8K
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.
34.8K
01:23Phylogeny
64.8K
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.
64.8K
02:56The Fossil Record
28.6K
The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms never become fossils. Moreover, the fossil record only exhibits fossils that have been discovered. Nevertheless, sedimentary rock fossils of long-lived, abundant, hard-bodied organisms dominate the fossil record. These fossils offer valuable information, such as an organism's physical form, behavior, and age. Studying the fossil record helps...
28.6K
02:55The Evidence for Evolution
50.9K
Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.
50.9K
01:24Eukaryotic Evolution
43.9K
The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the nucleus-first hypothesis, the ancestral prokaryote first evolved a membrane to enclose DNA and form the nucleus. Conversely, the mitochondria-first hypothesis suggests that the nucleus was formed after endosymbiosis of mitochondria.
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
43.9K