已知最古老的灵长类骨和早期的哈普洛林进化
Xijun Ni1, Daniel L Gebo, Marian Dagosto
1Key Laboratory of Vertebrate Evolution and Human Origin, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xi Zhi Men Wai Street, Beijing 100044, China. nixijun@ivpp.ac.cn
Nature
|June 7, 2013
概括
一个几乎完整的化石灵长类骨架来自中国早期的伊欧纪,可以追溯到5500万年前,揭示了已知的最基本的鱼. 这一发现澄清了早期灵长类动物的进化和分歧时间.
科学领域:
- 古生物学的古生物学
- 灵长类动物的进化
- 脊椎动物古生物学 脊椎动物古生物学
背景情况:
- 由于化石记录不完整,重建早期灵长类进化是具有挑战性的.
- 关于早期灵长类动物的古生物学和遗传学关系的分歧仍然存在.
研究的目的:
- 报告发现了重要的早期灵长类动物化石.
- 为了分析化石的形态学和遗传学位置.
主要方法:
- 发现和挖掘一个几乎完整的,关节的化石灵长类动物骨架.
- 详细的形态检查使用传播相位对比X射线同步子微图.
- 基于可获得的全部证据的遗传学分析.
主要成果:
- 发现了最古老,最完整的化石灵长类动物骨,来自中国的早期欧纪 (5500万年前).
- 遗传学分析确定化石是已知的最基本的类灵长类灵长类动物,具体来说是一只干.
- 这种化石提供了早期链状 - 链状分裂的证据,并完善了类动物和人类类动物的分歧估计.
结论:
- 这种化石支持了链类灵长类和类灵长类灵长类之间的早期二分法.
- 它限制了鱼类和人类类动物之间的分歧时间.
- 它强化了早期灵长类动物可能是白天活动的,树种的和食虫的假设,大小类似于现代矮鼠鼠.
相关概念视频
01:12Carbon Skeletons
114.5K
Life on Earth is carbon-based, as all macromolecules that make up living organisms contain carbon atoms. All organic compounds have a carbon backbone. Each carbon atom is tetravalent and can bond with four other atoms, making it an extraordinarily flexible component of biological molecules. Because carbon’s valence electrons are stable, it rarely becomes an ion. As the carbon chain increases in length, structural modifications such as ring structures, double bonds, and branching side...
114.5K
02:55The Evidence for Evolution
47.7K
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.
47.7K
01:54Convergent Evolution
31.6K
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.
31.6K
01:21Skeleton and Calcium Homeostasis
5.8K
Calcium is not only the most abundant mineral in bone but also the most abundant mineral in the human body. Calcium ions are needed for bone mineralization, tooth health, heart rate regulation and strength of contraction, blood coagulation, the contraction of smooth and skeletal muscle cells, and the regulation of nerve impulse conduction. The average calcium level in the blood is about 10 mg/dL. When the body cannot maintain this level, a person will experience hypo or hypercalcemia.
5.8K
01:09Overview of the Axial Skeleton
9.1K
The skeleton is subdivided into two major divisions—the axial skeleton and the appendicular skeleton. The axial skeleton forms the vertical, central axis of the body. It includes all of the bones of the head, neck, chest, and back. It protects the brain, spinal cord, heart, and lungs. It also serves as the attachment site for muscles that move the head, neck, and back and for muscles that act across the shoulder and hip joints to move their corresponding limbs.
The axial skeleton of the...
The axial skeleton of the...
9.1K
01:09Changes in the Appendicular Skeleton with Age
3.4K
The upper and lower limb initially develops as a small bulge called a limb bud, which appears on the lateral side of the early embryo. The upper limb bud appears near the end of the fourth week of development, with the lower limb bud appearing shortly after.
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
3.4K