概括
使用分子数据进行的人类起源研究表明,人类,黑猩猩和大猩猩之间存在更密切的关系. 新的血红蛋白序列数据表明进化减速,支持更长的分歧时间.
科学领域:
- 进化生物学 进化生物学
- 分子人类学分子人类学
- 灵长类动物遗传学
背景情况:
- 分子数据重塑了对人类起源的理解,使黑猩猩和大猩猩比猩猩更接近人类.
- 以前的分子时钟估计表明,Homo和Pan之间最近的分歧 (1-150万年前),与化石证据相冲突.
研究的目的:
- 严格确定黑猩猩 (Pan troglodytes),大猩猩 (Gorilla gorilla) 和矮猩猩 (Pan paniscus) 的α和β血球蛋白氨基酸序列.
- 用精确的血红蛋白序列数据重新评估类人猿分歧时间和进化速率.
主要方法:
- 从黑猩猩,矮黑猩猩和大猩猩中对α和β血红蛋白的氨基酸测序.
- 用获得的序列数据来构建进化树的类遗传分析.
- 从新数据中得出的分子钟估计与以前的发现进行比较.
主要成果:
- 精确地确定了对研究的原始人类中的关键血红蛋白蛋白的氨基酸序列.
- 这些发现支持在原始血红蛋白序列中的减速进化速率.
- 新的数据表明,原始人血统之间的分歧时间比以前从一些分子数据中估计的要长.
结论:
- 减速序列进化是分子钟估计与化石记录之间的差异更有可能的解释.
- 自然选择可能在进化过程中在保护高功能血红蛋白分子方面发挥了重要作用.
- 准确的分子序列数据对于完善我们对人类和灵长类动物进化历史的理解至关重要.
相关概念视频
What is Evolutionary History?
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.Phylogenetic trees illustrate the evolutionary relationships among these organisms. Scientists infer organisms’ common ancestry by evaluating shared morphological and genetic characteristics. Together, the fossil...
The Evidence for Evolution
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.The collection of fossils within sedimentary rocks give a record of common ancestry and often depicts the history of evolution.
Convergent Evolution
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.The structures that arise from convergent evolution are called analogous structures. They are similar in function even if they are dissimilar in structure. Further, structures can be analogous while also...
Gene Families
Gene families consist of groups of genes proposed to have originated from a common ancestor. Typically these arise through events in which a gene or genes are mistakenly duplicated during cell division. Unlike their parent genes (which are subject to selection pressure to maintain function), these gene copies do not need to preserve their sequences and may evolve at a relatively faster rate.
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Synteny and Evolution
John H. Renwick first coined the term “synteny” in 1971, which refers to the genes present on the same chromosomes, even if they are not genetically linked. The species with common ancestry tend to show conserved syntenic regions. Therefore, the concept of synteny is nowadays used to describe the evolutionary relationship between species.
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral chromosome underwent...
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral chromosome underwent...
Gene Duplication and Divergence
The seminal work of Ohno in 1970 popularized the idea of gene duplication and divergence. DNA sequence comparison studies reveal that a large portion of the genes in bacteria, archaebacteria, and eukaryotes was generated by gene duplication and divergence, indicating its critical role in evolution.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.


