东非最古老的丰富C4草和息地异质性的证据
Contact us if these videos are not relevant.
Contact us if these videos are not relevant.
在PubMed上查看摘要
概括
此摘要是机器生成的。在非洲发现了C4草原的早期证据,可以追溯到2100万年前. 这一发现改变了我们对非洲古老生态系统和哺乳动物进化的理解.
科学领域
- 古生态学
- 古植物学
- 哺乳动物进化
背景情况
- 非洲的C4草原生态系统对于理解哺乳动物进化至关重要,
- 非洲C4草的生态主导地位以前被认为发生在1000万年前 (Ma).
- 10万年前的古植物记录有限,这阻碍了对C4生物质扩张的时间和性质的理解.
研究的目的
- 记录非洲东部早期世哺乳动物遗址的植被结构.
- 评估C4生物质扩张的时间和性质.
- 根据新的古植物学数据,对哺乳动物进化的古生态解释进行修订.
主要方法
- 植物结构的多代理分析.
- 来自东非9个早期世哺乳动物遗址的采样.
- 古植物年代测定和C4草丰度分析.
主要成果
- 在大约21到16万年前,C4草在当地大量存在.
- 息地范围从森林到茂密的草原,表明异质性.
- 这将最古老的C4草生态证据在非洲和全球推迟超过1000万年.
结论
- 这些发现挑战了C4草在非洲占据主导地位的时间表.
- 早期的米奥森非洲生态系统比以前理解的更加复杂和受C4草的影响.
- 对于早期的哺乳动物和人类进化,需要修订古生态解释.
相关概念视频
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
Past Periods of Warming and Cooling
In...
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...
Most plants use the C3 pathway for carbon fixation. However, some plants, such as sugar cane, corn, and cacti that grow in hot conditions, use alternative pathways to fix carbon and conserve energy loss due to photorespiration. Photorespiration is the process that occurs when the oxygen concentration is high. Under such conditions, the rubisco enzyme in the Calvin cycle binds O2 instead of CO2, which halts photosynthesis and consumes energy.
C4 Pathway
The C4 pathway is used by plants such as...
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....
From Water to Land
Kingdom Plantae first appeared about 410 million years ago as green algae transitioned from water to land. This land was a relatively uncolonized environment with ample resources. Terrestrial environments also offered more light and carbon dioxide, required by plants to grow and survive.
However, the stark differences between land and sea posed a formidable challenge to early colonizing species prompting many new adaptations that have resulted in the wide variety of plant...
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...