2つの白期の哺乳類の化石と進化

Fangyuan Mao^1,2,3, Chi Zhang^4,5, Cunyu Liu⁶

¹Key Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences (CAS), Beijing, China. maofangyuan@ivpp.ac.cn.

Nature

|April 8, 2021

まとめ

新しく発見された白亜紀の化石は哺乳類の融合進化を明らかにしている. 骨格に発達的な可塑性の初期の兆候があります骨格に発達的な可塑性の初期の兆候があります

科学分野:

古生物学
脊椎動物の進化
発達生物学

背景:

マンマリアモルファにはトリチロドンチダとママリアの祖先と子孫が含まれています.
トリチロドント類はトライアス後期から白亜紀初期まで草食動物であった.
エウトリコノドンタは絶滅した哺乳類の一種と考えられ,分類は様々である.

研究の目的:

新種のトリチロドンチドとエウトリコドンチドの発見を報告する
遠い親戚の種で化石 (掘り起こし) の適応を調査する.
幹哺乳類における軸骨格の進化的変化とその発達的基盤を分析する.

主な方法:

ジェーホル・バイオタ内の化石の発見と分析
比較形質は,収束する特徴と骨格の適応を特定する.
脊椎の数と特徴を分析して発達パターンを推測する.

主要な成果:

ジェーホル生物系における最初のトリチロドンチドの発見
両種とも"スクラッチ・ディガー"として知られる化石生活への適応が収束している.
進化的シフトを示すメリスティックとホメオティックの変化を持つプレサクラ脊椎の増加が観察されました.

結論:

これらの化石は,哺乳類の軸性骨格の進化に関する洞察を提供します.
発見は,ソミトゲネシスとHOX遺伝子の発現における発達的な可塑性が幹哺乳類に存在することを示唆しています.
発達メカニズムと自然淘汰の相互作用は,哺乳類の多様体プランの進化を促した.

さらに関連する動画

07:26

Systematic Assessment of Mammalian Skull Specimens for Dental and Temporomandibular Joint Pathology

Published on: August 22, 2022

1.7K

09:38

Assessing Species-specific Contributions To Craniofacial Development Using Quail-duck Chimeras

Published on: May 31, 2014

11.2K

関連する概念動画

02:56

The Fossil Record

26.4K

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...

26.4K

02:35

What is Evolutionary History?

41.2K

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.

41.2K

01:54

Convergent Evolution

30.2K

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.

30.2K

01:23

Phylogeny

55.7K

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.

55.7K

01:22

Sutures of the Skull

9.0K

The human skull is composed of several bones that come together to protect the brain and support the structures of the face. The junctions where these bones meet are called sutures.
Sutures are immobile joints between adjacent bones of the skull. The narrow gap between the bones is filled with dense, fibrous connective tissue that unites the bones. The long sutures located between the skull bones are not straight but instead follow irregular, tightly twisting paths. These twisting lines tightly...

9.0K

02:22

The Colonization of Land

36.1K

Changes in the environment of the early Earth drove the evolution of organisms. As prokaryotic organisms in the oceans began to photosynthesize, they produced oxygen. Eventually, oxygen saturated the oceans and entered the air, resulting in an increase in atmospheric oxygen concentration, known as the oxygen revolution approximately 2.3 billion years ago. Therefore, organisms that could use oxygen for cellular respiration had an advantage. More than 1.5 years ago, eukaryotic cells and...