関連する実験動画
Updated: May 20, 2026

26:43
Computer-Generated Animal Model Stimuli
Published on: July 29, 2007
北米の白亜紀後期からの移行期ヘビ
Nicholas R Longrich1, Bhart-Anjan S Bhullar, Jacques A Gauthier
1Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520-8109, USA. nicholas.longrich@yale.edu
Nature
|July 27, 2012
まとめ
化石の発見は,最も原始的なヘビであるコニオフィス・プレセデンス (Coniophis precedens) を明らかにし,ヘビは陸上の環境で穴を掘るトカゲから進化したと示唆しています. この移行期のヘビは,トカゲのような頭とヘビのような体を持ち,頭蓋骨の進化における重要な革新であった.
科学分野:
- パレオントロジー・パレオントロジー
- 進化生物学の進化生物学について
- ヘルペトロジー ヘルペトロジー
背景:
- 蛇の起源と初期の進化は,移行期化石が不足しているため,ほとんど理解されていません.
- 重要な質問には,海洋と陸上の起源,そして彼らの栄養メカニズムの進化が含まれています.
関連する概念動画
The Fossil Record
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...
Phylogeny
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.
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.
Migration
Migration is long-range, seasonal movement from one region or habitat to another. This common strategy, carried out by many different organisms around the world, is an adaptive response that typically corresponds to changes in an organism’s environment, like resource availability or climate. Migrations can involve huge groups of thousands of animals as well as single individuals traveling alone and can range from thousands of kilometers to just a few hundred meters.
Comparative Excretory Systems
Animals have evolved different strategies for excretion, the removal of waste from the body. Most waste must be dissolved in water to be excreted, so an animal’s excretory strategy directly affects its water balance.
Types of Selection
Natural selection influences the frequencies of particular alleles and phenotypes within populations in several different ways. Primarily, natural selection can be directional, stabilizing, or disruptive. Directional selection favors one extreme trait and shifts the population towards that phenotype while selecting against individuals displaying alternate traits. Stabilizing selection favors an intermediate trait with a narrow range of variation. Deviation from the optimal phenotype towards an...

