普通の哺乳類は,ネオゲンにおけるヒプソドンティの進化的増加を促した
Jukka Jernvall1, Mikael Fortelius
1Developmental Biology Programme, Institute of Biotechnology, PO Box 56, FIN-00014, University of Helsinki, Helsinki, Finland. jvakudaret@aol.com
Nature
|May 31, 2002
まとめ
草食性哺乳類は,乾燥した環境で放牧するために,高い冠の歯 (hypsodonty) を進化させた. ヨーロッパでよく見られる哺乳類は,ネオゲン時代にヒプソドンティが増加し,生息地の変化に適応したことを示した.
科学分野:
- パレオントロジー・パレオントロジー
- パレオエコロジー (古生態学)
- 哺乳類の進化について
背景:
- 草食哺乳類は,過去2千万年の間に高冠の頬歯 (ヒプソドント) を進化させた.
- ハイプソドンティは,オープンで乾燥した環境で一般的な繊維状の,研磨性食品を処理するための適応です.
研究 の 目的:
- 欧州のネオゲン哺乳類におけるヒプソドンティの傾向を調査する.
- 地域分布が広い哺乳類 (地域覆蓋が大きい) が,希少種と同様にヒプソドンティの増加を示しているかどうかを判断する.
主な方法:
- 209の化石の場所を含むデータセットの分析.
- 哺乳類におけるヒプソドンティの測定は,地域における発生頻度に基づいています.
- 異なる時代における分類学および形態学的な分類の検討.
主要な成果:
- 哺乳類のヒプソドンティはミオセンの初期に低かった.
- ハイプソドンティの有意な増加は,ミオセンの中期以降,特に一般的に見られる哺乳類の種で観察されました.
- この傾向は,ミオセンの後半のヨーロッパ環境の乾燥に適応したことを示唆している.
結論:
- ヒプソドントイが増加した一般的に存在する哺乳類の種は,おそらく生態学的ニッチを拡大した.
- 複数の地域で見られる種は,希少な種とは独立して,古生態学的な変化の貴重な指標である.
関連する概念動画
02:39Predator-Prey Interactions
17.2K
Predators consume prey for energy. Predators that acquire prey and prey that avoid predation both increase their chances of survival and reproduction (i.e., fitness). Routine predator-prey interactions elicit mutual adaptations that improve predator offenses, such as claws, teeth, and speed, as well as prey defenses, including crypsis, aposematism, and mimicry. Thus, predator-prey interactions resemble an evolutionary arms race.
17.2K
02:35What is Evolutionary History?
31.1K
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.
31.1K
01:54Convergent Evolution
27.6K
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.
27.6K
02:31Synteny and Evolution
2.9K
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...
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral...
2.9K
01:15Teeth
2.2K
The formation of teeth, also known as odontogenesis, is a complex process that begins in utero, around the sixth week of embryonic development. There are three stages to this process: the bud stage, the cap stage, and the bell stage.
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin...
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin...
2.2K
01:24Evolution of New Traits in Microbes
199
Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and...
199