カロフィット藻から生じた陸上の植物の化石記録
Paul K Strother1, Clinton Foster2
1Weston Observatory, Department of Earth and Environmental Sciences, Boston College, Weston, MA 02493, USA. strother@bc.edu.
Science (New York, N.Y.)
|August 13, 2021
まとめ
初期のオルドビシウム (480万年) の植物胞子化石は,藻類の祖先と胚菌の間の進化のギャップを埋めています. この発見は陸上の植物の進化の歴史が これまで記録されたものより長く 連続していることを示しています
科学分野:
- 古植物学
- 進化生物学
- 分子遺伝学
背景:
- 分子時計のデータは,カンブリア時代に約5億年前に胚菌 (陸生植物) の起源を示唆している.
- しかし,陸上の植物の化石記録は,その最初の出現をシルウリア期中 (約430万年前) に示し,重要な時間的な不一致を生み出しています.
- このギャップは主に化石の記録が 欠けていることによるものですが 化石の胞子の役割は過小評価されています
研究 の 目的:
- 胚生物と藻類の祖先の初期進化史を調査する
- 陸上の植物の化石記録と 分子発散の時間間の不一致を 解決するためです
- 化石の胞子を通して 進化の連続性を証明するためです
主な方法:
- トレマドキア (オルドヴィキア初期,約480万年) の化石胞子集合体の記述と分析.
- カンブリア期と若い胚胎期の両方の胞子集合の比較.
- 化石の証拠と分子遺伝学的データの統合
主要な成果:
- カンブリア期と若い胚芽期の両方の特徴的な要素を含む初期のオルドビキア期 (約480万年) の胞子組の発見.
- この組み合わせは 初期の陸上の植物と 藻類の祖先の間の 進化の連続性を示しています
- この発見は,胚性発達ゲノムの獲得が,以前考えられていたより早く,おそらくエディアカラン・カンブリア期に始まったことを示唆している.
結論:
- 初期のオルドビケ紀の胞子記録は,胚生物の初期の進化の重要な証拠を提供します.
- 分子遺伝信号は,発達ゲノム獲得の潜在的進化史を反映している可能性があります.
- 胚性発達ゲノムの完全な獲得は徐々に起こり,シルウリア期半ばに頂点に達した可能性がある.
関連する概念動画
01:21Green Algae
303
Green algae, also referred to as chlorophytes, are different from red algae in having the chloroplasts containing chlorophylls a and b, which give them their distinct green hue. However, they lack phycobiliproteins, preventing them from developing the red or blue-green pigmentation seen in red algae. In terms of photosynthetic pigment composition, green algae closely resemble plants and share a close evolutionary relationship with them. Taxonomically Green algae belong to Phylum Chlorophyta in...
303
02:56The Fossil Record
26.3K
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...
26.3K
02:35What is Evolutionary History?
40.9K
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.
40.9K
02:22The Colonization of Land
36.0K
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...
36.0K
01:19Other Algae
144
The group Stramenopiles include some phototrophic microorganisms. Members of this group possess flagella covered in numerous short, hairlike extensions, a feature that inspired the group's name, derived from the Latin words for "straw" and "hair." Some of the main categories of Stramenopiles include diatoms, golden algae, and brown algae.Diatoms are unicellular, photosynthetic eukaryotes, with over 200 known genera. They play a key role in the planktonic communities of both marine and...
144
01:28Overview of Algae
418
The kingdom Archaeplastida encompasses red and green algae, along with land plants. Unlike other protists with chloroplasts that arose through secondary endosymbiosis, only red and green algae originated from primary endosymbiotic events. This diverse group of eukaryotic organisms contains chlorophyll and performs oxygenic photosynthesis.Algae exist in various forms, from large brown kelp in coastal waters to green scum in puddles and stains on rocks or soil. Some species are responsible for...
418