分野 | 自然科学
進化発生学入門-恐竜が鳥に進化した仕組み-
「鳥は恐竜から進化した」、、、あのダーウィンも主張した「鳥は恐竜から進化した」という学説は、150年以上も議論され続け、羽毛を持つ恐竜の発見によって、確実視されるようになっています。とは言っても、そもそも、恐竜が鳥に進化するというのは、具体的にどう考えればよいでしょうか。ポケモンやゴジラのように、成長していく過程で、姿が徐々に別の動物に変化していく、そういうわけではありません。 鳥は、卵の殻の中で、1個だった受精卵という細胞からはじまって、生まれてきます。恐竜も同じように、1個の受精卵から生まれてきていたはずです。なので、恐竜が鳥に進化するというのは、恐竜を作っていた発生過程が変化した、鳥を作る発生過程を持つ動物が生まれたことになります。本当にそんなことは起こり得るのか?本講座では、動物の進化のしくみを、動物の発生過程に求める「進化発生学」の観点から、恐竜が鳥に進化したしくみを考えるための基礎を、学んでいきます。
Content/学習内容
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We will learn the basics of embryology. That all animals are made of cells, that development occurs, and that cells differentiate will be explained.
- 1-0. Introduction
- 1-1. The Relationship between Dinosaurs and Birds
- 1-2. Living Things are Made up of Cells
- 1-3. Birth = Development: All Animals Generate from a Single Cell
- 1-4. The Basic Vertebrate Body Plan = Chikuwa
- 1-5. From Mammalian Egg to Baby
- 1-6. From Chicken Egg to Chick
- 1-7. From Single Cell to Sheet of Cells, to Chikuwa
- 1-8. Cell Lineage and Cell Differentiation
- 1-9. Cell Differentiation and Induction
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We will study the importance of proteins and genes in development and how genetic inheritance connects animals. We will also learn about terms such as genome, DNA, and gene expression.
- 2-0. Introduction
- 2-1. The Mechanism of Muscle Movement
- 2-2. The Importance of Cell Differentiation and Cell-specific Proteins
- 2-3. The Identity of Genetic Information (1): Protein Functions and Genes
- 2-4. The Identity of Genetic Information (2): the Relationship Between the Genome, DNA, and Genes
- 2-5. The Identity of Genetic Information (3): Transcriptional Regulation that Produces Specific Gene Expression
- 2-6. Examples of Differentiated Cell-specific Gene Expression
- 2-7. Reproduction: the Mechanism for Creating the Next Generation
- 2-8. Genetic Inheritance: the Mechanism for Passing Morphogenesis Information on to the Next Generation
- 2-9. From a Parent-child Relationship to a Family Tree, Then to a Phylogenetic Tree
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We will talk about the developmental process of hands and feet, particularly how fingers, or digits, develop. Furthermore, we will explain principles producing differences in animal morphology by changing the mechanisms of development.
- 3-0. Introduction
- 3-1. The Developmental Process and Morphogenesis
- 3-2. Limb Development (1): The Elongation of Limb Buds and Bone Formation
- 3-3. Limb Development (2): The ZPA
- 3-4. Limb Development (3): The shh Gene and the Concentration Gradient Theory
- 3-5. The Regulation of shh Gene Expression
- 3-6. Developmental Mechanism Shifts (1): Heterochrony
- 3-7. Developmental Mechanism Shifts (2): Heterotopy
- 3-8. Molecular Mechanisms Enabling Shifts (1): Meiosis and Recombination
- 3-9. Molecular Mechanisms Enabling Shifts (2): Mutation and Genetic Inheritance
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We will finally discuss the dinosaur-bird relationship and evolution. The avian enhancer sequence, which makes a bird a bird, was introduced into the genome during the dinosaur-to-bird evolutionary process. We will pull together what we have learned to understand what avian enhancers are.
- 4-0. Introduction
- 4-1.Structures and Morphology Specific Only to Birds
- 4-2.Limb Development and Feather Development
- 4-3.Genome Sequences Specific Only to Birds
- 4-4.Genome Sequences Specific Only to Birds: Are They Avian Enhancers?
- 4-5. How Widespread is the Use of Avian Enhancers Among Animals?
- 4-6. Are Dinosaurs Ancestors of Birds?
- 4-7. Understanding Developmental Mechanisms by Resolving Discrepancies in How the Digits are Numbered
- 4-8. The Possibility That Dinosaurs Also Used Avian Enhancers
- 4-9. Summary: The Evolution of Animal Morphology is an Accumulation of Changes in Developmental Mechanisms
Staff/スタッフ
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- 講師
田村 宏治東北大学 大学院生命科学研究科教授
Contact/お問合せ先
東北大学オープンオンライン教育開発推進センター
Email: secretary.mooc@grp.tohoku.ac.jp