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2.0.5 How Life Diversified: Biology - OverviewVersion 1.2 March 2012 (Previous Version) ( Paragraph 1 Trans Error: Unknown )Science understands how today’s complex life developed from early single cells. ( Paragraph 2 Trans Error: Unknown )Some people are so impressed with the complexity of life that they can't understand how it could happen with random mutations. But the selection process is NOT random. ( Paragraph 3 Trans Error: Unknown )Some organs, such as eyes, and other biological systems, are so complex that it once was difficult to see how these could have developed accidentally. Some people call it irreducible complexity. But it's not irreducible: it can be reduced to a sequence of stages. ( Paragraph 4 Trans Error: Unknown )The detailed pages I Chapter 2.5 go through the stages of the diversification of life. ( Paragraph 5 Trans Error: Unknown )We can see in daily life random differences between offspring, in our children and animals. We can see changes in bacteria in a few hours. But offspring still inherit most of their parents’ traits. Some traits are more useful in different environments, enabling the offspring to survive better, so they have more offspring of their own, passing on their own traits. Over many generations the descendents can end up quite different from their ancestors. The process of weeding out the less fit progeny is not random: it creates more complex designs more suited to the environment. ( Paragraph 6 Trans Error: Unknown )Asexual reproduction occurs in single cells when one cell splits into two, in some plants or simple animals by budding, and some fungi produce asexual spores genetically the same as the parent. ( Paragraph 7 Trans Error: Unknown )Sexual reproduction began with simple cells fusing and mixing their DNA molecules. Many (single celled) eukaryotes reproduce sexually, as do multicellular plants, animals, and fungi. Sexual reproduction is more complex but continued because it leads to more successful variation in the offspring, and reduces mistakes in the reproductive process. Species with the strongest drives to reproduce became more common, and many of us now naturally feel strong sexual desires. ( Paragraph 8 Trans Error: Unknown )The earliest single cells split into plant cells that grow through photosynthesis and animal cells, which survive by feeding on other animal or plant cells. Some single cells developed ‘sticky’ surfaces and evolved into multicellular organisms. Some cells switched on different genes, and grew into internal organs, muscles, cartilage and bone, and light sensitive parts evolved into eyes. Nervous systems began as simple networks in which appropriate reactions to pain and pleasure improved survival rates. Animal species especially built up more complex growth patterns, evolving into worms, insects, fish, amphibians, lizards, dinosaurs, birds and mammals. ( Paragraph 9 Trans Error: Unknown )Though species compete for food and for mates, many survived better when they also cooperated in group safety, locating food, water and shelter, and raising young. We see this in social insects (bees and ants), many birds (some mate for life), and mammals (hunting packs and herd animals). ( Paragraph 10 Trans Error: Unknown )
Life diversified, from single cells to multicellular plants and animals; animals evolved into predators and prey; some acquired nervous systems, giving rise to pleasure and suffering; some evolved into males and females, acquiring sexual drives, and some evolved cooperation to support individual survival instincts. ( Paragraph 13 Trans Error: Unknown )more Statement 11 ( Paragraph 14 Trans Error: Unknown )Science provides natural explanations for suffering, the so called problem of evil, as well as sexual drives and our instinctive need for cooperation and connection, and pleasure seeking behaviour. ( Paragraph 15 Trans Error: Unknown )
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Reconocemos a los propietarios y custodios tradicionales del territorio, en todas las tierras colonizadas, y sus vínculos con la tierra, las aguas y la comunidad. Rendimos homenaje a estos pueblos dando voz a la verdad, los valores y la justicia social, reconociendo nuestra historia compartida y valorando las culturas de los pueblos originarios.
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