Biology- Chapter 16 Evolution

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What are homologous structures?

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Homologous structures are anatomical features in different species that share a common ancestry, indicating evolutionary relationships. For example, the forelimbs of humans, whales, and bats have similar bone structures despite serving different functions.

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What are fossils?

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Fossils are the preserved remains or traces of ancient organisms, often found in sedimentary rock. They provide evidence of past life and can show how species have changed over time.

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Who proposed the idea of inheritance of acquired characteristics?

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Jean-Baptiste Lamarck proposed that organisms could pass on traits acquired during their lifetime to their offspring, a concept known as the inheritance of acquired characteristics.

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What is a vestigial structure?

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A vestigial structure is a body part that has lost its original function through evolution. An example is the human appendix, which is a remnant of a larger cecum used for digesting cellulose in herbivorous ancestors.

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What is natural selection?

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Natural selection is the process by which organisms better adapted to their environment tend to survive and produce more offspring. It is a key mechanism of evolution.

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What is the struggle for existence?

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The struggle for existence refers to the competition among organisms for limited resources such as food, space, and mates, which is essential for natural selection to occur.

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What is embryology in the context of evolution?

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Embryology is the study of embryos and their development. Similarities in embryonic development among different species can provide evidence for common ancestry.

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What is the significance of the fossil record?

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The fossil record provides a historical account of life on Earth, showing the progression of species over time and evidence of evolutionary changes.

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What are variations in a population?

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Variations are differences among individuals in a population, which can be due to genetic differences. These variations are crucial for natural selection.

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What is extinction?

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Extinction is the end of an organism or a group of organisms, often due to environmental changes, loss of habitat, or competition.