Exploring the principle of common ancestry, this content delves into how all organisms share a single ancestral life form. It discusses homological evidence, the fossil record, and DNA's role in tracing evolutionary lineages. The concept serves as a unifying theme in evolutionary theory, integrating biology disciplines and illustrating life's diversity and unity.
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Common ancestry posits that all living organisms on Earth share a single ancestral life form from which they have diverged over time
Natural Selection
Charles Darwin proposed that species evolve through natural selection and share common ancestors
Study of Finches on the Galapagos Islands
Darwin's study of finches on the Galapagos Islands exemplified the concept of common ancestry by showing how different species evolved from a common ancestor by adapting to various ecological niches
Homology
Homology, or the similarity in characteristics resulting from shared ancestry, supports the concept of common ancestry through anatomical, molecular, and developmental similarities among different organisms
Fossil Record
The fossil record provides a chronological sequence of life forms, documenting the gradual transitions that corroborate the theory of common descent
DNA Analysis
DNA analysis allows scientists to infer the degree of relatedness among species, providing genetic evidence for the concept of a universal common ancestor
Natural selection is a mechanism by which evolution operates, shaping the diversity of life by favoring traits that increase an organism's chances of survival and reproduction
Genetic drift is a mechanism of evolution that occurs through random changes in the gene pool of a population, leading to changes in allele frequencies over time
Phylogenetic trees graphically represent the evolutionary relationships among species, tracing their descent from common ancestors and illustrating the branching nature of evolutionary history
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Key proponent of common ancestry
Charles Darwin, who theorized species evolve through natural selection from common ancestors.
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Darwin's evidence of evolution
Study of Galapagos finches, showing species adaptation from a common ancestor to different niches.
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Purpose of phylogenetic trees
Illustrate evolutionary relationships, showing shared heritage and divergent adaptations among species.
