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Darwin’s Theory of Evolution

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Presentation on theme: "Darwin’s Theory of Evolution"— Presentation transcript:

1 Darwin’s Theory of Evolution
Evolution, or change over time, is the process by which modern organisms have descended from ancient organisms. A scientific theory is a well-supported testable explanation of phenomena that have occurred in the natural world.

2 Evidence supporting evolution
Fossil Record Variations Comparative anatomy homologous structures analogous structures vestigial structures Embryology Molecular

3 Evidence supporting evolution
Fossil Record Variations Comparative anatomy homologous structures analogous structures vestigial structures Embryology Molecular

4 Homologous Structures-
Same structure but different function

5 Analogous Structures Same  function but different structure

6 Evidence for Evolution
Vestigial organs- organs that serve no useful function in an organism

7 Vestigial organs in Human Body
Coccyx is also known as the tail bone, and it is the remnant of the lost tail. Almost every mammals had tail at one point during their evolution, and during the development of a child in the womb of the mother, the tail is present for a period of 4 weeks during the stage of the embryogenesis.

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9 Though they are vestigial, they still perform a simple function of fighting against the preliminary infection in the throat

10 The vermiform appendix had digestive functions in the ancestral human species which helped in the cellulose breakdown in the intestine The appendix has become vestigial in human beings because they have become very smaller in size and don’t contribute in cellulose fermentation and does not even possess necessary digesting bacteria in it

11 Similarities in Early Development

12 Peter and Rosemary Grant
Scientists Peter and Rosemary Grant have studied many of these species for the past thirty years. Spend months at a time on the islands Often know every finch on an island CCog Movie is 16 minutes

13 Evolution is: A change in the frequency of an allele, such as an allele for beak depth, is the basic definition of evolution. What controls the size of the beak? Genes? An allele is an alternate from of a gene

14 Q4: Did the finch population evolve from 1976 to 1978?
A: Yes B: No ]

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