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The process through which evolution is thought to happen. Descent with modification means that children inherit most of their physical traits and body systems from their parents, but that small changes (modifications) might happen in some children due to mistakes or miscopies in the children’s genetic code. If enough of these changes build up and completely change the physical traits of the children, a new species is formed. Through descent with modification, animal species can share many common traits (inherited from parents) while gaining unique traits (modifications due to mutations in DNA code).
Descent with modification Quotes in Your Inner Fish
The Your Inner Fish quotes below are all either spoken by Descent with modification or refer to Descent with modification. For each quote, you can also see the other terms and themes related to it (each theme is indicated by its own dot and icon, like this one:
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Chapter 11
Quotes
This law is so profound that most of us take it completely for granted. Yet it is the starting point for almost everything we do in paleontology, developmental biology, and genetics.
This biological "law of everything" is that every living thing on the planet had parents.
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Replace this family circus with real features - genetic mutations and the body changes that they encode - and you have a lineage that can be identified by biological features. If descent with modification works this way, then our family trees have a signature in their basic structure... Obviously, the real world is more complex than our simple hypothetical example. Reconstructing family trees can be difficult if traits arise many different times in a family… or if traits do not have a genetic basis and arise as the result of changes in diet or other environmental conditions.
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Descent with modification Term Timeline in Your Inner Fish
The timeline below shows where the term Descent with modification appears in Your Inner Fish. The colored dots and icons indicate which themes are associated with that appearance.
Chapter 11: The Meaning of It All
Shubin illustrates this idea of descent with modification using the analogy of a family of clowns. The first generation of clowns has a...
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...“clown features” with actual human traits, and Shubin has a simple model of human genetic descent with modification . The only problem is that humans (and other animals) tend to change more than...
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