Homework 1.1 and 1.2.docx

Inference 2 varying organisms show differential

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Inference 2: Varying organisms show differential survival and reproduction favoring advantageous traits - survival was not random, but based on traits that made the organism more suited to the current environment. Due to survivors passing these favored traits on to their offspring, advantageous traits tend to accumulate in a population over time. Inference 3: Over many generations, natural selection generates new adaptations and new species - natural selection causes a population to improve over time to reflect characteristics that are most suited for the environment. Through variation in characteristics new adaptations and species can arise. 3) Briefly summarize Lamarck’s concept of evolutionary process. What is wrong with this concept? Lamarck believed that acquired traits could be passed on to future generations of offspring. He thought that evolution occurred through use and disuse of various organs. For example he thought that because giraffes stretched their necks to reach tree limbs containing leaves that they would in turn pass on longer necks to their offspring. However, he was incorrect in his idea. He realized that the offspring tended to possess traits that were advantageous and did not possess those that were not, but he believed it to be passed through acquired traits. Now we know that only heritable traits are passed on to the offspring through the form of genetic material such as DNA. 4) Who were Gould and Eldridge? What was their major contribution to science? Gould and Eldridge were two evolutionary paleontologists who in 1972 proposed the idea of punctuated equilibrium. This idea stated that phenotypic evolution takes place during a very brief period of branching speciation which is then followed by long intervals of morphological evolutionary stasis. 1) Describe in detail ten recurring criticisms of Darwin’s theory of natural selection. How can these criticisms be refuted? Make sure to discuss the refutation for each rooted in good science. a. Orthogenesis - idea proposed that variation and evolution of lineages is driven by a momentum with a predestined direction that acted independently of external factors. This can be refuted through the fact that extinction is expected of most species and it is not necessarily contributed to evolved characteristics that were nonadoptive and detrimental to their survival. For instance the Irish elk was a common example for evidence of orthogenesis. However since extinctions occur frequently it is not unusual for a species such as the Irish elk to go extinct and it likely has nothing to do with their continually enlarging antler size.
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Zoology HW 1.1 b. Natural selection cannot create new species or structures but can modify old ones. This brings up how branching and speciation can occur if it is not attributed to natural selection. To refute this criticism, we must look at how the structures were originally used and how they are used in organisms today. The function of these structures has changed allowing for variation and speciation. For instance, rudimentary feathers may have
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