Biology 2483A Lecture Notes - Lecture 5: Adaptation, Guppy, Antimicrobial Resistance
13 Feb 2017
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Trophy hunting and inadvertent evolution: a case study. Bighorn sheep populations have been reduced by 90% by hunting, habitat loss, and introduction of cattle. Hunting is now restricted; must buy permits for a large (cid:498)trophy ram(cid:499) Trophy hunting removes the largest and strongest males the ones that would sire many healthy offspring. In one population, 10% of males were removed by hunting each year, the average size of males and their horns decreased over 30 years of study. Evolution can be viewed as genetic change over time or as a process of descent with modification. As a population accumulates differences over time and a new species forms, it is different from its ancestors. Can result from cell division errors, mechanical damage, and exposure to chemicals (mutagens) or high-energy radiation. Formation of new alleles is critical to evolution. One mutation would occur in every 10,000 to 1,000,000 copies of a gene.
