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Alainna Krzyzanowski Ch. 22 Macroevolution: Evolution Above the Species Level 12-02-09 What is the difference between Microevolution and Macroevolution? Microevolution— Macroevolution— Macroevolution & Gould: Evolutionary phenomenology from the origin of species on up a. b. c. What About Other Authors? Others: Restricted to the evolution of huge phenotypic changes or origin of characteristic that diagnose higher taxa. Main Point Of Macroevolution– What Is Meant By Patterns? Red Set: If only two species are identical there is no pattern Blue Set: If three or more are identical then you can say one is more closely related to the other 1 Alainna Krzyzanowski Rates of Evolution, According to Simpson: Best described as the rate at which single characters evolve from the rates at which taxa with different characteristics _________________________________________________________ ____________________________________________________________________________ Puzzling Existence of Living Fossils Living fossils: These organisms have changes so little over the many years that they closely resemble their relatives in Mesozoic/Paleozoic eras. Ginkgo Coelacanth (Latimeria) 2 Alainna Krzyzanowski Punctuated Equilibrium & Stasis Stasis Punctuated equilibrium Punctuated Equilibrium, Stasis & Gould _______________________ addresses the ____________ may be caused by genetic origin and position of species in geological constraints that prevent species from time. adapting. Rapid Evolution Not too Hard to Explain Rapid rates of change are shown in the ________________________ and are consistent with the information on mutation, genetic variation, and speciation. One Problem, Why So Slow? Looking at the rate a shell has changed/evolved over the years: Shell’s were compared (early shell fossils with closets living species) The differences seen over a 4 myr was not major (Picture on 587 in Futuyma) 3 Alainna Krzyzanowski Gradualism & Saltation Gradualism: Many characters evolved Independently and in sequence Living species and fossil records show evidence However, disagreement on characters of higher taxon evolved discontinuously. Saltation: Some intermediates can be found of lower taxa, however, intermediates of higher taxa are harder to find. Big Controversy in Evolutionary Biology: Are the phenotypic gaps a result of an poor OR Evolution was really proceeded by saltation fossil record? What makes Saltation different from Punctuated Equilibrium? 4 Alainna Krzyzanowski Punctuated Equilibrium Hypothesis=> The evolutionary changes in morphology that might/might not have been continuous __________________________________________, but were so rapid and geographically localized that fossil records presents the appearance of a Saltation Hypothesis => holds that intermediates ________________________ and that mutant individuals differed dramatically from parents. Goldschmidt and his “hopeful monsters” : He argued that species and higher taxa arise not from genetic variation that’s within the species but instead, in a single evolutionary step as a new genetic system. Gould and Hopeful Monsters: “The developmental theme of “hopeful monster” (despite its inappropriate name, virtually guaranteed to inspire ridicule and opposition) based on the important concept of “rare genes,” cam first in Goldschmidt’s thought, and always occupied more of his attention and research. Unfortunately, he bound this interesting challenge from development, a partially valid concept that could have been incorporated into a Darwinian framework as an auxiliary hypothesis (and now has been accepted, to a large extent, if under different names), to his truly oppositional and ultimately incorrect theory of systemic mutation, therefore winning anathema for his entire system. Goldschmidt may have acted as the architect of his own undoing, but much of his work should evoke sympathetic attention today." (Gould, page 86) Discussion Question: Despite the close relationship between humans and chimpanzees, and despite the genetic variations in most of their morphological characteristics, there are no records of a human giving birth to babies with chimpanzee morphology. Would you expect this to occur if humans have evolved gradually from apelike ancestors? –(Chapter 22, Question 2) 5 Alainna Krzyzanowski References Futuyma, Douglas J. Evolution. 2nd Ed. Sinauer associates, INC. 2009. Gould, Stephen Jay. The Structure of Evolutionary Theory. Belknep Harvard. 2002 University of California Museum of Paleontology. Patterns in Macroevolution. 2006. Accessed Nov. 29th 2009. <http://evolution.berkeley.edu/evosite/evo101/VIMacroevolution.shtml> Wilkins, John. The Talk Origins Archive. Exploring the Creation/Evolution Controversy. Macroevolution: Its Definition, Philosophy and History. Last updated 09/23/2006. Accessed Nov. 29th 2009. < http://www.talkorigins.org/faqs/macroevolution.html> Pictures Patterns Graph, Coelacanth <http://evolution.berkeley.edu/evosite/evo101/VIMacroevolution.shtml> Microevolution and Macroevolution Chart, Stasis Graph <http://www.talkorigins.org/faqs/macroevolution.html> Butterfly Gradualism <http://www.zazzle.com/hopeful_monsters_tshirt-235299209277384696> Hopeful Monster <http://www.markdrapeau.com/tag/google/> Ginkgo < http://www.naturephoto-cz.com/photos/others/ginkgo-tree-30300.jpg> 6 Alainna Krzyzanowski 7