Evolution of eukaryotes: Difference between revisions
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"The creative force of symbiosis produced eukaryotic cells from bacteria. Hence all larger organisms--protocoists, fungi, animals, and plants--originated symbiogenetically," write Lynn Margulis and Dorion Sagan.<ref>Lynn Margulis and Dorion Sagan, ''Acquiring Genomes: A Theory of the Origin of Species'' (New York: Basic Books, 2002), 55-56.</ref> Symbiogenesis refers to the formation of new species through symbiosis, two organisms of different species living together. Life began with bacteria, which are prokaryotes, meaning their cell has no nucleus. Margulis and Sagan argue that eukaryotes emerged from the symbiotic grouping of prokaryotes.<ref>ibid.</ref> | "The creative force of symbiosis produced eukaryotic cells from [[Bacteria|bacteria]]. Hence all larger organisms--protocoists, fungi, animals, and plants--originated symbiogenetically," write Lynn Margulis and Dorion Sagan.<ref>Lynn Margulis and Dorion Sagan, ''Acquiring Genomes: A Theory of the Origin of Species'' (New York: Basic Books, 2002), 55-56.</ref> Symbiogenesis refers to the formation of new species through symbiosis, two organisms of different species living together. Life began with bacteria, which are prokaryotes, meaning their cell has no nucleus. Margulis and Sagan argue that eukaryotes emerged from the symbiotic grouping of prokaryotes.<ref>ibid.</ref> | ||
There are a number of reasons to believe that components of eukaryotic cells originated as independent bacteria. The DNA of a eukaryote's component parts, specifically, mitochondria and plastids, is unlike the DNA of the nucleus. Mitochondria and plastids make proteins in ways that prokaryotes do and are affected by drugs that affect prokaryotes. One way that the symbiosis may have occurred is that the host cell may have preyed on and digested the bacteria. A second way is that the host cell and bacteria lived side by side, producing substances for each other, until the host took the bacteria inside itself.<ref>Richard Cowen, ''History of Life'', fourth edition (Malden: Blackwell Publishing, 2005), 30-32.</ref> | There are a number of reasons to believe that components of eukaryotic cells originated as independent bacteria. The DNA of a eukaryote's component parts, specifically, mitochondria and plastids, is unlike the DNA of the nucleus. Mitochondria and plastids make proteins in ways that prokaryotes do and are affected by drugs that affect prokaryotes. One way that the symbiosis may have occurred is that the host cell may have preyed on and digested the bacteria. A second way is that the host cell and bacteria lived side by side, producing substances for each other, until the host took the bacteria inside itself.<ref>Richard Cowen, ''History of Life'', fourth edition (Malden: Blackwell Publishing, 2005), 30-32.</ref> | ||
Revision as of 10:27, 14 May 2016
"The creative force of symbiosis produced eukaryotic cells from bacteria. Hence all larger organisms--protocoists, fungi, animals, and plants--originated symbiogenetically," write Lynn Margulis and Dorion Sagan.[1] Symbiogenesis refers to the formation of new species through symbiosis, two organisms of different species living together. Life began with bacteria, which are prokaryotes, meaning their cell has no nucleus. Margulis and Sagan argue that eukaryotes emerged from the symbiotic grouping of prokaryotes.[2]
There are a number of reasons to believe that components of eukaryotic cells originated as independent bacteria. The DNA of a eukaryote's component parts, specifically, mitochondria and plastids, is unlike the DNA of the nucleus. Mitochondria and plastids make proteins in ways that prokaryotes do and are affected by drugs that affect prokaryotes. One way that the symbiosis may have occurred is that the host cell may have preyed on and digested the bacteria. A second way is that the host cell and bacteria lived side by side, producing substances for each other, until the host took the bacteria inside itself.[3]
