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CHAPTER 24 Molecular and Genomic Evolution. Chapter 24: Molecular and Genomic Evolution. What Is Molecular Evolution? Determining and Comparing the Structure of Macromolecules Where Do New Genes Come From? How Do Proteins Acquire New Functions?. Chapter 24: Molecular and Genomic Evolution.
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Chapter 24: Molecular and Genomic Evolution What Is Molecular Evolution? Determining and Comparing the Structure of Macromolecules Where Do New Genes Come From? How Do Proteins Acquire New Functions?
Chapter 24: Molecular and Genomic Evolution Genome Organization and Evolution Using Biological Molecules to Reconstruct Phylogenetic Trees Molecular Studies of Human Evolution
What Is Molecular Evolution? • Molecular evolution differs from phenotypic evolution in that mutations and genetic drift are much more important determinants of molecular evolution. 4
What Is Molecular Evolution? • The goals of molecular evolution studies are to determine patterns of evolutionary change in organisms’ molecules, determine the processes that caused the changes, and use those insights to solve other biological problems. 5
What Is Molecular Evolution? • Neutral alleles are fixed slowly, whereas advantageous and disadvantageous alleles are fixed rapidly. Review Figure 24.1 6
figure 24-01.jpg Figure 24.1 Figure 24.1
Determining and Comparing the Structure of Macromolecules • The polymerase chain reaction method allows biologists to determine the nucleotide base sequences of organisms from their fossilized remains. 8
Determining and Comparing the Structure of Macromolecules • Biological molecules can be compared by aligning their sequences. Review Figure 24.3 9
figure 24-03.jpg Figure 24.3 Figure 24.3
Determining and Comparing the Structure of Macromolecules • Changes evolve slowly in regions of functionally significant molecules, • but more rapidly in regions where base substitutions do not affect molecule functioning. Review Figures 24.4 11
figure 24-04.jpg Figure 24.4 Figure 24.4
Determining and Comparing the Structure of Macromolecules • Rates of amino acid substitutions in some molecules are relatively constant over evolutionary time. Review Figure 24.6 13
figure 24-06.jpg Figure 24.6 Figure 24.6
Where Do New Genes Come From? • Most new genes arise from gene duplication. • The most important types are genome (polyploidy) and domain duplication. 15
Where Do New Genes Come From? • Globin diversity evolved via gene duplication. Review Figure 24.7 16
figure 24-07.jpg Figure 24.7 Figure 24.7
Where Do New Genes Come From? • Groups of genes aligned in the same order on chromosomes of distantly related species are likely to be homologs of one another. 18
How Do Proteins Acquire New Functions? • Changes in molecule function may result from gene duplication if one gene retains the original function and the other evolves a new one. 19
How Do Proteins Acquire New Functions? • Homeotic genes have acquired varied functions in development. 20
Genome Organization and Evolution • The genome sizes of organisms vary more than a hundredfold, but the amount of coding DNA varies much less. • In general, eukaryotes have more coding DNA than do prokaryotes; • Vascular plants and invertebrate animals have more coding DNA than do single-celled organisms; • Vertebrates have more coding DNA than do invertebrates. Review Figures 24.9, 24.10 21
figure 24-09.jpg Figure 24.9 Figure 24.9
figure 24-10.jpg Figure 24.10 Figure 24.10
Using Biological Molecules to Reconstruct Phylogenetic Trees • Biological molecules can be used to infer phylogenetic relationships among organisms. • For ancient splits and phylogenies of prokaryotes, molecular data are the only source of information about phylogenetic relationships. 24
Using Biological Molecules to Reconstruct Phylogenetic Trees • Molecules that have evolved slowly are useful for determining ancient lineage splits. • Those that have evolved rapidly are useful for determining recent splits. Review Figure 24.11 25
figure 24-11.jpg Figure 24.11 Figure 24.11
Molecular Studies of Human Evolution • Comparisons of mtDNA from more than 100 ethnically distinct modern human populations strongly suggest that they all shared a common African ancestor no more than 200,000 years ago. Review Figure 24.12 27
figure 24-12.jpg Figure 24.12 Figure 24.12
