This chapter define and discuss the limitations of the four species concepts, describe and provide examples of prezygotic and postzygotic reproductive barriers, distinguish between and provide examples of allopatric and sympatric speciation, explain how polyploidy can cause reproductive isolation, define the term hybrid zone and describe three outcomes for hybrid zones over time. | Ch. 23 Warm-Up Use the following information to help you answer the question below: Population = 1000 people AA = 160 Aa = 480 aa = 360 What are the genotypic frequencies? Allele frequencies? Use directional, stabilizing or disruptive selection to answer the following: The mice in the Arizona desert have either dark or light fur. Birds produce 4-5 eggs per clutch Average human baby weighs 7 lbs. Darwin's finches and beak size during drought Chapter 24 The Origin of Species What You Need to Know: The difference between microevolution and macroevolution. The biological concept of a species. Prezygotic and postzygotic barriers that maintain reproductive isolation in natural populaitons. How allopatric and sympatric speciation are similar and different. How autopolyploid or an allopolyploid chromosomal change can lead to sympatric speciation. How punctuated equilibrium and gradualism describe two different tempos of speciation. Speciation = origin of species Microevolution: changes within a single gene pool Macroevolution: evolutionary change above the species level cumulative effects of speciation over long periods of time HHMI Video Clip: Reproductive Isolation and Speciation Running Time: 2:38 min Species = population or group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring Reproductively compatible Reproductive isolation = barriers that prevent members of 2 species from producing viable, fertile hybrids Prezygotic Barriers: Impede mating/fertilization Types: Habitat isolation Temporal isolation Behavioral isolation Mechanical isolation Gametic isolation Postzygotic Barriers: Prevent hybrid zygote from developing into viable adult Types: Reduced hybrid viability Reduced hybrid fertility Hybrid breakdown REDUCED HYBRID VIABILITY REDUCED HYBRID FERTILITY HYBRID BREAKDOWN Types of Reproductive Barriers REDUCED HYBRID VIABILITY REDUCED HYBRID FERTILITY HYBRID BREAKDOWN Types of Reproductive Barriers Other . | Ch. 23 Warm-Up Use the following information to help you answer the question below: Population = 1000 people AA = 160 Aa = 480 aa = 360 What are the genotypic frequencies? Allele frequencies? Use directional, stabilizing or disruptive selection to answer the following: The mice in the Arizona desert have either dark or light fur. Birds produce 4-5 eggs per clutch Average human baby weighs 7 lbs. Darwin's finches and beak size during drought Chapter 24 The Origin of Species What You Need to Know: The difference between microevolution and macroevolution. The biological concept of a species. Prezygotic and postzygotic barriers that maintain reproductive isolation in natural populaitons. How allopatric and sympatric speciation are similar and different. How autopolyploid or an allopolyploid chromosomal change can lead to sympatric speciation. How punctuated equilibrium and gradualism describe two different tempos of speciation. Speciation = origin of species Microevolution: changes within
