(a) Similarity between different species (b) Diversity within a species

Fig. 24-1

Fig. 24-2 (a) Similarity between different species (b) Diversity within a species

Fig. 24-2a (a) Similarity between different species

Fig. 24-2b (b) Diversity within a species

Fig. 24-3 EXPERIMENT Example of a gene tree for population pair A-B Gene flow event Allele 1 B Population 2 3 4 A A A Allele 1 is more closely related to alleles 2, 3, and 4 than to alleles 5, 6, and 7. Inference: Gene flow occurred. 5 6 7 B B B Alleles 5, 6, and 7 are more closely related to one another than to alleles in population A. Inference: No gene flow occurred. RESULTS Pair of populations with detected gene flow A-B K-L A-C B-C F-G G-I C-E Estimated minimum number of gene flow events to account for genetic patterns 5 3 2 3 2 2 2 1 2 Distance between populations (km) 340 720 1,390 1,190 760 1,110 1,310

Fig. 24-3a EXPERIMENT Example of a gene tree for population pair A-B Gene flow event Allele 1 B Population 2 3 4 A A A Allele 1 is more closely related to alleles 2, 3, and 4 than to alleles 5, 6, and 7. Inference: Gene flow occurred. 5 6 7 B B B Alleles 5, 6, and 7 are more closely related to one another than to alleles in population A. Inference: No gene flow occurred.

Fig. 24-3b RESULTS Pair of populations with detected gene flow A-B K-L A-C B-C F-G G-I C-E Estimated minimum number of gene flow events to account for genetic patterns 5 3 2 3 2 2 2 1 2 Distance between populations (km) 340 720 1,390 1,190 760 1,110 1,310

Fig. 24-3c Grey-crowned babblers

Fig. 24-4 Prezygotic barriers Postzygotic barriers Habitat Isolation Temporal Isolation Behavioral Isolation Mechanical Isolation Gametic Isolation Reduced Hybrid Viability Reduced Hybrid Fertility Hybrid Breakdown Individuals of different species Mating attempt Fertilization Viable, fertile offspring (a) (c) (e) (f) (g) (h) (i) (l) (d) (j) (b) (k)

Fig. 24-4a Prezygotic barriers Habitat Isolation Temporal Isolation Behavioral Isolation Mechanical Isolation Individuals of different species Mating attempt (a) (c) (e) (f) (d) (b)

Fig. 24-4b Prezygotic barriers Habitat Isolation Temporal Isolation Behavioral Isolation Mechanical Isolation Individuals of different species Mating attempt

Fig. 24-4c (a) Water-dwelling Thamnophis

Fig. 24-4d (b) Terrestrial Thamnophis

Fig. 24-4e (c) Eastern spotted skunk (Spilogale putorius)

Fig. 24-4f (d) Western spotted skunk (Spilogale gracilis)

Fig. 24-4g (e) Courtship ritual of bluefooted boobies

Fig. 24-4h (f) Bradybaena with shells spiraling in opposite directions

Fig. 24-4i Prezygotic barriers Postzygotic barriers Gametic Isolation Reduced Hybrid Viability Reduced Hybrid Fertility Hybrid Breakdown Fertilization Viable, fertile offspring (g) (h) (i) (l) (j) (k)

Fig. 24-4j Prezygotic barriers Postzygotic barriers Gametic Isolation Reduced Hybrid Viability Reduced Hybrid Fertility Hybrid Breakdown Fertilization Viable, fertile offspring

Fig. 24-4k (g) Sea urchins

Fig. 24-4l (h) Ensatina hybrid

Fig. 24-4m (i) Donkey

Fig. 24-4n (j) Horse

Fig. 24-4o (k) Mule (sterile hybrid)

Fig. 24-4p (l) Hybrid cultivated rice plants with stunted offspring (center)

Fig. 24-5 (a) Allopatric speciation (b) Sympatric speciation

Fig. 24-6 A. harrisi A. leucurus

Fig. 24-7 Mantellinae (Madagascar only): 100 species Rhacophorinae (India/Southeast Asia): 310 species Other Indian/ Southeast Asian frogs 100 80 60 40 20 0 1 2 3 Millions of years ago (mya) 1 2 3 India Madagascar 88 mya 65 mya 56 mya

Fig. 24-7a Mantellinae (Madagascar only): 100 species Rhacophorinae (India/Southeast Asia): 310 species Other Indian/ Southeast Asian frogs 100 80 60 40 20 0 1 2 3 Millions of years ago (mya)

Fig. 24-7b 1 2 3 India Madagascar 88 mya 65 mya 56 mya

Fig. 24-8 Degree of reproductive isolation 2.0 1.5 1.0 0.5 0 0 50 100 150 200 250 300 Geographic distance (km)

Maltose Starch population 2 Male Male Starch Starch population 1 Fig. 24-9 EXPERIMENT Initial population Some flies raised on starch medium Mating experiments after 40 generations Some flies raised on maltose medium RESULTS Female Female Starch Starch Starch Maltose population 1 population 2 22 9 18 15 8 20 12 15 Mating frequencies in experimental group Mating frequencies in control group

Fig. 24-9a EXPERIMENT Initial population Some flies raised on starch medium Mating experiments after 40 generations Some flies raised on maltose medium

Fig. 24-9b Male Maltose Starch Male Starch Starch population 1 population 2 RESULTS Female Female Starch Starch Starch Maltose population 1 population 2 22 9 18 15 8 20 12 15 Mating frequencies in experimental group Mating frequencies in control group

Fig. 24-10-1 2n = 6 4n = 12 Failure of cell division after chromosome duplication gives rise to tetraploid tissue.

Fig. 24-10-2 2n = 6 4n = 12 Failure of cell division after chromosome duplication gives rise to tetraploid tissue. 2n Gametes produced are diploid..

Fig. 24-10-3 2n = 6 4n = 12 Failure of cell division after chromosome duplication gives rise to tetraploid tissue. 2n Gametes produced are diploid.. 4n Offspring with tetraploid karyotypes may be viable and fertile.

Fig. 24-11-1 Species B 2n = 4 Unreduced gamete with 4 chromosomes Meiotic error Species A 2n = 6 Normal gamete n = 3

Fig. 24-11-2 Species B 2n = 4 Meiotic error Unreduced gamete with 4 chromosomes Hybrid with 7 chromosomes Species A 2n = 6 Normal gamete n = 3

Fig. 24-11-3 Species B 2n = 4 Meiotic error Unreduced gamete with 4 chromosomes Hybrid with 7 chromosomes Unreduced gamete with 7 chromosomes Species A 2n = 6 Normal gamete n = 3 Normal gamete n = 3

Fig. 24-11-4 Species B 2n = 4 Meiotic error Unreduced gamete with 4 chromosomes Hybrid with 7 chromosomes Unreduced gamete with 7 chromosomes Species A 2n = 6 Normal gamete n = 3 Normal gamete n = 3 Viable fertile hybrid (allopolyploid) 2n = 10

Fig. 24-12 EXPERIMENT Normal light Monochromatic orange light P. pundamilia P. nyererei

Fig. 24-13 Allele frequency (log scale) EUROPE Yellow-bellied toad, Bombina variegata Hybrid zone Yellow-bellied toad range Fire-bellied toad range 0.99 Fire-bellied toad, Bombina bombina 0.9 0.5 0.1 0.01 40 30 20 10 0 10 20 Distance from hybrid zone center (km)

Fig. 24-13a Yellow-bellied toad, Bombina variegata

Fig. 24-13b Fire-bellied toad, Bombina bombina

Fig. 24-13c Allele frequency (log scale) Hybrid zone Fire-bellied toad range Yellow-bellied toad range 0.99 0.9 0.5 0.1 0.01 40 30 20 10 0 10 20 Distance from hybrid zone center (km)

Fig. 24-14-1 Gene flow Population (five individuals are shown) Barrier to gene flow

Fig. 24-14-2 Isolated population diverges Gene flow Population (five individuals are shown) Barrier to gene flow

Fig. 24-14-3 Isolated population diverges Hybrid zone Gene flow Population (five individuals are shown) Barrier to gene flow Hybrid

Fig. 24-14-4 Isolated population diverges Hybrid zone Possible outcomes: Reinforcement OR Gene flow Population (five individuals are shown) Barrier to gene flow Hybrid Fusion OR Stability

Fig. 24-15 Number of females Sympatric male pied flycatcher Allopatric male pied flycatcher 28 24 20 Pied flycatchers Collared flycatchers 16 12 8 4 0 Females mating with males from: Own species (none) Other species Own species Other species Sympatric males Allopatric males

Fig. 24-15a Sympatric male pied flycatcher Allopatric male pied flycatcher

Fig. 24-15b Number of females 28 Pied flycatchers 24 20 Collared flycatchers 16 12 8 4 (none) 0 Females mating Own with males from: species Other species Own species Other species Sympatric males Allopatric males

Fig. 24-16 Pundamilia nyererei Pundamilia pundamilia Pundamilia turbid water, hybrid offspring from a location with turbid water

Fig. 24-17 (a) Punctuated pattern Time (b) Gradual pattern

Fig. 24-18 (a) The wild sunflower Helianthus anomalus H. anomalus Chromosome 1 Experimental hybrid H. anomalus Chromosome 2 Experimental hybrid H. anomalus Chromosome 3 Experimental hybrid Key Region diagnostic for parent species H. petiolaris Region diagnostic for parent species H. annuus Region lacking information on parental origin (b) The genetic composition of three chromosomes in H. anomalus and in experimental hybrids

Fig. 24-18a (a) The wild sunflower Helianthus anomalus

Fig. 24-18b H. anomalus Chromosome 1 Experimental hybrid H. anomalus Chromosome 2 Experimental hybrid H. anomalus Chromosome 3 Experimental hybrid Key Region diagnostic for parent species H. petiolaris Region lacking information on parental origin Region diagnostic for parent species H. annuus (b) The genetic composition of three chromosomes in H. anomalus and in experimental hybrids

Fig. 24-19

Fig. 24-20 (a) Typical Mimulus lewisii (b) M. lewisii with an M. cardinalis flower-color allele (c) Typical Mimulus cardinalis (d) M. cardinalis with an M. lewisii flower-color allele

Fig. 24-UN1 Original population Allopatric speciation Sympatric speciation

Fig. 24-UN2 Ancestral species: AA Triticum monococcum (2n = 14) BB Wild Triticum (2n = 14) DD Wild T. tauschii (2n = 14) Product: AA BB DD T. aestivum (bread wheat) (2n = 42)

Fig. 24-UN3