Please answer all three parts of the question & refer below for the documents with fig & tables:

Figure 2.- What is the take home message of this figure? (include a description of the x and y axis and what the dots and error bars represent). a. Was there anything confusing or hard to understand about this figure? b. How does this figure demonstrate "evolution of character displacement"? Table 1- What are the authors trying to show with this table? a. What type of statistical analysis was used for this data? b. How does this figure demonstrate "evolution of character displacement"? C. Does the presentation of this table make sense based on the described methods? Table 2- What are the authors trying to show with this table? a. How does this figure demonstrate "evolution of character displacement"? b. Does the presentation of this table make sense based on the described methods? CH REPORTS Evolution of Character have anything but a mild competitive effect on G. fortis. Their numbers gradually increased as a result of local production of recruits, aug Displacement in Darwin's Finches mented by aditional immigrants (22, 25), and reached a maximum of 354 47 (SE) in 2003 Peter R. Grant and B. Rosemary Grant (Fig. 3). Little rain fell in 2003 (16 mm) and 2004 (25 mm), there was no breeding in either Competitor species can have evolutionary effects on each other that result in ecological year, numbers of both species declined drasti character displacement that is, divergence in resource-exploiting traits such as jaws and beaks. cally, and from 2004 to 2005 G. fortis ex- Nevertheless, the process of character displacement occurring in nature, from the initial encounter perienced strong directional selection against of competitors to the evolutionary change in one or more of them, has not previously been individuals with large beaks (26). investigated. Here we report that a Darwin's finch species (Geospiza fortis) on an undisturbed Selection differentials in Gets were un fuernly negative for both males and females Galpagos island diverged in beak size from a competitor species (G. magnirostris) 22 years after the competitor's arrival, when they jointly and severely depleted the food supply. The observed treated separately (Table 2). Average selection evolutionary response to natural selection was the strongest recorded in 33 years of study, and differentials in standard deviation units for the close to the value predicted from the high heritability of beak size. These findings support the role six measured traits that quantify bill size and of competition in models of community assembly, speciation, and adaptive radiations. shape and body size were 0.774 for males and 0.649 for females. Compared with values re- ported in other studies elsewhere (27), they are Wharacter displacement (1, 2) is an evolu: termined by the tradeoff in energetic rewards unusually large. The six traits are positively tionary divergence in resource-exploiting from feeding on small and large seeds, and the correlated to varying degrees. Selection gradi- traits much as jaws and beaks that is tradeoff is affected by variation in beak mor ent analysis helps to identify which particular caused by interspecific competition (3-5). It has phology and rates of seed depletion and traits were subject to selection independent of the potential to explain nonrandom patterns of replenishment (7, 18, 19). Competitors can mod correlations among traits (28). However, bill co-occurrence and morphological differences ify the tradeoff (7) depth and width are so strongly correlated in between coexisting species (6-10). Supporting The situation on Daphne changed in 1982 these samples (r -0.861 for males, 0.946 for evidence has come from phylogenetic analyses with the arrival of a new competitor species, females) that their independent effects on sur (II) and from experimental studies of stickle- setting up the potential for character displacevival cannot be distinguished. Selection gradient hacks, in which the role of directional selection ment to occur. Between 1973 and 1982, a few analysis without these two variables shows bill in character divergence has been demonstrated individuals of the large ground finch (G. length to be the only significant entry into the (12). The process of character displacement magnirostris; -30 g) visited the island for gradient, for both males (partial regression co- occurring in nature, from the initial encounter short periods in the dry season but never bred efficient (B) - -0.931 +0.334 SE, P-0.0079; of competitors to the evolutionary change in (15). In late 1982, a breeding population was R2 -0.190) and ferrales (3--0.814 +0.295, P- one or more of them as a result of direction established by two females and three males at al natural selection, has not previously been the beginning of an exceptionally strong El investigated. Nio event that brought abundant rain to the Table 1. Proportions of seeds in the diets of three The situation on the small Galpagos island island (1359 mm) (20-22). G. magnirostris is finch species. Small seeds are a composite group of Daphne Major (0.34 km) has been referred a potential competitor as a result of diet of 22 species, medium seeds are o echios, and to as the classical case of character release Overlap with G. fortis (Table 1), especially in large seeds are 1. cistoides. N is the number of (1, 2, 13), which is the converse of character the dry season when food supply is limiting observations. There is strong heterogeneity in the displacement. Here, in the virtual absence of 19, 23). The principal food of G. magnirostris G. fortis feeding data 2 - 30.979, PC the small ground finch (Geospizu fuliginos, is the seeds of Tribulus cistoides, contained 0.0001). The reduction in a fortis feeding on weighing - 12 g) and released from compe- within a hard mericarp and exposed when a Tribulus in 2004 makes a significant contribution tition, the medium ground finch (G fortis, finch cracks or tears away the woody outer x - 3.912, P 0.1), and only 1 of 38 measured females G. maynirostris deplete the Tribule seed sup- seeds from more than two mericarps; whereas survived ply faster than do G. fortis. The seeds that are under the more typical conditions prevailing in the 1970s, a total of eight birds observed for the same length of time fed on 9 to 22 mericarps, with an average interval between successive mericarps of only 5.5 10.5 (SE) (24) Third, numbers of G. fortis declined to a lower level (83) in 2005 than at any time since the study began in 1973, and numbers of G. magnirostris declined so strongly from the 2003 maximum that by 2005, only four females and nine males were left. The popu- lation was almost extinct, apparently as a result of exhaustion of the standing crop of large seeds and subsequent starvation. Of the 137 G. wagnirostris that disappeared in 2004- 2005, 13.0% were found dead, and so were 21.7% of 152 G. fortis. Consistent with the starvation hypothesis, the stomachs of all dead birds (23 G. magnirostris and 45 G. fortis, banded and not banded individuals combined) were empty The principal alternative food for both spe- cies is the seeds of Opuntia cactus, but production in 2004 was low, the fourth lowest since records were first kept systematically in 1982 (23). Not only were cactus seeds insuffi- cient for the two granivore species to escape the Fig. 1. Large-beaked G. fortis (A) and magnirostris (B) can crack or tear the woody tissues of dilemma of a diminishing supply of their pre T. cistoides mericarps (D), whereas small-beaked fortis (C) cannot. Five mericarps constitute a ferred foods, they were insufficient for the single fruit. In (D), the left-hand mericarp is intact. The right-hand mericarp, viewed from the other cactus specialist G. scandens (--20 g), whose (mesial) side, has been exploited by a finch, exposing five locules from which seeds have been numbers, like those of G. fortis, fell lower to extracted. Mericarps are -8 mm long and are shown at twice the magnification of the finches. 50) than in any of the preceding 32 years. The [Photos are by the authors] only escape was available to the smallest, most G. fuliginosa-like, members of the G. fortis population, which are known to feed like G. Fig. 2. Mean beak size 1 fuliginosa on small seeds with little individual PC of adult G. fortis energy reward (13, 18). We have no feeding (sexes combined) in the 0.5 observations to indicate that they survived as a years 1973 to 2005. Ver- tical lines show 95% con- result of feeding on the typical components of fidence intervals for the the G. fuliginosa diet: the very small seeds of estimates of the mean. Sesuvium edmonstonei and Tiquilia fusca -0.5 Horizontal lines mark the (13, 15, 23). Nevertheless, it may be signifi 95% confidence limits on cant that two G fuliginosu individuals were the estimate of the mean present on the island in 2004 and both survived in 1973 to illustrate sub- ta 2005. sequent changes in the -1.5 The fourth line of evidence is the contrast 1975 1980 1965 1990 1996 2000 2005 mean. Sample sizes vary betwe directions of strong selec from 29 in 2005) to 950 Year the G. fortis population in the presence (2004) (in 1987). Signs of the PC and near absence (1977) of G magwirostris. In values are reversed so that mean size increases from the origin. 1977, a year of only 24 mm of rain and no cog 0 PC1 Beak size an breeding, body size and beak size of both male he expected from strong directional selection to null or neutral models (6, 7). Replicated and female G. fortis considered separately were against large size (32). This was observed. The experiments with suitable organisms are subject to selection (Table 2). Average selec mean beak size (PCI) of the 2005 generation needed to demonstrate definitively the causal tion differentials were 0.642 for males and measured in 2006 was significantly smaller role of competition, not only as an ingredient 0.668 for females, and they were uniformly than that in the 2004 sample of the parental of natural selection of resource-exploiting positive. In the intervening years, 19782003, generation before selection ( 4- 4.844, PC traits (12) but as a factor in their evolution there was a weaker selection episode favoring 0.0001). The difference between generations is (33). Our findings should prove useful in G. fortis with small beaks when the food 0.70 SD, which is exceptionally large (27, 29). designing realistic experiments, by identifying supply changed toward a predominance of It may be compared with the range of values ecological context high densities at the start of an small seeds and scarcity of large ones after the predicted from the breeders equation, namely environmental stress) and by estimating the El Nio event of 1982-1983 (20, 21, 23). At the product of the average selection differential magnitude of natural selection that time, G. magnirostris were rare (22, 25) of the two sexes and the 95% confidence numbers varied from 2 to 24. The selection intervals of the heritability estimate. The ob- events of 1977 and 2004 stand out against a served value of 0.70 SD falls within the References and Notes background of relative morphological stability predicted range of 0.66 to 1.00 SD. Although 1 W. L. Brown Jr., E. O. Wilson, Syst. Zool. 5, 49 (1956 (29) (Fig. 2). Immediately before 2004 there a small component of the response is probably 2 P. R Gant, Biol. ). Line. Soc. 4, 39(1972). was no unusual rainfall to cause a change in the attributable to environmental factors [food 3. B. W Robinson, D. S Wilson, Am. Mat. 144.596 composition of the food supply and no other supply and finch density (30, 32)], the major (1994). unusual environmental factor such as tempera 4 D.C. Adams, J. Rohit. Proc Natl Acad Sci USA 97, component is genetic. This is the strongest 4106 02000 ture extremes or an invasion of predators, yet evolutionary change seen in the 33 years of the 5. D. W. Piennig, P.). Murphy, Ecology 34, 1248 with the same amount of rain as in 1977, and study. (2001 with the same community of plants in the The evolutionary changes that we observed 6 t W. Schoenec in Ecological Communities: Concepts environment, large finches survived at a high Issues and the Evidence, D. R. Strong LG Abele, are more complex than those envisaged by A. B.Thistle, Eds. Princeton Univ. Press, Princeton, NL frequency in 1977 but survived at a low Lack. Nevertheless, they provide direct support 1984), pp. 254-281. frequency in 2004. The conspicuous difference for his emphasis on the ecological adjustments 7. D. Schluter, Price, P. R Grant Science 227. 1056 (1995) between these years was the number of G. that competitor species make to each other, BLB. Leses, Proc Natl Acad Sci USA 97.5693 magnirostris: 2 to 14 occasional visitors in specifically in the final stages of speciation and (20001 1977 (15) versus 150 19 residents at the more generally in adaptive radiations (9-12, 14). 9. P. R. Grant, Ecology and Evolution of Darwin's Finches beginning of 2004. They also support models of ecological com Princeton Unia Press, Princeton, NL 19991 Given the high heritability of beak size of munity assembly that incorporate evolutionary 10. D. Sche, All No. 156, 54 (2002). 11 1. Lasos, Evolution 44, 59 (19900 G. fortis (30, 31), an evolutionary response is to effects of interspecific competition, in contrast 12 D. Schus, Science 266,798 (1994. 13. P. T. Brag. P. R. Grant, Biol. I. Line Sec 22, 243 (19841 1500 Fig. 3. Numbers of G. fortis 14 D. Lack. Dato's Finches (Cambridge Unia Press, and G. magnirostris. Breed- Cambridge, 1947). ing was extensive in 1997- G. 15. R.T. Boog, P. R. Grant, Ecal Monogr. 54, 443 1998 and 2002, and as a 1000- (19841 result finch numbers were 16 PT. Bang, PR Grant Science 214. 2 (1981) 17. L.Price , Nowe 309,787 (1934). elevated in the following 18. t Price, Ecology 68, 101 (1997). years. There was no breeding 500- 19. C. W. Beniman, Ecol. Monagr. 57, 251 (1987). in 2003 and 2004. Numbers 20 ML Gibbs, Grant Anim. Ecol 56,797 before 1997 have been omitted (1987). because G magrostris were 21 H L Gibbs, Grant, Nature 327 511 (1967 scarce (13 pairs) (25) 22. P. R Gant, B. R. Grant, Evolution 49, 229 (1995). 0- 1996 1998 2000 2002 2004 2006 23. P. R. Grant, BLR Grant in Long-Term Studies of Vertebrate Commun, M. L. Cod. L. A Smallwood, Eds. Year Academic Press, New York, 1996), pp38-390 24 P. R Gant Animex 29,785 (1981). 25 PR Gant B. Grant, Petren, Genetics 112-113. 359 0001). Table 2. Selection differentials for G. fortis in the presence (2004) and absence (1977) of a 26. See methods in supporting material on Science Online magnirostris. Statistical significance at P 0.1), and only 1 of 38 measured females G. maynirostris deplete the Tribule seed sup- seeds from more than two mericarps; whereas survived ply faster than do G. fortis. The seeds that are under the more typical conditions prevailing in the 1970s, a total of eight birds observed for the same length of time fed on 9 to 22 mericarps, with an average interval between successive mericarps of only 5.5 10.5 (SE) (24) Third, numbers of G. fortis declined to a lower level (83) in 2005 than at any time since the study began in 1973, and numbers of G. magnirostris declined so strongly from the 2003 maximum that by 2005, only four females and nine males were left. The popu- lation was almost extinct, apparently as a result of exhaustion of the standing crop of large seeds and subsequent starvation. Of the 137 G. wagnirostris that disappeared in 2004- 2005, 13.0% were found dead, and so were 21.7% of 152 G. fortis. Consistent with the starvation hypothesis, the stomachs of all dead birds (23 G. magnirostris and 45 G. fortis, banded and not banded individuals combined) were empty The principal alternative food for both spe- cies is the seeds of Opuntia cactus, but production in 2004 was low, the fourth lowest since records were first kept systematically in 1982 (23). Not only were cactus seeds insuffi- cient for the two granivore species to escape the Fig. 1. Large-beaked G. fortis (A) and magnirostris (B) can crack or tear the woody tissues of dilemma of a diminishing supply of their pre T. cistoides mericarps (D), whereas small-beaked fortis (C) cannot. Five mericarps constitute a ferred foods, they were insufficient for the single fruit. In (D), the left-hand mericarp is intact. The right-hand mericarp, viewed from the other cactus specialist G. scandens (--20 g), whose (mesial) side, has been exploited by a finch, exposing five locules from which seeds have been numbers, like those of G. fortis, fell lower to extracted. Mericarps are -8 mm long and are shown at twice the magnification of the finches. 50) than in any of the preceding 32 years. The [Photos are by the authors] only escape was available to the smallest, most G. fuliginosa-like, members of the G. fortis population, which are known to feed like G. Fig. 2. Mean beak size 1 fuliginosa on small seeds with little individual PC of adult G. fortis energy reward (13, 18). We have no feeding (sexes combined) in the 0.5 observations to indicate that they survived as a years 1973 to 2005. Ver- tical lines show 95% con- result of feeding on the typical components of fidence intervals for the the G. fuliginosa diet: the very small seeds of estimates of the mean. Sesuvium edmonstonei and Tiquilia fusca -0.5 Horizontal lines mark the (13, 15, 23). Nevertheless, it may be signifi 95% confidence limits on cant that two G fuliginosu individuals were the estimate of the mean present on the island in 2004 and both survived in 1973 to illustrate sub- ta 2005. sequent changes in the -1.5 The fourth line of evidence is the contrast 1975 1980 1965 1990 1996 2000 2005 mean. Sample sizes vary betwe directions of strong selec from 29 in 2005) to 950 Year the G. fortis population in the presence (2004) (in 1987). Signs of the PC and near absence (1977) of G magwirostris. In values are reversed so that mean size increases from the origin. 1977, a year of only 24 mm of rain and no cog 0 PC1 Beak size an breeding, body size and beak size of both male he expected from strong directional selection to null or neutral models (6, 7). Replicated and female G. fortis considered separately were against large size (32). This was observed. The experiments with suitable organisms are subject to selection (Table 2). Average selec mean beak size (PCI) of the 2005 generation needed to demonstrate definitively the causal tion differentials were 0.642 for males and measured in 2006 was significantly smaller role of competition, not only as an ingredient 0.668 for females, and they were uniformly than that in the 2004 sample of the parental of natural selection of resource-exploiting positive. In the intervening years, 19782003, generation before selection ( 4- 4.844, PC traits (12) but as a factor in their evolution there was a weaker selection episode favoring 0.0001). The difference between generations is (33). Our findings should prove useful in G. fortis with small beaks when the food 0.70 SD, which is exceptionally large (27, 29). designing realistic experiments, by identifying supply changed toward a predominance of It may be compared with the range of values ecological context high densities at the start of an small seeds and scarcity of large ones after the predicted from the breeders equation, namely environmental stress) and by estimating the El Nio event of 1982-1983 (20, 21, 23). At the product of the average selection differential magnitude of natural selection that time, G. magnirostris were rare (22, 25) of the two sexes and the 95% confidence numbers varied from 2 to 24. The selection intervals of the heritability estimate. The ob- events of 1977 and 2004 stand out against a served value of 0.70 SD falls within the References and Notes background of relative morphological stability predicted range of 0.66 to 1.00 SD. Although 1 W. L. Brown Jr., E. O. Wilson, Syst. Zool. 5, 49 (1956 (29) (Fig. 2). Immediately before 2004 there a small component of the response is probably 2 P. R Gant, Biol. ). Line. Soc. 4, 39(1972). was no unusual rainfall to cause a change in the attributable to environmental factors [food 3. B. W Robinson, D. S Wilson, Am. Mat. 144.596 composition of the food supply and no other supply and finch density (30, 32)], the major (1994). unusual environmental factor such as tempera 4 D.C. Adams, J. Rohit. Proc Natl Acad Sci USA 97, component is genetic. This is the strongest 4106 02000 ture extremes or an invasion of predators, yet evolutionary change seen in the 33 years of the 5. D. W. Piennig, P.). Murphy, Ecology 34, 1248 with the same amount of rain as in 1977, and study. (2001 with the same community of plants in the The evolutionary changes that we observed 6 t W. Schoenec in Ecological Communities: Concepts environment, large finches survived at a high Issues and the Evidence, D. R. Strong LG Abele, are more complex than those envisaged by A. B.Thistle, Eds. Princeton Univ. Press, Princeton, NL frequency in 1977 but survived at a low Lack. Nevertheless, they provide direct support 1984), pp. 254-281. frequency in 2004. The conspicuous difference for his emphasis on the ecological adjustments 7. D. Schluter, Price, P. R Grant Science 227. 1056 (1995) between these years was the number of G. that competitor species make to each other, BLB. Leses, Proc Natl Acad Sci USA 97.5693 magnirostris: 2 to 14 occasional visitors in specifically in the final stages of speciation and (20001 1977 (15) versus 150 19 residents at the more generally in adaptive radiations (9-12, 14). 9. P. R. Grant, Ecology and Evolution of Darwin's Finches beginning of 2004. They also support models of ecological com Princeton Unia Press, Princeton, NL 19991 Given the high heritability of beak size of munity assembly that incorporate evolutionary 10. D. Sche, All No. 156, 54 (2002). 11 1. Lasos, Evolution 44, 59 (19900 G. fortis (30, 31), an evolutionary response is to effects of interspecific competition, in contrast 12 D. Schus, Science 266,798 (1994. 13. P. T. Brag. P. R. Grant, Biol. I. Line Sec 22, 243 (19841 1500 Fig. 3. Numbers of G. fortis 14 D. Lack. Dato's Finches (Cambridge Unia Press, and G. magnirostris. Breed- Cambridge, 1947). ing was extensive in 1997- G. 15. R.T. Boog, P. R. Grant, Ecal Monogr. 54, 443 1998 and 2002, and as a 1000- (19841 result finch numbers were 16 PT. Bang, PR Grant Science 214. 2 (1981) 17. L.Price , Nowe 309,787 (1934). elevated in the following 18. t Price, Ecology 68, 101 (1997). years. There was no breeding 500- 19. C. W. Beniman, Ecol. Monagr. 57, 251 (1987). in 2003 and 2004. Numbers 20 ML Gibbs, Grant Anim. Ecol 56,797 before 1997 have been omitted (1987). because G magrostris were 21 H L Gibbs, Grant, Nature 327 511 (1967 scarce (13 pairs) (25) 22. P. R Gant, B. R. Grant, Evolution 49, 229 (1995). 0- 1996 1998 2000 2002 2004 2006 23. P. R. Grant, BLR Grant in Long-Term Studies of Vertebrate Commun, M. L. Cod. L. A Smallwood, Eds. Year Academic Press, New York, 1996), pp38-390 24 P. R Gant Animex 29,785 (1981). 25 PR Gant B. Grant, Petren, Genetics 112-113. 359 0001). Table 2. Selection differentials for G. fortis in the presence (2004) and absence (1977) of a 26. See methods in supporting material on Science Online magnirostris. Statistical significance at P