Predation, herbivory, and parasitism are types of ______ interaction.

The ______ species is the species that has either the most individuals or the most combined biomass. In most species this is some type of producer. The ______ species is a species that plays a particularly important role in keeping the community diverse and healthy.

Rhagoletis pomonella is a parasitic fly native to North America that infests fruit trees. The female fly lays her eggs in the fruit. The larvae hatch and burrow through the developing fruit. The next year, the adult flies emerge. Prior to the European colonization of North America, the major host of Rhagoletis was a native species of hawthorn, Crataegus marshallii. The domestic apple tree, Malus domestica, is not native to North America, but was imported by European settlers in the late 1700s and early 1800s. When apple trees were first imported into North America, there was no evidence that Rhagoletis could use them as hosts. Apples set fruit earlier in the season and develop faster, where hawthorns set later and develop more slowly. Recent analysis of Rhagoletis populations has shown that two distinct populations of flies have evolved from the original ancestral population of flies that were parasitic on hawthorns. One population infests only apple trees, and the other infests only hawthorns. The life cycles of both fly populations are coordinated with those of their host trees. The flies of each population apparently can distinguish and select mates with similar host preferences and reject mates from the population specific to the other host tree. There is very little hybridization (only about 5 percent) between the two groups. Initially, which of the following isolating mechanisms is likely to have been the most important in preventing gene flow between the two populations of Rhagoletis?

Researchers studied the diversity of macroscopic invertebrates in different areas of watershed ecosystems. They collected samples from 58 sites along 11 streams in the same geographical area. Their data were classified by stream type and can be found in Figure 1. The stream-type classifications range from the perennial stream type, which always has water, to the intermittent stream type, which is dry for more than nine months during the year. The horizontal axis is labeled Stream Type, and the 4 bars indicated along it are labeled Perennial, Transitional, Seasonal, and Intermittent respectively. An error range is given for each bar. The vertical axis is labeled Simpson’s Diversity Index, and the numbers 0 through 0.45, in increments of 0.05, are indicated. Each bar is described as follows. Note that all values are approximate. Perennial. 0.40, plus or minus 0.02. Transitional. 0.34, plus or minus 0.5. Seasonal. 0.39, plus or minus 0.2. Intermittent. 0.32, plus or minus 0.4. Figure 1. Diversity of macroscopic invertebrates in different stream types. Error bars represent a 95% confidence interval (±two Standard Errors from the mean). Which of the stream types had a statistically lower macroscopic invertebrate species diversity than the seasonal streams?

In a large, isolated population of an insect species, a specific gene locus has one dominant allele (A) and one recessive allele (a). The genotype frequencies of the gene were collected for ten generations, as shown in Table 1. Table 1. Genotypic frequencies over ten generations in an insect species AA Aa aa Generation 1 0.47 0.43 0.10 Generation 5 0.32 0.60 0.08 Generation 10 0.20 0.75 0.05 Which of the following could best account for the change in genotypic frequencies over the ten generations?

What is the most likely reason the carrying capacity of the human population is difficult to estimate?

The condition in which there are barriers to successful interbreeding between individuals of different species in the same community is referred to as

The graph is titled Wolf and Elk Population Sizes in Yellowstone National Park. The horizontal axis is labeled Year, and has values from left to right of 1993 to 2006. Each year is represented with a tick mark, and the years 1995, 2000, and 2006 are labeled appropriately. The left vertical axis is labeled Wolf Population and has values from bottom to top of 0 to 20 in increments of five. The right vertical axis is labeled Elk Population and has values from bottom to top of 0 to 120, in increments of 20. Two separate lines with points are shown on the graph. The first line is dashed and is labeled Elk. The second line is solid and is labeled Wolves. The approximate values of each respective line are as follows. Year, 1993; Elk Population, 90. Year, 1993; Wolf Population, 2. Year, 1994; Elk Population, 95. Year, 1994; Wolf Population, 2. Year, 1995; Elk Population, 80. Year, 1995; Wolf Population, 2. Year, 1996; Elk Population, 75. Year, 1996; Wolf Population, 6. Year, 1997; Elk Population, 60. Year, 1997; Wolf Population, 7. Year, 1998; Elk Population, 55. Year, 1998; Wolf Population, 8. Year, 1999; Elk Population, 57. Year, 1999; Wolf Population, 11. Year, 2000; Elk Population, 70. Year, 2000; Wolf Population, 10. Year, 2001; Elk Population, 60. Year, 2001; Wolf Population, 16. Year, 2002; Elk Population, 55. Year, 2002; Wolf Population, 17. Year, 2003; Elk Population, 40. Year, 2003; Wolf Population, 18. Year, 2004; Elk Population, 38. Year, 2004; Wolf Population, 22. Year, 2005; Elk Population, 44. Year, 2005; Wolf Population, 18. Year, 2006; Elk Population, 28. Year, 2006; Wolf Population, 12. Figure 1. Wolf and Elk Population Sizes in Yellowstone National Park The graph is titled Browsing of Aspen in Yellowstone National Park. The horizontal axis is labeled Year, and has values from left to right of 1993 to 2006. Each year is represented with a tick mark, and the years 1995, 2000, and 2006 are labeled appropriately. The vertical axis is labeled Percent Aspen Browsed and has values from bottom to top of 0 to 100 in increments of twenty. Two separate lines with points are shown on the graph. The first line is dashed and is labeled Riparian. The second line is solid and is labeled Uplands. The approximate values of each respective line are as follows. Year, 1998; Percent Aspen Browsed in Uplands, 98. Year, 1998; Percent Aspen Browsed in Riparian, 98. Year, 1999; Percent Aspen Browsed in Uplands, 98. Year, 1999; Percent Aspen Browsed in Riparian, 96. Year, 2000; Percent Aspen Browsed in Uplands, 96. Year, 2000; Percent Aspen Browsed in Riparian, 93. Year, 2001; Percent Aspen Browsed in Uplands, 95. Year, 2001; Percent Aspen Browsed in Riparian, 85. Year, 2002; Percent Aspen Browsed in Uplands, 93. Year, 2002; Percent Aspen Browsed in Riparian, 83. Year, 2003; Percent Aspen Browsed in Uplands, 91. Year, 2003; Percent Aspen Browsed in Riparian, 81. Year, 2004; Percent Aspen Browsed in Uplands, 87. Year, 2004; Percent Aspen Browsed in Riparian, 48. Year, 2005; Percent Aspen Browsed in Uplands, 73. Year, 2005; Percent Aspen Browsed in Riparian, 25. Year, 2006; Percent Aspen Browsed in Uplands, 65. Year, 2006; Percent Aspen Browsed in Riparian, 16. Figure 2. Browsing of Aspen in Yellowstone National Park The graph is titled Growth of Aspen in Yellowstone National Park. The horizontal axis is labeled Year, and has values from left to right of 1993 to 2006. Each year is represented with a tick mark, and the years 1995, 2000, and 2006 are labeled appropriately. The vertical axis is labeled Aspen Height in centimeters, and has values from bottom to top of 0 to 250 in increments of fifty. Two separate lines with points are shown on the graph. The first line is dashed and is labeled Riparian. The second line is solid and is labeled Uplands. The approximate values of each respective line are as follows. Year, 1998; Aspen Height in Centimeters in Uplands, 35. Year, 1998; Aspen Height in Centimeters in Riparian, 35. Year, 1999; Aspen Height in Centimeters in Uplands, 32. Year, 1999; Aspen Height in Centimeters in Riparian, 38. Year, 2000; Aspen Height in Centimeters in Uplands, 29. Year, 2000; Aspen Height in Centimeters in Riparian, 48. Year, 2001; Aspen Height in Centimeters in Uplands, 35. Year, 2001; Aspen Height in Centimeters in Riparian, 58. Year, 2002; Aspen Height in Centimeters in Uplands, 45. Year, 2002; Aspen Height in Centimeters in Riparian, 75. Year, 2003; Aspen Height in Centimeters in Uplands, 50. Year, 2003; Aspen Height in Centimeters in Riparian, 95. Year,2004; Aspen Height in Centimeters in Uplands, 70. Year, 2004; Aspen Height in Centimeters in Riparian, 135. Year, 2005; Aspen Height in Centimeters in Uplands, 90. Year, 2005; Aspen Height in Centimeters in Riparian, 180. Year, 2006; Aspen Height in Centimeters in Uplands, 120. Year, 2006; Aspen Height in Centimeters in Riparian, 225. Figure 3. Growth of Aspen in Yellowstone National Park Wolves, a top predator, were reintroduced to Yellowstone National Park in 1995 after a 50-year absence. In a multiyear study, the numbers of wolves and elk were monitored. The data are shown in Figure 1. In two different environments scientists monitored the percent of aspen trees browsed by herbivores (Figure 2) as well as the growth of the trees (Figure 3). The upland environments consist mostly of flat forested areas. The riparian environments are areas along streams with steep, wooded banks. The graph above represents the number of individuals in a population of wolves and in a population of moose observed in the same isolated geographic area over a 40-year period, from 1955 through 1995. Which of the following statements about the two populations is best supported by the information presented in the graph?

Individuals of a particular species of ground beetle are either light tan or dark brown. Light-tan beetles are predominant in habitats with light-colored sandy soils, and dark-brown beetles are predominant in habitats with dark-colored loam soils. In an experiment designed to determine the survival rates of light-tan beetles and dark-brown beetles in different habitats, 500 light-tan beetles and 500 dark-brown beetles were released in each of four habitats. Each beetle had been marked with a small spot of red paint on the underside of its abdomen before it was released. One week after the beetles had been released, any marked beetles that could be found were recaptured. The results are presented in the table below. It is assumed that differences in the numbers of beetles recaptured are directly related to differences in survival rates. Columns 2 thru 5 have 2 sub-columns each. The top row contains the column labels: columns one is blank; Column two: Habitat 1: Sandy soil, no insectivorous birds present. Column three: Habitat 2: Sandy soil, insectivorous birds present. Column four: Habitat 3: Loam soil, no insectivorous birds present. Column five: Loam soil, insectivorous birds present. From top to bottom the data is as follows: Row two: Color of Beetle: Habitat 1, sub-column one, Light tan; sub-column two, Dark brown. Habitat 2, sub-column one, Light tan; sub-column two, Dark brown. Habitat 3, sub-column one, Light tan; sub-column two, Dark brown. Habitat 4, sub-column one, Light tan; sub-column two, Dark brown. Row three: Number Released: Habitat 1, sub-column one, five hundred; sub-column two, five hundred. Habitat 2, sub-column one, five hundred; sub-column two, five hundred. Habitat 3, sub-column one, five hundred; sub-column two, five hundred. Habitat 4, sub-column one, five hundred; sub-column two, five hundred. Row four: Number Recaptured: Habitat 1, sub-column one, one hundred thirty; sub-column two, one hundred fourteen. Habitat 2, sub-column one, one hundred twenty-three; sub-column two, twenty-two. Habitat 3, sub-column one, sixty-five; sub-column two, seventy-four. Habitat 4, sub-column one, thirteen; sub-column two, eighty-seven. Which of the following processes best explains why fewer light-tan beetles than dark-brown beetles were recaptured in habitat 4?

When humans observe animals in their natural habitat, what are the animals most often found doing?