It takes about 38 m3 of boards and plywood to build an average-size, single-family home. Can an average-size, single-family home be built with one day’s output from the saw mill? About how many days will it take for the saw mill to produce enough lumber to build a neighborhood of 100 average-size homes?

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.

Nkentucky, intoxicating beverages (beer, whiskey, wine, etc.) are involved to some extent in approximately % of collisions fatal to pedestrians.

The main ingredient of magma is a pahoehoe. b silca c dissolved gases d obsidian