Noble Fir Case Study
1. What characteristic do Mathiasen and Daugherty (2008) use to distinguish between red fir and noble fir, and how do they justify using this characteristic?
Mathiasen and Daugherty initially classified noble and red fir through attributes such as the needles, bracts, bark, and age of the female cones. Nevertheless, categorization of the morphological affiliations of red fir, noble fir, and Shasta red fir are challenging because of their variations. Due to that reason, they analyzed different degrees of mistletoe infection of host-specific mountain hemlock and Pacific silver fir dwarf mistletoes as the characteristic to differentiate between the geographic distribution of red fir and noble fir in Oregon. They justified using this characteristic …show more content…
Describe the unusual geographic distribution of this characteristic that Mathiasen and Daugherty (2008) documented. What do they think this distribution tells us?
Mathiasen and Daughtery documented the percent infection of different mistletoes on fir trees. Located south of latitude 44°N, red firs and trees that share a resemblance to noble fir were completely immune to Pacific silver fir dwarf mistletoe; however, trees also resembling noble fir north of 44°N were drastically parasitized by the mistletoe. Additionally, mountain hemlock dwarf mistletoes only infected mountain hemlock. They concluded that their data gave support to the geographic distribution and classification of red fir and noble fir; those immune to pacific silver fir dwarf mistletoes were red fir, and the others were noble. Mathiasen and Daugherty discovered an unexpected genetic shift to noble fir from the red fir that morphologically looked like noble fir at latitude 44°N. They related the situation to the youth-on-age population in the Coast Range of Oregon. Youth-on-age that are north of latitude 44°N are tetraploids, while those below are diploids. Previous researchers once hypothesized that the evolution of tetraploid populations may be due to glaciation in Oregon from the Wisconsin glacial epoch, so Mathiasen and Daugherty reasoned that the Cascade Mountains’ glacial history may be the answer to the genetic shift and distribution between red fir and noble fir at latitude
Mathiasen and Daugherty initially classified noble and red fir through attributes such as the needles, bracts, bark, and age of the female cones. Nevertheless, categorization of the morphological affiliations of red fir, noble fir, and Shasta red fir are challenging because of their variations. Due to that reason, they analyzed different degrees of mistletoe infection of host-specific mountain hemlock and Pacific silver fir dwarf mistletoes as the characteristic to differentiate between the geographic distribution of red fir and noble fir in Oregon. They justified using this characteristic …show more content…
Describe the unusual geographic distribution of this characteristic that Mathiasen and Daugherty (2008) documented. What do they think this distribution tells us?
Mathiasen and Daughtery documented the percent infection of different mistletoes on fir trees. Located south of latitude 44°N, red firs and trees that share a resemblance to noble fir were completely immune to Pacific silver fir dwarf mistletoe; however, trees also resembling noble fir north of 44°N were drastically parasitized by the mistletoe. Additionally, mountain hemlock dwarf mistletoes only infected mountain hemlock. They concluded that their data gave support to the geographic distribution and classification of red fir and noble fir; those immune to pacific silver fir dwarf mistletoes were red fir, and the others were noble. Mathiasen and Daugherty discovered an unexpected genetic shift to noble fir from the red fir that morphologically looked like noble fir at latitude 44°N. They related the situation to the youth-on-age population in the Coast Range of Oregon. Youth-on-age that are north of latitude 44°N are tetraploids, while those below are diploids. Previous researchers once hypothesized that the evolution of tetraploid populations may be due to glaciation in Oregon from the Wisconsin glacial epoch, so Mathiasen and Daugherty reasoned that the Cascade Mountains’ glacial history may be the answer to the genetic shift and distribution between red fir and noble fir at latitude