Question

Evolution

You work for a forestry department. Your colleague asks your opinion of a proposal to use artificial selection to breed a population of lodgepole pines that are resistant to the mountain pine beetle. They have managed to clone a large number of seedling lodgepole pines all from a single parent. They want to take those clones that are most resistant to the mountain pine beetle and breed those together and then use this next generation to replant in a national park. Will this proposal work? Briefly justify your answer

Answer 1

In my opinion, a proposal to use artificial selection to breed a population of lodgepole pines that are resistant to the mountain pine beetle has positive potential to work.

Justification:

Selective breeding (also called artificial selection) is a promising advent as it selectively develops a pure phenotypic trait/characteristic in the seedling of lodgepole pines from a single parent. The use of resistant lodgepole pines seedling clones against the mountain pine beetle by breeding them together put a selection pressure for the endurance of best phenotype. The genetically selected next resistant generation can be successfully used to replant a national park. Though, the success of this proposal depends upon following key conditions:

• If clone selection begins early in the life of lodgepole pines as older tress have sustained beetle infestations which remove the most vigorous element from the trees.
• If parent lodgepole pines is devoid of serotinous process (an ecological adaptation in which seed release occurs in response to an environmental trigger e.g. fire, rather than spontaneously at seed maturation) in its life span.
• If a pilot study could ascertain the propagation of best phenotypes in selected seedlings as great does exist in lodgepole pines. An understanding of the resistance mechanisms may also reveal underlying phenotypic markers (such as ellagic acid, a fungistatic compound, in coast live oak; Quercus agrifolia) that can be measured and used to predict a tree's response to attack by mountain pine beetle in future.
• Presence of constitutive defence mechanisms in lodgepole pine seedlings against mountain pine beetle which deter their infection and hence more plantation success.