adkikani wrote:
GMATNinja
I am finding it difficult to stay engaged in passage, especially ones like this.
Can you help implementation of taking notes by identifying passage structure based on your post:
https://gmatclub.com/forum/experts-topi ... l#p1857560
Can you explain last sentence of passage and Q3 in light in your understanding?
In playing more safely to not deviate from author's view I am trying to do exactly what is not recommended: facts - facts - facts; and hence missing crucial flow.
WR,
Arpit
In this passage, it is tricky to apply the techniques recommended in the
Ultimate RC Guide for Beginners because we only have one paragraph!
In this case, you might break down the passage into logical chunks and ask yourself WHY the author has written each chunk:
Quote:
While the most abundant and dominant species within a particular ecosystem is often crucial in perpetuating the ecosystem, a “keystone” species, here defined as one whose effects are much larger than would be predicted from its abundance, can also play a vital role. But because complex species interactions may be involved, identifying a keystone species by removing the species and observing changes in the ecosystem is problematic.
Okay, so it looks like the author is trying to introduce/define the concept of a "keystone" species and to tell us that identifying/studying a keystone species using a seemingly simple approach is actually problematic. So you might jot down: "introduce/define "keystone" species; identifying/studying K.S. by removing/observing is problematic".
Great, that gives us an idea of WHY the author wrote that first chunk. Even though we might not completely understand every detail, let's move on to the next chunk:
Quote:
It might seem that certain traits would clearly define a species as a keystone species; for example, Pisaster ochraceus is often a keystone predator because it consumes and suppresses mussel populations, which in the absence of this starfish can be a dominant species. But such predation on a dominant or potentially dominant species occurs in systems that do as well as in systems that do not have species that play keystone roles.
The purpose of this chunk is described in the first sentence. The author wants us to realize that even though it might
seem that certain traits would clearly define a species as a keystone species, those traits do not necessarily indicate that we have a keystone species. So you might jot down: "cannot determine K.S. solely by identifying certain traits".
Quote:
Moreover, whereas P. ochraceus occupies an unambiguous keystone role on wave-exposed rocky headlands, in more wave-sheltered habitats the impact of P. ochraceus predation is weak or nonexistent, and at certain sites sand burial is responsible for eliminating mussels. Keystone status appears to depend on context, whether of particular geography or of such factors as community diversity (for example, a reduction in species diversity may thrust more of the remaining species into keystone roles) and length of species interaction (since newly arrived species in particular may dramatically affect ecosystems).
The same species can be keystone in some habitats and not keystone in other habitats. Keystone status depends not solely on certain traits but rather on context (i.e. geography and community diversity). The purpose of this chunk is to explain that "keystone status depends on habitat/geography, community diversity, and other factors".
Okay, so we have
Chunk 1: "introduce/define "keystone" species; identifying/studying K.S. by removing/observing is problematic"
Chunk 2: "cannot determine K.S. solely by identifying certain traits"
Chunk 3: "keystone status depends on habitat/geography, community diversity, and other factors"
Now, what is the purpose of the passage as a whole? It seems like the author wants to introduce the concept of a keystone species and then explain and provide evidence to support that determining keystone status is not a simple task. So, for the purpose of the passage, you might write: "introduce/define "keystone" species; show that determining keystone status is complex".
Hopefully that helps you get your head around this complicated passage without getting bogged down in the details!
See if question #3 makes more sense in light of this analysis. As a starting point, remind yourself of the purpose of that chunk (chunk #3).
I hope that helps!