Let's break down the argument.
1.
New methods developed in genetic research have led taxonomists to revise their views on the evolutionary relationships between many species. (the main premise leading us to the info that - new techniques have led to a revision of the old understanding) 2.
Traditionally the relatedness of species has been ascertained by a close comparison of their anatomy. (Info about traditional) 3.
The new methods infer the closeness of any two species’ relationship to each other directly from similarities between the species’ genetic codes.(Info about new method) Hence the author wants to put the focus on the fact that for whatever reason - something that could not be caught by the anatomical similarity in the old technique has been thought to be cleared up by the new (genetic code based) method and has lead to a "revision of views"
We are looking for a conclusion that the author would make based on above information - A. The apparent degree of relatedness of some species, as determined by anatomical criteria, is not borne out by their degree of genetic similarity.
HOLD - sounds complex on first reading. Correct choice! Two species which "were apparently related" as per the (old method) anatomical criteria is not upheld by the new method of genetic similarity and this is where the two methods diverge.B. When they know the differences between two species’ genetic codes, taxonomists can infer what the observable anatomical differences between those species must be.
TRAP - this reads that the new approach has helped get a better understanding of the old one - this is not the case as there is a "revision of views" and hence the two approaches are not in sync but the new approach has replaced the old one.C. The degree to which individuals of the same species are anatomically similar is determined more by their genetic codes than by such environmental factors as food supply.
Unnecessary comparison - we are not talking about enviornmental factors and hence this is out of scope.D. The traditional anatomical methods by which taxonomists investigated the relatedness of species are incapable of any further refinement.
Too extreme - the old appraoch can possibly be refined but the argument the author is making is about new vs. old. Discard.E. Without the use of genetic methods, taxonomists would never be able to obtain any accurate information about species’ degrees of relatedness to one another.
Too extreme - "will never be able to ontain any accurate information" is too harsh as the old approach does work but only fails with respect to the new one in certain cases. Discard.Hope this helps!
carcass wrote:
New methods developed in genetic research have led taxonomists to revise their views on the evolutionary relationships between many species. Traditionally the relatedness of species has been ascertained by a close comparison of their anatomy. The new methods infer the closeness of any two species’ relationship to each other directly from similarities between the species’ genetic codes.
Which of the following conclusions is best supported by the information?
A. The apparent degree of relatedness of some species, as determined by anatomical criteria, is not borne out by their degree of genetic similarity.
B. When they know the differences between two species’ genetic codes, taxonomists can infer what the observable anatomical differences between those species must be.
C. The degree to which individuals of the same species are anatomically similar is determined more by their genetic codes than by such environmental factors as food supply.
D. The traditional anatomical methods by which taxonomists investigated the relatedness of species are incapable of any further refinement.
E. Without the use of genetic methods, taxonomists would never be able to obtain any accurate information about species’ degrees of relatedness to one another.