Experts have differed about where the genus Varanus

Experts have differed about where the genus Varanus (monitor lizards) originated. Because most existing species live in Australia, early researchers concluded that Varanus originated in Australia and subsequently island hopped westward along the Indo-Australian archipelago. Herpetologist Robert Mertens later argued that Varanus probably originated in the archipelago. Chromosomal analysis has since supported Mertens’ contention, and in addition, geologic evidence points to a collision between the archipelago and the Australian landmass after Varanus evolved—a fact that could account for the genus’ present distribution.

A related puzzle for scientists is the present distribution of Varanus’ largest surviving species, the Komodo dragon. These carnivores live only on four small islands in the archipelago where, scientists note, the prey base is too small to support mammalian carnivores. But the Komodo dragon has recently been shown to manage body temperature much more efficiently than do mammalian carnivores, enabling it to survive on about a tenth of the food energy required by a mammalian carnivore of comparable size.


1. It can be inferred from the passage that the geographical distribution of the Komodo dragon is

A) currently less restricted than it was at the time researchers first began investigating the origins of the genus Varanus
B) currently more restricted than it was at the time researchers first began investigating the origins of the genus Varanus-if this assumption established, then it means that “ when these researcher first began investigating the origins of the genus Varanus”, the geographical distribution of the Komodo dragon is “less restricted”, however, we don’t know for sure that whether its true or not, we can only infer from the beginning of the second paragraph that “present distribution does very restricted
(comparing to the distribution of the genus Varanus as a whole, since they live on the whole archipelago…)

C) less restricted than is the distribution of the genus Varanus as a whole
D) more restricted than is the distribution of the genus Varanus as a whole
E) viewed as evidence in favor of the hypothesis that the genus Varanus originated in the Indo-Australian archipelago


2. Which of the following elements in the debate over the origin of Varanus is NOT provided in the passage?- not limit only to passage one or two..

(A) The evidence that led Mertens to argue that Varanus originated in the Indo-Australian archipelago
 Robert Mertens later argued that Varanus probably originated in the archipelago. Chromosomal analysis has since supported Mertens’ contention…so further analysis support Mertons argument, not the evidence earlier led Mertons to argue that Varanus originated in the Indo-Australian archipelago…???

B) The evidence that led early researchers to argue that Varanus originated in Australia
C) A possible explanation of how Varanus might have spread to the Indo- Australian archipelago if it had originated in Australia
D) A possible explanation of how Varanus might have spread to Australia if it had originated in the Indo-Australian archipelago(para1 lower part)

E) An indication of the general present-day distribution of Varanus species between Australia and the Indo-Australian archipelago-para1, last sentence

3. It can be inferred that which of the following is true of the “geologic evidence” (Highlighted) ?

A) It was first noted by Mertens as evidence in favor of his theory about the origins of Varanus.
B) It cannot rule out either one of the theories about the origins of Varanus discussed in the passage.
 collision between the archipelago and the Australian landmass after Varanus evolved, so theory 1&2(origin from Australia or
Archipelago) cannot be ruled out
In passage 1,
theory 1 early researcher
AustraliaIndo-Australian archipelago
theory 2herpetologist Mertons
originate Indo-Australia archipelago, then spread to Australia(because of collision)

C) It accounts for the present distribution of the Komodo dragon.
I don’t know why this option is wrong
somebody explain thus
it could account but we can't say for sure
geologic evidence points to a collision between the archipelago and the Australian landmass after Varanus evolved—a fact that could account for the genus’ present distribution.
maybe present distribution of ‘Komodo dragon” isn’t same as “genus”???it is only a subset belonging to a larger group--genus

D) It has led to renewed interest in the debate over the origins of Varanus.
E) It confirms the conclusions reached by early researchers concerning the origins of Varanus