207It is known that in recent years, industrial pollution has caused the Earth's ozone layer to thin, allowing an increase in the amount of ultraviolet radiation that reaches the Earth's surface. At the same time, scientists have discovered, the population of a species of salamander that lays its eggs in mountain lakes has declined. Since ultraviolet radiation is known to be damaging to delicate tissues and since salamander eggs have no protective shells, it must be the case that the increase in ultraviolet radiation has damaged many salamander eggs and prevented them from hatching. This process will no doubt cause population declines in other species, just as it has in the salamander species.

In this argument,the author concluded that many species of animals’ population will declines .To justify this conclusion,the author pointed out that the Earth’s ozone layer had been thinner because of the industrial pollution, the author also cited the study about recent years the decrease of the population of one species of salamander that lays eggs in mountain lakes.However,this argument suffers from several doubtful flaws,and is therefore unconvincing.

In the first place,the author fallacious assumes that the population of total salamander eggs declined. No evidence is offered to substantiate the specie of salamander who lays its eggs in mountain lakes can represent the whole species. It’s entirely possible that some of the others’ population had increased thus the whole population of salamander has been sprouted.

Secondly,mere fact that many salamander eggs has been damaged is insufficient evidence to conclude that it’s because of the ultraviolet radiation. It’s quite possible for the water pollution or the increase of shipment. Unless the author can provide other valid evidence concerning the relation between the decrease of salamander’s eggs and the increase of the ultraviolet radiation,the assumption is open to doubt.

Finally,even assuming the ultraviolet radiation is the reason to the death of the salamander eggs,the author provides no evidence to indicate that other species will face the same problem. As the argument mentioned that the salamander eggs have been damaged since they have no protective shells, then the spcies,whose eggs have shells,wont have this problem.Inversely,as everybody knows, the ultraviolet radiation can bring many benefits to some species’ growth.

In sum,this argument is unpersuasive as it stands.To bolster this conclusion,the author must show the relations concerning the environment and animals. To better evaluate this argument,we need more information about the studies not only to the salamander but also other different species.