The author of the argument purportedly highlights that the major reason of extinction of mammal species is human's hunting when they arrived in Kaliloe Island 7000 years ago. However, the premises upon which he puts his claim are fallacious.
The first assumption that lacks some semblance of truth and can be overtly impugned is that humans arrived in Kaliloe by 7000 years ago and by 3000 years many species extinct enormously. However, it does not lend credence to the argument since there are many reasons that could result in extinction and the author does not provide any information about extinction. In fact, climate change, the paucity of foods, natural disasters like earthquake or flood and so forth, may play a consequential role in the extinction of mammal species. Indeed, there is no cogent reason to prove allegedly that human intervention is the only factor of mammal extinction.
The author also attributes that archaeologists have found majorities of a site that represent bones of fishes and prove that early humans relied on fish and hunting. Although it might seem tenable at a face, it has some defects since there would many reasons for remaining of bones. Indeed, there is a possibility that fishes died because of water contamination or drought. These two factors are enough to die out the population of any species. Alongside that maybe ecological mutation be the other reason for fishes' bones, who knows? Even if human relied on fishes, it is not logical to assume that they feed on fish for thousands of years.
Putting the two previous assumptions aside, there is still room for doubt. As set forth by the author researchers have discovered simple tools like stone knives that early people used for hunting. Nevertheless, the rationale behind this premise could be challenged since there might be another purpose to use stone knives. Maybe they used this tools in order to protect themselves against attacks, or maybe religious value, who knows? Also, we all know that hunting needs many skills and the author does not provide any data about early humans' skills. Maybe they did not have enough skill to hunt and used stone knives just for other purposes.
Having scrutinized the premises, a logical conclusion that can be drawn is that the author has ignored the number of assumption, the presence of which could strengthen the author's claim. 
The  
author
 of the argument  
purportedly
 highlights that the major  
reason
 of  
extinction
 of mammal species is human's  
hunting
 when they arrived in  
Kaliloe
 Island 7000 years ago.  
However
, the premises upon which he puts his claim are fallacious.
The  
first
 assumption that lacks  
some
 semblance of truth and can be  
overtly
 impugned is that  
humans
 arrived in  
Kaliloe
 by 7000 years ago and by 3000 years  
many
 species extinct  
enormously
.  
However
, it does not lend credence to the argument since there are  
many
  reasons
 that could result in  
extinction
 and the  
author
 does not provide any information about  
extinction
. In fact, climate  
change
, the paucity of foods, natural disasters like earthquake or flood and  
so
 forth, may play a consequential role in the  
extinction
 of mammal species.  
Indeed
, there is no cogent  
reason
 to prove allegedly that  
human
 intervention is the  
only
 factor of mammal extinction.
The  
author
  also
 attributes that archaeologists have found majorities of a site that represent bones of fishes and prove that early  
humans
 relied on fish and  
hunting
. Although it might seem tenable at a face, it has  
some
 defects since there would  
many
  reasons
 for remaining of bones.  
Indeed
, there is a possibility that fishes  
died
  because
 of water contamination or drought. These two factors are  
enough
 to  
die
 out the population of any species. Alongside that maybe ecological mutation be the other  
reason
 for fishes' bones, who knows? Even if  
human
 relied on fishes, it is not logical to assume that they feed on fish for thousands of years.
Putting the two previous assumptions aside, there is  
still
 room for doubt. As set forth by the  
author
 researchers have discovered simple tools like stone knives that early  
people
  used
 for  
hunting
.  
Nevertheless
, the rationale behind this premise could  
be challenged
 since there might be another purpose to  
use
 stone knives. Maybe they  
used
 this tools in order to protect themselves against attacks, or maybe religious value, who knows?  
Also
, we all know that  
hunting
 needs  
many
  skills
 and the  
author
 does not provide any data about early humans'  
skills
. Maybe they did not have  
enough
  skill
 to hunt and  
used
 stone knives  
just
 for other purposes.
Having scrutinized the premises, a logical conclusion that can  
be drawn
 is that the  
author
 has  
ignored
 the number of assumption, the presence of which could strengthen the author's claim.