A huge marine mammal known as Steller’s sea cow once lived in the waters around Bering Island off the coast of Siberia. It was described in 1741 by Georg W. Steller, a naturalist who was among the first Europeans to see one. In 1768 the animal became ex

The lecturer argued each of the theories which were made to explain the extinction of sea cows in the reading article. Those theories assume that the extinction was caused by overhunting by natives, the shortage of food support, or hunting by traders with new weapons. However, the lack of evidence questioned theories above.

First, it claimed that sea cows was the main food sources for native Siberian people, and sea cows had been overhunted by them. Yet it is true that Siberian people hunted sea cows for life-sustaining, the problem is that sea cows are large mammals. This huge marine mammal weights ten tons and the population of Siberian people were not large. Thus, one sea cow is sufficient for small Siberian village to live in a long periods of time.

The second theory developed by the research on the food sources of sea cows. Kelp is the main food sources of this huge marine mammal, and it said because of the ecosystems disturbances that caused a decline of them. However, this theory is insufficient since there is no further evidence report that there was a wide range of decline of other animals or plants which inhabited in Bering Island.

The third theory was based on the historical event. Notwithstanding the European fur traders came to this island after 1741, and with new weapons can kill large amount of sea cows easily, the evidence shows that the population of sea cows declined drastically before the traders entered this area. In this case, the causation of sea cows population can be other factors which existed before the coming of the fur traders.

Reasons above explain the flaws in those three theories. Further evidences are needed to fully explain the mysterious extinction of sea cows during 1700s around Berlin Island.

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Notwithstanding the European fur traders came to this island after 1741, and with new weapons can kill large amount of sea cows easily
Notwithstanding the European fur traders came to this island after 1741, and with new weapons they can kill large amount of sea cows easily

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No. of Words: 298 250 //doesn't need the conclusion paragraph.

Attribute Value Ideal
Score: 26 in 30
Category: Very Good Excellent
No. of Grammatical Errors: 1 2
No. of Spelling Errors: 0 2
No. of Sentences: 15 12
No. of Words: 298 250
No. of Characters: 1433 1200
No. of Different Words: 150 150
Fourth Root of Number of Words: 4.155 4.2
Average Word Length: 4.809 4.6
Word Length SD: 2.46 2.4
No. of Words greater than 5 chars: 105 80
No. of Words greater than 6 chars: 73 60
No. of Words greater than 7 chars: 38 40
No. of Words greater than 8 chars: 22 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 19.867 21.0
Sentence Length SD: 8.172 7.5
Use of Discourse Markers (%): 0.467 0.12
Sentence-Text Coherence: 0.355 0.35
Sentence-Para Coherence: 0.622 0.50
Sentence-Sentence Coherence: 0.129 0.07
Number of Paragraphs: 5 4