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 extinct. The reasons for the extinction are not clear. Here are three theories about the main cause of the extinction.
The reading provides some claims about the main causes of the extinction of Steller's sea cow, who was a huge marine mammal used to live in parts of Siberian seas. However, the lecture finds all the ideas dubious and refute them all.
First, the author argues that overhunting of Siberian people can be the cause of the sea cows extinction since these animals were a proper source of food in the Siberian harsh climate. Conversely, lecturer brings the idea that the sea cows were massive animals so that one sea cow could feed all the people of that village. In the other hand, that villages were were small with a small population and did not need to hunt much of them.
Furthermore, the reading passage holds the view that ecosystem disturbances were another possible reason of the sea cow extinction, and because of this disturbances the amount of kelp, which was the main source of sea cows food, was enormously decreased. On the contrary, the professor underlines the fact that if this sever situation had happened, the number of other marine animals like Wales should have declined. In other words, the other plants should have been affected by this these disturbances, not just Kepls. However, there is no evidence about the food shortage at that time.
Finally, the reading asserts that European fur trade was the main reason for the extinction since European fur traders were well equipped so that they could hunt a large number of animals in a short time. In contrast, the speaker dismisses this issue due to the fact by the time of the arrival of the European fur traders, the number of sea cows was already small. It has been indicated that before the 1700s, the decline in the number of these animals was ongoing.
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Grammar and spelling errors:
Line 2, column 357, Rule ID: ENGLISH_WORD_REPEAT_RULE
Message: Possible typo: you repeated a word
Suggestion: were
...llage. In the other hand, that villages were were small with a small population and did n...
^^^^^^^^^
Line 2, column 362, Rule ID: BEEN_PART_AGREEMENT[1]
Message: Consider using a past participle here: 'been'.
Suggestion: been
.... In the other hand, that villages were were small with a small population and did n...
^^^^
Line 3, column 148, Rule ID: THIS_NNS[1]
Message: Did you mean 'these'?
Suggestion: these
... the sea cow extinction, and because of this disturbances the amount of kelp, which ...
^^^^
Line 4, column 163, Rule ID: LARGE_NUMBER_OF[1]
Message: Specify a number, remove phrase, or simply use 'many' or 'numerous'
Suggestion: many; numerous
...e well equipped so that they could hunt a large number of animals in a short time. In contrast, t...
^^^^^^^^^^^^^^^^^
Transition Words or Phrases used:
conversely, finally, first, furthermore, however, if, so, well, in contrast, in other words, on the contrary
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 16.0 10.4613686534 153% => OK
Auxiliary verbs: 6.0 5.04856512141 119% => OK
Conjunction : 3.0 7.30242825607 41% => More conjunction wanted.
Relative clauses : 13.0 12.0772626932 108% => OK
Pronoun: 22.0 22.412803532 98% => OK
Preposition: 39.0 30.3222958057 129% => OK
Nominalization: 7.0 5.01324503311 140% => OK
Performance on vocabulary words:
No of characters: 1435.0 1373.03311258 105% => OK
No of words: 300.0 270.72406181 111% => OK
Chars per words: 4.78333333333 5.08290768461 94% => OK
Fourth root words length: 4.16179145029 4.04702891845 103% => OK
Word Length SD: 2.37292833623 2.5805825403 92% => OK
Unique words: 156.0 145.348785872 107% => OK
Unique words percentage: 0.52 0.540411800872 96% => OK
syllable_count: 441.9 419.366225166 105% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 11.0 8.23620309051 134% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 4.0 2.5761589404 155% => OK
Performance on sentences:
How many sentences: 12.0 13.0662251656 92% => OK
Sentence length: 25.0 21.2450331126 118% => OK
Sentence length SD: 53.6135218226 49.2860985944 109% => OK
Chars per sentence: 119.583333333 110.228320801 108% => OK
Words per sentence: 25.0 21.698381199 115% => OK
Discourse Markers: 9.0 7.06452816374 127% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 4.0 4.19205298013 95% => OK
Sentences with positive sentiment : 6.0 4.33554083885 138% => OK
Sentences with negative sentiment : 5.0 4.45695364238 112% => OK
Sentences with neutral sentiment: 1.0 4.27373068433 23% => More facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.202541607588 0.272083759551 74% => OK
Sentence topic coherence: 0.0731779903217 0.0996497079465 73% => OK
Sentence topic coherence SD: 0.0701975323836 0.0662205650399 106% => OK
Paragraph topic coherence: 0.129273135402 0.162205337803 80% => OK
Paragraph topic coherence SD: 0.0393237862766 0.0443174109184 89% => OK
Essay readability:
automated_readability_index: 13.6 13.3589403974 102% => OK
flesch_reading_ease: 54.56 53.8541721854 101% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 11.9 11.0289183223 108% => OK
coleman_liau_index: 10.74 12.2367328918 88% => OK
dale_chall_readability_score: 7.67 8.42419426049 91% => OK
difficult_words: 53.0 63.6247240618 83% => More difficult words wanted.
linsear_write_formula: 13.0 10.7273730684 121% => OK
gunning_fog: 12.0 10.498013245 114% => OK
text_standard: 12.0 11.2008830022 107% => OK
What are above readability scores?
---------------------
Rates: 80.0 out of 100
Scores by essay e-grader: 24.0 Out of 30
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.