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 European 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.
First, the sea cows may have been overhunted by groups of native Siberian people. If this theory is correct, then the sea cow population would have originally been quite large, but hundreds of years off too much hunting by the native people diminished the number of sea cows. Sea cows were a good source of food in a harsh environment, so overhunting by native people could have been the main cause of extinction.
Second, the sea cow population may have become extinct because of ecosystems disturbances that caused a decline in their main source of food, kelp (a type of sea plant). Kelp populations respond negatively to a number of ecological changes. It is possible that ecological changes near Bering island some time before 1768 caused a decrease of the kelp that the sea cows depend on.
Third, the main cause of extinction of the sea cows could have been European fur traders who came to the island after 1741. It is recorded that the fur traders caught the last sea cow in 1768. It thus seems reasonable to believe that hunting by European fur traders, who possessed weapons that allowed them to quickly kill a large number of the animals, was the main cause of the sea cow’s extinction.
The reading states three possible reasons would have occurred the extinction of sea cows and provides three reasons of support. the lecturer says that these reasons for extinction are not convincing and refutes each of the author's claims.
First of all, the article states that sea cow extinction would be happened by the overhunting of native Siberian people.
The article said that native people have occurred because Sea cow is the good sources of food in a harsh environment.
This specific argument is challenged by the lecturer. He says that It would not possible to extinct sea cows by the native people because sea cows are a massive and greater size. Additionally, He explains that sea cow is a 9 meter long and approximately 10 ton. So, a sea cow provides whole month food purposes and the native Siberian society has not been large society, thus they did not kill large
the number of sea cows.
Secondly, the article argues that kelp, a type of sea plant is a main source of food for sea cow had declined by the ecosystems disturbances and then sea cows become extinct. The lecturer, however, rebuts this claim that This hypothetical causes rarely happened because when it was happening in 1768, not only kelp was disturbance also
Other sea plants had declined but other animals like whales have not become any declination.
So, the lecturer says that since wales declining did not report hence sea cows would not decline for kelp disturbances.
Finally, The article posits that European fur traders use weapons that allowed quickly kill a large
number of animals and that could have occurred sea cow extinction. In contrast, the lecturer's position is that sea cow extinction has occurred before the European trader reaching the island. Moreover, he says that this extinction already happening before 100 years before so it is very speculating that sea cow's extinction mainly happened by the trades.
Grammar and spelling errors:
Line 1, column 129, Rule ID: UPPERCASE_SENTENCE_START
Message: This sentence does not start with an uppercase letter
Suggestion: The
... and provides three reasons of support. the lecturer says that these reasons for ex...
^^^
Line 9, column 315, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...w provides whole month food purposes and the native Siberian society has not been...
^^
Line 11, column 1, Rule ID: UPPERCASE_SENTENCE_START
Message: This sentence does not start with an uppercase letter
Suggestion: The
...society, thus they did not kill large the number of sea cows. Secondly, the ...
^^^
Line 25, column 1, Rule ID: UPPERCASE_SENTENCE_START
Message: This sentence does not start with an uppercase letter
Suggestion: Number
...ons that allowed quickly kill a large number of animals and that could have occurred...
^^^^^^
Line 25, column 308, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'cows'' or 'cow's'?
Suggestion: cows'; cow's
...fore so it is very speculating that sea cows extinction mainly happened by the trade...
^^^^
Transition Words or Phrases used:
also, but, finally, first, hence, however, if, moreover, second, secondly, so, then, thus, in contrast, first of all
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 12.0 10.4613686534 115% => OK
Auxiliary verbs: 5.0 5.04856512141 99% => OK
Conjunction : 8.0 7.30242825607 110% => OK
Relative clauses : 15.0 12.0772626932 124% => OK
Pronoun: 26.0 22.412803532 116% => OK
Preposition: 24.0 30.3222958057 79% => OK
Nominalization: 12.0 5.01324503311 239% => Less nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1621.0 1373.03311258 118% => OK
No of words: 320.0 270.72406181 118% => OK
Chars per words: 5.065625 5.08290768461 100% => OK
Fourth root words length: 4.22948505376 4.04702891845 105% => OK
Word Length SD: 2.57530148417 2.5805825403 100% => OK
Unique words: 156.0 145.348785872 107% => OK
Unique words percentage: 0.4875 0.540411800872 90% => More unique words wanted or less content wanted.
syllable_count: 493.2 419.366225166 118% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 4.0 3.25607064018 123% => OK
Article: 12.0 8.23620309051 146% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 1.0 2.5761589404 39% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 14.0 13.0662251656 107% => OK
Sentence length: 22.0 21.2450331126 104% => OK
Sentence length SD: 46.1886106643 49.2860985944 94% => OK
Chars per sentence: 115.785714286 110.228320801 105% => OK
Words per sentence: 22.8571428571 21.698381199 105% => OK
Discourse Markers: 8.28571428571 7.06452816374 117% => OK
Paragraphs: 10.0 4.09492273731 244% => Less paragraphs wanted.
Language errors: 5.0 4.19205298013 119% => OK
Sentences with positive sentiment : 5.0 4.33554083885 115% => OK
Sentences with negative sentiment : 5.0 4.45695364238 112% => OK
Sentences with neutral sentiment: 4.0 4.27373068433 94% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.135697524366 0.272083759551 50% => OK
Sentence topic coherence: 0.056628757762 0.0996497079465 57% => OK
Sentence topic coherence SD: 0.0319898872281 0.0662205650399 48% => Sentences are similar to each other.
Paragraph topic coherence: 0.0611585854197 0.162205337803 38% => Maybe some paragraphs are off the topic.
Paragraph topic coherence SD: 0.0302503201821 0.0443174109184 68% => OK
Essay readability:
automated_readability_index: 13.9 13.3589403974 104% => OK
flesch_reading_ease: 57.61 53.8541721854 107% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 10.7 11.0289183223 97% => OK
coleman_liau_index: 12.42 12.2367328918 101% => OK
dale_chall_readability_score: 8.23 8.42419426049 98% => OK
difficult_words: 71.0 63.6247240618 112% => OK
linsear_write_formula: 7.5 10.7273730684 70% => OK
gunning_fog: 10.8 10.498013245 103% => OK
text_standard: 11.0 11.2008830022 98% => OK
What are above readability scores?
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Maximum four paragraphs wanted.
Rates: 73.3333333333 out of 100
Scores by essay e-grader: 22.0 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.