At the end of the Triassic period 200 million years ago, there was a mass-extinction event that caused the extinction of more than half of all living species. It was this extinction event that allowed dinosaurs to become the dominant species for the next 145 million years. We do not know exactly what happened that eliminated so many species in a relatively short period of time, but there are several possible explanations.
One theory involves the decline of sea levels. Near the end of the Triassic period, sea levels were fluctuating. When sea levels fall, the habitats for ocean populations that live in the shallows and land species that live on the coast are destroyed. The destruction of coastal and shallow-ocean species would have had a profound effect on food chains worldwide, leading to mass extinctions.
Another theory involves massive climate cooling. The end of the Triassic period was marked by widespread volcanic activity. The volcanoes released large amounts of sulfur dioxide (SO2). A rise in atmospheric SO2 is known to cause a lowering in global temperatures. Such climate change could have devastated many species and led to the extinctions.
The third theory involves an asteroid strike. Asteroids (objects from outer space) occasionally collide with Earth. When an asteroid hits Earth’s surface, it often displaces large amounts of soil and crushed rock, leaving behind a depression, or crater. The displaced debris is thrown up into the atmosphere where it can block out sunlight for many months or even a few years. A sufficiently massive asteroid impact at the end of the Triassic period may have blocked sunlight long enough for most plants to die and many animal species to then starve.
Both the reading passage and the lecture discuss the possible explanations of mass extinction in the Triassic period. The passage proposes three explanations to account this phenomenon. However, the professor in the lecture casts doubt on all the explanations mentioned in the passage.
First of all, the passage states that the decline of sea levels could be the cause of the mass extinctions, since the fluctuation of the sea levels could destroyed the habitats for ocean populations. Nevertheless, the professor counters the passage by arguing that species that live in the costal ecosystem are good at adapting the fluctuation of sea levels. Moreover, the decline of sea levels happened gradually, yet only sudden decline was able to cause mass extinction.
Secondly, the passage claims that massive climate cooling could be the reason for mass extinctions, since the Triassic period was marked by widespread volcanic activity, and volcanoes released large amounts of sulfur dioxide, which is known to cause a lowering in global temperatures. Notwithstanding, the professor disagrees with the passage. Since sulfur dioxide clear out quickly from the atmosphere, it is unlikely that sulfur dioxide could stay long enough to cause massive climate cooling.
Finally, the passage mentions that asteroid strike is the candidate that caused mass extinctions. Since the collision from asteroid could displace large amounts of soil and crushed rock, those displaced debris can block out sunlight for a long time. However, the professor refutes the passage by pointing out that most of craters found by scientists were formed two to three million earlier than the mass extinction. Thus, asteroid strike cannot be the convincing reason.
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Grammar and spelling errors:
Line 3, column 155, Rule ID: DID_BASEFORM[1]
Message: The verb 'could' requires the base form of the verb: 'destroy'
Suggestion: destroy
...the fluctuation of the sea levels could destroyed the habitats for ocean populations. Nev...
^^^^^^^^^
Line 7, column 315, Rule ID: MOST_SOME_OF_NNS[1]
Message: After 'most of', you should use 'the' ('most of the craters') or simply say ''most craters''.
Suggestion: most of the craters; most craters
...efutes the passage by pointing out that most of craters found by scientists were formed two to ...
^^^^^^^^^^^^^^^
Transition Words or Phrases used:
finally, first, however, moreover, nevertheless, second, secondly, so, thus, first of all
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 10.0 10.4613686534 96% => OK
Auxiliary verbs: 7.0 5.04856512141 139% => OK
Conjunction : 4.0 7.30242825607 55% => More conjunction wanted.
Relative clauses : 9.0 12.0772626932 75% => More relative clauses wanted.
Pronoun: 11.0 22.412803532 49% => OK
Preposition: 36.0 30.3222958057 119% => OK
Nominalization: 5.0 5.01324503311 100% => OK
Performance on vocabulary words:
No of characters: 1472.0 1373.03311258 107% => OK
No of words: 268.0 270.72406181 99% => OK
Chars per words: 5.49253731343 5.08290768461 108% => OK
Fourth root words length: 4.04607285448 4.04702891845 100% => OK
Word Length SD: 2.79276026775 2.5805825403 108% => OK
Unique words: 143.0 145.348785872 98% => OK
Unique words percentage: 0.533582089552 0.540411800872 99% => OK
syllable_count: 440.1 419.366225166 105% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 9.0 8.23620309051 109% => OK
Subordination: 4.0 1.25165562914 320% => Less adverbial clause wanted.
Conjunction: 2.0 1.51434878587 132% => OK
Preposition: 4.0 2.5761589404 155% => OK
Performance on sentences:
How many sentences: 13.0 13.0662251656 99% => OK
Sentence length: 20.0 21.2450331126 94% => OK
Sentence length SD: 61.2654521023 49.2860985944 124% => OK
Chars per sentence: 113.230769231 110.228320801 103% => OK
Words per sentence: 20.6153846154 21.698381199 95% => OK
Discourse Markers: 6.84615384615 7.06452816374 97% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 2.0 4.19205298013 48% => OK
Sentences with positive sentiment : 1.0 4.33554083885 23% => More positive sentences wanted.
Sentences with negative sentiment : 8.0 4.45695364238 179% => 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: 0.158853401132 0.272083759551 58% => OK
Sentence topic coherence: 0.0534471942334 0.0996497079465 54% => OK
Sentence topic coherence SD: 0.0450799403241 0.0662205650399 68% => OK
Paragraph topic coherence: 0.0901258074864 0.162205337803 56% => OK
Paragraph topic coherence SD: 0.0240335529056 0.0443174109184 54% => OK
Essay readability:
automated_readability_index: 14.7 13.3589403974 110% => OK
flesch_reading_ease: 51.18 53.8541721854 95% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 11.1 11.0289183223 101% => OK
coleman_liau_index: 14.56 12.2367328918 119% => OK
dale_chall_readability_score: 9.05 8.42419426049 107% => OK
difficult_words: 75.0 63.6247240618 118% => OK
linsear_write_formula: 11.5 10.7273730684 107% => OK
gunning_fog: 10.0 10.498013245 95% => OK
text_standard: 15.0 11.2008830022 134% => OK
What are above readability scores?
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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.