Divyadisha wrote:
Can anyone please help me with this CR.
I chose 'A' as my answer because paleontologists reached to the conclusion, based on fossil record, that B and D are related after finding similar characteristic in them.
Dinosaur expert disagree with paleontologist.
Can't 'A' by the assumption that similar characteristics doesn't mean B and D are evolutionary related. Even if we negate the statement, it breaks down expert's conclusion.
I did'nt get why 'D' is the answer. What is the fossils have relative dates of origin? Does that mean B and D can't be related? Nothing in support of this is present in the argument.
Lets try -
Quote:
Dinosaur expert: Some paleontologists have claimed that birds are descendants of a group of dinosaurs called dromeosaurs. They appeal to the fossil record, which indicates that dromeosaurs have characteristics more similar to birds than do most dinosaurs. But there is a fatal flaw in their argument; the earliest bird fossils that have been discovered date back tens of millions of years farther than the oldest known dromeosaur fossils. Thus the paleontologists' claim is false'.
Dinosaur expert's claim that birs are descendants of a group of dinosaurs called dromeosaurs is proved by -
Quote:
fossil record, which indicates that dromeosaurs have characteristics more similar to birds than do most dinosaurs.
But the flaw with the reasoning of the Dinosaur expert is -
Quote:
earliest bird fossils that have been discovered date back tens of millions of years farther than the oldest known dromeosaur fossils.
Bird fossils =====tens of millions of years======dromeosaur fossils.If Bird fossils> dromeosaur fossils{ Bird fossils existed before fossils of dromeosaur fossils } then the argument put forward by the Dinosaur expert is flawed.Our argument here completely relies on the fossils of birds vs dromeosaur.Now go through options (A) and (D) { Not going through all the options }
(A) Having similar characteristics is not a sign that types of animals are evolutionary related.The stimulus presented to us talks about the fossil record to prove that the Dinosaur expert's reasoning is fasle. The author proves the fact by the use of the relative dates of origin of birds and dromeosaurs fossils in support of his reasoning.
Similar characteristics may be a sign of evolutaionary impact of birds/dromeosaurs but may we can not be 100% certain about it because the author uses scientific methods { dating fossils of birds and dromeosaurs }
(D) Known fossils indicate the relative dates of origin of birds and dromeosaurs.
Try to negate this option.
Known fossils do not indicate the relative dates of origin of birds and dromeosaurs.
If fossil records do not indicate the relative dates of origin of birds and dromeosaurs then the argument put forward by the author falls apart.
Hence IMHO (D)Loved the detailed explanation, and I really appreciate this effort.
However, one more query on the statement- 'earliest bird fossils that have been discovered date back tens of millions of years farther than the oldest known dromeosaur fossils.' - is that isn't it states the difference between the time of discovery of these fossils? Now the possibility is that bird's fossils were discovered first (tens of millions of year before D's fossils) or dremosaur's fossils were discovered first (bird's fossils were discovered tens of millions of year after D's fossil). The statement doesn't tell us that which fossil was discovered first.
I welcome critical analysis of my post!! That will help me reach 700+