The reading passage claims that many animals use various ways to migrate long distances and how they migrate is still a matter of debate. But there is a creature called humpback whale, which navigate by stars like early humans did. Indeed, there are several reasons why this creature use stars for navigation. However, the lecturer finds all the ideas dubious and presents some evidence to refute them all.
First, the lecturer holds the view that humpback whales are intelligent animals with well-developed cognitive ability, which allows them to navigate. In contrast, the lecturer underlines the idea that there is no connection between animals' intelligence and navigation owing to the fact that some other animals migrate in this way like ducks, which are not clever.
The author also embraces the idea that humpback whales migrate in straight lines and use physical landmarks to help them stay in a way. Conversely, the professor brings up the idea that these creatures are able to sense external forces like earth magnetite field. In fact, they have bio magnetite in their brains, which is sensitive to earth magnetite field. So, they use this sense to orient themselves in any direction.
Finally, as set forth by the author humpback whales use especial behavior dubbed as spy-hopping, which is rare among animals. This behavior allows the whale to float straight up and look at stars for navigation. On the contrary, the speaker dismisses this issue due to the fact that although it is rare, other animals do like humpback whales. In fact, sharks use this behavior for hunting or there are other animals which use this behavior during the day when there is no star.
Having scrutinized all the ideas, a logical conclusion that can be drawn is that there are pieces of evidence having been ignored by the author while the presence of which could strengthen the author's claim. 
The reading passage claims that  
many
  animals
  use
 various ways to  
migrate
 long distances and how they  
migrate
 is  
still
 a matter of debate.  
But
 there is a creature called humpback  
whale
, which navigate by stars like early humans did.  
Indeed
, there are several reasons why this creature  
use
 stars for navigation.  
However
, the lecturer finds all the  
ideas
 dubious and presents  
some
 evidence to refute them all. 
First
, the lecturer holds the view that humpback  
whales
 are intelligent  
animals
 with well-developed cognitive ability, which  
allows
 them to navigate.  
In contrast
, the lecturer underlines the  
idea
 that there is no  
connection between
 animals' intelligence and navigation owing to the  
fact
 that  
some
 other  
animals
  migrate
 in this way like ducks, which are not clever.
The author  
also
 embraces the  
idea
 that humpback  
whales
  migrate
 in straight lines and  
use
 physical landmarks to  
help
 them stay in a way.  
Conversely
, the professor brings up the  
idea
 that these creatures are able to sense external forces like earth magnetite field. In  
fact
, they have bio magnetite in their brains, which is sensitive to earth magnetite field.  
So
, they  
use
 this sense to orient themselves in any direction. 
Finally
, as set forth by the author humpback  
whales
  use
 especial  
behavior
 dubbed as spy-hopping, which is rare among  
animals
. This  
behavior
  allows
 the  
whale
 to float straight up and look at stars for navigation.  
On the contrary
, the speaker dismisses this issue due to the  
fact
 that although it is rare, other  
animals
 do like humpback  
whales
. In  
fact
, sharks  
use
 this  
behavior
 for hunting or there are other  
animals
 which  
use
 this  
behavior
 during the day when there is no star.
Having scrutinized all the  
ideas
, a logical conclusion that can  
be drawn
 is that there are pieces of evidence having been  
ignored
 by the author while the presence of which could strengthen the author's claim.