Self-study
Many bird and reptile species use hissing as a threat device against potential predators. ███ ███ █████ ███████ ███████ ███████ ██████ ██ ███████ ██████ ████ ██ ██ ██████ ████ ████ ████████ █████████ ██ ██ █████ ██████ █████████ ██ ███ ████ ████ ██████ ████████ █████ ████ ██████ ████████ ████ ██ ███ █████████ █████████ █████ ████ ███ ████████ ███ ███████ █████████ ██ ████ ███████ ███████
"Surprising" Phenomenon
Even though some bird and reptile species’ use of hissing as a threat device is likely to have developed in an early common ancestor, that common ancestor’s predators would not have been able to hear such hissing sounds.
Objective
The right answer will provide an alternate explanation for the common ancestor’s hissing. It will be a hypothesis that explains how the common ancestor’s hissing might have been useful as a threat device against potential predators, even though those predators could not hear the hissing.
25.
Which one of the following, ██ █████ ████ █████ ██ ███████ ███ ████████ ███████████ ██ ███ ███████████ ██████
a
Like its potential ██████████ ███ ██████ ████████ ██ ████ ███ ███████ ███████ █████ ████ ██████ ███ ███████ █████████ ██ ████ ███████ ███████
The common ancestor’s inability to hear its own hissing does not provide any explanation for why it would have developed hissing in the first place. We need an answer that explains why hissing was advantageous for the common ancestor, even though its predators couldn’t hear it.
b
The common ancestor ██ ████ ███ ███████ ███████ █████ ████████ ████ ████████ ████████ ██████ ███████ ███████ █████████ ██████████
Even if the common ancestor defended itself in other ways, we still need an explanation for why the common ancestor developed hissing as a threat device even though its predators could not hear it. There must be some other reason for using hissing as a threat device.
c
The production of █ ███████ █████ █████ ████ █████████ ███ ████████ ████ ████ ██ ███ ██████ ████████ ██ ████ ███ ███████ ████████
This gives a reason why the common ancestor’s hissing might have been useful against predators: it made the animal seem larger. This explains why it developed hissing sounds, even though its predators couldn’t hear them.
d
The use of ███████ ██ █ ██████ ██████ █████ ████ ████ ████ █████████████ ██████ ████ █████ ██████ █████████ █████████ ██ ███ ██████ ████████ ██ ████ ███ ███████ ████████
Whether hissing was energetically costly does not explain why the common ancestor used it as a threat device even though predators couldn’t hear it. We need an answer that gives a different reason for using hissing as a threat device.
e
Unlike most modern ████ ███ ███████ ████████ ███ ██████ ████████ ██ █████ ███████ █████ ████ ███ ███ ██████████
Even if the common ancestor had few predators, it would still have needed to defend itself against those predators. So, we still need an alternate reason that explains why the common ancestor developed hissing as a threat device.