Humans Share Several Features with Salamanders

question 55

Multiple Choice

Humans share several features with salamanders. Certain genes and proteins are nearly identical between the two species; both species have four limbs with a similar skeletal structure; the species' early embryos are very similar; and where the salamander has a functional tail, humans have a vestigial tailbone. In evolutionary terms, these are examples of

• A)geographic similarity.
• B)homology.
• C)adaptation by natural selection.
• D)coincidental similarity.

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Definitions:

Sum

The outcome obtained by summing two or more numbers or amounts.

Expression

A combination of symbols and operators representing a mathematical value or relationship.

X

A common symbol used to represent a variable or an unknown value in mathematics.

Difference

What remains after one quantity is taken away from another.