An Index Fossil Is

question 48

Multiple Choice

An index fossil is

• A) a fossil found in a particular site.
• B) the ideal specimen of that species to which all later descriptions must refer.
• C) a fossil used to categorize a stratigraphic layer.
• D) the type specimen of a species.

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Definitions:

Evolutionary Changes

Modifications and adaptations that occur in living organisms over generations, driven by natural selection, genetic drift, mutations, and gene flow.

Nucleotide Sequences

The order of nucleotides in a segment of DNA or RNA, determining the genetic information carried.

Primates

Mammals that share such traits as flexible hands and feet with five digits; a strong social organization; and front-facing eyes; includes lemurs, tarsiers, monkeys, apes, and humans.

Distantly Related

Refers to organisms that share a common ancestor far back in the evolutionary tree, indicating a low level of genetic similarity.