What is an index fossil?

a. a fossil formed by the impression of a once-living thing

b. a fossil that is found only in one particular time period

c. a fossil that appears to show an evolutionary change from one
species to the next

d. a fossil that appears periodically throughout earth's history

What must be true for natural selection to heppen

Taq polymerase is an enzyme isolated from the organism thermophilus aquaticus. this organism has been found living in the hot springs of yellowstone national park. this enzyme is used to copy human dna from crime scenes. most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? view available hint(s)taq polymerase is an enzyme isolated from the organism thermophilus aquaticus. this organism has been found living in the hot springs of yellowstone national park. this enzyme is used to copy human dna from crime scenes. most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? the enzyme will not work on human dna.nothing should be altered.the ph should be decreased.the temperature should be raised.

Which is the most likely reason the writer of the play pygmalion chose to change the character of galatea from a statue to working-class woman?