Evidence for evolution: fill in the blanks · Grade 10

The word bank and sentences

Directions: Read each sentence. Choose the best word from the word bank and write it on the line. Some words are not used.

• Word bank: cross out each word as you use it
• vestigial · 4.5 billion ____ isolation ____ genetic drift ____ cladogram common ancestor ____ radiometric · analogous · years · transitional
• 1 Similar DNA sequences in different species point to a ____.
• 2 Tiktaalik is a · fossil with features of both fish and four-limbed animals.
• 3 Whales have tiny · hip bones inherited from four-legged ancestors.
• 4 has its biggest effect in small populations.
• 5 The wings of birds and insects are · structures.
• 6 Radiometric dating shows that Earth is about · years old.
• 7 Geographic ____, such as a new river or mountain range, can lead to new species.
• 8 Antibiotic resistance shows that bacterial evolution can be observed within a few