Page 126 - Science Course 3 (Book 1)
P. 126
Mo3-L3b: How Are Organism Related?
Many scientists think that natural selection produces new species slowly and steadily. Other scientists think
species exist stably for long periods, and change occurs in short bursts.
No No No
variation variation variation
Rapid
Rapid Change
Change occurs Change
slowly as small
variations are Changes occurs quickly.
gradually selected Long periods of time
in a population. pass with no variations.
Gradual
Change
Burst of
Change
SUMMARY
How Are Organisms Related?
Scientists use evidence from developmental
and molecular biology to help determine if
organisms are related.
Mo3-L3: Vocabulary Review
Direction: On each line, write the term from the word bank that correctly completes each sentence.
NOTE: You may need to change a term to its plural form.
analogous structure comparative anatomy embryology
homologous structure vestigial structure
1. The forelimbs of bats, humans, and frogs are examples of .
2. The wings of birds and flies are examples of .
3. The wings of flightless cormorants are examples of .
4. A scientist working in the field of might research the
.
development of internal structures of organisms before the organisms are born.
5. is the study of the similarities and differences among structures of
living species.
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