Balies are a group of birds often characterized by being flichtless and having long legs. Biogeographical
information from fossils indicates that ratites lived on most parts of the supercontinent called Gondwanata
connected South America, Ainca, Arabia, India, Australia, and Antarctica. Modern species of ratites include the
strich found in Africa, the the found in South America and the emu found in Australia. As seen in the photos
low all of these birds are similar in appearance and share many structural features
Ostrich
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Rhea
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Which of the following best explains the similarities of these different birds on different continents?
A Ostriches, rheas, and emus share a common ratite ancestor that lived on the Gondwana supercontinent, but
geographic isolation due to continental drift caused speciation
© Ostriches, rheas, and emus are an example of convergent evolution; similar environmental pressures on
different continents caused them to develop similar features independent of a common ancestor
© Fossils of ratites from the Gondwana supercontinent do not represent ancestry to common ratites found on
different continents because the fossils differ from specific modem species.
0 Once ratite populations were separated due to continental drift, they were forced to interbreed with other
species of birds, as a result, ratites on different continents retained some similar features but also acquired
different traits from other bird species.