Discussion 3: Drifting Continents and Shifting Theories- The Flightless Birds and Continental Drift

What do the ostrich in Africa, emu in Australia, rhea in South America, cassowary in New Guinea, and the kiwi from New Zealand have in common? They all belong to a particular species called ratites or 'birds that cannot fly.'Notice something unique about where these birds are found? They are all located in the Southern Hemisphere! The birds also had a common ancestor known as the elephant bird which once lived in Madagascar. As the name implies, these were huge birds - 10 feet (3 meters) tall. Researchers believed that original flightless birds spread-out as our Earth's continents drifted apart around 200 million years ago.  Our Earth had 2 distinct masses of land called Gondwana and Laurasia - both of which had split from Pangaea, a unified super-continent. Gondwanaland split again 145 million years ago, forming South America, Africa, the Arabian peninsula, the Indian subcontinent, Australia and Antarctica. It also included many islands and island groups, such as Madagascar and New Zealand. The huge herbivorous elephant bird was known to have existed in Madagascar till around the 18th century. Given how close Africa is to Madagascar, and that Africa was the first country to break away from Gondwanaland, researchers concluded that ostriches were the closest relatives of the elephant birds. 

Now, a new study has shed light on a fascinating new theory. Advances in DNA technology have revealed that the closest relatives of the elephant birds are in fact the much smaller kiwis of New Zealand. But how could that be possible? Madagascar and New Zealand had been separated by huge distances across the water by then. Therefore, scientists conclude that the Elephant bird and the Kiwi must have had a common ancestor - one that could fly! This ancestor would have flown across the water to reach new lands left vacant by the dinosaurs around 65 million years ago. The environment in these new lands would have forced these flighted ancestors to become ground feeders -- that is, they foraged for food on the ground, and over time, lost their ability to fly. Scientists believe at least six different flightless branches have evolved independently from the common flying ancestor.  Scientists are looking for more fossils and further DNA studies of flightless birds to validate this new theory.

You may also watch this video that discusses this research. How Did Flightless Birds Spread Across The World?

Your Assignment

For this discussion, you will post a response to the question

"What role would this discovery have had if it occurred prior to/during Wegener's development of his Theory of Continental Drift?"

To receive full credit for this Discussion, you will 

1) post your initial response by the due date of this discussion

2) reply to at least one (1) classmate by the due date either supporting or rejecting their claims to the answer above. Because a rejection statement is possible, please adhere to all rules of netiquette in this response.