Continental drift and phylogenetic lines

Continental drift is the proposition that plates of the earths crust  have a history of separations and collisions. That historic movement pattern has become integrated with macroevolutionary explanations of animal distributions. Geologists who try to trace the positions of land masses back through the history of the earth have constructed a model that brings all of the major continental masses together as one back beyond 220 million years ago. On such a large single land mass (Pangea) there would be no major seas to serve as barriers to the spread of terrestrial species. The initial split of Pangea divided the animals and their lineages of descendants onto two isolated  landmasses, Gondwana, to the south, and Laurasia, to the north. To this day there are major groups of organisms that can be referred to as either gondwanan  or laurasian in origin. Historical geologists propose a time for the subsequent fragmentation of Gondwana and Laurasia to be about 160 million years ago. Those areas traced to the breakup of Gondwana include Africa, India, Antarctica, Australia, and South America. Those attributed to Laurasia include Eurasia and North America. Again, there are lineages which are unique to each of these fragmented landmasses as well.

There are some obvious reconnections between the continents that are said to be more recent, and that have allowed new colonizations from formerly isolated neighboring lands. Currently the panamanian connection joins South America to North America and the middle eastern connection joins Africa to Eurasia. There is also evidence of recent periods of connection between Alaska and Siberia, and between Europe and eastern Canada.

Continental Separations
Pangea (triassic,220my)
Laurasia – Gondwana (jurassic, 160my)
N. America, Europe, Asia (cretaceaous, 100my)
S. America, Antarctica, Australia, Africa, India  (cretaceaous, 100my)

New Land Bridges
Berringea, DeGeer/Thule passages, panamanian connection, Middle Eastern