[MUSIC] Here is an example of one of the poor weight groups that expanded out of the New Guinea area, namely the Orioles. There are a number of the basal or may we say, primitive species in the New Guinea area that we see here. Most of them are all the drab by colors. And then all the groups that gradually expanded up through Indonesia and into Asia, a number of them. And let us now look at the maps. The maps are divided according to route path quartiles. The first map, 25% of species that are closest to the route of the they are found mainly in New Guinea. A few of them back colonized into Australia. Next map we see that it has moved up into Indonesia. Third map is suddenly all over Africa and Asia. Generally one species in each area as a pale blue color. And the fourth map, now they are also continuing all over the area. So a group that originates in New Guinea and then expands all over the region. [SOUND] So now I will show you a really super tramp group. The Paradise Flycatcher is very colorful. The birds that are distributed all the way across the old world, the tropics. This genus, terpsiphone, apparently started radiating in the Philippine area of the colonization from New Guinea. And very rapidly they went all over southeast Asia and Africa and across the archipelagos in a very bouncy fashion. We can see that they are extremely variable in their color, polymorphic in the colors. And it has been really difficult for just morphology to tell how they are related. One other forms here is distributed [INAUDIBLE] to me in northwestern Africa. Its nearest relative, actually, appears to be a species on the St. Chells, in the Indian Ocean showing how bouncy the whole expansion had been. So they just go on very rapidly colonize, or have become expert in colonizing new islands where there is no competition. Phylogenetic expansions involve a remarkable shift in rate of speciation as we see in extinction, as we see in these slides. The ancient Australian groups diversified slowly at a slow rate, they maybe a constrained by a cooperative breeding which may have been a good way of resisting this parasites by coocoos in Australia. But it could also be a good bet hedging strategy in a stable environment. That, simply, many individuals who work together to raise young, they stay in one place, and, under these circumstances speciation goes slow. It depends on Vicarians, landscape changes, that break up populations in new units. So that goes on at a slow pace. Colonization of islands meant a rapid shift to pure breeding. And probably a range of other changes in life strategies, feeding innovations in the new environment and kind of new behavior. This went, was quite easy because the cooperative breeding system of ancestor had already selective of big brains. So these are smart birds, really smart. The lineages underwent very rapid speciation then, as we see from the arrow, here. But, these birds also experience high extinction rates on islands, especially on the small islands. In the long term they only survive on larger and more mountainous islands. That dominates the early phase of colonization move rapidly on. And actually, they are more likely to hit a continent in a continental coast then another small island in the ocean. So there is actually a higher rate of back colonization to the continents. In the predictor free island environment, birds rapidly evolve so called island. And they should therefore be unable to survive in an environment with snakes and land mammals. So when McCarter and Wilson of island biography, it was generally assumed that colonization always went from mainland out through the islands. At the islands where dead-ends in the course of evolution. Sooner or later it will lead to extinction. But the molecular phylogenies allow you to provide massive evidence of the contrary. You under saturated island environments may favor adaptive shift innovation and new life strategies that allow for the dispersal. At least during the first couple of million years. This include bat colonization to the mainland, and the island life, therefore, was the start of a remarkable global expansion. The corvoid birds underwent a remarkable global expansion. Some groups may have dispersed directly over from the Austral-Asian area, from New Guinea over to Africa. Maybe we are stepping stones in the Indian islands in the Indian Ocean. Most of it went through the Southeast Asia, the Sunda Islands and Southeast Asia. But they were all over the world within quite few many million years. On this map, the purple hue shows the piece species that make up the first root path quartile of the fellow genie, that is the ancient species. So we see that they are especially in Australia but also southeast Asia, some in Africa. The green colors represent the more terminal parts of the phylogeny. So the more recent species, speciation And we see that the high turnover is of young species are mainly in the north, in the more harsh environment, but also on the small island around New Guinea because where bright green color shows that there is all the time new species coming out and diversifying in this In these islands. So, what about the arctic? The arctic area has very poor fauna but a few special birds like the Snow Bunting lives all the way around the polar region, in the whole Arctic region. However, the map suggests continuous diversification indicted by the green color here in the Siberian mammoth steppe. Many of the birds in this area have been wintering in the southern latitudes in central Asia. Or even going down in the tropic but they we're up here in the high north in the breeding season. And that was actually speciation going on all the time. And probably strong build up of diversity in the mountains of Central Asia sending recruits ip into the Siberia. This is acquired much neglected pattern. But look at a map here of the western poly-arctic, northern Europe. For most other song bird groups here, exemplified on this map by the more than 1000 species of warbler like birds northern Europe appear purplish on the map. That means dominated by all species. So that probably will be an extreme change here during the place that's in period with the whole Northern Europe covered by ice for periods. Species had to colonize intermittently from Refugia in the south. There may have been some degree of local specialization, incipient speciation. But then, as they move back in between ice periods, the population picks up again and hybridise and a pattern of differentiation is erased. It is quite different from Siberia and the interior of Asia, where which mainly remained ice free. This was a, Asia was a region with continuous diversification, while Europe stands out as the other extreme of what we call speciation in reverse. Climate instability actually erasing patterns of differentiation. We can look an a molecular phylogeny of this bird, the Red Star, which is an extreme case of this phenomenon. We see on the graph here, a haplotype phylogeny for Red Stars where two populations colored with red and blue. They have diverged for two million years and then they have mixed up completely again, hybridized, and they are mixed all over Europe. It is plausible to believe that one of them may have come from the mountain region of Southern Europe. The other somewhere in Western Asia, but today, the overlap between them is nearly complete. And the difference in mitochondrial genes is not matched by any difference in plumage or any mating differences. Although, it is rare to find successful mixing for genetically so divergent population. The phenomenon of secondary integration may be quite widespread phenomenon of unstable climate zones. Northern Europe have the same species just maintained over long periods of time with little differentiation, except in some cases where isolated breeding populations established themselves in southern winter quarters. That actually has been documented by DNA analysis as garden warblers, barred warblers, black caps, leave breeding populations in Africa, and then evolve into new African species. [MUSIC]
