Original lemurs may have come from Kenya!
Madagascar’s biomass is more unique than any other area in the world, except Australia which is 13 times larger. There are about 35 species of lemurs and twice that number if subspecies are differentiated. The lemur is a fuzzy little svelte panda-squirrel found only in Madgascar.
In fact, 90 percent of all the country’s mammals, amphibians and reptiles are found nowhere else!
How did this happen?
First, natural selection at its most basic can explain Madagascar’s biological uniqueness. Most of the current life forms on the island began evolving 65-62 million or so years ago.
Isolate any ecosystem for that long and you’re going to get some very neat things.
In fact, lots of neat things began to evolve 65 million years ago, including us! This was right around the time that huge meteorite crashed into the Yucatan ending the reign of the dinosaurs and plunging earth into a nuclear winter for hundreds of thousands of years.
Jay Gould’s still controversial theory of punctuated equilibrium add-in to natural selection can make things even clearer: with so much wiped out, there were enhanced opportunities for rapid evolutionary development.
So if Madagascar was really isolated – like Australia – from the rest of the world but large enough to provide a viable ecosystem, then all sorts of marvelous things could happen!
Ooops.Only about ten percent of Madagascar’s life forms seem to have really started out there. Among them were the ancestors of the dodo bird. But lemurs? Sorry. They’re ancestral to the African continent’s prehistoric bushbabies, the lorises, many of whose fossils have been found in Kenya.
These original conclusions were all originally taxonomic, but current DNA studies have affirmed them.
No one has ever disputed the 1861 assertion by Austrian scientist, Eduard Suess, that Madagascar came from the giant single continent of Gondwana, then broke off from India long before the dinosaur extinction. Seuss’ simple observational deductions have been affirmed numerous ways by modern science.
Madagascar has been a lonely isolated island for almost 90 million years.
So how did the Madagascar’s lemur’s gene stock (and most of its other life forms) from the prehistoric African continent get to the island 65 million years ago?
Rafts. (Sort of like Madagascar, eh?)
The idea was floated (pun intended) as early as 1915, but in 1940 George Gaylord Simpson, a famous paleontologist and geologist, published a detailed rafting theory.
Given the vast periods of time available (nearly 30 million years) during which ancestral bushbaby forms didn’t seem to be evolving very much, Dr. Simpson surmised that it was statistically likely that enough ancestral biota rafted to the island to allow for such subsequent unique evolution of lemurs.
Two problems. Why did the rafting stop? Or more specifically even if it didn’t, why did its effects on evolution in Madagascar stop 65 million years ago?
And oops two. The prevailing winds are off the island to the south and southwest, and climatologists have no reason to believe those jet streams have changed even over the last hundred million years.
Ancestral lemurs should have been rafting to Africa, not ancestral bush babies to Madagascar!
How’d Spielberg know?
Ahoy! exclaim Profs Jason Ali of the U of Hong Kong and Matthew Huber of Purdue in a February article in Nature.
Ali is a plate tectonics specialist, and Huber, a palaeoclimatologist who reconstructs and models the climate millions of years in the past. Their collaboration proves that as Madagascar swam away from all the other continents on earth, it “disrupted a major surface water current running across the tropical Indian Ocean, and hence modified [the] flow around eastern Africa and Madagascar.”
See their complete article in Science.
Huber using his super algorithmic computer modeling genius then proved that just about the time Madagascar started evolving its mythic biota, that these currents were strong enough – like a liquid jet stream in peak periods – to get the animals to the island without dying of thirst. The trip appears to have been well within the realm of possibility for small animals whose naturally low metabolic rates may have been even lower if they were in torpor or hibernating.
And then, well then some 60 million years ago, Madagascar’s movement slowed into its current position where the ocean currents are weaker than the prevailing winds off the island. Whap! The little feisty island shut its door to the outside world of evolution.
And that let all sorts of marvelous things grow and evolve into the magical, near mythic world we know today as Madagascar.
Kudus (or Dodos!) to Dr. Simpson for thinking it up in the first place. And hey, what’s a half century or more for the techies like Ali and Huber to evolve, anyway, in order to prove it. It took lemurs 65 million years to do it in the first place!
And Spielberg? Heh, this meets all Liberty University’s criterion for an honorary degree!