Atlantis Online
March 29, 2024, 06:07:41 am
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Scientists to drill beneath oceans
http://atlantisonline.smfforfree2.com/index.php/topic,8063.0.html
 
  Home Help Arcade Gallery Links Staff List Calendar Login Register  

Study: Animals populated Madagascar by rafting there

Pages: [1]   Go Down
  Print  
Author Topic: Study: Animals populated Madagascar by rafting there  (Read 220 times)
0 Members and 29 Guests are viewing this topic.
Major Weatherly
Superhero Member
******
Posts: 4848



« on: January 24, 2010, 01:44:00 am »

"What we've really done is prove the physical plausibility of Simpson's argument," Huber said.

Anthropologists and paleontologists have good reason to be interested in Madagascar's animals. The island is located in the Indian Ocean roughly 300 miles east of Africa over the Mozambique Channel and is otherwise isolated from significant land masses. Its isolation and varied terrain make it a living laboratory for scientists studying evolution and the impact of geography on the evolutionary process.

Madagascar has more unique species of animals than any location except Australia, which is 13 times larger. The island's population includes 70 kinds of lemurs found nowhere else and about 90 percent of the other mammals, amphibians and reptiles are unique to its 226,656 square miles.

The question has always been how the animals arrived there in the first place. Madagascar appears to have been an island for at least 120 million years, and its animal population began arriving much later, sometime after 65 million years ago.

The raft hypothesis, which scientists refer to as “dispersal,” has always presented one big problem, however. Currents and prevailing winds between Madagascar and Africa flow south and southwest, away from, not toward, the island.

Yet, the land bridge hypothesis also is problematic in that there is no geologic evidence that such a bridge existed during the time in question. Also, there are no large mammals such as apes, giraffes, lions or elephants, indigenous to Madagascar. Only small species such as lemurs, the island's signature species; hedgehog-like tenrecs; rodents; mongoose-like carnivores; and similar animals populate the island.

The animals of Madagascar also appear to have arrived in occasional bursts of immigration by species rather than in a continuous, mixed migration. They likewise appear to have evolved from single ancestors, and their closest relatives are in Africa, scientists say. All of which suggests Simpson's theory was correct.
Report Spam   Logged


Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by EzPortal
Bookmark this site! | Upgrade This Forum
SMF For Free - Create your own Forum
Powered by SMF | SMF © 2016, Simple Machines
Privacy Policy