| VOL. 23, NO. 13||JANUARY 30, 1998 |
Macaque Mondeys2nd Most Successful PrimateMay Explain Global Spread of Humans (Ranked 1st)
BY BOB NELSON
|Scientists hope to learn more about the distribution and evolution of mammals by studying the macaques, a genus of monkeys more widespread than any other primateexcept humans.|
enetic detective work at Columbia has unraveled the complicated lineages of African and Asian macaques, a genus of cocker-spaniel-sized monkeys that is more widespread than any other primate except humans.
New information about how, when and where the macaques spread across three continents over the last 5 million years is expected to tell anthropologists more about how other mammals dispersed and adapted to the same conditions.
The study of all 19 living macaque species, which is reported in Januarys Journal of Human Evolution, confirms that the genus is one of the oldest among Asian monkeys, dating to at least 7 million years ago, and one of the most successful, radiating from its home base in Africa to Europe and across southern Asia, from eastern Afghanistan through Pakistan, India, southern China, Burma, Thailand, Japan, Taiwan and the Indonesian archipelago.
The research was reported by Juan Carlos Morales, associate research scientist at the Center for Environmental Research and Conservation, who conducted the genetic analysis, and Don J. Melnick, professor of anthropology and biological sciences and director of the Center, who gathered most of the field specimens for genetic analysis over a period of 20 years and worked with Morales to interpret the results.
Because it shows how and where macaques spread most rapidlythroughout Asia over the past 5 million yearsthe new work will serve as a road map to Asian primate evolution, and to the evolution of many other mammalian species in Asia during this time, according to its co-authors. Data on macaque distribution at different periods in history will give researchers clues to what factors influenced that distribution, and will be of most immediate use in helping decipher the movements of two other widespread primate groups, the leaf monkeys and the gibbons.
With each successive genus that is analyzed in this manner, we will get a better and better idea of exactly what was going on in this part of the world and which geological and climatological events were more important than others in shaping the evolutionary history and dispersal paths of a diverse group of organisms, such as primates, Melnick said.
Macaques invaded Asia in what appears to be a series of waves, each time spreading and diversifying across the continent over a relatively short period of time, according to the studys authors. Their rapid differentiation into different species indicates that the environment was conducive to both colonization and diversification. The many isolated species of macaques further indicates that periodic lowering of sea levels allowed the spread and subsequent isolation of macaques on what are now offshore islands. Glaciers and river systems probably also contributed to the isolation of populations and creation of new species.