Very Important Scientist of the Month: Olaf Thalmann

Meet the Relatives
Robert Langreth 01.07.08
From Forbes magazine

Gorillas are among our closest living relations. For $500 you can make a one-hour house call in their jungle habitat. Hunters, disease and habitat loss are decimating our closest living relatives--chimpanzees, orangutans, gorillas and bonobos. In West Africa the Ebola virus killed 5,000 gorillas in just one corner of the Republic of the Congo. Chimpanzees are hunted for their meat, considered a luxury in some parts. In Asia orangutans are being overrun by palm oil plantations and coffee farms.

One unlikely success story amid this gloom are the mountain gorillas of Rwanda, Uganda and the Democratic Republic of the Congo. By the late 1970s poaching and deforestation had reduced the gorilla population to 250. The late American naturalist Dian Fossey brought their plight to world attention, but it was two researchers working for the Wildlife Conservation Society, Bill Weber and Amy Vedder, who pioneered the idea of using ecotourism as a way to save the animals.

Thanks to ecotourism, 700 of these giant beasts are alive today, wedged into small parks surrounded by subsistence farms in one of the most populated parts of Africa. Park rangers even protected them during the 1994 Rwandan genocide. "There is no doubt the mountain gorillas would have been wiped out, were it not for ecotourism," says Allard Blom, a primatologist at the World Wildlife Fund in Washington, D.C. Threats, though, remain ever present. In July four mountain gorillas were shot execution-style.

Last year in Rwanda 14,000 visitors paid $500 each for a one-hour guided tour to see the primates. Virunga Lodge, completed on a hilltop near the gorilla park in 2005, gets several hundred customers a year, who typically pay $4,825 for an eight-day trip with multiple gorilla viewings in Rwanda and Uganda. "Rwanda is very much the flavor of the month," says safari operator Aris Grammaticas. "The gorillas are very sought after." He operates the $650-a-night (per person) Sabyinyo Silverback Lodge, which opened in September adjacent to the gorilla park.

Getting to Rwanda isn't easy. From Europe there are only a few flights a week to the
capital city of Kigali. You'll need lots of cash (there are no ATMs, and only a handful of hotels accept credit cards), a yellow fever vaccination, malaria preventatives and bug spray. Plastic bags are banned to prevent litter, and modern hotel rooms are in limited supply. But Rwandans are to a person courteous and friendly. Expatriates swear it is one of the safest places in Africa.

Sightseeing opportunities in Kigali are few and grisly. A well-done genocide museum pays tribute to the kids who died. At one massacre site near the capital, Nyamata Church, thousands of skulls, some with gaping holes in them, are piled high on basement shelves. Pink-uniformed prison work gangs, many of them former "genocidaires," are a common sight in the countryside.

Gorilla day begins for me with a 4:30 a.m. wake-up call at the Serena Hotel, then a
two-hour drive to the Volcanoes National Park, where gorillas live on the
Rwanda-Congo-Uganda border. There are seven gorilla families in Rwanda that tourists can visit. Each can be visited for only one hour a day and by a group of no more than eight people. Four other gorilla families can be seen in Uganda.

I'm angling to see the 38-member Susa family. But after the guides confer in Kinyarwanda, I end up assigned to the 9-member Sabyinyo clan. I'm cured of any disappointment, though, when our guide, Francis Bayingana, explains in broken English that this group boasts not just the biggest silverback, Guhonda, but also an infant only days old.

Gorillas are our closest relatives, after chimpanzees and bonobos, having diverged from our common ancestors 8 million years ago. Only 1.6% of their DNA differs from ours. The gentle vegetarians eat up to 45 pounds a day of things like bamboo shoots, wild celery and berries. They live in stable harems led by a male silverback, with several females and several children. Females have three to six kids over a lifetime and copulate every three hours when in heat. In the wild they live to about age 40.

They are thought to have once ranged across equatorial Africa. But about 1 million years ago the mountain gorillas were cut off from their cousins in West Africa, perhaps by drought, says Olaf Thalmann of the Max Planck Institute for Evolutionary Anthropology in Germany.

To get to the gorillas, my fellow tourists and I walk through farms to a low stone wall that marks the entrance to the park. There's no buffer zone between human and gorilla. Armed guards follow to protect both us and the gorillas. (In 1999 rebels murdered eight tourists in Uganda's Bwindi Impenetrable National Park.)

We climb over the fence and enter a thick bamboo forest, heading steeply uphill. Francis tells us to tuck our socks over our jeans (lest driver ants swarm up our legs) and to avoid touching the stinging nettles that are everywhere. One of the guides uses a machete to clear the way. The thick mud nearly sucks off my shoes. After half a mile we reach a clearing, where Francis points out elephant tracks. I try to tie my shoe on what looks like a big rock. It turns out to be a pile of dung.

We continue uphill for 500 yards. Suddenly there is a rustling of bamboo, and one gorilla appears; then another and another. The adults pay us no heed and are mostly interested in finding the next piece of roughage. But a curious youngster comes right up to us; he gets so close that the guards hurriedly tell us to back away. Then the gorillas disappear again into the woods, leading us on a slow-speed chase through the dense foliage for half an hour. Finally the family settles down for a midmorning rest on a vine-covered hill.

The 500-pound silverback, Guhonda, sits 15 feet away. He chews on a bamboo shoot and eyes us with world-weary boredom, as if we were tiresome in-laws. The youngsters somersault down the hill, some bouncing so close to us that we have to jump out of their way. Then, for the briefest moment, a mother gorilla opens her arms, revealing her tiny baby.

To read the original paper by Thalmann et al. cited in this paper go here or here
Thalmann O, Fischer A, Lankester F, Pääbo S, Vigilant L (2007) The complex evolutionary history of gorillas: insights from genomic data. Molecular Biology and Evolution 24: 146-158.