Tasirin says that Wallace saw the island's natural history in terms of how species had migrated to new environments on the island, adapted to them, and then evolved.Publication of theory of natural selectionĭarwin, as photographed in 1860, was still clean shaven at this time. However, if you subtract bats - which are highly migratory mammals - from that figure, it jumps to 86 percent. Sulawesi naturalist John Tasirin says that Wallace found that 64 percent of mammals on Sulawesi are unique to the island. He concluded that these animals had been on this island isolated from other species for a very long time, and slowly evolved into new species. Wallace believed that Sulawesi is unique because most of the animals that live here are not found anywhere else on earth. The line is now called the Wallace Line, and the transitional region around it is called Wallacea. Wallace didn't know it at the time, but that line is actually the divide between two continental shelves. "And so came the thought of this line that could be drawn between Borneo and Sulawesi, that would separate the Asian fauna from the Australian fauna." "Clearly this was a transition between the Asian world and the Australian world," Whitten says. They dig into the earth, which is heated by hot springs, are able to sense spots that are exactly 86 to 97 degrees, and lay their eggs there. Maleos are a prime example of an animal that has adapted to its environment, using geothermal energy to incubate their eggs rather than body heat.
That keeps them safe from local predators such as the monitor lizard. Lela says that after eight weeks, the buried eggs hatch and the maleo chicks struggle up through the dirt and immediately fly away. Wallace believed that maleos had developed this webbing to help them dig into the earth and bury their eggs. We could see that unlike other species similar to it, the maleo has webbing between three of its claws. They can sense where the temperature is just 86 to 97 degrees, and that's where they lay their eggs.Īt the park's hatchery, ranger Max Lela showed us a downy, three-day-old maleo chick. They dig into the earth, which is heated by hot springs. Instead of sitting on their eggs like hens, maleos use geothermal energy to incubate them. In his book The Malay Archipelago, Wallace wrote that students of natural history should avoid thinking of animal behavior as "fixed points." He argued that this has "the bad effect of stifling inquiry into the nature and causes of 'instincts and habits.' " Wallace's insatiably curious mind was constantly thinking about how animals' behavior reflected their changing natural surroundings.įor example, Wallace observed that maleos have adapted so perfectly to the environment that they even use Sulawesi's geology to survive. He was on the island of Halmahera, ill with a fever, when it came to him: Animals evolve by adapting to their environment. But he didn't figure out how until one night three years later. Wallace collected more than 100,000 insect, bird and animal specimens, which he gave to British museums.īy 1855, Wallace had come to the conclusion that living things evolve. Few places on earth can rival this vast archipelago's tremendous diversity of plant and animal life. Wallace developed some of his most important ideas about natural selection during an eight-year expedition to what was then the Dutch East Indies - modern-day Indonesia - to observe wildlife and collect specimens. In fact, Alfred Russel Wallace, another British naturalist, was a co-discoverer of the theory - though Darwin has gotten most of the credit. But over time, Charles Darwin became almost universally thought of as the father of evolution.Īsk most folks who came up with the theory of evolution, and they'll tell you it was Charles Darwin.
The research of British naturalist Alfred Russel Wallace (1823-1913) played a pivotal role in developing the theory of natural selection.
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