Submarine Morphology
Feral Goat Eradication
Galapagos Population Growth and Tourism
Galapagos Sustainable Ecotourism
Evolution in the Galapagos
Darwin began his journey to the Galapagos in 1831, at the age of 22, setting off on a ship named the Beagle, which took him around South America and eventually, to the group of islands in the Pacific we now know as the Galapagos. What Darwin saw on these islands began his intellectual voyage that would last 20 years, and would lead to the radical idea that living things are not designed according to an unchangeable plan, but are rather shaped by their environment. Darwin was only in the Galapagos for 5 weeks, and was only able to visit four of the several islands, but he was still able to obtain hundreds of specimens from these four islands, including plants, birds, and other animals. Through these 5 weeks, Darwin began to notice “aboriginal creations,” plants and animals that were found nowhere else other than the Galapagos, these were the first identifications of what are now known as “endemic” species. Even within the Galapagos, each island was home to slightly different versions of these species. Darwin noticed that many of the unique plants and animals on these islands held a striking resemblance to the species he had observed on the Beagle around South America. This resemblance led Darwin to his first culmination for the idea of The Origin of Species. It would take another 2 years for the Beagle’s journey to come to an end and for Darwin to work through this “mystery of mysteries.” The realization would come to Darwin from a group of animals that didn’t immediately grab his attention during his time in the Galapagos, but would later become synonymous with his name, finches. While he did collect some specimens of the finches, Darwin was uninterested in the animals, and even neglected to label the specimens or keep track of which island they were from. But the finches on a specific island unvisited by Darwin in his time in the Galapagos would become the single greatest proof of his theory of evolution. Daphne Major, known to some as the “laboratory of evolution,” has a relatively simple ecology, boiling down simply to what seeds are present, and what tools the finches have to crack them. Researchers have found that when smaller seeds are more abundant on the island, the beaks of the finches born the following year are also smaller, and vice versa. This island presents great proof for evolution because the changes in these finches are able to be seen in relatively short periods of time, rather than occurring over thousands of generations.
Galapagos Finch Evolution
Today, researchers continually study species around the world to answer the question naturalists have been working towards for years, the “mystery of mysteries,” how new species are formed. Two biologists, Peter and Rosemary Grant have been working towards this question on one of the smaller islands of the Galapagos, Daphne Major. The Grants have been researching the finches on Daphne Major every summer since 1973 to study the Galapagos finches.
They study the beaks of finches to show the diversity that has evolved through the Galapagos. At first, there were two main theories of how the many finch species could have come to the Galapagos, one being that all of these species have come over from the mainland of South America separately, and another being that they first came to the islands, and then began to evolve and fill the different niches on each of the separate islands. Peter Grant explains that through DNA analysis, researchers have found that all of the species of finches throughout the Galapagos are more closely related to each other than any one is related to species from the mainland. This shows that the second theory is correct, a single common ancestor of the finches came to the islands and diversified over years. This brings a new question to the biologists; how did one ancestral species give rise to the diversity of finches on the islands today?
The Grants set out on Daphne Major to answer this question, tracking as much information of each finch on the island as they could. The greatest breakthrough during their research came after a great drought on the island. Due to the drought, small seeds became very scarce, causing over 80% of the medium ground finches to die. When they observed the remaining finches, they had found that beak size was an extremely important factor of survival, and the offspring from these remaining birds had noticeably larger beak sizes. This was a clear example of Darwin’s theory of natural selection. Sometime after, a heavy rain season caused the opposite effect, when the smaller seeds had become more abundant, the offspring following this had significantly smaller beaks, further proving the concept of natural selection.
While this showed the theory of evolution, it did not answer the question of different species, which are defined as specific populations that do not interbreed. The Grants decided to use the difference in bird calls and appearance to answer this. They found that males only reacted to calls or dummies of their own species, showing both sound and appearance played a role, the Grants were able to show that changes in these characteristics over time play a key role in the formation of distinct species.
Through this, the Grants were able to show how a single common ancestor from the mainland was able to come to the Galapagos, and due to changes brought on by environmental conditions, change enough on one island that when they came in contact with their ancestral species, had become different enough to not breed with their ancestor, classifying them as a separate population, a new species.
The Origin of Birds
Feral Goat Eradication
Galapagos Population Growth and Tourism
Galapagos Sustainable Ecotourism
Evolution in the Galapagos
Darwin began his journey to the Galapagos in 1831, at the age of 22, setting off on a ship named the Beagle, which took him around South America and eventually, to the group of islands in the Pacific we now know as the Galapagos. What Darwin saw on these islands began his intellectual voyage that would last 20 years, and would lead to the radical idea that living things are not designed according to an unchangeable plan, but are rather shaped by their environment. Darwin was only in the Galapagos for 5 weeks, and was only able to visit four of the several islands, but he was still able to obtain hundreds of specimens from these four islands, including plants, birds, and other animals. Through these 5 weeks, Darwin began to notice “aboriginal creations,” plants and animals that were found nowhere else other than the Galapagos, these were the first identifications of what are now known as “endemic” species. Even within the Galapagos, each island was home to slightly different versions of these species. Darwin noticed that many of the unique plants and animals on these islands held a striking resemblance to the species he had observed on the Beagle around South America. This resemblance led Darwin to his first culmination for the idea of The Origin of Species. It would take another 2 years for the Beagle’s journey to come to an end and for Darwin to work through this “mystery of mysteries.” The realization would come to Darwin from a group of animals that didn’t immediately grab his attention during his time in the Galapagos, but would later become synonymous with his name, finches. While he did collect some specimens of the finches, Darwin was uninterested in the animals, and even neglected to label the specimens or keep track of which island they were from. But the finches on a specific island unvisited by Darwin in his time in the Galapagos would become the single greatest proof of his theory of evolution. Daphne Major, known to some as the “laboratory of evolution,” has a relatively simple ecology, boiling down simply to what seeds are present, and what tools the finches have to crack them. Researchers have found that when smaller seeds are more abundant on the island, the beaks of the finches born the following year are also smaller, and vice versa. This island presents great proof for evolution because the changes in these finches are able to be seen in relatively short periods of time, rather than occurring over thousands of generations.
Galapagos Finch Evolution
Today, researchers continually study species around the world to answer the question naturalists have been working towards for years, the “mystery of mysteries,” how new species are formed. Two biologists, Peter and Rosemary Grant have been working towards this question on one of the smaller islands of the Galapagos, Daphne Major. The Grants have been researching the finches on Daphne Major every summer since 1973 to study the Galapagos finches.
They study the beaks of finches to show the diversity that has evolved through the Galapagos. At first, there were two main theories of how the many finch species could have come to the Galapagos, one being that all of these species have come over from the mainland of South America separately, and another being that they first came to the islands, and then began to evolve and fill the different niches on each of the separate islands. Peter Grant explains that through DNA analysis, researchers have found that all of the species of finches throughout the Galapagos are more closely related to each other than any one is related to species from the mainland. This shows that the second theory is correct, a single common ancestor of the finches came to the islands and diversified over years. This brings a new question to the biologists; how did one ancestral species give rise to the diversity of finches on the islands today?
The Grants set out on Daphne Major to answer this question, tracking as much information of each finch on the island as they could. The greatest breakthrough during their research came after a great drought on the island. Due to the drought, small seeds became very scarce, causing over 80% of the medium ground finches to die. When they observed the remaining finches, they had found that beak size was an extremely important factor of survival, and the offspring from these remaining birds had noticeably larger beak sizes. This was a clear example of Darwin’s theory of natural selection. Sometime after, a heavy rain season caused the opposite effect, when the smaller seeds had become more abundant, the offspring following this had significantly smaller beaks, further proving the concept of natural selection.
While this showed the theory of evolution, it did not answer the question of different species, which are defined as specific populations that do not interbreed. The Grants decided to use the difference in bird calls and appearance to answer this. They found that males only reacted to calls or dummies of their own species, showing both sound and appearance played a role, the Grants were able to show that changes in these characteristics over time play a key role in the formation of distinct species.
Through this, the Grants were able to show how a single common ancestor from the mainland was able to come to the Galapagos, and due to changes brought on by environmental conditions, change enough on one island that when they came in contact with their ancestral species, had become different enough to not breed with their ancestor, classifying them as a separate population, a new species.
The Origin of Birds