David Attenborough Explains: Charles Darwin | Nature Bites

animals and plants are evolving throughout the natural world but it was the strange creatures of Galapagos that first revealed how that happens nearly 200 years ago the islands were visited by a young naturalist on September the 16th 1835 HMS Beagle arrived in the Galapagos Islands and the 26 year old Charles Darwin stepped ashore to explore at the time very little was known about the natural history of the islands Darwin initially was fascinated by its geology [Music] but it was the animals that gave him his historic insight Darwin was only on these islands for five weeks but in that short time there were things he saw and conversations he had which stuck in his mind for example the British Vice governor of floriana Island said that he could tell which island the giant tortoise came from Simply by the shape of its shell he pondered on the vice Governor's casual remark why were populations of tortoises on separate islands all slightly different from one another [Music] he set about making a collection of animals and plants from all the islands he visited thank you although it was the tortoises at first alerted Darwin to the differences between animals on different Islands it was his collection of these undramatic little birds the finches which provided him with the most substantial evidence for his great Theory we now know that the ancestral Galapagos finches arrived in these islands about two million years ago since then they have Diversified into a number of different species today there are 13 of them distributed throughout the archipelago each has its own special talents the Woodpecker Finch has discovered how to use a tool to wrinkle grubs out of their Burrows in the branches of trees the vampire Finch has learned how to extract blood from sitting Birds [Music] Darwin when he returned to England brought back with him a wide variety of specimens of all kinds and he spent years studying his collections he had a range of finches from several of the islands and he noticed one particular way in which they differed they had beaks of different sizes why an idea grew in his mind it would also apply to tortoises maybe to all animals and plants wherever they occurred [Music] painstakingly meticulously he started to accumulate evidence from all over the world to support his idea and he called the process to produce new species evolution by natural selection [Music] and nowhere is its workings more vividly evident than here when it first occurred to him in the Galapagos he realized why it was that there were several species of giant tortoises that original species probably had a high Dome shell like this one and that's very useful on well-watered islands like this where you have to barge your way through the vegetation but on other Islands there are other problems shouldn't every species of has its own unique evolution Ary story that's closely coupled with the animals that pollinated but one family of flowering plant has developed this relationship in more complex ways than any other and in doing so has become the most numerous and diverse on the planet there are an estimated 25 000 species of orchid foreign [Music] had a particular Fascination for Charles Darwin as he reveals in one of his letters that's kept here at Q he says I have been extremely much interested with catacetam that's an orchid and indeed with many exotic orchids orchids have interested me as much as almost anything in my life Charles Darwin one species of these amazing plants can be found growing outside in the grounds of Q orchids are extraordinary plants from many points of view but one of them is that the lower lip of the flower is controlled by a special set of genes so that means that it can evolve and change its shape and color while the rest of its petals remain the same the lower lip of this little orchid has evolved to look roughly like a bee and people used to think that was a kind of warning to warn cows not to weak it on the grounds that they wouldn't want to get stung on the tongue but now we know that's not the case this is a mimic of a female bee that's attracting a male to mated and when the male mates it will pollinate the flower how do we know that's true because this Little Flower produces the scent which is exactly the same as that of a female bee trying to attract a mate the unique genetic makeup of orchids has allowed them to evolve an almost unbelievable degree of complexity and they produce their greatest variety and complexity in the Wet Zone [Music] at Q they're cultivated inside the Princess of Wales Conservatory [Music] in this section conditions are perfect for them foreign [Music] species has its own characteristic form and color [Music] foreign they represent the Pinnacle of evolutionary cooperation between animals and plants [Music] in their most extreme form the relationship for the plant is an exclusive one only one species of insect will have the right equipment to claim the plant's nectar foreign

Channel: Nature Bites

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Keywords: Charles Darwin, Charles Darwin biography, David Attenborough discovery, David Attenborough research, Galapagos Islands, Galapagos wildlife, Nature Bites, biodiversity conservation, biological diversity, botanical exploration, evolution theory, evolutionary process, historical evolution, natural habitat preservation, nature conservation, origin of species, plant adaptation, plant genetics study, plant kingdom, species survival tactics, unique plant life

Id: 5x6KQvtOg-s

Length: 9min 27sec (567 seconds)

Published: Mon Nov 14 2022