[00:06.35]READING
[00:07.58]THE BIRTH OF A SCIENCE
[00:10.19]Before the eighteenth century, botany was merely a branch of medicine.
[00:13.90]Unit then, mostly doctors and surgeons studied herbs.
[00:17.97]Attempts had been made by others to classify plant species into groups,
[00:21.81]but the breakthrough came with the work of Carl Linnaeus.
[00:24.56]Showing how plants were related was a complex and strange thing before Linnaeus developed his system.
[00:29.96]The idea to give each species two names was not new, but names were not truly fixed and accepted.
[00:35.89]Some scientists classified plants into herbs and trees,
[00:39.65]or according to the shape of the fruit, or whether they had flowers or not.
[00:43.10]But Linnaeus’ idea of grouping plants in families was unique.
[00:47.28]In his system the identification of different species was based on the arrangement of the male and female organs in the flowers.
[00:54.65]As a result, fruits such as peaches and pears are in fact related, although they are different at first sight.
[01:01.31]Linnaeus’ system soon conquered the world.
[01:04.42]In 1759, Linnaeus’ student, Daniel Solander, traveled to England to promote the new system.
[01:10.11]In London, Solander developed a lifelong friendship with Joseph Banks,
[01:09.11]who would late ask him to join his team of botanical explorers on the Endeavour in 1768.
[01:14.76]Born into a life of privilege, Joseph Banks was the son of wealthy family.
[01:18.96]When his father died in 1761, Banks was only eighteen years old.
[01:23.53]Many young men in his position would lead a cosy life, but young Banks had an appetite for knowledge.
[01:28.81]Despite his wealth, he worked to make a career in science.
[01:32.60]He made a first journey to study wild plants in 1766.
[01:36.54]His next expedition was the great voyage with James Cook to Oceania.
[01:35.54]In 1768, the Royal Navy appointed James Cook as the commander of the Endeavour to take members of the Royal Society on an expedition to Tahiti.
[01:44.66]According to the instructions given to Captain Cook,
[01:47.35]the expedition had three goals.
[01:48.89]The primary goal was to study the passing of the planet Venus across the sun.
[01:53.23]This would give astronomers a change to calculate the distance between the earth and the sun.
[01:57.61]Secondly the purpose of the expedition was to record, classify and describe all plant and animal life observed during the trip.
[02:01.14]Thirdly, Captain Cook received secret instructions to search for an unknown southern continent.
[02:06.55]As astronomy was one of the most important branches of science,
[02:10.57]it was the British government that paid for all the equipment and expenses for that of the expedition.
[02:14.94]Since the government would not pay for such a new field of science as botany, Joseph Banks,
[02:20.11]at the age of 25, had to supply about￡10,000 of his own money to equip the expedition.
[02:25.85]On their three-year voyage, Joseph Banks did not only study and describe new plants he found,
[02:43.36]but also looked out new economic species: plans that could be grown in England or other parts of the world to produce crops that could be sold.
[02:50.96]Banks was the first to move crops from one continent to another on a large scale,
[02:55.66]helping to develop local economies with these new imports.
[02:58.85]Some plants that were spread over the globe in this way include cocoa, hemp and tea.
[03:03.97]The Endeavour, returned to England in 1771.
[03:07.42]The voyage had been a great success.
[03:09.56]Wonderful discoveries had been made of strange new lands, cultures, animals and plants.
[03:14.26]After that Captain Cook made two more voyages around the world, but Joseph Banks never undertook another.
[03:20.08]From behind his desk, however, he was involved in enterprises such as the exploration of Africa and the settlement of Australia.
[03:27.16]In 1778, Banks was elected president of the Royal Society, a position he held for 42 years
[03:33.83]During these years Banks helped to develop the royal gardens at Kew into one of the greatest botanical gardens in the world.
[03:40.25]He accumulated a great deal of knowledge about plants and agriculture.
[03:43.54]In growing strawberries Banks went back to the abandoned practice of spreading straw under the fruit to reduce the necessary amount of watering.
[03:50.73]He also built a greenhouse to experiment with growing pineapples.
[03:55.01]It was Joseph Banks who made Kew a centre of scientific and economic research.
[03:59.32]INTEGRATING SKILLS
[04:03.06]Reading
[04:04.21]WILDLIEF AND GRARDEN ROSES
[04:06.87]In his youth Charles Darwin enjoyed all the freedom to experiment and do whatever he liked.
[04:12.70]The study of physics, chemistry, and later botany, was his hobby
[04:16.38]At the age of 22, Darwin was invited to join the scientific expedition on the Beagle.
[04:21.63]During its five-year voyage, the Beagle followed almost the same route as Cook’s Endeavour sixty years earlier.
[04:27.59]Darwin’s observations on the voyage let him to write his famous book On the Origin of Species.
[04:33.12]It was Darwin’s visit on the beagle to the Galapagos Isles that gave him the key to his new theory.
[04:38.69]Darwin soon realized that the wildlife of the Galapagos Isles was very curious and deserved special attention.
[04:44.28]Most of the life forms could be found nowhere else.
[04:47.80]There were even difference between the species of the different islands;
[04:50.89]yet all showed a clear relationship with those of America,
[04:53.63]though separated from that continent by about 600 miles.
[04:56.87]Darwin counted 225 flowering plants, of which he collected and brought home 193.
[05:03.22]Of these 100 were new species which are only found in the Galapagos islands.
[05:08.34]Altogether the group of island formed a little world within itself.
[05:12.12]Darwin first understood the development of different plant species from developments in bird species that he observed in Galapagos.
[05:18.60]He found 13 kinds of finches, related to each other in the structure of their beaks, tails,shape of body and colour of their feathers.
[05:25.68]The most curious fact was the differences in the size of the beaks.
[05:29.21]This could only be explained by the difference in habitat and source of food.
[05:32.92]The birds with broad beaks would eat hard seeds, while the birds with smaller beaks would eat soft seed or insects.
[05:39.42]Back home, in England, Darwin realised that differences in habitat could lead to explaining differences between species.
[05:46.47]During the 1840s and 1850s Gregor Mendel conducted his experiments with flowers and peas Mendel’s attraction to research was based on his love of nature.
[05:59.75]Although his experiments. Were designed to support the ideas concerning the influence of environment upon plants,
[06:05.54]he found that many characteristics were passed on from one generation to the next,
[06:09.20]without influence by the environment.
[06:11.32]His research gave birth to the science of genetics.
[06:14.01]As a result of Darwin and Mendel’s research, scientists of the nineteenth century formed the belief that the influence of the environment was behind the development of new species.
[06:23.67]Still, both Darwin and Mendel observed that within species, different varieties could occur.
[06:28.95]Darwin studied many varieties of garden roses.
[06:31.98]It would take a next generation of scientists to bring the importance of the environment on species back in view.
[06:37.36]In 1922, Gote Turesson found evidence for existence of stable varieties within species in nature.
[06:44.55]He showed that differences between plants of one species occurred as result of environmental conditions in their habitat.
[06:51.05]He made his discoveries by studying a wild plant found on the Swedish west coast.
[06:55.62]When growing on rocks, the plant grows to a bush, having broad leaves and large flowers.
[07:00.56]However, when growing on sand, the plant grows close to the ground, having narrow leaves and small flowers
[07:06.31]If plants from one habitat were moved to the other of habitat,
[07:09.86]they changed their appearance and adapted to the new environment.
[07:12.99]The research of Darwin, Mendel and Turesson shows that both genetics and the environment are important to plants.
[07:18.79]For the improvement of crops Mendel’s genetics were long considered the most important.
[07:23.13]However, Tursson’s findings show that habitat,
[07:26.03]such as soil conditions, is of equal importance to the output of crops |