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EVOLUTION Biology James Hutton and Charles Lyell studied geological processes that shaped the earth. HUTTON AND LYELL The earth is several billion years old and the processes that changed earth in the past are the same as the processes that operate in the present. This is called uniformitarianism. HUTTON AND LYELL Jean-Baptiste Lamarck was a French naturalist who lived in the early 1800’s He fought in the Pomeranian war, studied medicine, botany, and later became a professor of zoology. LAMARCK Lamarck proposed that all organisms have an inborn urge to become more complex and perfect. As a result, organisms change and acquire features that help them live more successfully in their environment. He called these acquired characteristics/traits. LAMARCK Proposed 1. Two Hypotheses Organisms can change during their lifetimes by selectively using or not using various parts of their bodies LAMARCK Proposed 2. Two Hypothesis Individuals can pass these acquired traits on to their offspring, enabling species to change over time LAMARCK Thomas Malthus reasoned that if the human population grew unchecked, there wouldn’t be enough living space and food for everyone. Darwin would later draw upon this idea and discuss how it impacts organisms in the wild. THOMAS MALTHUS Charles Darwin developed a scientific theory of biological evolution that explains how modern organisms evolved over long periods of time through decent from common ancestors. CHARLES DARWIN Charles 1809. Darwin was born in England in Despite having a natural interest in the environment, Darwin studied medicine. Eventually he gave up medicine to pursue his passion of studying different species found in nature. CHARLES DARWIN In 1831, Darwin partook in a five year voyage on the HMS Beagle. The goal of the captain and crew was to map the coastline of South America. CHARLES DARWIN Darwin, however, wanted to collect specimens of plants and animals he encountered in the various geographical regions. CHARLES DARWIN As Darwin collected specimens and recorded information in his notebooks, he began noticing patterns. CHARLES DARWIN Darwin observed that: Species vary globally. Species vary locally. Species vary over time. CHARLES DARWIN Darwin noticed that different, yet ecologically similar, animal species inhabited separate, but ecologically similar, habitats around the globe. SPECIES VARY GLOBALLY Rheas in South America, Ostriches in Africa, Emus in Australia Why no rabbits in ideal Australian habitats? Why no kangaroos in England? SPECIES VARY GLOBALLY Different, yet related, animal species often occupied different habitats within a local area. i.e. – Two species of rheas living in South America, but each in a different type of grassland. SPECIES VARY LOCALLY Tortoises from Isabella Island have dome shaped shells and short necks. On this island, vegetation is abundant and close to the ground. SPECIES VARY LOCALLY Tortoises from Hood Island have shells that are curved and open around their long necks and legs. This enables them to reach the island’s spare, high vegetation. SPECIES VARY LOCALLY Darwin noticed that some fossils of extinct animals were similar to living species. SPECIES VARY OVER TIME After his voyage on the Beagle, Darwin began trying to explain the changes he observed in nature. Hutton, Lyell, Lamarck, and Malthus’ observations and theories were considered. He learned about a process known as artificial selection from plant and animal breeders. CHARLES DARWIN In artificial selection, nature provides the variations and humans select those they find useful. CHARLES DARWIN Years later Darwin would publish his work in a book he named Origin of the Species. This book serves as a cornerstone of evolutionary biology. ORIGIN OF THE SPECIES In his book, Darwin explains that his data and observations in nature led him to the following conclusions: There is a struggle for existence The influence of variation and adaptation Survival of the fittest ORIGIN OF THE SPECIES Natural Selection is the process by which organisms with variations most suited to their local environment survive and leave more offspring NATURAL SELECTION Adaptation – Any heritable characteristic that increases an organisms ability to survive and reproduce in its environment. NATURAL SELECTION Fitness – how well an organism can survive in its environment. NATURAL SELECTION When does this occur? Natural Selection occurs in any situation in which more individuals are born than can survive (struggle for existence), there is natural heritable variation (variation and adaptation), and there is a variable fitness among individuals (survival of the fittest). NATURAL SELECTION Natural selection does NOT make organisms better or perfect – just good enough to enable an organism to pass its genes on to the next generation. (too bad bruh.) NATURAL SELECTION Just as well adapted individuals in a species survive and reproduce, well adapted species survive over time. Living species are descended, with modification, from common ancestors. An idea called descent with modification. COMMON DESCENT