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Evolution: - Coggle Diagram
Evolution:
Adaptation, Variation, and Natural Selection (L1):
Reproduction:
Sexual Reproduction: Requires two different parents (male female) which will have a sexual interaction allowing for sperm to fertilize an egg. The offspring will be genetically different from each parent individually but will contain (50 50) genetics from each of them. Allows for variation.
Asexual Reproduction: Is reproduction with only 1 parent. This means that a clone will be made of the parent because the offspring will have an identical genetic makeup. This allows for much quicker reproduction, but less variation, making the population more vulnerable to selective pressures and natural forces killing of the population.
Survival of the Fittest:
Selective Disadvantage: A characteristic or trait that provides an organism a disadvantage to living in their environment. Also decreases their chance of passing down their genes.
Selective Pressure: Refers to an evolutionary force which favors certain traits/characteristic over others, allowing organisms to have a higher or lower chance of servival. Pressure from things such as the environment or preditors may cause the need for an organism to change/adapt, allowing it to overcome these limitation.
E.g: Zebras stripes to camouflage them from predators. The predator of a Zebra was the selective pressure which forced the evolution of zebras with stripes. Any other zebras without stripes would die off, because they were easier to hunt (process of natural selection).
Selective Advantage: A characteristic or trait that gives an organism a better/higher chance of survival within their environment as well as the opportunity to pass down it's genes.
Artificial Selection: When humans select certain organisms out of a population that will best suite our needs. It is when humans will create a controlled environment, and place organisms with the best traits (for our needs) and will allow those traits to continue manifesting without the disruption of natural selection. Often, when that artificially selected population breeds, we choose the best offspring to allow those traits to become better each time.
Natural Selection: A process in which a population will change/adapt due to its environment. Because of selective pressures, only organisms with the best traits (selective advantage) will survive, having the opportunity to pass their genes, allowing for the advantageous traits to manifest until change is necessary again. However organisms with undesirable traits (selective disadvantage) will die off, not having the chance pass down their genes. Natural selection is all about natures forces causing only the best organisms within a population to survive, killing off the rest.
Genetic Mutations: Occur when there is error in DNA replication. This can lead to both a selective advantage or disadvantage, or both at the same time.
E.g. E.g. Sickle Cell Anemia. This disease can occur in humans. It's when the red blood cells are deformed and in a crescent moon shape. This disease allows for less oxygen to be carried by red blood cells (selective disadvantage), but this disease also makes people immune to malaria (selective advantage)
Variation: Is the visible or invisible differencesd between organisms within the same population. These variations help the organisms survive best based on their surroundings. If there is enough variation, it can lead to the creation of a new distinct species.
Adaptations: The ability for an organism to make modifications to themselves to enable them to best survive in their environment. This process usually occurs through multiple sets of offspring in which each time, the offspring has sight differences compared to their parents which allow them to survive better. This process involves natural selection.
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How Species Form:
Adaptive Radiation: Radiation (to spread out). Adaptive radiation is when one common ancestral species rapidly diversifies into multiple species. This happens because the ancestral species had individuals travel to and be exposed to different environments in which they adapted to.
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Gradualism: An evolutionary process in which a species experiences very slow evolution and changes over a long period of time. This is because the environment is remaining constant and has very little change. These changes are very linear.
Punctuated Equilibrium: Is when there is long periods of equilibrium (little or no change in environment and adaptation) interrupted by rapid change causing quick and immediate periods of speciation in which new species emerge.
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Speciation: The formation of new species from natural selection. Sometimes the need for adaptation/change causes massive changes in a species causing very considerable differences to the point where the new variation becomes a new distinct species. Sometimes the old species will die off because of the natural selection, but also because they are being out-competed by the new one (transformation). Other times, the old species will survive with the new species (divergence).
Transformation: Where one species gradually changes into another species in which the old species in completely replaced. Due to natural selection, the old species completely dies off.
Divergance: Is when one or more new species will emerge from the parent species but the parent/original species will continue to exist. The new and old species will be able to differentiate from one another and will stop interbreeding creating the new distinct species. These species will then have to compete for resources.
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