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If every organism in a population had the same genes, then they would all be affected in exactly the same way by any outside factors from the environment.
This means that if some factor resulted in those genes being lethal or not suited to survival, the entire population would suffer in exactly the same way: they would all die and the species becomes extinct. The idiom "all your eggs in one basket" comes to mind when describing such a situation.
Variation allows for some organisms to survive different factors. If some genes were lethal or not suited for survival, then only the affected members die and the majority (or at least enough to ensure continuation) of the population survive.
What else can I help you with?
What is the 4 main points of natural selection?
natural selection (4 tenants) -genetic variation -overproduction of offspring -struggle for existence (competition) -differential survival and reproduction
What is the smallest level on which evolution can occur?
Natural selection acts upon the individual organism, whilst evolution occurs at the population level. The environment selects for organisms best adapted for highest survival and reproductive success. Natural selection requires three key things - variation, inheritable traits, and differential survival/reproduction. Species will produce more offspring than the environment can support(carrying capacity), and the population tends to be fairly stable until resources are limited. A struggle for existence is created, and natural selection ensures that weaker traits die out while stronger traits live on. Organisms show variation in characteristics, and that variation is heritable. Survival depends on inherited traits, and unequal survival/reproduction leads to adaptation and evolution. Therefore, while the individual organism can adapt, the population is what actually evolves.
What is Darwin's theory of evolution by natural selection?
The theory states that there is inheritable variation among offspring, and that as environments change some variations will enjoy an advantage over others. In other words, there will be preferential survival of beneficial inheritable traits, which will ultimately be reflected in the general population. This constitutes evolution.
What is needed for natural selection to occur?
Environmental pressure. Amongst a certain population of a certain species, there will be many different mutations which developed and were passed on evenly due to neither being beneficial nor detrimental. Any change to their habitat can be considered an environmental pressure. A drop in temperature, invasion of a competing species, etc. Natural selection will occur, as those with now-beneficial mutations are more likely to pass their genes on.
What must exist in a population before natural selection can act?
Competition + Variation. Classic example: Giraffes not always had long necks. There were variation in the species. When food sauces grew low competition increases and those with longer necks survived (more fruit/food at the top of trees) as they were more suited to the conditions. These long necked giraffes then breed and the offspring have long necks, thus natural selection of a "fitter" species. Hense - survival of the fittest.
How can mutation lead to evolution in a population?
Mutation introduces variation in the genetic material of individuals within a population. This variation can result in different traits that may provide a survival advantage in a particular environment. Over time, individuals with beneficial mutations are more likely to survive and reproduce, passing on these advantageous traits to their offspring, ultimately leading to evolutionary change in the population.
Why is genetic variation among individuals beneficial for a population's overall health and survival?
Genetic variation among individuals is beneficial for a population's overall health and survival because it increases the likelihood that some individuals will have traits that allow them to survive and reproduce in changing environments. This diversity helps the population adapt to new challenges, such as diseases or environmental changes, reducing the risk of extinction.
Two dissimilar individuals are crossed in the process of?
When two dissimilar individuals are crossed in a process, it can lead to genetic variation and potentially produce offspring with a combination of traits from each parent. This can lead to increased diversity within a population, which can be beneficial for adaptation and survival in changing environments.
How do mutations relate to natural selection?
Mutation, a copying error in the replication of DNA, can give rise to variation in an organisms phenotype and if this new phenotype is beneficial to survival and reproductive success ( as little as 1% ) it will be selected naturally against the immediate environment, then if this so selected organism leave many descendents with the same beneficial traits then the populations gene pool will change in allele frequency and you have evolution. ( a 19th century sentence Darwin would be proud of! )
What where the 3 steps that lead to the formation to new species according to the theory of natural selection?
Variation: Within a population, individuals have different traits. Selection: Certain traits provide individuals with a better chance of survival and reproduction. Reproduction: Individuals with beneficial traits are more likely to pass on these traits to their offspring, leading to a shift in the population's gene pool over time.
Does natural selection increase or decrease variation in a population?
Natural selection tends to decrease variation in a population by favoring certain traits that are better suited for survival and reproduction. As individuals with advantageous traits have higher fitness, their genes are passed on more frequently, reducing the frequency of less beneficial traits in the population over time.
Suppose a variation makes an individual member of a species better adapted to its environment how might that variation affect the individuals reproduction?
If a variation makes an individual better adapted to its environment, it might increase the individual's chances of survival and reproduction. This individual may have more opportunities to find a mate, produce offspring, and pass on its beneficial traits to the next generation. Overall, the variation can lead to an increase in the frequency of the advantageous trait within the population over time.
How does variation work to help cause evolution?
You have to have variation in order to be able to have more successful variations, which succeed in evolutionary terms, and less successful variations which fail. If there were no variation in a species, there would be no natural selection.
How is variation beneficial to a population of organisms?
If that variation is selected on the basis of survivability and reproductive success then the populations gene pool allele frequency changes and the population becomes better adapted to the immediate environment, or adapted to a new and changing environment.
What are Darwin's four postulates?
1. There is variation in individuals within a species 2. Variation ensures that individuals that are better suited to their environment will survive. 3. Traits that assist individuals in survival and allow them to reprduce gradually spread throughout population. 4. Individuals produce more offspring than the local resources can support.
Why is the variation is important?
For survival. Disease immunity of offspring and defense against evolving diseases. Natural occuring phenomenon that attracts a mate.
What are the five main points of Darwin's theory of natural selection?
Variation: Individuals within a species exhibit variation in traits. Competition: Resources are limited, leading to competition for survival. Survival of the fittest: Individuals with advantageous traits are more likely to survive and reproduce. Heritability: Traits that confer a survival advantage are passed on to offspring. Gradual change: Over time, the population evolves as advantageous traits become more common.
