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Heterozygous induviduals pass the dominant and recessive alleles to offspring
Sickle cell anemia alleles are maintained in human populations because of a phenomenon called heterozygote advantage. Though it is true that sickle cell anemia is a very debilitating disease and will lower an individual's fitness tremendously, it also confers immunity to malaria, a very prevalent and deadly disease in many parts of the world. This is because the protist parasite that causes malaria normally spends a part of its life cycle inside the host's red blood cells, and the strange shape and excessive aggregation of red blood cells in a person with sickle cell anemia is too hostile an environment for the parasite to colonize. However, even though sickle cell anemics can survive a malaria infection, it still shortens the individual's life span considerably and therefore this immunity may not actually increase the individual's fitness. Now what is important to realize is that heterozygotes, i.e. individuals who are heterozygous for the sickle cell anemia locus are also immune towards malaria without the deleterious effect of full-blown sickle cell anemia. This way, a heterozygote has an advantage because he neither suffers the ill effects of sickle cell anemia nor is susceptible to malaria infection. This confers increased fitness to heterozygotes, and when they mate there is at least a 50% probability that the offspring will also be heterozygous. This way the sickle cell anemia allele persists in human populations.
Heterozygous induviduals pass the dominant and recessive alleles to offspring
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How is the sickle cell maintained through natural selection?
Heterozygous individuals pass the dominant and recessive alleles to offspring.
How is the sickle allele maintained through natural selection?
Heterozygous individuals pass the dominant and recessive alleles to offspring.
How is the sickle-celled allele maintained through natural selection?
Individuals with two recessive alleles have very high rates of reproduction.
How is sickle cell alleles maintained through natural selection?
Heterozygous induviduals pass the dominant and recessive alleles to offspring
Did penguins go through natural selection?
Yes, penguins, like all animals, have gone through natural selection. Scientific evidence supports this notion.
How is the sickle cell allele maintained through natural selection?
Individuals with two recessive alleles have very high rates of reproduction.
Did natural selection give rise to our ability to drive automobiles?
No, our ability to drive automobiles is not a trait that has evolved through natural selection. Driving is a learned skill and is not influenced by genetic traits that are subject to natural selection.
How do adaptations arise in a species?
Through natural selection and evolution
The great pattern of organization in nature is maintained by?
The great pattern of organization in nature is maintained by various interconnected ecological processes, such as nutrient cycling, energy flow, and adaptation through natural selection. These processes work together to create and maintain the balance and diversity of life on Earth.
Which scientist is known for the theory of evolution through natural selection?
Charles Darwin is known for the theory of evolution through natural selection. He proposed that all species of life have descended over time from common ancestors, and that the process of natural selection is the mechanism through which this evolution occurs.
Why does natural selection not directly affect genes?
Natural selection acts on the way organisms interact with one another and with their environment. The genes of organisms are not usually themselves involved in this interaction: they direct it through intermediaries such as proteins. So natural selection must work through these intermediaries to affect genes.
Who presented the theory of evoloution through natural selection?
Charles Darwin
