Answer:
Allele frequency can be described as a phenomenon which measure how common an allele is in a particular population. It tells about the genes which are richest in a gene pool and it also shows the genetic diversity in a population. Allele frequency is often expressed in percentages.
Natural selection tends to favour those organisms that are best adapted to live in an environment and which can withstand changes occurring in the ecosystem. If due to some circumstances, a trait becomes less useful to organisms in a population then by natural selection the allele frequency for those alleles will reduce with time. Similarly, the alleles which code for better genes for an environmental change will be increased due to the phenomenon of natural selection.
Believe it or not, 99.9% of the species on Earth have gone extinct. Now, not all of these were caused by Humans, some were caused by MAJOR cataclysmic events such as the extinction of dinosaurs or other prehistoric animals that make up a large amount of the species on Earth. And remember that all the prehistoric plants are also included, because every plant organism is ALSO a species.
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