A change in allele frequency can be caused by various reasons. Mutations, recombination, gene drift, gene flow, and hybridization are some of the examples. Basically anything that would cause microevolution to happen would change allele frequencies. The Hardy Weinberg equilibrium might be helpful, too.
Answer:
Nuclear magnetic resonance is a method of physical observation in which nuclei in a strong constant magnetic field are perturbed by a weak oscillating magnetic field and respond by producing an electromagnetic signal with a frequency characteristic of the magnetic field at the nucleus.
Explanation:
In the case of castrated or neutered male<span> rats, the medial preoptic area </span>has as much dopamine as normal rats, but the presence of a receptive female does not evoke much release of dopamine. Dopamine helps male sexual behavior in many species and is released just before and/or during copulation in three neural systems.
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The total number or fossils discovered by paleontologists, and the information you get from them.