Answer:
Hey there!
I believe that David's prediction would be: If the amount of pollutants in the atmosphere reached an amount unhealthy for the salamanders, then the salamander population would decrease.
Let me know if this helps :)
I'm pretty sure it was yellow fever.
Answer:
<h2>Recessive to
</h2>
Explanation:
1. As given here, both parents are black, and their 247 progeny out of 333 are black, it clearly indicates that 3/4 progeny is parental phenotype and 1/4 is different type.
2. This clearly show that both parents are heretogyzous, one allele is dominant and one is recessive.
3. Here black is dominant over blue.
4. Dominant allele express them-self in dominant homogyzous as well as heterogyzous condition.
Changes in the gene pool are closely related to genetic mutations, which are a major part of evolution.