These animals were preyed upon by equally large carnivores such as saber toothed cats, cave bears and dire wolves.
Btw it's (QUATERNARY) *
Dominant' traits will actually disappear faster if they are disadvantageous.
Think about it: if everyone who has even a single copy of a particular allele is at a disadvantage (manifests the phenotype, in this case six fingers), then even single copies are selected against.
In the case of recessive traits, selection occurs only against homozygous carriers, who may be very rare if the allele itself is rare.
A concrete example would be something like Tay-Sachs disease. If the allele that causes this were dominant, every carrier would die before adulthood, and it would occur only as a very rare de novo mutation. But because it is recessive, it persists for now; heterozygous carriers have no disadvantage.
The answer is <span>c. Cold and flu season occurs when the weather is cold, so there must be a connection.
Even though choices a. and b. could make sense, nothing in Joel's research implies the connection between the choices and cold. Therefore, this leaves choice c. as the right one. If cold and flu season occurs</span><span> when the weather is cold, there must be a connection between cold and cold weather.</span>