Differential equations question

Some heterozygous alleles create variations in expression so that there is not a clear dominant or recessive allele. question 1 options: true false

Which of the following occurs most often in a population when genetic variation and overproduction are present? some organisms have a lower reproductive success than others. some organisms have a higher reproductive success than others. some organisms have no reproductive success. some organisms do not have genetic variation.

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?