Question

Chapter 21,23

Read the following statements about the role of chance in evolution.

Identify each statement as TRUE or FALSE.

1.The ultimate source of new alleles is mutation, random changes

in the nucleotide sequences of an

organism’s DNA.

2.Evolutionary change proceeds by an accumulation of changes

that occur by chance.

3.An allele may be lost from small populations due to chance

events unrelated to the fitness consequences of the allele

Chapter 24

1.Identify each statement as TRUE or FALSE.

a.Speciation can be observed only over millions of years.

b.Some features (such as the human eye) are too complex to evolve by

natural selection.

Answer 1

TRUE or FALSE.

1.The ultimate source of new alleles is mutation, random changes in the nucleotide sequences of an

organism’s DNA. TRUE

2.Evolutionary change proceeds by an accumulation of changes that occur by chance. TRUE

3.An allele may be lost from small populations due to chance events unrelated to the fitness consequences of the allele. FALSE

Chapter 24

a.Speciation can be observed only over millions of years. FALSE (It may take lesser time of few hundred years)

b.Some features (such as the human eye) are too complex to evolve by natural selection. FALSE (Many independent natural selections lead to the evolution of human eye)