Evolution and Taxonomy

The fact that species today look different from their ancestors can be described as

• Descent with modification

• Fitness

• Migration

• Mutation

The differences in the species in the image are most likely a result of?

• Length of mating season

• population size

• color of feathers

• available food source

According to fossil records, the horses that lived 50 million years ago were much smaller, weaker, and slower than modern horses. Which process is most likely responsible for the changes that have led to the increased size, strength, and speed in horses?

• Mutation

• Inbreeding

• Competition

• Natural Selection

If a mutation introduces a new skin color in a lizard population, which factor might determine whether the frequency of the new allele will increase?

• How many other alleles are present

• whether the mutation makes some lizards more fit for their environment

• how many phenotypes the population has

• whether the mutation was caused by nature or by human intervention

If an organism has similar bone structure but different function what type of structures are these?

• Analogous

• Homologous

• Vestigial

• None

What do homologous structures help to prove?

• Common ancestry

• using structures for the same function

• same level in the food pyramid

• adapted to same type of environment

In whales, the pelvis and femur are no longer used. What are these structures called?

• examples of fossils

• Vestigial structures

• acquired traits

• examples of natural variation

The strongest evidence for relationships among organisms is ___.

• Amino acid sequencing

• genetic drift

• vestigial structures

• comparative anatomy

Some organisms have genes that improve their ability to survive and reproduce. If the genes also help their offspring survive and reproduce, then which of the following will most likely increase?

• The frequency of the genes in one individual

• The frequency of the genes in the population

• The number of genes in one chromosome

• The number of genes in the species

How can the pattern of change in the fossil record best be explained from the image?

• The mollusks were well adapted to their stable environment. A large, sudden change occurred in their environment. After the change the mollusks with the bigger shells were better adapted for the new environment.

• The mollusks were well adapted to their stable environment. The mollusks hybridized with a smaller species of mollusk. A new species of mollusk with a bigger shell resulted.

• The mollusks were not well adapted to their environment. The length of the mollusks’ shells changed gradually over time. The mollusks in the original population that had small shells died over a period of many years.

• The mollusks were well adapted to their environment. Humans introduced a new species of mollusk that was not adapted to this environment. The introduced mollusk outcompeted the native mollusk species.