Question

which of the following is a distinguishing feature of humans from other primates?

a. arboreal locomotion
b. opposable thumbs
c. quadrupedalism
d. bipedalism

what is the primary mechanism by which species change over time according to evolutionary theory?

a. natural selection
b. genetic drift
c. artificial selection
d. environmental adaptation

what is the primary significance of examining molecular evidence in understanding human evolution?

a. analyzing environmental changes
b. identifying ancient technologies
c. revealing evolutionary relationships and common ancestry
d. exploring historical civilizations

Explanation:

• First question: Bipedalism (walking on two legs) is a key distinguishing feature of humans from other primates. Arboreal locomotion (tree - dwelling movement) is common in many primates. Opposable thumbs are also present in some other primates (e.g., chimpanzees). Quadrupedalism (walking on four legs) is the typical locomotion for most non - human primates.
• Second question: According to evolutionary theory, natural selection is the primary mechanism by which species change over time. It acts on heritable variations within a population. Genetic drift is a random change in allele frequencies (more significant in small populations). Artificial selection is human - driven (e.g., breeding of plants and animals). Environmental adaptation is a result of natural selection rather than the primary mechanism.
• Third question: Molecular evidence (such as DNA sequences) is mainly used to reveal evolutionary relationships and common ancestry. Analyzing environmental changes is more related to geological and ecological studies. Identifying ancient technologies and exploring historical civilizations are not the main purposes of molecular evidence in the context of human evolution.

Answer:

1. d. Bipedalism
2. a. Natural selection
3. c. Revealing evolutionary relationships and common ancestry