Bipedal Movement in Human Ancestors: Australopithecus

Bipedalism, or the ability to walk upright on two legs, is one of the key characteristics that distinguish humans from other primates. The first evidence of bipedal movement in our human ancestors can be traced back to the Australopithecus genus. Australopithecus is a group of extinct hominins that lived in Africa between approximately 4.2 and 1.9 million years ago.

1. Cro-Magnon
Cro-Magnon refers to a group of early modern humans (Homo sapiens) who lived in Europe between approximately 40,000 and 10,000 years ago. They were not the first to exhibit bipedal movement, as bipedalism had already evolved much earlier in our evolutionary history.

2. Australopithecus
Australopithecus is the correct answer to the question. This genus includes several species, such as Australopithecus afarensis and Australopithecus africanus, which lived between 4.2 and 2 million years ago. These early hominins had a unique combination of ape-like and human-like features, including adaptations for bipedal locomotion.

3. Java Man
Java Man, also known as Homo erectus, is an extinct species of hominin that lived in Java, Indonesia, approximately 1.8 million years ago. While Homo erectus is an important species in human evolution, it is not the ancestor who first showed bipedal movement.

4. Peking Man
Peking Man, also known as Homo erectus pekinensis, is an extinct hominin species that lived in China approximately 700,000 to 200,000 years ago. Similar to Java Man, Peking Man is not the ancestor who first exhibited bipedal movement.

Conclusion
The correct answer to the question is Australopithecus. This genus of early hominins, which lived between 4.2 and 2 million years ago, was the first to exhibit bipedal movement. The bipedal adaptations seen in Australopithecus species laid the foundation for the evolution of modern humans and our unique ability to walk upright.