One of the misconceptions about human evolution is expressed in the question 'If chimpanzees were our ancestors, then why do chimpanzees still exist?' Use Figure 19.10A to explain the answer.

Verified step by step guidance

1. Examine the phylogenetic tree in Figure 19.10A. It shows the evolutionary relationships among primates, including humans, chimpanzees, and other groups. Note that the tree starts with an ancestral primate and branches out over millions of years.
2. Understand that humans and chimpanzees share a common ancestor, but neither species evolved directly from the other. Instead, both species evolved independently from this shared ancestor along separate evolutionary paths.
3. Observe that the branching point between humans and chimpanzees occurred approximately 6-7 million years ago. This indicates that humans and chimpanzees diverged from their common ancestor at that time, leading to the development of distinct species.
4. Recognize that the existence of chimpanzees today does not contradict human evolution. Both species adapted to their respective environments and survived independently. Evolution does not imply that one species must replace another; rather, it explains how species diversify over time.
5. Conclude that the misconception arises from misunderstanding evolutionary relationships. The phylogenetic tree illustrates that humans and chimpanzees are evolutionary cousins, not direct descendants of one another, and both species continue to exist because they occupy different ecological niches.

Key Concepts

Common Ancestry

Common ancestry refers to the idea that different species share a common ancestor from which they evolved. In the context of human evolution, both humans and chimpanzees share a common ancestor that lived millions of years ago. This means that while humans and chimpanzees have diverged into separate species, they both descended from the same lineage, which explains why both still exist today.

Evolutionary Divergence

Evolutionary divergence is the process by which two or more related species become more dissimilar over time, often due to different environmental pressures or adaptations. In the case of humans and chimpanzees, after diverging from their common ancestor, each species adapted to its own ecological niche, leading to the distinct physical and behavioral traits observed today. This divergence does not imply that one species must replace the other.

Survival of Species

The survival of species is influenced by various factors, including environmental changes, reproductive success, and adaptability. Just because one species evolves into another does not mean the original species must go extinct. Chimpanzees have successfully adapted to their environment, allowing them to thrive alongside humans, demonstrating that multiple species can coexist and evolve from a shared ancestor.