Which scientist is associated with the idea that organisms become more complex as they move up a ladder of progress?

Which scientist is associated with the idea that organisms become more complex as they move up a ladder of progress?

• A. Jean-Baptiste Lamarck
• B. Charles Darwin
• C. Gregor Mendel
• D. Alfred Wallace

Answer: (A)

Think of evolution as a process that some historical thinkers pictured as life climbing a ladder toward greater complexity. Jean-Baptiste Lamarck is the one most closely tied to that idea. He argued that organisms can acquire traits during their lifetimes through use or disuse of organs, and those acquired traits are passed on to offspring. Over many generations, this would lead to a progressive increase in complexity, lining up organisms on a linear scale from simple to more complex forms. In contrast, Darwin and Wallace described evolution through natural selection, where variation among individuals and differential survival and reproduction shape populations. This creates branching, not a single upward ladder. Mendel, meanwhile, explained how traits are inherited through discrete genes, without invoking a directional ladder of progress. So the notion of life climbing toward more complexity fits Lamarck’s perspective best.

Think of evolution as a process that some historical thinkers pictured as life climbing a ladder toward greater complexity. Jean-Baptiste Lamarck is the one most closely tied to that idea. He argued that organisms can acquire traits during their lifetimes through use or disuse of organs, and those acquired traits are passed on to offspring. Over many generations, this would lead to a progressive increase in complexity, lining up organisms on a linear scale from simple to more complex forms.

In contrast, Darwin and Wallace described evolution through natural selection, where variation among individuals and differential survival and reproduction shape populations. This creates branching, not a single upward ladder. Mendel, meanwhile, explained how traits are inherited through discrete genes, without invoking a directional ladder of progress. So the notion of life climbing toward more complexity fits Lamarck’s perspective best.