Question

Why does the presence of extinct forms and transitional features in the fossil record support the pattern component of the theory of evolution by natural selection? a. It supports the hypothesis that individuals change over time. b. It supports the hypothesis that weaker species are eliminated by natural selection. c. It supports the hypothesis that species evolve to become more complex and better adapted over time. d. It supports the hypothesis that species change over time.

Short answer

d. The presence of extinct forms, and transitional features in the fossil record support the pattern component of the theory of evolution by natural selection because it supports the hypothesis that species change over time.

Step-by-step solution

Understanding the pattern component of the theory of evolution by natural selection

The pattern component of the theory of evolution focuses on the observable patterns and global trends in the history of life on Earth- such as the distribution of fossil species in the geologic record and their relationships to living species. These patterns help us to draw inferences about the underlying processes that have shaped the tree of life, such as common ancestry and the inheritance of traits through generations.

The importance of extinct forms and transitional features in the fossil record

Extinct forms and transitional features in the fossil record provide key evidence for the existence of intermediate stages in the evolution of species over time. They act as a "snapshot" of the past, showing us how species have changed, and they help to establish links between different lineages of organisms. This supports the idea that species on Earth have a history of change and that evolution is an ongoing process.

Comparing the hypotheses

Now that we understand the importance of the fossil record in demonstrating the patterns of evolution, let's compare the given hypotheses: a. The hypothesis that individuals change over time is a concept related to individual development, rather than evolution. Evolution deals with the changes in populations or species over many generations, not an individual organism. b. The hypothesis that weaker species are eliminated by natural selection is a part of the theory of evolution, but it does not directly address the pattern component. c. The hypothesis that species evolve to become more complex and better adapted over time is also a part of the theory of evolution, but it focuses more on the process component (how species evolve) rather than the pattern component (what we can observe through the fossil record). d. The hypothesis that species change over time aligns with the observed patterns in the fossil record, including extinct forms and transitional features, which show a history of change in species over time.

Conclusion

Based on the analysis above, the correct answer is: d. The presence of extinct forms, and transitional features in the fossil record support the pattern component of the theory of evolution by natural selection because it supports the hypothesis that species change over time.

Key concepts

Understanding Natural Selection

Natural selection is a fundamental concept in biology that explains how species evolve over time. It is often referred to as 'survival of the fittest.' This process occurs when there are variations within a species, and some traits become more common because they provide a competitive advantage in a given environment.

For instance, imagine a population of insects where some are green and others are brown. In a forest environment, the green insects might be more likely to survive and reproduce because they're better camouflaged from predators. Over time, the population will have more green insects, illustrating natural selection.

It's important to note that 'fittest' doesn't necessarily mean the strongest or fastest; it refers to the best fit for the environment, which is why sometimes surprising traits prevail through this mechanism. This concept helps us understand the exercise's question, as natural selection is a key driver behind the evolution of species and the emergence of new traits.

The Fossil Record as a Window into the Past

The fossil record is a historical archive of life on Earth, laid down over billions of years. It contains traces or remains of organisms from the past, such as bones, teeth, and imprints. These fossils are often found in sedimentary rocks, which are formed by the accumulation of sediments in lakes, rivers, and other environments.

Through the study of the fossil record, scientists can uncover the sequence in which species appeared and disappeared. This record can show gradual changes in species over time, or it can reveal sudden mass extinctions followed by the emergence of new forms of life. It's essentially a chronicle of the past that supports the hypothesis of species evolution, as it shows direct evidence of organisms that have lived and how they have gradually transformed over the eons.

Transitional Features as Evidence of Evolution

Transitional features provide some of the most compelling evidence for the theory of evolution. These are traits that exist in fossilized remains and illustrate an evolutionary bridge between earlier and later species. Imagine an old family photo album: just as we can see resemblances between generations of family members, transitional features show us the gradual modifications that lead from one species to another.

One classic example is the transitional forms found between fish and amphibians, showing a change from fins to limbs that could support weight on land. These forms help us understand the stepwise nature of evolutionary change and the common ancestry of diverse groups of organisms, which are fundamental elements of the theory of evolution.

Species Evolution Over Deep Time

Species evolution is the process that leads to the diversity of life we see today, shaped by millions of years of genetic changes. Evolution isn't goal-oriented; it doesn't strive for perfection but is instead a natural outcome of variations that better suit organisms to their environment.

Species don't evolve in isolation; they're part of a complex web of life that includes not just their environment but also interactions with other species. This deep-time perspective is crucial to understand why certain species thrive while others become extinct. The exercise's correct option highlights this view by indicating that the species do indeed change over time, a fundamental aspect recognized through various lines of evidence in natural history.