Question

Suppose that all of geologic time were proportional to the length of a football field ( 100 yards). Earth would have formed at the opposing team's goal line ( 100 yards), and the present day would represent the home team's goal line ( 0 yards). Metaphor equation Metaphor value \(=(\) years before present \(/\) age of Earth \() \times\) metaphor maximum Example Oldest fossil bacteria \(=3,500\) million years old Age of Earth \(=4,600\) million years Metaphor maximum \(=100\) yards Metaphor value \(=(3,500,000,000 / 4,600,000,000) \times 100=76\) yards Key metaphor dimensions 100 yards \(=4,600\) million years 10 yards \(=460\) million years 1 yard \(=46\) million years 1 foot \(=15.3\) million years 1 inch \(=1.3\) million years Calculate the yardage of the extinction at the end of the Paleozoic era. Then fill in the blank cell in the table and label the following figure. Develop your own metaphor for geologic time and describe it. Choose some of the most significant geologic events from the geologic timescale and convert them into your own metaphor equation. Don't try to be too detailed in your analysis. The intention here is to recognize the length of the geologic timescale and the relative positions of key events. Approximate lengths, distances, heights, widths, depths, sizes, time periods, and so on are okay as long as you recognize the relative proportions of the time intervals. \begin{tabular}{|l|l|l|} \hline Distance from home goal line & Time, million years & Event \\ \hline 76 yards & 3,500 & Oldest fossil bacteria \\ \hline 26 yards & 1,200 & Oldest known animal fossil (jellyfish) \\ \hline 12 yards & 542 & Hard skeletons become common (fossils) \\ \hline 10 yards & 458 & First land plants (mosses) \\ \hline & 251 & Widespread extinction ends Paleozoic era \\ \hline \(1.4\) yards & 66 & Dinosaurs become extinct \\ \hline \(0.00036\) inch & \(0.00051\) & Columbus landed, 1492 \\ \hline \end{tabular}

Short answer

The extinction event is approximately 5.46 yards from the home team's goal line.

Step-by-step solution

Determine Proportional Metaphor Value

We need to find the proportional metaphor value which corresponds to the extinction at the end of the Paleozoic era. This extinction occurred 251 million years ago. Using the metaphor equation: \[\text{Metaphor value} = \left( \frac{\text{years before present}}{\text{age of Earth}} \right) \times \text{metaphor maximum}\]Substitute the given values:\[\text{Metaphor value} = \left( \frac{251,000,000}{4,600,000,000} \right) \times 100\]

Simplify the Fraction

Simplify the fraction within the metaphor equation: \[\frac{251,000,000}{4,600,000,000} = \frac{251}{4,600}\]This simplifies further to approximately 0.05457 when calculated.

Calculate Metaphor Value

Now, multiply the simplified fraction by the metaphor maximum:\[\text{Metaphor value} = 0.05457 \times 100 = 5.457\]

Convert to Yards

Since we need to find the distance in yards, convert the metaphor value to yards. Thus, it approximates to 5.46 yards.

Fill the Blank Cell

Using the calculated metaphor yardage, fill in the blank cell in the table for the extinction event at the end of the Paleozoic era. The distance is approximately 5.46 yards from the home goal line.

Summary

The extinction event at the end of the Paleozoic era is positioned approximately 5.46 yards from the home team's goal line on the metaphorical football field.

Key concepts

Metaphors in Geology

In geology, metaphors can be a powerful tool to help us visualize the immense scales of time the Earth has experienced. Imagine trying to comprehend billions of years; it's an abstract concept that can be hard to truly grasp. That's where metaphors come in.

Take the example of mapping the geologic timescale to a football field. The metaphor makes it easy to see the relative distance of key events in Earth's history. If Earth's entire existence were laid out on a 100-yard football field, each yard corresponds to millions of years.

• The Earth forming is at the 100-yard mark.
• The extinction of the dinosaurs happens just a short step away from the endzone at around 1.4 yards.
• The emergence of the first land plants? About 10 yards from the present day endzone.

This metaphor allows you to easily visualize how close or far apart significant events are in retrospect. It highlights how recent many developments, like human civilization, are in the grand scheme of geologic history.

Paleozoic Era

The Paleozoic Era is one of the major intervals of Earth's history, lasting from about 541 to 251 million years ago. Often dubbed the "Age of Ancient Life," it's a period teeming with significant evolutionary milestones.

This era began with the Cambrian Explosion—a radical burst in biodiversity—and ended with one of the most catastrophic extinction events in Earth's history. A few key developments during the Paleozoic include:

• The development of hard-shelled organisms, which began appearing around 542 million years ago.
• The colonization of land by plants around 460 million years ago.
• The emergence of amphibians and fully terrestrial vertebrates towards the end of the era.

Understanding this timeline helps us appreciate the slow crescendo of life evolving from simple creatures in the ocean to more complex forms that paved the way for future terrestrial ecosystems.

Extinction Events

Extinction events are pivotal moments when dramatic natural changes have resulted in the widespread dying out of species. The end of the Paleozoic Era, specifically the Permian-Triassic Extinction Event, is one of the most significant. At this time, approximately 251 million years ago, more than 90% of marine species and 70% of land species perished.

This mass extinction is often referred to as "The Great Dying" due to its severity and scale. While the exact causes are still debated, possible factors include massive volcanic eruptions, climate shifts, and changes in ocean chemistry.

• Volcanic activity could have increased greenhouse gases, raising global temperatures.
• Changes in the water cycles could have led to acidification in oceans.

These events underscore the dynamic nature of Earth's environment and how life has had to continually adapt—or face extinction.

Fossil Record

The fossil record is like a history book of life on Earth, albeit one with missing pages and faded words. Fossils, the preserved remnants of ancient organisms, give scientists snapshots of past life and help us piece together the evolution of species over millions of years.

When looking at the fossil record, significant evolutionary markers become clear. Organisms start with basic forms, such as single-celled bacteria, the oldest of which date back 3.5 billion years. Over time, complexity increases—leading to hard-bodied animals in the Paleozoic and eventually mammals and birds.

• Fossils show us the transition of life forms from simple to complex, like early fish in the Cambrian seas evolving into amphibians during the Devonian.
• They provide evidence for major evolutionary leaps and even extinctions, which reshaped the course of life.

Through meticulously studying these relics, scientists continuously refine our understanding of life's intricate history and the dynamics that shaped our planet's biological narrative.