Evidence of species changing over time examples for 8th grade

📚 Quick Study Guide

• ⏳ Fossil Record: 🦴 Fossils provide a history of life on Earth, showing how organisms have changed over millions of years. Older layers of rock contain fossils of simpler organisms, while younger layers contain fossils of more complex organisms.
• 📊 Comparative Anatomy: 🧮 Comparing the body structures of different species can reveal similarities that suggest common ancestry. For example, the bones in the limbs of humans, bats, and whales are similar, even though these limbs have different functions. These are called homologous structures.
• 👶 Embryology: 👀 Studying the development of embryos can also provide evidence of evolution. Embryos of different species often look very similar in their early stages, suggesting that they share a common ancestor.
• 🧬 DNA Evidence: 🔬 Comparing the DNA of different species can reveal how closely related they are. The more similar the DNA, the more recently the species shared a common ancestor.
• 🌍 Biogeography: 🗺️ The study of the geographic distribution of species. Species that live in the same area are more likely to be related to each other than species that live in different areas, even if they have similar environments.
• 🐛 Observed Evolution: 🌱 Sometimes we can observe evolution happening in real-time! Examples include bacteria developing resistance to antibiotics and insects developing resistance to pesticides.

Practice Quiz

1. Which of the following provides evidence of species changing over time?
   1. A. The color of a bird's feathers
   2. B. The songs whales sing in the ocean
   3. C. The fossil record showing changes in organisms over time
   4. D. The size of a tree's leaves
2. What is the study of the geographic distribution of species called?
   1. A. Anatomy
   2. B. Embryology
   3. C. Biogeography
   4. D. Geology
3. What do we call similar body structures in different species that suggest common ancestry?
   1. A. Analogous structures
   2. B. Homologous structures
   3. C. Vestigial structures
   4. D. Random structures
4. Comparing the DNA of different species is like:
   1. A. Reading different books
   2. B. Comparing different recipes
   3. C. Comparing different languages
   4. D. Comparing different versions of the same story
5. Which of the following is an example of observed evolution?
   1. A. A volcano erupting
   2. B. A river flowing to the sea
   3. C. Bacteria developing resistance to antibiotics
   4. D. The Earth rotating around the Sun
6. Why are embryos of different species often similar in early stages?
   1. A. Because they live in the same environment
   2. B. Because they eat the same food
   3. C. Because they share a common ancestor
   4. D. Because they are exposed to the same sunlight
7. Fossils found in older layers of rock are generally:
   1. A. More complex than fossils in younger layers
   2. B. Simpler than fossils in younger layers
   3. C. The same as fossils in younger layers
   4. D. Nonexistent