Lesson Idea

Scientific Articles about 4 Extinct Animals

This collection of research articles introduces students to four extinct animals – woolly mammoth, Christmas Island rat, American mastodon, and Falkland Islands warrah.

Engage students with standards-matched adaptations, introductory video content, comprehension questions, and vocabulary to further the lesson outcomes. Each adapted article also comes with additional suggestions for activities to enhance the readers’ understanding and make the class more exciting.

1. What made woolly mammoths Ice Age icons?

Abstract: What does it take to survive an ice age? Woolly mammoths are extinct today, but they thrived during the Late Pleistocene era. But what genetic adaptations separate woolly mammoths from their modern-day elephant relatives? To discover this, we analyzed the genomes of 23 woolly mammoths. This included one of the oldest woolly mammoth specimens ever discovered – 700,000 years old! We compared these to the genomes of living Asian and African elephants and looked for unique mutations in woolly mammoth genes. We found that woolly mammoths had changes in genes linked to hair growth and fat storage. These may have helped the woolly mammoth survive in its cold environment. The earliest woolly mammoths already had thick fur coats and large fat deposits. But these and other traits, like small ears, continued to evolve over time.

This article is suitable for lower high school students. An audio version is available in English.

Key terms: elephants, evolution, extinction, genetics, natural selection, paleogenetics, paleontology
Scientific figures: pictograph
Scientific method: DNA sequencing

2. Why is it so hard to bring back extinct species?

Abstract: De-extinction is the science of bringing back extinct species. But it’s very challenging. Scientists are testing out lots of different ideas. One promising idea is to use genetic engineering to piece together the DNA of an extinct species. We analyzed old, fragmented DNA of the Christmas Island rat, which went extinct about 100 years ago. For an extinct species, the only option is to use the genome of a similar, living species as a reference. By comparing DNA fragments to the reference, you can put the pieces in the right order. We used brown rats as a reference. Unfortunately, we found that some of the genes of the extinct species can’t be recovered. This means that an animal brought back by genetic engineering wouldn’t be an exact copy of the extinct species.

This article is suitable for middle school students. An audio version is available in English and Spanish, and a written translation is available in English, Spanish, and Chinese.

Key terms: extinction, genetics
Scientific figures: pie chart
Scientific method: case study, DNA sequencing, gene editing

3. What can tusks tell us about the lives of mastodons?

Abstract: Did you know that tusks are enormous teeth? Many animals have them, but the biggest ones belong to elephants and their relatives, including mastodons. Mastodons are now extinct, but paleontologists can use fossil tusks to study the lives of these ancient giants. For our study, we analyzed the right tusk of a male mastodon found in 1998. We also analyzed two chemical elements preserved in the tusks: oxygen and strontium. Using different forms of these elements (called isotopes), we tracked the season when a particular layer of tusk was grown, as well as where he grew it. We learned that he traveled long distances to mate with females. He also had fights with other mastodons and even died during his final battle!

This article is suitable for middle school students. An audio version is available in English.

Key terms: extinction, fossils, migration, paleontology
Scientific figures: map, pictograph
Scientific method: data reconstruction, mass spectrometry, proxy data, representative sampling, scientific modeling

4. How did the warrah cross the ocean to the Falkland Islands?

Abstract: When Charles Darwin visited the Falkland Islands, he was puzzled to find only one species of land-dwelling mammal – a fox-like animal called the warrah [WAH-rah]. How could the warrah have reached the Falkland Islands? Until now, scientists have assumed humans weren’t responsible for bringing the warrah to the islands. However, we showed that it is very likely that Indigenous people from the Tierra del Fuego visited the islands centuries before the first European explorers arrived. The Yaghan people are traditionally nomadic hunter-gatherers and often traveled with domesticated foxes. We believe that the Yaghan people probably brought the warrah to the islands centuries ago.

This article is suitable for middle school and lower high school students. An audio version is available in English. This article includes a Lesson Idea video demonstrating a classroom lab using M&Ms to model radioisotope decay, a technique used in this research. This article also includes three different Ask-A-Scientist interviews with the original researcher, PhD candidate Kit Hamley, talking about why she picked the warrah, why research can be hard, and what it is like to do field work.

Key terms: archaeology, extinction, paleontology, wildlife
Scientific figures: map
Scientific method: field study, proxy data, radiocarbon dating