Attack Of The Killer Fungi

Description:  The cordyceps fungi has a fascinating life cycle. Spores from the fungi are ingested by an insect (like an ant). The fungi takes over the insect causing it to climb to a high branch and hold tight with its mandibles. A fruiting body then emerges from the head of the insect and spreads more spores that infect more insects. Different species of cordyceps infect different species of insects. This phenomenon can be used to introduce the diverse and unique life cycles found in organisms.

Web Resource:  Cordyceps Fungi - Wikipedia

Want more natural history and wildlife videos? Visit the official BBC Earth channel: http://bit.ly/BBCEarthWW BBC Earth The BBC Earth YouTube channel is home to over 50 years-worth of the best animal videos from the BBC archive. With three new videos released every week there's something for all nature loves from astounding animal behaviour to beautiful imagery.

Megafauna Extinction: Humans or Climate?

Description:  North America (like Africa today) was once covered with large megafauna (animals weighing more than 100 pounds). This included giant mammoths, ground sloths, and beavers the size of a large bear. However most of these animals disappeared by 11,000 years ago. What was the cause of this extinction? Humans, climate, or a combination of the two? Phenomenon like this can be found around the World and can introduce the idea of human impacts on the environment.

Web Resource:  What Killed the Great Beasts of North America?

Complete video at: http://fora.tv/2010/05/18/Dr_Elizabeth_Hadly_Mammals_and_Climate_Change Stanford biologist Elizabeth Hadly recaps a debate among biologists over whether prehistoric megafauna like mammoths, giant sloths and saber-toothed cats became extinct due to overhunting by humans, or by a combination of hunting and a changing climate.