Cute, Furry, Fuzzy
Some of the characteristics which define mammals as a phylogenetic class are hair or fur and the production of milk to nourish their young. Mammals are well known to us, because not only are Homo sapiens mammals but most of the large charismatic animals we are familiar with are mammals. Think of your favorite animal, for most of you it probably has hair or fur and it's probably a mammal. But as some of you may know, there is more than one type of mammal. Marsupial mammals care for their young in pouches utilizing a very different life history strategy than the placental mammals with which we are so familiar. Marsupial mammals are distributed worldwide but are particularly concentrated on one continent, Australia. Watch this video to find out some about the behavior and status of marsupials in Australia.
So that's the current state of marsupials in Australia, but how did Australia wind up with so many unique species? Watch this video to find out how scientists think marsupial mammals arrived in Australia.
Use the resources below to answer the following questions:
- How aware is the general Australian public of the diversity of marsupial mammals in Australia? How do you think this compares to the awareness in other countries? Can you think of a similar situation in the country where you live?
- Review the characteristics of mammals. Looking at them is it clear that marsupials are mammals? Does having a pouch cause any difference in their body form you can see as compared to a placental mammal? Observe closely.
- What behavior of most surviving marsupials make them harder for people to see? What are some possible adaptive advantageous of this strategy?
- How does the ability of marsupial mammals to produce milk differ from placental mammals ability to produce milk? How is this linked to the life history of marsupials? Can you think of environmental conditions where this would give marsupial mammals and advantage over placental mammals? (Hint: consider how gestation time affects an animal in answering this question.)
- Where has the oldest marsupial fossil been found? How old is it? What conditions lead to Australia having so many marsupial mammals compared to the rest of the world?
- http://www.ferris.edu/card/kids_corner/marsupials.htm (note:recent fossil finds have changed the location of the earliest known marsupial)