Lesson 2 - Extinction is forever - or is it?

Lesson 2 (of 2) for the fabulous Year 7 students!

Hi Year 7's - Welcome back to Bush Blitz! Take a moment to refresh your memory on the purpose of this exciting conservation program?

Now - take a few minutes to look at these pictures and read the text. Discuss the issue of extinct species - both plant and animal, in Australia and the rest of the world. The Scientific species names are in italics - have a go at pronouncing them out loud!

               Moa (a flightless bird) from New Zealand

The moa were a group of nine species (in six genera) of large flightless birds that lived in New Zealand. The largest, Dinornis robustus and Dinornis novaezelandiae, dwarfed the modern ostrich, reaching a height of 3.6 meters weight of 230 kilograms.

Moa disappeared by the year 1400, after being hunted by the Maori, and after their habitat was disturbed for farmland.

              

Thylacine (Tasmanian tiger) from Australia

Roughly the size of a large dog, the thylacine (http://phenomena.nationalgeographic.com/2011/05/03/thylacine-was-more-tasmanian-tiger-than-marsupial-wolf/) or Tasmanian tiger (Thylacinus cynocephalus) was a striped carnivorous marsupial that lived on Australia, Tasmania, and New Guinea. Tasmania was its last stronghold, but the animal was pronounced extinct in the 1930s. Loss of habitat and introduced dogs likely played a role, although most biologists point to hunting as a primary cause.   

               

               Woolly mammoth

A museum worker inspects a replica of a woolly mammoth (Mammuthus primigenius), a species that went extinct 3,000 to 10,000 years ago (http://news.discovery.com/animals/endangered-species/woolly-mammoth-extinction.htm). In March 2012, scientists in Russia and South Korea announced a partnership (http://en.sooam.com/html/?code=B01&div=16) to try to clone the mammoth and generate a living specimen.

              

Gastric brooding frog

In this novel form of parental care, the female swallowed her fertilized eggs. Her stomach then stopped producing acid, becoming a makeshift womb. Later, she regurgitated fully formed froglets.

Two species of gastric-brooding frogs made their homes in creeks in a relatively small area of tropical forest in Queensland, Australia, the southern gastric-brooding frog (Rheobatrachus silus) and the northern gastric-brooding frog (Rheobatrachus vitellinus). The species were discovered in 1973 and 1984, respectively, but by the mid-1980s they had both disappeared.

Biologists aren't sure why the frogs went extinct, but they suspect habitat degradation, pollution, and possibly disease, including chytrid fungus (http://news.nationalgeographic.com/news/2012/121217-chytrid-fungus-amphibian-frog-crayfish-science/).         

               

              

The information above (and immediately following) plus the photos were obtained from the National Geographic website where you can find many other examples of extinct or endangered species.

What do the thylacine, Tasmanian tiger, woolly mammoth and gastric-brooding frog all have in common? For one, they’re all extinct – however, there are some scientists who think that the extinction of these animals (and others) might not have to be permanent.

Even if it does become possible to bring back extinct species, there is the question of whether or not we should. Those who support ‘de-extinction’ say that it allows us to correct past mistakes and helps with species conservation. Plus the idea of being able to see living dodos, moas and thylacines is appealing to many.

You might like to share the wonderful book 'As Dead as a Dodo' at this point.

There are many scientists who oppose the idea. Attempting to bring back extinct species takes a lot of time and money – effort that some conservationists say would be better spent addressing things like habitat destruction which cause extinction in the first place.

Another problem for species that have been extinct for hundreds or thousands of years is that the ecosystems in which they once flourished may have changed or disappeared. Individual species may be able to be brought back, but recreating lost ecosystems may be too hard.

This debate shows that 'de-extinction' is not just scientifically complicated, but ethically complicated too.

                             

How would you feel if you could see living specimens of these and other previously extinct species??????

Bringing back extinct species is becoming potentially possible!!!

The technology of using DNA (cell information) extracted from museum or university specimens of extinct animals to implant into the eggs of living animals, which then give birth to babies of the extinct animals, is currently being developed. If you saw the movie – Jurassic Park – this is the scientific process behind the development of the living dinosaurs in the park! Mmmm. I wonder if you would visit Jurassic Park?

Would it give conservation movements something new to generate excitement, or does it generate apathy, so people ask 'why do we need to care about saving them in the wild if we can bring them back?’

A very interesting question.

Bush Blitz and Earthwatch are trying to learn about and improve the conservation status of many plants, animals and natural areas in Australia. Their aim is to protect the species we have now rather than lose more.

What do you think?

Think about the positives and negatives of ‘cloning’ extinct species ( de-extinction). Discuss in your groups some of the good things or the bad things that may arise if we can perfect this process and start to bring back to life some of the extinct animals.

There are many ideas you could consider during your discussion.

•             Food requirements – especially for species from long ago

•             Environment needs – has the earth changed significantly – can the species adapt to new physical environments?

•             Climate needs - has the earth changed significantly – can the species adapt to new climatic environments?

•             Safety of both people and the animals

•             Size of populations – do you just keep cloning/growing new ones as the die or do you develop large enough populations to breed and reproduce naturally?

•             Knowledge of species medical/veterinary needs

•             Is the artificial introduction into the current world appropriate for an extinct species – animals may live in groups or pairs or in a solitary situation. How will we know? We may not know – they may have been too long extinct.

•             Competition with modern species – food, space, habitats.

•             Would they be kept in zoos, as pets, in scientific research institutions or let out in to the natural environment?

•             Who would be responsible for them?

These points are available to print for group discussions:

Ideas to consider if you could bring extinct species back to life through cloning (http://bushblitz.teachlive.org.au/content/download/9495/28388/file/Ideas to consider if you could bring extinct species back to life through cloning.pdf) (PDF) 176.81 kB

As a group, keep notes and make a decision – would you vote

•             for the conservation of today's natural world and the prevention of further extinction and destruction

or

•             do you think we should not bother, seeing as we may soon be able to re-create any species we can extract suitable DNA from?

Elect 1 or 2 speakers to represent your group and present some of your arguments in a class debate/discussion.

Please collate your responses in a file for me to look at when I return. I will be very interested in your opinions on this controversial and ethical debate. Even many Scientists cannot agree about this!

Persuasive Text (To be started in class if there is time but completed as a homework activity)–

After participating in the group discussion and the joint discussion in the class forum, decide what you think is the answer to the question –

Should scientists forget about trying to conserve our current natural environment and the species we have, and instead put all our resources into developing techniques to bringing extinct species back to life?

You may not have agreed with your group's decision or you may have changed your mind after hearing other points of view.

•             Present a persuasive text to explain your answer with your most important reasons presented as justification.

•             You may present your text in any form you choose - handwritten, typed, audio or video form.

•             You might like to attempt to extend your skills and produce a persuasive poster or alternative presentation.

•             Just remember to apply the persuasive text skills you have been developing. (Ask your classroom teacher if you need a gentle reminder!)

I look forward to reading your personal ideas! Don't worry - it will be due in at the end of week 4 so you have a while to complete it to a good standard.

These Persuasive Text notes are available to print out if needed.

Persuasive Text (http://bushblitz.teachlive.org.au/content/download/9496/28391/file/Persuasive Text.pdf) (PDF) 407.95 kB