This election is acquiring quite a few back-to-the-future touches.

There’s John Howard, in robust campaign mode. One of those he’s spruiking for is the embattled Tony Abbott, with a letter to Warringah voters, a video and a planned street walk.

Then there’s a prospect that independent Rob Oakeshot might be set for resurrection. Oakeshott, remembered for that 17-minute speech when he (finally) announced he’d support the Gillard government, could strip the Nationals of the northern NSW seat of Cowper.

And bizarrely, there’s Clive Palmer, becoming a player to be reckoned with.

Only last June Morrison said of Palmer’s renewed political push that he thought Australians would say “the circus doesn’t need another sideshow.”

Well, the sideshow’s here and the Liberals are grabbing a prize from its spinning wheel, with an in-principle preference deal with Palmer’s United Australia Party (still to be formally announced by the UAP on Monday).

With Morrison, preferences are a matter of cost-versus-benefit.

That assessment led him to declare recently the Liberals would place One Nation behind Labor. Given the expose of One Nation’s cavorting with the US gun lobby, and how vulnerable the Liberals are in Victoria, Morrison needed to make a gesture.

Read more: View from The Hill: James Ashby rocks a few boats, including his own

Anyway, the One Nation preference issue is most relevant to the Nationals, and the edict didn’t apply to them.

Indeed on Thursday, Nationals’ senator Steve Martin announced the Tasmanian Nationals Senate how-to-vote card will have One Nation third, behind the Liberals (and ahead of Labor) after an agreement between the two parties. “One Nation is less objectionable than the Labor/Greens cohort,” Martin said.

A cost-benefit analysis leads Morrison to turn a blind eye to the times Palmer stymied the Coalition government when he had the power to do so, let alone his business practices, including leaving his nickel refinery workers in the lurch. As is his style, Morrison simply throws a blanket over such inconvenient history.

Read more: View from The Hill: Can $55 million get Clive Palmer back into parliamentary game?

Preference deals are all very well but if Palmer’s comeback takes more votes off the Coalition than from Labor it’s damaging for the government. They won’t all be returned via preferences. Of course Pauline Hanson also has a lot to worry about from any Palmer surge.

The Australia Institute, releasing its latest round of Senate polling in a report out on Friday, notes a “striking rise in support” for the UAP over its last four polls – from 0.8% in August last year to 3.1% earlier this month.

The current figures wouldn’t get the UAP a Senate seat, the report says. “But if the party’s vote continues to grow sharply, it will be an outside chance in Queensland and (surprisingly) Victoria.”

Victoria sounds far-fetched but in the Senate polling the UAP in that state was on 4.7%. Last week, Newspoll surveys in four marginal seats across the country had the UAP polling an average 8%, and 14% in the Queensland seat of Herbert.

Read more: Poll wrap: Palmer’s party has good support in Newspoll seat polls, but is it realistic?

With two weeks gone in the campaign, there’s a good deal of confusion about the state of play. The public holidays have broken the flow, and while parties have their research, publicly we’re lacking evidence about whether Labor’s 52-48% Newspoll lead of around a fortnight ago has held.

But a couple of points seem clear. First, Morrison so far has more than held his own on the campaign trail; Bill Shorten has under-performed. Second, the Liberals’ relentlessly negative campaign looks dangerous for Labor. This is especially so as Shorten is facing the full weight of News Corps’ hostility.

Labor entered the campaign in a good position. Its challenge is to limit the extent to which its initial advantage is eroded by its opponents’ scare tactics.

Although Morrison is battling for the survival of the government, it can be argued Shorten has more at stake personally.

That sounds counter-intuitive, but think of it this way.

Morrison has been leader well short of a year. The government has been generally written off. If the Coalition’s loss was small, many Liberals would see Morrison as having done a good job.

It would be another matter with a big defeat, but the blame for a relatively narrow one would likely (and rightly) be rammed home less to him, and more to the disgraceful shambles of the whole Coalition outfit.

But a Shorten loss, against the odds and after years of polling in Labor’s favour, would see the blame heaped on him (and shadow treasurer Chris Bowen, a driver of much of Labor’s ambitious policy).

Shorten would be criticised not just for his campaign – more fundamentally, he’d be condemned for adopting the big target strategy, so open to scare attacks.

And he’d be blamed for being who he is, a leader with an X factor when X stands for some hard-to-identify (and seemingly impossible to rectify) political gene that makes voters wary of him.

For two terms, Shorten’s government enemies and critics on his own side have underestimated him.

The Liberals thought he could be slain at the royal commission into trade unions that Tony Abbott set up. Malcolm Turnbull did not grasp how tough an opponent he’d be in 2016. Anthony Albanese was ready for him to stumble at the Super Saturday byelections.

Once again, facing this ultimate test, watchers are wondering whether Shorten’s has the goods.

Nonetheless, he and others in Labor appear confident of the numbers, even if in the melee it’s not just Coalition seats up for change, but some held by Labor and independents too.

Labor is encouraged that health, its signature issue and at the centre of Shorten’s first-week campaigning, is coming through strongly in its research, and climate change has been climbing up the issues scale.

Now the holidays are over, the campaign will ramp up quickly, with a new Newspoll, increasing voter tune-in, and prepolling beginning on Monday.

Also on Monday, Morrison and Shorten meet in Perth for a debate sponsored by the West Australian newspaper, an encounter where body language might be as revealing as content.

On Friday next week, they’ll be at a “people’s forum” in Brisbane. By then, with only a fortnight left, the trajectory of the campaign may be clearer.

– ref. Grattan on Friday: All is forgiven in Liberal-Palmer embrace – http://theconversation.com/grattan-on-friday-all-is-forgiven-in-liberal-palmer-embrace-116011

The islands of Sumatra, Borneo and Java were once part of a much larger landmass connected to Asia called Sundaland.

But there are some species that are unique to each island today – such as the two species of orangutan – so in research, published today in Scientific Reports, we looked at what could have kept them apart.

And that involves looking at ancient poo samples.

Land exposed

Sundaland was largest during times of lowest sea level, when it was bigger than all of today’s Europe combined.

Most recently, this was about 20,000 years ago at the peak of the last ice age. Glacial (ice age) periods are much longer than interglacials (warm – like today).

This means Sundaland was exposed above sea level for about 90% of the time over the last few million years, and looked like it does today about 10% of that time.

Sundaland when sea level was at its lowest 20,000 years ago. Study sites are shown that support savanna (orange) or rainforest (green) during that time. Also shown are the Molengraf rivers, on the now-submerged shelf, originally identified from early bathymetric surveys in 1921.

But what did the ancient landscapes look like across this vast – now largely underwater – continent?

Drop what you eat

To find this out we looked at thick accumulations of bat and bird poo in caves across the region.

Bats flying out of an Indonesian cave for a nightly feed. Chris Wurster, Author provided

Insect-feeding bats and birds live in caves. Every night, millions leave their roosts to feed, eating insects from the landscapes surrounding the cave.

After returning to sleep, the bats and birds “do their business”, defecating on the cave floor. The piles of excrement are mostly made up of insect skeletons. So the bats effectively act as mini-scientists, “sampling” the insects that were around the cave during each feed.

Over time, droppings accumulate in deposits several metres thick, which contain insect skeletons many thousands of years old.

Although we can’t identify the insects, as they are too broken up, we can look at chemical fingerprints to figure out what kind of plants the insects were feeding on. This is because insects that feed on tropical grasses leave a very different chemical imprint to those that feed on trees.

Bats clumping on a cave wall: look out below. Chris Wurster, Author provided

So these deposits tell us what type of vegetation was around the cave, and how this changed over time. This is lucky for us, because many other types of records of past environments simply don’t exist in the region, or are now under the sea.

Rainforest refuges

Because there aren’t many other sources of information, there is no agreement on what the landscapes were like across Sundaland in the past.

Some argue, and many models support this idea, that tropical rainforests always covered the whole region, similar to what exists on the islands today.

But there is another idea: that a savanna cut through Sundaland from north to south. This was flanked east and west by wet tropical rainforest, which served as a refuge for rainforest animals and plants during ice ages.

The whole Indonesian region is a biodiversity hotspot with lots of species found only on specific islands and nowhere else. Why? Think of the two species of orangutan, one found only in Sumatra and another only in Borneo. Why are there two subspecies of the Sunda clouded leopard, each unique to Borneo and Sumatra? What about the small Indian civet, found on mainland Asia and Java, but mostly absent from Borneo and Sumatra?

This is curious considering that for most of the time these weren’t in fact islands. So how did these species evolve separately if, for most of the time, they should have been able to move freely from Borneo to Sumatra through rainforest?

The answer to this question has implications for the conservation of many species in the region.

Chris, in over his head in cave poo. Hamdi Rifai, Author provided

We need more caves

We scoured Malaysia and Indonesia for caves with deposits that can answer this question. So what does the cave poo say?

In our latest published study, we present results from a 3-metre pile of ancient excrement covering almost 40,000 years.

Saleh Cave is on the southeastern end of Borneo and at the southern equatorial end of a savanna corridor, if one existed. Today, lush tropical rainforest covers the region.

Being guided to Saleh Cave. Chris Wurster

The chemical fingerprint in the cave poo is clear. Tropical grasses were a dominant part of the landscape during the ice age until recently – geologically speaking.

Putting this in the context of our earlier work in Malaysia, we conclude that a savanna corridor north of the equator was likely. Or, to put it another way, tropical forests did retreat to refuges on Sumatra and Borneo and did not cover Sundaland during the ice age.

Other ocean records also show that tropical grasses expanded, but these records are well to the south and east, and not in the heart of the proposed savanna corridor.

A barrier landscape

The savanna corridor acted as a barrier for rainforest specialists that wanted to move across Sundaland. On the other hand, the savanna corridor served as a bridge for species adapted to the open non-forest environments north and south of the equator.

This neatly explains many of the odd patterns of animal, insect and bird distributions we see across a region of major significance as a biodiversity hotspot.

It might also partly explain how people managed to move through the region so rapidly and on into Sahul (Australia and New Guinea) – the companion ice age continent to Sundaland – more than 50,000 years ago.

– ref. Bat and bird poo can tell you a lot about ancient landscapes in Southeast Asia – http://theconversation.com/bat-and-bird-poo-can-tell-you-a-lot-about-ancient-landscapes-in-southeast-asia-115628