Biology provides the answer; or rather, evolution.

The paradox was debated in 1995 by Ernst Mayr, a great biologist, and Carl Sagan, a great physicist, in the context of US government funding for SETI (the search for extraterrestrial life).

As against the physicist's probability argument, the biologist made a couple of points: evolution (DNA) is not goal oriented, it is adaptive. Out of some 3.8 billion years of existence, life consisted of simple prokaryotes for nearly half of the time.

Out of perhaps 50 billion species that ever lived, high intelligence evolved only once. According to Mayr, this is because high intelligence is not favoured by natural selection.

In other words, higher intelligence (human intelligence) is not adaptive for survival and evolution (The Sagan-Mayr debate revisited, Pauli Erik Laine, researchgate.net, May 2015).

Plus most species don't last long. Mammalian species, which are limited in number in any case, have very limited lifespans.

Noam Chomsky, the greatest public intellectual of the late 20th and early 21st centuries (90 years old and still going strong) summarised the biological argument with the phrase "lethal mutation"; human intelligence is a lethal mutation which guarantees an early demise of the species.

Kenneth Griffiths, O'Connor

Just like the introduction of another national disaster, the cane toad, it is widely believed that African lovegrass was introduced to Australia by a government agency, for stabilising banks.

There are many more examples of government mistakes that have a huge impact on farming in this country, but let's not dwell on that.

African lovegrass is aggressively and relentlessly spreading, not just around Canberra but in so many more areas across Australia.

Here on Monaro its impact is devastating grazing land and the financial cost to farmers is huge, billions of dollars.

It now completely dominates the corridor from Canberra to Cooma and is spreading out across the Monaro plains, destroying the native grasslands.

The drought will only accelerate this spread and while we are developing good controls on arable land, so much of Monaro is non-arable and rocky and basically current controls are totally inadequate.

The fire risk alone makes it a national disaster and fire authorities consider it a huge occupational health and safety issue, acknowledging that it burns three times as fiercely as ordinary grasslands.

Many bodies are researching ways to combat this devastating threat, which is made far worse by government regulations restricting the use of improved pastures to prevent it spreading.

All of them need much more funding. We need more co-operation and increased funding to try to combat this very vexing, depressing and expensive problem.

Howard Charles OAM, Trustee Coolringdon Agricultural Research Station, Cooma

The Canberra Times editorial ("Why are we so overrun with weeds?", January 14, p12) is an excellent reminder to those of us who have lived in Canberra for a long period of time and witnessed how the growth of Canberra has failed to live up to its reputation as Australia's capital city, with wonderful surroundings, together with lovely kept parks and gardens.

The degradation of our beautiful city primarily rests at the feet of the ACT government and the responsibility of two ministers: Meegan Fitzharris, Minister for Transport Canberra and City Services, and Mick Gentleman, Minister for Roads and Parking.

I fail to see how a small jurisdiction such as the ACT can let such a beautiful place like Canberra city go to rack and ruin, through its neglected efforts to maintain the physical and visual appearance of our gardens, parklands and the streetscape of our suburbs.

It seems that other bigger jurisdictions have the knack of making their cities attractive for visitors.

After all, I would have thought the exorbitant rates we pay the government works on the business model of a "fee for service".

I think we've been misled into believing that our demands for a beautiful city with lovely and attractive surrounds actually do rate on the government's list of priorities.

It would seem to me that the government doesn't see that visitation numbers to our wonderful city of Canberra goes hand-in-hand with the visual and attractive parks and recreation amenities, that surround our national institutions.

I think it is justifiable that we get the services we deserve if the government is raking in money from our rates and other sources of revenue.

Thomas Natera, Ngunnawal

How soon we forget. There is no mention in the media that during the Cold War and detente, the United States repeatedly and angrily pointed out that the Berlin and East German Walls were paradigms of tyranny and repression ("Mr Gorbachev, tear down that wall").

Now it is a national emergency for America to keep out a few thousand victims of crime, poverty and failed states. Trump, who is totally immune to irony, defames these folk without any nuance as criminals, rapists and drug dealers, just as the East German authorities used to libel escapees as "traitors", "scum" and "work shy".

But the horse of unauthorised immigration has well and truly bolted, with more than 12 million undocumented immigrants already in the United States. At least no one is getting shot – yet.

David Roth, Kambah

Let's adopt a new regulation that requires politicians to resign if any pre-election promises they made are not introduced within a year.

To save the high cost of another election in that seat, the candidate who received the second highest primary vote count could be offered that position.

I believe a pre-election promise is a contract between a candidate and the voters. Failure to fulfil any electoral promise may be a result of deceptive marketing spin or fraud and deserves a penalty.

An honest election campaign with promised outcomes may address the growing distrust of politicians by the voters in our country. It only now seems to be working in the finance sector so, sadly, enforced honesty for politicians may be due.

Gary Smith, Tuross Head, NSW

Concerns Australia Day has no relevance outside NSW are unfounded. Much of the continent was part of NSW back in 1788. The arrival of British people may rightly be celebrated in NSW and beyond.

David D'Lima, Sturt, SA

Ebony Bennett from the Australia Institute ("Policy, politicians failing our future"; canberratimes.com.au, January 12) correctly implies that by ignoring environmental problems in the Murray-Darling Basin we are leaving a 'toxic economic and environmental burden' for future generations to clean up.

But is that argument enough to convince politicians and others to do something effective?

The first European colonists in western New South Wales severely degraded the land by clearing vegetation and running far too many livestock.

Rabbits and feral livestock added to the problem. Things came to a head with the 'Federation Drought' (1895-1903) when extreme overgrazing of native vegetation destroyed the natural ecosystems which had enabled development of the pastoral industry.

Has any subsequent generation ever tried to fix the damage? Some minor changes to pastoral lands administration perhaps, some earth-works by soil conservation services on individual properties to get shrubs to regenerate and stop erosion, the introduction of myxomatosis to control rabbits, and some expenditure on water management.

None led to major restoration and all have been offset by further land clearance, water theft and continued over-grazing.

Most people don't realise how badly land and river health have been damaged. We conveniently ignore problems we have caused despite reminders when red dust descends on eastern capital cities.

Experience over the last 120years says that governments of all persuasions will make inquiries and promises only to walk away from fixing problems as soon as politically expedient.

The same will happen with any inquiry into the recent massive fish-kill in the Darling River.

It seems inevitable western NSW will become more arid, its rivers more toxic, and its small towns increasingly abandoned while pointlessly waiting for real action.

To make a difference, it requires arguments far stronger than the notion that we are leaving a mess for future generations to clean up.

Brian Cooke,Waramanga

With a group of close friends I recently camped at Tilpa Weir, which is located on the Darling River north of Lake Cargelligo. The river flow could best be described as a trickle.

Little wonder we now witness the catastrophic death of a staggering one million fish, some estimated to be approximately 100 years old. And, as has been widely reported, there has been an over allocation of water rights upstream along the Darling River System for well over a hundred years.

For instance, Cubbie Station, located on the Darling Riverine Plains Bioregion near Dirranbandi in Queensland is the largest irrigation property in the southern hemisphere, given the rights to well over 400,000 megalitres of water. This represents the equivalent of all of the watering entitlements downstream in north-western NSW.

And for what? The water is used to supply approximately 130 to 200 square kilometres of irrigated cotton, which requires large amounts of water during extreme drought periods in eastern Australia.

Cotton farming is the largest consumer of water in the apparel supply chain and is used in 40 per cent of all clothing worldwide. It takes the use of an incredible 2700 litres of water to make a single cotton T-shirt. Little wonder also that Broken Hill is running out of water, not just to mention all the small communities suffering all along the Darling. Hard to believe there were once paddle steamers transporting goods along the river.

Cubbie Station is owned by a textile manufacturing company (Lempriere and Shandong RuVi Group) funded by Chinese and Japanese investors. So where do you think the profits go ?

A "Darling" of a river no more, just a national disgrace!

Lud Kerec, Forde

The pictures of dry Lake Menindee show land misuse in Australia that is a tiny scale of what occurred to the Aral Sea.

In the time of the Soviet Union, starting in the 1960s there was massive diversion of water for water intensive cotton farming.

By 2002, the Aral Sea had disappeared, leaving as relics the North and South Aral Seas and a huge salt desert.

Today the World Bank and the government of Kazakhstan are spending millions of dollars to refill the North Aral Sea.

The first step is to make sure that one of the main inflowing rivers is more split between agriculture and the sea.

The surface of the North Aral is recovering and is now 50 per cent larger than it was at its lowest point.

In Australia however, flow in the Murray Darling Basin continues to diminish as unsuitable crops, principally cotton, persist, and the national government vaguely listens to inquiries. The result resembles on a smaller scale, the massive environmental degradation incurred by the Soviet Union.

The time for massive Australian national environmental recovery is now.

Jack Palmer, Watson

I see that that indefatigable defender of human rights, Peter Dutton, wants the public to have access to a database of sex offenders' names, photographs and locations. If it prevents only one offence, he thunders, it will have been worth the effort.

But why stop at sex offenders? Why not a database of pollies who have ripped off the public purse? They're just as prone to repeat offences.

I'd like to be able to browse a list of names, photos and locations of the likes of Tony Abbott on his fake visit to a Victorian hospital so that he could attend a Liberal Party function; Bronwyn Bishop of helicopter charter fame, for that and other rorts; or Barnaby Joyce and Julie Bishop who used our dollars to fund the return leg of a trip to India to "study" a Gina Rhinehart family wedding; or George Brandis and Barnaby again (isn't he just an old romantic) touching us up for attending a radio presenter's wedding; or Sussan Ley's plane charters to buy an investment unit on the Gold Coast. If such a database prevents even just one rort, I reckon it would be worth it.

Bronis Dudek, Calwell

WORKSAFE FUNDS

Happy to be corrected, but didn't the ACT government allocate funds to ACT Worksafe for an additional three inspectors to focus on general safety of the light rail project?

Don't they look at electrical issues? You would have thought that would be a high priority given the light rail runs on electricity.

Perhaps the government should request the return of the allocated funds and employ private Work Health and Safety experts/specialists.

J. R. Ryan, Phillip

FLIGHT BUDDIES?

Just wondering. Did Scott and Bill share the same aircraft on their trip to Kakadu last week?

Barry Maher, Richardson

SETTING RECORD STRAIGHT

With Rahaf Al-Qunun's situation in the media, many believe that Islam sanctions the ill-treatment of women, in order for men to maintain dominance over them. Islam provides complete freedom of conscience and religion and absolutely rebukes violence against women. It also establishes no reason for inciting punishment on anyone for denouncing their faith.

Bushra Nasir, Darling Heights, Qld

STRAIGHT TALK

Let's call domestic violence what it really is: domestic terrorism. Then apply the full extent of the anti-terrorism laws rigorously.

Peter Snowdon, Aranda

DEFENDING TOLERANCE

Karl Popper was right to say a tolerant society should not tolerate those who are openly intolerant or the tolerant will end up being destroyed and tolerance with them. Any movement that preaches intolerance must be outside the law (banned). Defending tolerance means we must not tolerate the intolerant. This would rightly include intolerant faiths.

Richard Lutz, Payneham, SA

WHY TAKE THEM?

Why do people need to take drugs to enjoy a music festival? Is the music so bad that they have to be revved up to make the experience enjoyable?

Ken McPhan, Spence

DITCH THE CARS

To iron out any problems in the proposed ACT transport policy I suggest that MLAs and senior public servants hand in their cars and use MyWay cards, cycle or walk for six months. At the end of the winter they will be well placed to finetune the policy.

Steve Thomas, Yarralumla

TRANSPORT LEAD

People are wondering why our ACT transport minister thinks her bus disaster will discourage car use. Our assembly representatives should lead by example, abandoning their cars and their convenient carparking spaces in Civic.

Lead by example.

Maria Greene, Curtin

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