This year, as every schoolboy knows, is the 200th anniversary of the birth of Charles Darwin and the 20th anniversary of the launch of Sky News.
Milestone birthdays are good moments for taking stock. Since Darwin's bicentenary has prompted a small industry it seems appropriate to assess the influence of Sky on the evolution of the news industry.
Over two decades of research, Darwin established that if you don't innovate, you die. During its 20-year history, Sky News' innovative techniques have played a pivotal role in the transformation of news.
Before Sky News launched as the first European news channel, on 5 February 1989, the television news landscape was a grey place. CNN, initially derided as Chicken Noodle News, was gaining a foothold. But in Europe the 24 hour news cycle did not exist.
When the news eventually arrived on TV, at prescribed bulletin times, it was handed down by newsreaders with clipped tones and patrician airs. The relationship between news provider and news consumer was unequal.
Rupert Murdoch had just emerged from the bitter Wapping dispute, in which he overcame trade union opposition to modernisation plans for his newspapers. Most national papers were now following Murdoch's lead and switching from hot metal printing to the new offset litho method.
Now it was television's turn to be shaken up.
Sky News challenged the status quo by offering viewers choice. Its pioneering journalists set out to shake up the cosy duopoly of BBC and ITN.
The station's first slogan, 'We're there when you need us', emphasised that difference from the terrestrial channels with their fixed bulletins.
The BBC eventually followed Sky's lead by launching News 24 in 1997, and has grown into a potent competitor.
Around the world, the capacity of satellite news to broadcast across borders has driven its proliferation: Sky News is watched by 145 million people in Europe and in the Middle East, Africa, Asia and Australia.
There are now at least 80 news channels worldwide, and many have their own distinct influences. Al-Jazeera, criticised in the West for its coverage of terrorism, nevertheless brought non-state controlled TV news to millions of people throughout the Middle East. Another Arabic rolling news station, Al-Aribiya, secured Barack Obama's first formal interview as President.
Others have their own agendas. France 24 was the brainchild of Jacques Chirac as part of his campaign to defend the French language and promote a Francophile view of the world.
Russia Today is another state-backed channel seeking to present an "unbiased portrait" of the country. Even Iraqi insurgents launched their own channel, Al-Zawraa, although it was forced to close down.
24 hour news allowed TV audiences to "witness the event". From the trials of OJ Simpson and Louise Woodward to 9/11, the start of the Iraq war and the Mumbai shootings – viewers have been able to watch news stories unfold live. The inauguration of Barack Obama was watched by 2.5 million people on Sky News alone.
News does not usually break cleanly. Details emerge in dribs and drabs, in bits of information from many sources and are often conflicting. Before Sky, news providers were reluctant to share information until they had what they considered to be the whole story. Sky believes in taking the audience into its confidence and sharing facts as soon as possible.
The recent book about 24-hour news, No Time To Think, by Howard Rosenberg and Charles S Feldman, dredges up the joke that Sky's slogan should be 'Never wrong for long'. This completely misses the point. When a big news story is unfolding, Sky reports new information, clearly attributed to its source.
A shift took place after the London bombings on 7 July 2005. While the authorities were insisting that the explosions on the Tube were caused by a power surge, Sky News reported the facts as they emerged, pieced them together and reached the conclusion that London was under attack. Sir Ian Blair, the Metropolitan Police Commissioner, has said: "At that stage [09.20am] we were pretty unclear, because we didn't know whether these were bombs or an electrical surge ... and we switched on Sky as everybody else does to try to get some idea of what's going on ..."
The BBC, which for a while stuck with what it could confirm officially, subsequently carried out audience research which showed that 24-hour news viewers trusted Sky more than BBC News 24. As a result, the BBC adjusted its policy and now reports information as it emerges much more readily.
The growth in news on the web and on mobile phones means that every news provider is now in the 24 hour news business. Sky has carried this spirit on to the web. We were the first to put video at the heart of our website. And we created a web-only programme genre – "Unplugged" – which Andrew Keen in this newspaper suggested "... is where all news media is headed."
Innovation has many forms. Tim Gardam, the distinguished journalist and academic, noted the irony that it was Sky, a non public-service broadcaster, which had lifted the curtain on China's human rights abuses with a series of award-winning reports by Dominic Waghorn.
What of the next 20 years? Despite the recession, technological innovation will be crucial. Our online and TV journalists already work cheek-by-jowl, but convergence will demand improved newsroom systems.
For the customers, convergence will make news even more interactive. Future satellite boxes may combine TV and the web: High Definition pictures embedded with HTML making them completely clickable.
The consumers will increasingly also be contributors: Sky News' coverage of the Glasgow terror attack in 2007 for the first hour or so consisted entirely of videos, stills and reports by the public.
I, for one, will approach Sky's 20th birthday like any other day. Evolution is about looking forward.