The final list of nominees or the shortlist of the Man Booker Prize is out. All six tales share a common dark theme. There might be a fair bit of humour present in these novels but most dwell on grim challenges faced by the protagonists while being starkly different from one another.

The list features American author Anne Tyler's A Spool Of Blue Thread, Jamaican author Marlon James's A Brief History Of Seven Killings, British author Sunjeev Sahota's The Year Of The Runaways, Nigerian author Chigozie Obioma's debut novel, The Fishermen, American author Hanya Yanagihara's A Little Life, and British author Tom McCarthy's Satin Island.

This is the second year that the prize has been open to writers of any nationality, writing in English and published in the United Kingdom. Until 2014, the Man Booker Prize was open to authors only from the UK and Commonwealth nations, Republic of Ireland and Zimbabwe. Many feel this has broadened the horizon much more for English writers around the world. It is in fact a testimony to the same that only two British writers have made the cut this time. The chairman of the judges, Michael Wood, said, "We are delighted by the diversity of the list but it is an accident. We were not looking for diversity."

Each of the shortlisted authors will receive £2,500 ($3,848), while the Man Booker winner will get an additional £50,000 ($76,955), all of which will be announced on 13 October.

Let's take a look briefly at the shortlisted novels, which represent themes majorly distanced from humour and laughter.

Hanya Yanagihara (US) for A Little Life: Yanagihara has been tipped as the favourite among the bookies. Her first novel, The People In The Trees, based on the real-life case of virologist Daniel Carleton Gajdusek, was praised as one of the best novels of 2013.

A Little Life follows the lives of four friends talking about the limits of friendship and revolves around the depths of pain and shame that a human can endure about the unending legacy of abuse. Keeping in tune with its dark theme, this book is probably the grimmest of the listed novels asking questions about humanism, euthanasia, psychiatry, child abuse and many other gloomy quarters of life.

Marlon James (Jamaica) for A Brief History Of Seven Killings: James is Jamaica's first representative to the Man Booker Prize. His book has appeared in almost all leading books of the year lists, with most describing it as a theatrical pot-boiler, good enough to be turned into a Hollywood script.

The book narrates the attempted assassination of Bob Marley in the late 1970s, events that unfold over three decades after the incident through the lives of drug barons, MPs, beauty queens, journalists and even the CIA.

Tom McCarthy (UK) for Satin Island: Tom McCarthy has come a long way from his debut novel, Remainder (written in 2001) being rejected by mainstream UK publishers, to making the cut for the short list of this coveted title. In fact he is the only writer on the list to feature on the short list of the Man Booker Prize for the second time this year after 2010 when his novel C was nominated.

Set in contemporary London, McCarthy's Satin Island tells the story of a corporate anthropologist who works for an elite consultancy. He embarks on a data-gathering project to help "decode and manipulate the world around them".

Chigozie Obioma (Nigeria) for The Fishermen: For Obioma, the shortlist itself is a stellar achievement at the young age of 28, that too for his first novel. Although his short stories have appeared in the Virginia Quarterly Review and New Madrid, this is the author's first full-fledged novel. The Fishermen tells the story of a Nigerian family falling apart after a local man predicts one of four brothers will kill another.

Sunjeev Sahota (UK) for The Year Of The Runaways: A British author of Indian descent, Sahota's debut, Ours Are The Streets won him a place on the 2013 Granta Best of Young British Novelists list. The Year Of The Runaways is his second novel, and centres around the lives of three Indian men and a woman, all migrants from India. The novel sheds light on immigration through the lives of the characters before and after they came to Britain.

Anne Tyler (US) for A Spool Of Blue Thread: Tyler is a veteran in the game. A Pulitzer prize awardee for Breathing Lessons (1988), her novel The Accidental Tourist (1985) was adapted into a film starring William Hurt, Kathleen Turner, and Geena Davis.

A Spool Of Blue Thread was also nominated for this year's Baileys Women's Prize for Fiction. It tells the story of three generations of the Whitshank family exploring the resentment that develops and festers between siblings, spouses, and in parent-child connections — as well as their affectionate bonds.

The writers this year are a diverse mix of not just nationalities and descents but also reflect a growing trend where good quality writing supersedes age, experience and number of awards. While Obioma, the youngest writer on the list is 28, the oldest writer, at 73, is Tyler who is nominated for her 20th novel.