ANSWERS TO CORRESPONDENTS: It is now common for films to be adapted into TV series. What are the earliest examples of this?

QUESTION It is now common for films to be adapted into TV series. What are the earliest examples of this?

These days successful films often make the transition from big screen to small; The Mandalorian (Star Wars), The Gentlemen, Fargo and Cobra Kai (The Karate Kid) are some successful examples.

The benchmark was set in the 1970s with M*A*S*H, the TV spin-off of Robert Altman’s film about American medics in the Korean War. This was followed in the 1990s by Buffy The Vampire Slayer, in which Sarah Michelle Gellar was so successful in the leading role that few people remember Kristy Swanson was the original ‘chosen one’.

However, the TV spin-off is nothing new. The first big success was CBS’s Mama. It was based on the 1943 novel Mama’s Bank Account by Kathryn Forbes and the subsequent film I Remember Mama (1948). Set in the 1910s, it told the story of a Norwegian family in San Francisco. The light-hearted drama ran from 1949 until 1957 and became a must-watch for millions of Americans.

The benchmark was set in the 1970s with M*A*S*H, the TV spin-off of Robert Altman’s film about American medics in the Korean War 

Other early entrants include The Front Page (1949-50) about reporters on a police beat which was based on a 1928 Broadway comedy and a 1931 film. There were also the sci-fi series Buck Rogers and the detective drama Dick Tracy (both 1950-1951). These were both based on comic strips that became popular film serials in the 1930s.

The most successful was Lassie. British writer Eric Knight’s 1940 novel Lassie Come-Home, following the exploits of a courageous rough collie, was adapted into a feature film in 1943 that starred Roddy McDowall and Elizabeth Taylor. Lassie, the TV series, ran for 19 seasons between 1954 and 1973 and remains one of the best-loved shows of all time.

Elaine Murray, Inverness.

QUESTION Why has Berlin been cited as the least favourable place to site a nation’s capital?

In 1417, Frederick I, elector of Brandenburg, moved his capital from Brandenburg an der Havel to Berlin (stock image) 

Berlin’s story is, to an extent, that of Germany.

Fate bequeathed Germany a difficult strategic geography. The country was situated in a central position among powerful rival states, with sparse natural defences. For centuries, petty German kingdoms, duchies and other minor states were the battleground for quarrels among the major powers of France, Austria and Russia.

Historically, there were dozens of German-speaking territories in Central Europe. Border regions were known as Mark (from the Old German for ‘frontier’). Mark Brandenburg was the largest and most important of these.

In 1417, Frederick I, elector of Brandenburg, moved his capital from Brandenburg an der Havel to Berlin, a flat, marshy area susceptible to invasion. However, Berlin had the advantage of being on the River Spree and Frederick I wanted to forge trade links along it.

During the 17th century, Brandenburg inherited the Duchy of Prussia and in 1701, Frederick III of Brandenburg declared himself King of Prussia and determined to establish Berlin as a modern city. He was followed by Frederick William I, the Soldier King, who instituted a huge army and efficient bureaucracy while his son, Frederick the Great, took the army to war, conquering the wealthy Austrian region of Silesia and proving Prussia’s military might.

This period established the supremacy of Prussia in Germany and Berlin as the nation’s capital.

Graeme Klein, Faversham, Kent.

QUESTION What determines the shape — and even colour — of a piece of fruit or vegetable?

Environmental conditions such as sunlight, temperature, soil nutrients, water availability and even latitude have influenced the development of fruits and vegetables (stock image) 

This is the story of evolution. The shape and colour of a fruit or vegetable is determined by genetics, environmental factors and human intervention. Each plant species has its own genetic code that determines the general shape and colour of its fruits or vegetables.

Environmental conditions such as sunlight, temperature, soil nutrients, water availability and even latitude have influenced the development of fruits and vegetables.

Pollination may affect the shape and characteristics of fruits. It is speculated — although scientists claim the evidence is mixed — that the colours of fleshy fruits evolved in order to get the attention of certain animals, which would then eat them and ultimately spread their seeds.

In some cases, the shape and colour of fruits and vegetables may be influenced by the need to resist pests and diseases.

Over centuries, humans have selectively bred plants to emphasise desirable traits, including specific shapes, colours and flavours. This has resulted in a wide variety of fruits and vegetables with a diverse range of characteristics.

Dr Ian Smith, Cambridge.