When I looked at this question my initial response was, well it’s a fruit so how could it [possibly be man-made? But as it turns out the facts are very interesting and as you will see, it is not what we think it to be.
Banana’s are man-made and are considered hybrids of two wild species of Banana. The wild Musa acuminata and the Musa balbisiana species. The Musa acuminata species has a fleshy inside, with a taste that is very unpleasant. The Musa balbisiana species is pleasant-tasting however it contains many seeds.
Apparently, after thousands of years of cross-breeding, we have the banana as we know it today that you buy from your local grocer or supermarket. And since they are sterile they do not grow from seeds but rather from plants.
In this article we will also consider:
The Musa acuminata species of banana is native to Southeast Asia. Most of the bananas you buy in the store are from this variety.
The Musa balbisiana species of banana is native to Southern China. Along with Musa acuminata is one of the ancestors of the modern banana. The seeds they contain are large, numerous and generally inedible. However, it contains many useful traits for the modern banana such as disease resistance.
There is a very big problem with bananas being man-made hybrids and sterile, that is not being able to be grown from seeds. There appears to be very little diversity genetically in modern plants, and this lack of diversity makes bananas very vulnerable to diseases and pests. A new disease has the potential to devastate a whole banana species if it is able to somehow exploit a weakness genetically among the clones.
This is exactly what happened back in the 1950s with the Gros Michel dessert species of banana, which was a sweeter and richer taste than the modern Cavendish banana.
The Gros Michel became infected by a soil fungus and the cultivators were left powerless to breed resistance into the sterile clones. Being unable to remove the fungus from the soil, farmers had to abandon the Gros Michel variety of banana in favour of the Cavendish which was hardier.
As of today, the Cavendish has managed to be resistant to diseases and pests, however, as with the Gros Michel variety, its lack of diversity genetically leaves it vulnerable to opportunistic diseases and pests. Many scientists are worried that the Cavendish banana too will eventually become extinct. 
You might be interested to read our article on: Do Bananas Have Seeds? It will explore also how to grow bananas from seeds.
Are Bananas Natural?
The modern cavendish banana that you buy in the local grocery store is not natural. It is a hybrid, having been bred over many years to produce a fruit that is tasty and soft yet sterile.
Varieties of natural wild bananas have large seeds that make eating the flesh difficult. Through selective breeding, these large seeds have been reduced considerably in size over many years, just leaving very small seeds that do not mature. You might also be interested in checking out our article: Are Bananas a Berry a Herb or a Fruit & Why Are Bananas Curved?
You can still find natural bananas growing in eastern South Asia, northern Southeast Asia, and also in southern China.
You might be interested to know that the sweet variety you buy in the local grocery store called cavendish is also known as dessert bananas to separate them from plantain bananas which tend to be larger in size, and tend to also have a thicker skin. Plantain bananas are also starchier than the dessert bananas and not as sweet due to the lower sugar content. They are generally cooked before eating.
Are Real Bananas Extinct?
Real bananas are not extinct, however, the hybrids that we have come to know and love such as the cavendish may be under threat by a fungal disease, such as happened to the Gros Michel variety back in the 1950s.
Because the modern bananas are clones, they are very susceptible to being wiped out by a fungal disease, such as the Panama disease. Since the fungus was in the soil and it couldn’t be eradicated, it devasted many of the crops. However, the Gros Michel is still grown today but only on land that does not have the fungal infection.
There have been ongoing efforts to use gene editing through genetic modification to create a variety of the Gros Michel banana which has a resistance to Panama disease. There are also some successful hybrids of the Gros Michel and Cavendish that are displaying resistance to the fungal Panama disease.
Where Do Bananas Come From Originally?
Bananas are of the genus Musa species which are native to tropical Indomalaya and Australia, and they were probably first domesticated in Papua New Guinea.
For those of you who do not know where Indomalaya is, It extends across most of South Asia and Southeast Asia and also extends into the southern most parts of East Asia. It is also called and known as the Oriental realm.
Several wild bananas are native to Papua New Guinea which includes the Eumusa and Australimusa species.
There appear to be hundreds of different banana varieties grown on plantations in Papua New Guinea and in village gardens. Whats also interesting is do bananas grow on trees? Check out the answer here in our article: Do Bananas Grow on Trees?
It seems that given the amount of variety of bananas in both the village and forest landscapes in Papua New Guinea, there appear to be a growing amount of real evidence supporting their early cultivation there.
New evidence is now suggesting that there is a very long history of banana cultivation, perhaps dating back as far as 7000 years, in Papua New Guinea. This makes it the longest record of banana cultivation worldwide.
Ever wondered Why Fruit Grows on Plants? Check out our article here: Why Do Plants Make Fruit
Modern bananas, such as the cavendish are man-made in the sense that they have been bred to display the traits that we so like in the dessert banana. The soft creamy and sweet texture with practically no seeds are sterile hybrids of two more ancient varieties, the Musa acuminata and Musa balbisiana.
 Science Direct: Insights into Musa balbisiana and Musa acuminata species divergence and development of genic microsatellites
 Britannica: Banana
 National Institutes of Health: Transgenic Cavendish bananas with resistance to Fusarium wilt tropical race 4
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