ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Gregor Mendel, the Father of Genetics

Updated on June 23, 2012
Gregor Mendel
Gregor Mendel | Source

The father of genetics

With most branches of modern science it is difficult to point to the one person who really started it all, usually the beginnings of the discipline can be traced to many different discoveries, made by many brilliant scientists that all complement each other and give rise to ongoing research. Discovering the main principles of inheritance, however, can be traced back to one man, Gregor Mendel, who is appropriately called the Father of Genetics.

What is most remarkable is that correct rules about how traits are passed on from parents to offspring were discovered by an obscure Augustinian monk breeding common pea plants in the abbey garden. Equally remarkable is the fact that he proposed correct mechanisms, despite not knowing anything about the structure of chromosomes, genes or DNA, which we now know are the carriers of genetic information.

Sweet peas and monks

In the 19th century, the generally accepted theories of inheritance were that what made individuals be as they were was a blending of the characteristics inherited from their parents. At first glance, this sort of makes sense, if a tall woman has a child with a short man, you might expect the child to be of medium height. However, scientists need to rely on empirical observations, not on lazy ‘common sense’.

Mendel worked in the gardens of his abbey, where he noticed that sweet peas had several traits that were always either of one type or another with no intermediates. For example the flowers were either purple or white, with no pink flowers, the seeds are either round or wrinkled, and the pods are either yellow or green.

The sweet pea plant, Pisum Sativum,
The sweet pea plant, Pisum Sativum, | Source

Yellow or green pea pods?

Between 1856 and 1863, Mendel set up 29000 crosses between plants with different traits by cross-pollination. The pea flower are hermaphroditic and can produce seeds either by self-pollination or cross-pollination. Mendel reproducibly observed certain patterns of inheritance that led him to formulate his two laws of Segregation and of Independent Assortment.

For example he observed that if he crossed a plant that always produced yellow pods in the next generation through self-pollination with the a plant that always produced green pods, all the offspring plants had yellow pods. However when he then crossed the yellow podded F1 offspring to each other, 25% of their offspring (F2 generation) had green pods.

When the F2 plants with green pods where crossed to each other, they always produced pea plants with green pods (F3) generation, one third of the F2 plants with yellow pods always produced F3 plants with yellow pods, but two thirds of the F2 yellow pod plants produced F3 offspring with yellow pods, and F3 offspring with green pods always in the ratio of 3:1. This pattern of inheritance is now called classic Mendelian genetics, and is observed not just with pea plants but with other plants and animals including humans. Many genetic diseases are inherited in a classic Mendelian fashion, where the disease will only be passed on to the children if both parents are carriers of the disease, and the chance of a child having the illness is 1 in 4.

Now we know about genes!

Mendel postulated that traits were inherited from parents to offspring in discrete ‘units’, which we now know are genes made up of DNA. He thought that the patterns he observed could be best explained if each parent carried two units (genes) for each trait, and the offspring inherited one unit from each parent. The genes segregated to the offspring independently of each other, and one allele (‘type’ of gene which determined, for example, whether a seed pod was green or yellow) was dominant over the other.

In the case of the colour of the pods of a plant, the two alleles for the gene for pod colour are yellow and green, with the yellow being the dominant allele. In the first generation the yellow podded plants must have had two yellow alleles (YY) while the green podded plants must have had two green alleles (gg). Offspring from crossing the YY plants to the gg plants had a yellow allele and a green allele (Yg), since they inherited one from each parent. Since the Y allele is dominant all the Yg plants had yellow pods, but when they were crossed to each other their offspring could be YY, Yg or gg. There was a 25% chance of the F2 offspring being gg, so one quarter of the plants had green pods.

Mendel doodle
Mendel doodle | Source

The Mendel Google doodle

Sadly, although Gregor Mendel published his work, it was ignored by the scientific community at the time and, after he became abbot, he gave up on scientific research. The importance of his discoveries was only appreciated when his observations were reproduced by scientists more than a hundred years after his death. We now know the molecular basis of his work, we know that the ‘instructions’ for our traits are coded in the sequence of DNA which makes up our genes.

It is pretty amazing to think that Gregor Mendel worked out the basics of Mendelian inheritance without knowing any of the above, merely by looking at the empirical data from his pea plants and figuring out a model which would agree with his observations. For working all of this so far ahead of his peers he is rightly known as ‘the Father of Genetics’. To commemorate his achievement Google dedicated one of its doodles to celebrate the 189th anniversary of his birth, to his pea pods.


This website uses cookies

As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

Show Details
HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
LoginThis is necessary to sign in to the HubPages Service.
Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
AkismetThis is used to detect comment spam. (Privacy Policy)
HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
MavenThis supports the Maven widget and search functionality. (Privacy Policy)
Google AdSenseThis is an ad network. (Privacy Policy)
Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
Index ExchangeThis is an ad network. (Privacy Policy)
SovrnThis is an ad network. (Privacy Policy)
Facebook AdsThis is an ad network. (Privacy Policy)
Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
AppNexusThis is an ad network. (Privacy Policy)
OpenxThis is an ad network. (Privacy Policy)
Rubicon ProjectThis is an ad network. (Privacy Policy)
TripleLiftThis is an ad network. (Privacy Policy)
Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
ClickscoThis is a data management platform studying reader behavior (Privacy Policy)