Apples, Mangoes, Rice , Corn, Pot, Pears … have all been selectively “bred” (not sure if that’s the right word in the plant context) by humans for centuries.
Which plant has the most DNA different from the original plant ?
(It’s not an answer to your question, but I was surprised to learn that the seemingly very different
[ul][li]cabbage,[/li][li]broccoli,[/li][li]cauliflower,[/li][li]kale,[/li][li]Brussels sprouts,[/li][li]collard greens,[/li][li]savoy,[/li][li]kohlrabi, and[/li][li]gai lan[/ul][/li]are all human-bred cultivars of a single species, Brassica oleracea.)
It wouldn’t surprise me if the answer was common bread wheat. That shit is hexaploid, from a diploid ancestor.
I think there could possibly be a weak inverse correlation between variety of cultivars and amount of genetic change from the wild ancestor (although we must also consider the timespan over which the varieties were developed)
My reasoning (of which I am not very certain, so open to challenge) is that: when a plant species yields a large number of seemingly-different varieties with relatively low effort/time, it’s probably just the case that small genetic differences happen to work out to largish morphological changes; a change to just one gene might yield a relatively small change (different shade of flower colour) or the same scale of genetic change, elsewhere in the genome, might alter something that works out to change the shape and growth structure of the whole plant - but they would both be just one little change.
I’d suggest teosinte -> corn/maize.
But it’s hard to say, because a small genetic change can result in great morphological change.
My vote as well. The difference between the original and the cultivar is immense.
Wheat and such are minor changes by comparison.
What these examples show is that very small changes in the genes can causes massive changes in the appearances. I think I read somewhere that it took only 7 genetic modifications to go from teosinte to modern corn (maize). And the fact that all those brassica are still considered the same species tells us the same thing.
I agree - I think we should be looking for examples where centuries of effort resulted in minor improvement; some vegetables can be reselected from wild to something usable in just a few generations - which tends to indicate that the genetic change is small (it could indicate that the plant is highly genetically mutable, but probably not - because, I think, highly-mutable things should have a tendency to die out in favour of more stable forms)
Corn was my first thought, as well. Not only is modern maize vastly different from the original teosinte, with a phenomenal increase in kernels and their packing*, but corn exists in a huge variety, which most people rarely see.
But there’s arguably a better candidate – Bananas. The original banana wasn’t seedless, but had a prominent seed, with our modern banana “fruit” being the “packaging” around the seed. there was, fro what I’ve read, hardly anything worth eating in the ancestral banana, whereas now the seed has been bred out (“breeding” bananas is still possible, though complicated) and only the packaging remains
http://cwh.ucsc.edu/bananas/Site/Early%20History%20of%20the%20Banana.html
*I recall one article that called modern corn a “biological monstrosity”. From the point of view of humans, it’s great, with all that edible corn. From the point of view of the plant, all those kernels/seeds require a ridiculously large input of resources and energy, then fall to close together and choke each other off.
We can splice firefly genes into tobacco plants so they glow green when they need water …
B.t. genes spliced into corn plants …
We’re in the day and age of mix and match … who knows what crazy frankenfood is the most bizarre …
Yeah, that was mine as well. The sheer time it took is astonishing, as have been the changes from the original to today.
Naah - as Broomstick hints at, maize is a great morphological change of teosinte, it’s still diploid. To quote Wiki, my emphasis: “The difference between the two is largely controlled by differences in just two genes”
Wheat is a hybrid of 3 different grasses. It’s much further away, genetically, from any one parent plant. Sure, appearance-wise wheat may not be as different as maize, but that wasn’t the OP’s question (or B. oleracea would be my vote, too.)
Strawberries, being octoploid, are even more hybridized, but there, even the wild forms can be polyploid, so there’s no set of simple diploid parent to point to. For wheat, there is.
I don’t know about genetics, but the original maize plant had a single one inch long cob.
On a somewhat related note, I’m wondering if anyone can confirm something I read.
I’m sure a lot of people have heard the story about how everyone use to believe tomatoes were poisonous. For hundreds of years, people refused to eat tomatoes because of this belief. Until one day, somebody actually bit into a tomato and said “Hey, this isn’t poisonous! Somebody get me some bacon and lettuce and two slices of bread!”
But what I read was that the common belief that tomatoes were poisonous was based on reality. Tomatoes really were poisonous for a long time. They were grown as ornamental plants because people liked their appearance. But they’re closely related to other poisonous species and also contained poison.
Then somebody happened to breed a non-poisonous tomato and that’s when people starting eating them. (Granted, it took a little while for word to get around that there were now non-poisonous tomatoes being grown.) But the point is that the belief that tomatoes were poisonous wasn’t just an irrational superstition; it actually was true at the time it was believed. The story is just an example of people wanting to believe that their ancestors were dumb.
Not sure where you read that; I can’t find any cites.
Instead, there’s a claim that the tomato’s poisonous reputation was due to the pewter plates that reacted badly with the acidity of the tomato sauce. That, combined with the fact that the tomato is a member of the nightshade family, could have caused some people to be cautious.
In the meantime, though, the Aztecs had been using tomatoes in their meals since 500 BCE. Only the Europeans thought it was poisonous; everyone else was enjoying pico de gallo and other delicious tomato dishes.
Then why are you answering a question about DNA?
Thank you MR Dribble. So far Corn seems to be the winner
The various squashes and gourds are another good example of a large variety of edible derivatives from a few much simpler (and largely inedible) ancestors, partially through hybridization.
Apparently there are some sugar cane hybrids that are dodecaploid (12x) having arisen from diploid ancestors.
This discussion reminds me of a lab session on polyploidy under my cytogenetics professor. While we students were perusing karotypes of many different commercially important plants he had set out a nice spread of fruits and snacks including a limited wet bar.
Wheat and oat crackers, slices of apple, kiwi, strawberries, sour cherries, watermelon, and banana; potato vodka, rum and so on. Lots of nice things to nibble on. The wrap up of the lesson was that the entire spread was comprised of products from polyploid plants.
I’d like to see documentation of this story before believing it, as tomatoes had been eaten safely for centuries before their acceptance in (for example) America.
Confusion may have arisen because tomatoes are in the nightshade family (genus Solanum) and certain species like woody nightshade are indeed quite toxic. Other Solanum have fruits which are dangerous to consume when unripe but fine when ripened (including crosses like the wonderberry). Note: potatoes and eggplant are also Solanum species.
For what it’s worth, the first plant I thought of when reading the OP was also teosinte/corn. However, others like watermelon and peaches have changed drastically as well. Carrots little resemble their ancestors (I remember reading Euell Gibbons on the subject, and he described using wild carrots for food and then over time selecting the thickest, tastiest roots until he’d redomesticated them into something resembling modern carrots).