# Rice has larger and more complex genome than humans. What does it mean?
**URL:** https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999
**Category:** Great Debates
**Created:** [April 5, 2002, 2:43pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999 "2002-04-05T14:43:21Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Parameter\_928\_178](https://boards.straightdope.com/u/Parameter_928_178)
#### Post date: [April 5, 2002, 2:43pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/1 "2002-04-05T14:43:21Z")
Today’s _ **Financial Times** _ (page 5) reports that the “full genetic sequence of rice…has been decoded for the first time…by research teams from Syngenta, the Swiss based biotechnology company, and the Beijing Genomics Institute.” The decoding was published in the journal **Science**.
Of peculiar interest in the story is that the rice genome may be **far** more complex than previously thought and that the rice genome contains between 42,000 and 63,000 genes whereas the human genome is estimated to contain between a mere 30,000 to 40,000 genes.
Since we frequently measure how advanced and superior a species by its complexity and, implicitly, by the size of its genome, does this new research indicate that rice is a more advanced, and perhaps even a superior, species than humanity?
Or is it simply the case that superiority is not a matter of complexity nor of the relative size of the species’ genome?
Here is [a link](http://news.ft.com/ft/gx.cgi/ftc?pagename=View&c=Article&cid=FT3VWQZTMZC) to the actual\*\*\* Financial Times\*\*\* story.
---
### Author:  [@SuaSponte](https://boards.straightdope.com/u/SuaSponte)
#### Post date: [April 5, 2002, 3:18pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/2 "2002-04-05T15:18:40Z")
> [@](#):
>
> \*Originally posted by Parameter Π² \*
> Since we frequently measure how advanced and superior a species by its complexity and, implicitly, by the size of its genome, does this new research indicate that rice is a more advanced, and perhaps even a superior, species than humanity?
I’m sure the rice think they are superior. 😃
Complexity of a species and the size of its genome are not directly corrolative.
Sua
---
### Author:  [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)
#### Post date: [April 5, 2002, 3:24pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/3 "2002-04-05T15:24:55Z")
Er, actually, in the category of “things a Financial Times puff piece isn’t going to mention”:
[http://botany.sinica.edu.tw/english/menu/project4-n.html](http://botany.sinica.edu.tw/english/menu/project4-n.html)
> [@](#):
>
> Genome sequencing project of rice chromosome 5
> Rice has been chosen as the first crop genome sequencing by an international rice genome sequencing consortium, IRGSP (International Rice Genome Sequencing Project) for the following reasons:
>
> rice is an important crop in the world;
>
> **the genome size of rice is 430 Mb, the smallest one among crops…** [bolding mine]
But hey, it sounds really cool for the writer to say, “Yeah, it has way more genes than humans!”
But actually, compared to corn and wheat, it’s dinky. 😃
I’m just guessing that all it means is that plants, and flowering plants specifically (angiosperms, which emerged during the Early Cretaceous, 90 to 130 million years ago), and then grasses (which emerged during the Cenozoic–rice is a grass), have been evolving for much, much longer than humans. Organisms tend to keep copies of genes that represent a “been there, done that” stage of evolution, even though they don’t need those genes anymore, and the longer they’ve been evolving, the more copies of “bought the T-shirt” genes they tend to have.
---
### Author:  [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)
#### Post date: [April 5, 2002, 3:54pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/4 "2002-04-05T15:54:06Z")
> [@](#):
>
> Since we frequently measure how advanced and superior a species by its complexity and, implicitly, **by the size of its genome** …
Looking for plant genome sizes on Google…
Corn (maize).
[http://www.ncbi.nlm.nih.gov/PMGifs/Genomes/mays\_1.html](http://www.ncbi.nlm.nih.gov/PMGifs/Genomes/mays_1.html)
> [@](#):
>
> First, the maize genome, at 2365 Mbp, is approaching the size of the human genome, at 3180 Mbp, with all of the technical difficulties encountered during the effort to determine the nucleotide sequence of the human genome.
Wheat.
[http://www.nsf.gov/od/lpa/news/press/00/pr0060.htm](http://www.nsf.gov/od/lpa/news/press/00/pr0060.htm)
> [@](#):
>
> The smallest of these, known as the D genome, carries most of the important genes for bread wheat improvement. A project funded at the University of California at Davis will use a new fingerprinting method that should allow construction of a physical map of the D genome, the largest genome to be tackled to date. This part of the wheat genome alone is more than two and half times the size of the whole maize genome, and ten times the size of the whole rice genome.
Size of genomes:
Rice the smallest of the crop plants.
Corn equals human.
Wheat at least 2 1/2 times size of corn.
Wheat 10 times size of rice.
Looks to me like rice is the least of your worries, Parameter–have you noticed what that box of Wheaties has been up to lately? Pretty quiet out there in the kitchen, eh?
Not to mention the Venezuelan spiny rat (_Proechimys trinitatis_).
Tables of genome size.
[http://www.genomesize.com/mammals.htm](http://www.genomesize.com/mammals.htm)
Homo sapiens: 3.50
Venezuelan spiny rat: 6.30
Better watch out.
---
### Author:  [@edwino](https://boards.straightdope.com/u/edwino)
#### Post date: [April 5, 2002, 4:28pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/5 "2002-04-05T16:28:08Z")
From a geneticist:
The zebrafish has a genome approximately the size of humans. I work on fruitflies (_Drosophila melanogaster_), who have a tiny genome (1/3 as many genes as humans, 1/25 the size), and they have a sister species (_D. virilis_) whose genome is twice as big. Granted, they have something like 30 million years of evolution between them (the distance between humans and mice) but they are not that much more complex, if at all.
Genome size means nothing. Most of the space is repeats. Zebrafish and humans have lots of repeated genes and padding between the genes. Crops have more, not including pseudopolyploidy and true polyploidy that happens pretty often IIRC.
The nature of genomic instability, expansion of repeats, genome size regulation, etc. are very poorly understood at present. There is some correlation with -ploidy (number of copies of a genome) and cell size, and true polyploidy may evolve into a normal diploid with lots of repeats.
As mentioned above, there are only a handful of genes that really count in separating us from mice or from other great apes. The trick is finding out what they are and how they are regulated.
---
### Author:  [@mswas](https://boards.straightdope.com/u/mswas)
#### Post date: [April 5, 2002, 4:36pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/6 "2002-04-05T16:36:51Z")
I find the idea that rice is a more complex species than humans to be offensive! :o
Erek
---
### Author:  [@easy\_e](https://boards.straightdope.com/u/easy_e)
#### Post date: [April 5, 2002, 5:05pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/7 "2002-04-05T17:05:49Z")
Dogs have way more chromosomes than humans, and presumably a larger genome (though that last bit is a WA assumption). I’ve heard that that’s one reason we’ve been able to breed such a wide variety out of a single species.
---
### Author:  [@artemis](https://boards.straightdope.com/u/artemis)
#### Post date: [April 5, 2002, 5:36pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/8 "2002-04-05T17:36:59Z")
What does it mean? It means that plants are WIERD!
Seriously, plant genetics is complex and very interesting. Plant can be polyploid (domesticated wheat is a hexaploid, as I recall) and even aneuploid, while in nearly all animal species polyploidy and aneuploidy are lethal. The size of plant mitochondrial DNA is variable, and often huge, while animals have small mitochondrial genomes which are tightly conserved. And many plants can be mated, not just across species barriers, but across genera; the classic example are orchids, many modern hybrids of which are complex crosses of multiple species in 3 or 4 different genera.
---
### Author:  [@Parameter\_928\_178](https://boards.straightdope.com/u/Parameter_928_178)
#### Post date: [April 5, 2002, 6:21pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/9 "2002-04-05T18:21:46Z")
The **FT** article, which I do not think was a “puff piece” as you suggest, Ms. **Goose** , is as-of-now research, announced just yesterday as I read the story; where all of **your** references, Ms. **Goose** , were last reviewed back in antiquity–and who knows _when_ they were written?
Many thanks, **artemis** , for a very enlightening reply. Does anyone have any speculations as to why plant mitrochondria would have a much bigger genome than animal mitrochondria? It seems, plants having nothing to do beside stand there, that just the opposite would be the case: that our busy, hard-working muscles would require snazzy, sophisticated power-houses. 🙂
---
### Author:  [@Parameter\_928\_178](https://boards.straightdope.com/u/Parameter_928_178)
#### Post date: [April 5, 2002, 6:27pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/10 "2002-04-05T18:27:07Z")
The **FT** article, which I do not think was a “puff piece” as you suggest, Ms. **Goose** , is as-of-now research, announced just yesterday as I read the story; where all of **your** references, Ms. **Goose** , were last reviewed back in antiquity–and who knows _when_ they were written?
Many thanks, **artemis** , for a very enlightening reply. Does anyone have any speculations as to why plant mitrochondria would have a much bigger genome than animal mitrochondria? It seems, plants having nothing to do beside stand there, that just the opposite would be the case: that our busy, hard-working muscles would require snazzy, sophisticated power-houses. 🙂
---
### Author:  [@NurseCarmen](https://boards.straightdope.com/u/NurseCarmen)
#### Post date: [April 5, 2002, 6:42pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/11 "2002-04-05T18:42:04Z")
It just means they taste better. This can be seen on the new Rice Chex boxes showing up on store shelves today. “Now, with more Genomes!”
What has allowed the human species to progress and evolve is that we thankfully did not fall into the “tastes like chicken” range of 50 to 53 thousand genomes.
Plants such as broccoli and beets have virtually no genomes, causing the genome sensative area of the tongue to be repulsed, while complex plants such as the cocoa bean, vanilla, and beer plants have an extremely high genome count.
---
### Author:  [@blowero](https://boards.straightdope.com/u/blowero)
#### Post date: [April 5, 2002, 9:46pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/12 "2002-04-05T21:46:38Z")
> [@](#):
>
> \*Originally posted by Parameter Π² \*
> Since we frequently measure how advanced and superior a species by its complexity and, implicitly, by the size of its genome, does this new research indicate that rice is a more advanced, and perhaps even a superior, species than humanity?
Yes, in fact rice has even developed it’s own religious beliefs, which is why it is now called “converted rice”.
Ugh! That was a groaner, wasn’t it?
---
### Author:  [@SpartanDC](https://boards.straightdope.com/u/SpartanDC)
#### Post date: [April 5, 2002, 10:11pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/13 "2002-04-05T22:11:33Z")
It’s all about proteins, folks:
[http://news.bbc.co.uk/hi/english/sci/tech/newsid\_1910000/1910949.stm](http://news.bbc.co.uk/hi/english/sci/tech/newsid_1910000/1910949.stm)
For those uninclined to read, the gist is that the human genome, while it has fewer genes than less-complicated forms of life, has a few more tricks up its sleeve allowing it to build many, many more different kinds of protein. In this story, one scientist says that human DNA can synthesize nearly double the number of proteins compared to rice.
It’s not the size of the genome that counts, it’s how you use it. 😃
---
### Author:  [@musicguy](https://boards.straightdope.com/u/musicguy)
#### Post date: [April 5, 2002, 10:24pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/14 "2002-04-05T22:24:30Z")
And here I thought this thread was going to be about Condoleezza Rice. 😉
---
### Author:  [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)
#### Post date: [April 5, 2002, 10:58pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/15 "2002-04-05T22:58:16Z")
If a sizeable fraction of that genome goes toward brain power it means that we are dumber than a grain of rice, which wouldn’t surprise me a bit.
When they get down to the genome of a clod of dirt I’ll start to sweat.
---
### Author:  [@Terminus\_Est](https://boards.straightdope.com/u/Terminus_Est)
#### Post date: [April 5, 2002, 11:48pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/16 "2002-04-05T23:48:01Z")
In the first place, why do you consider humans to be superior to other species?
In the second place, rice does **not** have a larger genome than humans, as the esteemed **Duck Duck Goose** pointed out. It was, in fact, chosen precisely because it has such a small genome size. There are other organisms which have much larger genomes than humans. There’s absolutely nothing wrong with any of the references that **DDG** posted. In fact, her citations are closer to the scientists who are actually doing the sequencing work: The [National Science Foundation](http://www.nsf.gov), the [National Center for Biotechnology Information](http://www.ncbi.nlm.nih.gov) (a branch of the [National Institutes of Health](http://www.nih.gov)), and the [Academia Sinica](http://www.sinica.edu.tw/index.html).
---
### Author:  [@happyheathen](https://boards.straightdope.com/u/happyheathen)
#### Post date: [April 5, 2002, 11:59pm UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/17 "2002-04-05T23:59:52Z")
Maybe we all started out to be rice, but just didn’t make the cut?
(I’ve heard WORSE theologies 😃 )
---
### Author:  [@Smeghead](https://boards.straightdope.com/u/Smeghead)
#### Post date: [April 6, 2002, 12:18am UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/18 "2002-04-06T00:18:05Z")
> [@](#):
>
> \*Originally posted by Parameter Π² \*
> \*\*Since we frequently measure how advanced and superior a species by its complexity and, implicitly, by the size of its genome…
> \*\*
No we don’t. At least scientists don’t, as **edwino** explained. If someone does, it indicates a poor understanding of science. For more information, do a search on the C value paradox.
---
### Author:  [@capacitor](https://boards.straightdope.com/u/capacitor)
#### Post date: [April 6, 2002, 1:05am UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/19 "2002-04-06T01:05:30Z")
I tend to agree with the OP. Condoleeza Rice does exhibit skills and talents exceeding many other humans. Maybe it is in the genes…
Oh wait…you are talking about rice grains!!
---
### Author:  [@TheeGrumpy](https://boards.straightdope.com/u/TheeGrumpy)
#### Post date: [April 6, 2002, 2:41am UTC](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999/20 "2002-04-06T02:41:05Z")
Listen to **edwino**. Size doesn’t matter, in terms of genomes.
In fact, I was just reading Stephen Jay Gould’s essay on the subject (“The Ant and the Plant” in _Bully For Brontosaurus_") last night. He notes that a species of ant, _Myrmecia pilosula_, was found in the 1980s to actually be several different, though physically similar, species. There are types with nine, ten, 16, 24, 30, 31, and 32 pairs of chromosomes, with concomitantly more and more genetic material. In one of the varieties, the males have but a single chromosome (not even a pair). But they’re all functionally the same type of ant.
[Next page](https://boards.straightdope.com/t/rice-has-larger-and-more-complex-genome-than-humans-what-does-it-mean/101999.md?page=2)