Would you give up sex for eternal life? This little invertebrate, a bdelloid rotifer, has lived a celibate life for ~80 million years. The males have disappeared and the females reproduce by parthenogenesis. A drawback to this convenient scheme is that our DNA is usually repaired during meiosis, when we form gametes or germ cells.
• Scientists bombarded these little creatures with gamma rays that would typically shatter DNA into little bits. To their astonishment, the rotifers kept reproducing even at levels of radiation five times more than other animals can endure. Their secret lies in genetic redundancy: their genomes have duplicated, so that each gene is in 4 copies. When one is damaged, the others serve as template to copy off a new version (gene conversion).
• How did this resistance to radiation damage evolve? These animals live in fresh water pools that can dry up at any time. The rotifers can go dormant for weeks to years, springing back to life with water. Dessication has the same effect on DNA as radiation so the rotifers must have evolved to survive in their ephemeral habitats. “There could be some benefit to millions of years without sex after all”, says Dr. Alan Tunnacliffe, University of Cambridge 🙂
Live image of Philodina roseola , details at http://www.cellimagelibrary.org/images/41670
Refs: (1) Gladyshev, E., and M. Meselson. 2008. Extreme Resistance of Bdelloid Rotifers to Ionizing Radiation. Proc. Natl. Acad. Sci. 105 (13): 5139-5144.
(2) Mark Welch, D.B., J.L. Mark Welch and M. Meselson. 2008. Evidence for degenerate tetraploidy in bdelloid rotifers. Proc. Natl. Acad. Sci. 105 (13): 5145-5149.
Tsk, Jerry Nguyen . We could have a parthenogenesis party.
You can have 80 million years to ponder the question, take your time guys.
Did someone say “parthenogenesis party”? Count me in.
80Mn years of cellibacy? Sounds like my teen years.
Uh, to clarify, would I be giving up sexual activities or procreation? 😉 (‘Cause if it’s only the latter, well sign me up!)
I was poking around one day and was reading about this. I think it’s in my stuff somewhere.
Rachel Blum: those little guys do an awful lot of rubbing up against each other, so at least there’s that as an alternative.
+Jim Carver, there’s no good way to parse your sentence, so you know…
Your definition of eternar life is quite weird. Animals with sexual reproduction have been around for more than 80 million years.
Full slideshow of your favorite Rotifers: http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artnov99/rotih.html
i am haviing visions of nightmarish experiments….i guess this could be useful to the survivors of a global thermonuclear holocaust!
Rachel Blum , you would be giving up the former 🙂 Second thoughts?
Víktor Bautista i Roca , the allusion is to parthenogenesis which is essentially cloning of the same genotype.
Rotifers, Ribosomes and Mitochondria might make a great title for a book. 🙂
I wish you science-y types would hurry up and figure this stuff out so the human race can experiment with this sort of thing. 😉
Rajini Rao In that case, count me out. Thomas Jones’ suggestion is not doing enough for me 😉
(And I actually do mean that seriously. Eternal life without pleasure is not that much fun, IMHO)
Beautiful pic and interesting post !!
Eternal life could become really unpleasant when the sun burns off the earth 😦
We tend to fool around quite a bit, Richard Healy 🙂 Perhaps we could focus better if we were celibate.
Rajini Rao So, a clone of you would be you???? By the way, they have more than 300 species, so some change in the genotype happens…
Richard Healy if you can predict the end result of 80 million yrs of natural selection on the human genome you will have your answer
Awesome. Some people I guess are not aware that there are organisms that do not die unless they are killed somehow or run out of food. Possibly some of the earliest life forms ever are still alive somewhere on the planet, billions of years old.
Life evolved death. It’s an odd thing to contemplate.
Mike Clancy , why do I sense that you would be having way to much fun in the control group?
Víktor Bautista i Roca , don’t take things literally, okay?
How a bout no sex for an eternity, that would be my first marriage. Insert rim shot here and I’ll be here all week; don’t forget to tip the servers and bartenders! Good Night, America!
Jim Carver How’s “Rotifers, Ribosomes and Mitochondria, Oh My”.
Once they’re tipped, who rights them?
Rajini Rao uh wow I don’t know about that… I’m not a science genius but to me that sounds like torture… 🙂
asexual reproduction… hummm, a room full of “me”… Yikes, not the sort of party I would want to go to…
Hmm, apparently the strict definition of sex is exchange of DNA and not copulation, according to this article which begins: Birds do it. Bees do it. Bdelloid rotifers, it seems, eschew it .
Harvard mag calls this scandalous 🙂
Rajini Rao If all sex is is the exchange of DNA then I can spit in someone’s hand and be done with it.
this true i not know before thanx
For the sticklers of accuracy re. “eternal life”:
“Meselson and Mark Welch studied four genes in four species of bdelloids. (There are about 360 bdelloid species, all reproducing asexually, and all thought to be descended from a common female ancestor.) Sexual organisms carry two copies of any given gene, each supplied by one parent. But in asexual organisms, there is only one parent, which supplies its offspring with both of its own copies. In each subsequent generation, the two copies of the gene are reproduced. Over time, tiny mistakes in the copying process can independently accumulate in each gene (if the mutations are not fatal). After many millions of years, the difference betwen the two copies will have become far greater than it is in sexually-reproducing species. This is exactly what Mark Welch and Meselson found. Using standard rates of mutation in other animals, they estimate that the common female ancestor of all bdelloid rotifers lived 50 million to 100 million years ago.”
Rajini Rao do you mind if I re-share this?
Share away, Kiele J.K 🙂 I’ll look forward to some mayhem on your post.
Hmm we will see Rajini Rao I hope so it would be a highlight of my day lol!
I’m still looking for sock DNA, Mike Clancy . Not going to argue with you 🙂
Cam Loon Why predict when we have 6+ billion living, breathing, walking examples to study right now?
I want to drive – but first the world’s scientists need to figure out how the pedals work and lay down some basic traffic rules so we all don’t end up turning into dead ends and going extinct.
This is quite a heaven-sent idea, Rajini Rao — almost an immaculate conception.
A tidy idea, William McGarvey 😀
Rajini Rao Perhaps extend the human lifespan so there’s plenty of time to experience all the things that the human condition has to offer and do research 🙂
Fun? What is this “fun” you speak of Feisal Kamil ? We got another 80 million years of this job ahead of us…
I’d have to be having sex to give it up.
We have a tumor cell line that’s sensitive to radiation and a cell line derived from it that is radioresistant. I’ll try to dig up some of the genetic info when I get to the office.
Hmm, some rad gene(s) got amplified? Interesting..there is also this bacteria called Deinococcus radiodurans that can survive a lot of radiation. One way is that accumulates tons of Mn2+ which is an inorganic scavenger of free radicals.
Is there anyone who can translate from science genius language to common blue collar English? 🙂
Richard Healy because no one knows what will be adaptive…..i agree it will take alot more knowledge
Of course, Kiele J.K ! Shall I try rewording my post on your reshare? Or was there some particular part to focus on?
Rajini Rao if you don’t mind re-wording the whole post that I re-shared that would be great I get some of it but sort of… then I just get lost.. never was all that great in science classes.
Will be happy to, Kiele J.K , in a bit. Would be a pleasure and a challenge 🙂
James Harris , I don’t know much about this, thanks for the info. What about the evolution of apoptosis? Also, budding yeast do get senescent and die after ~20 generations, I’m told.
Thanks Rajini Rao I really love all your science articles but half the time I get lost. Meh what can I say not a genius. Just a regular plain jane lol.
DNA RAID 1? 😀
hmmm, if I remember correctly bacteria got the ability for sexual reproduction by an infection by a plasmid (first sexually transmitted disease)… so if you can live forever then when things get boring, decide to infect yourself and have sex…. best of both worlds http://en.wikipedia.org/wiki/Bacterial_conjugation
let’s just say sexual reproduction has been very adaptive and pleasurable for our species …hehe
Rajini Rao apoptosis in yeast?!? Please have this as another discussion… I would NEVER have thought that they would have evolved such a mechanism. And it was such a complicated mechanism (from what I remember) that it doesn’t seem like something that would just spring up.
+1 to everyone who thanked you for this fascinating post. This is the first I have ever heard of a tetraploid organism. Once again, nature comes up with an incredible solution!
Jean Liss apoptosis in yeast is a bit controversial but there is also good evidence for “altruistic suicide” in colonies. Fungi can form fruiting bodies, and live in colonies so there is reason to believe they have programmed cell death. We can discuss evidence for and against some time.
A Life with a little sex in it,
Is better than a lot of it with none in it!
Matt Kuenzel , genome duplication is not unusual. I believe teleost fish did it? But then, random genes disappear because they are redundant. The argument here is that redundant genes are important as templates for repair, so they stick around. Perhaps there are no organisms that are complete tetraploids like this one?
Rajini Rao It’s a great way to avoid Muller’s ratchet (the process by which the genomes of an asexual population accumulate deleterious mutations in an irreversible manner) – why didn’t I think of that?!?
But you have raised a really interesting question … what would humanity be like if we reproduced asexually? For instance, if we had no sexual nature at all, would we still have the desires and passions that propel humanity forward?
As to your second point, why not? Creative people can be ascetic. I believe there are people who now classify themselves as asexual. Maternal instincts/passion is very strong but asexual. But then, in futuristic dystopias which have done away with reproduction as we know it, people are depicted as robotic and lacking animation.
By the way, Matt Kuenzel , I’ve seen gene conversion at work. A mutation was made in a yeast gene that was essential for life and the yeast continued to grow. Turned out there was another version of the gene, very poorly expressed, but it served as a template to copy and correct the mutation.
80 million years! I think 80 years on this planet is enough for me, thanks, sex or no sex. 🙂
Stop the world and let me off, eh U-Ming Lee ? I feel like that at times 🙂
The thing about gene conversion is this: how does the organism know which one is the original and which one the mutation
About asexual reproduction: that’s true. The biological need for the maternal bond wouldn’t diminish. Maybe we would still have music and art and literature but in very different forms.
Matt Kuenzel : Something to do with the way DNA is modified? The damaged DNA will stick out like a sore thumb and be excised. DNA on either side will be deleted to make way for strand invasion by the other gene. The other gene copy will be found by base pairing, I guess.
Scott Hatch , such as? 🙂
Come to think of it, dessication is a sure way to kill off cells, denature proteins and damage DNA. I’m beginning to respect these rotifers!
lol Scott Hatch ….. who needs intelligent life
A pointless and endless life. Yay!
Nobody said it was pointless, Sridhar Jagannathan 🙂
Rajini Rao if you like rotifera, you will really love tardigrada…..lol
RAID IRL… 🙂
Feisal Kamil hahaha, no.
And the point of life without sex would be???….. You have got to be kidding!!!
a little radiation was what probably gave us sexual reproduction in the first place …hehe
Tardigrades would not be drop bears, would they Cam Loon ? 🙂
Feisal Kamil 🙂 Need to sign off, g’night all.
Feisal Kamil not if they chose immortality, then they wouldn’t come at all. 😉
Goodnight Rajini Rao we had to make it R-rated before you go to bed. If there is a demerit coming, Feisal started it.
Uh oh, here come the R-rated comments.
Perhaps dish washing is a good indoor substitute for weeding?
I don’t know. Maybe that’s why Kawthar AL ABDALLA likes dish washing or was it Aida Hazlan ?
Rajini Rao tardigrades or water bears, etc….but they have some unique adaptations….. they can be completely dessicated for 100yrs and be revived ….they have been taken to space for experiments…they might lead to eternal life also…goodnight and sweet dreams:-)
Chad Haney is slightly dyslexic, this time he misread bdelloid as bordello, evidently.
Thanks, Cam Loon …will look them up..really must get my beauty zzz’s 🙂
Was that a right or left turn to the bordello?
The monks from Shao lin temple can stay away from that stuff for 100 years. Human doesn’t live long enough so we can’t compare with some live forms that can live that long ( 80 mil yrs). I don’t know why, but this post reminds me of the movie Indiana Jones and the Temple of Doom ( or Jason the Argonaut ?…or some Hercules movies) in which a medusa monster keeps reproducing its own organs when one got cut off, until it encounters a special gem to destroy it. Perhaps the radiation used in that experiment was not the right weapon to take care of that bdelloid rotifer.
Radiation is a product of electromagnetic energy. Depending on what it is locate in the spectrum it can be harmful or not. Probably the bdelloid rotifer was bombarded with the frequencies that similar to radio wave frequency from Frampton’s Baby I Love Your Way tune.
Tom Lee The fact is that those live forms can’t live that long. Those 80 million years refer to the start of that clade. So, as if we were talking about the start of primates. See, we are also eternal!
Okay. I shouldn;t have read Rajini post so fast, should’ve been word by word . The reproduction doesn’t involve a male. Interesting. It’s still intriguing that the creature can reproduce, its genomes can be duplicated (getting back to the medusa head). Perhaps that x 5 times amount of gamma ray also makes it happy, but the lower audio freq can stop that creature genomes to reproduce. This thing makes me think again of the movie Aliens. Weird, isn’t it?
I don’t recall a Medusa monster in Temple of Doom…
Chad Haney i will not answer that till i read the whole thread, i don’t want to lose any points like Feisal Kamil 😉
First, life is not only metabolism and reproduction of DNA but also, the creation of memes, in Dawkins sense. Life is finally an individual experience as I am a conscious animal.
So, reproduction of my DNA is not sufficient to consider me as immortal. My memes will be forgotten or altered in few dozens of years. My individual experience and conscience will die with my body (yes sorry I am not religious ). So the Bdelloid solution won’t apply, even without sex, I shall remain mortal.
Good morning! Feisal Kamil! 🙂
Yes!! i do like dish washing! 😉 Chad Haney
do they have a hobby ?
Is that 10 petaled floret on the Tardigrave, an eye or an mouth
So female went about regeneration for millions of years leaving the male dead and extinct! Don’t know why some guys liked this?!
Maybe those guys were happy at the prospect of not having to deal with women for 80Mn years?
Gnotic Pasta: “Interesting…I’m going to have to go with sure…There are plenty of things in life that gives pleasure…the ability to live essentially forever and be able to see the world has it evolves and changes would be a hard act to pass up.”
Couldn’t have said it better myself.
I also agree with Olivier Malinur: I am my mind, not the duplication of my DNA (hopefully I am paraphasing him correctly).
Great post, Rajini Rao And I love the name, rotifer, sounds vaguely culinary, I can imagine a rotifer of chestnuts and some choice specimens of Boletus Edulis smothered in red wine.
That is not dead which can eternal lie, And with strange aeons even death may die.
Although I could never fully comprehend this quote, your post eerily reminded me of it.
Everyone has moved on to philosophy and I’m still stuck trying to understand exactly how the tetraploid genome is superior to diploid … how exactly gene conversion works to give tetraploidy an advantage … seems that four are better than two but how does that all work ???
“The difference between sex and love is that sex relieves tension and love causes it.”
― Woody Allen
Must be a very tense bdelloid rotifer.
The hypothesis that the relatively large and complex vertebrate genome was created by two ancient, whole genome duplications has been hotly debated, but remains unresolved … [this work] provides unmistakable evidence of two distinct genome duplication events early in vertebrate evolution … http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.0030314
Matt Kuenzel : Thanks, I’ll check it out. Here is one that discusses whole genome duplication in fish: http://genome.cshlp.org/content/13/3/382.full
BTW, they mention that Xenopus laevis (model frog) is tetraploid. I didn’t know that..
If I could live as long as I wanted I would give up sex in a heartbeat. I don’t even really have to think about it. I’ve already missed out on experiencing most of the past so if given the chance to not miss the future, I would totally go for it. So much I want to do, so little time!
Ronald Woodhouse And the point of life without sex would be???….. You have got to be kidding!!! – I would turn that around and instead ask; your point in life is to have sex??? You have got to be kidding!!! :p
Rajini Rao did you see Peter Lindelauf reference to parthenogenetic snakes in his post
I think the most weird mode of reproduction is gynogenesis. It’s actually a form of parthenogenesis.
I heard about it when I was having an aquarium and I had a deep interest in fishes. Some fishes, namely carps of Amur river (I am serious), drop their eggs among the eggs of other fishes. The sperm of the male of the other species will trigger the cellular division. Now, the interesting thing is these carps will inherit some characters of the “father”, meaning despite there was no real fertilization of the egg, a part of the genetic patrimony of the male of the other species was passed to the carp.
The snake link is interesting, thanks Chad Haney . As for the curious case of carps, Olivier Malinur , I wonder what chemical in the sperm triggers development and how genetic info was passed to the egg without fusion between egg and sperm? Or perhaps there is fusion but the egg is already a diploid and good to go..equally mysterious.
Other strange stuff: in biological terms, obligatory asexual animals (or plants) can be immortal. There are a few examples: planaria S. mediterranea which has a way of maintaining telomere length and avoiding senescence. A PNAS paper by Aziz Aboobaker’s lab also notes, “Longevity experiments to investigate senescence in Hydra that reproduced asexually suggest that they are immortal”. Not all asexually reproducing organisms can go on infinitely without dying. Others need to be refreshed by sexual reproduction after a certain number of generations (~70 in budding yeast) otherwise they show signs of aging.
Clonal asexual reproduction produces genetically identical offspring with the occasional rare mutation or mitotic recombination event. Check out the YouTube video and comments in this link:http://aboobakerlab.com/?e=18
Would you live longer… or would it only feel like you’re living longer?
Hehe, you would feel like you lived forever, Paul Duggan . The classic joke re. abstinence of any kind.
Without sex…no reproduction,nothing…so if every one opts for the option…then humans would be extinct after 80 years…..
naaa I’d prefer sex…just for the sake of human race…lol
Sudhanshu Pathania , this post describes how there can be reproduction without sex. No extinction.
Rajini Rao it says the males have disappeared….well that means extinction at least of the XY chromosome…
Was not the original post a proposal to eradicate the “Y” chromosome from “homo-sapiens???
Sudhanshu Pathania : not all animals use the XY system of gender determination. Rotifers do not have a Y chromosome. The males are essentially unfertilized eggs that have half the chromosomes that the females have. Very few males are produced. The type described in this post have none. So the males are extinct but the females live on. No need for males, I’m afraid 🙂
Ronald Woodhouse , the Y chromosome of Homo sapiens is nearly gone anyway 🙂 See my old post: https://plus.google.com/u/0/114601143134471609087/posts/GgyHofLhbk6
Even in homosapiens the trend has began socially. Single moms!!? Biology will follow. Man you are gone.
This seems some master plan to eradicate males…
and your earlier post tells that Y chromosome would be lost in about 10 million years….and I don’t expect to live that long so no worries for me… 🙂
Aww, no way, R Prakash Prakash ! We’d like to have you guys around. As long as you’re useful 😉
No worries, Sudhanshu Pathania . That old post explained how the Y chromosome is sneaky! Important genes are stored as palindromes (“Madam, I’m Adam”) so that errors in one can be repaired by the other. If you did live for 10 million years, there would be other guys.
I checked out your post as suggested. My degree is in History, it’s not that I avoid Science, it’s that I avoid Math. But, why, pray tell, are more males than females born? (I never expected to see anybody top Susan Brownmiller!!)
Hey, Ronald Woodhouse . Only in some cultures are the male to female ratios skewed to males…sadly, this has nothing to do with biology. Who is Susan Brownmiller?
We can reboot the Y chromosome with X Xmales
Cure a pile of genetic diseases
Klinefelter’s syndrome! Cool idea..
Rajini Rao awesome pic………..
Shaker Cherukuri , the link between caloric restriction and longevity is pretty solid!
Haha! All the great stuff we read about on G+ but never have time to experience 😉
good one Rajini
wao ! Rajini u have this much information to share. i really apriciate 2 with u.
I’d opt for cloning over sex in a heartbeat, though it’s my consciousness that I really want to persist, rather than my genes. I guess my mind’s memes can be even more “selfish” than my body’s genes. I wonder whether bonobos or chimps live longer [I feel the urge for a Google search coming on], and whether frequent sexual activity [of various kinds] increases or decreases an ape’s longevity and lifespan. Are there any known causal correlations in primates (especially apes) and for mammals in general? I also wonder what the current thinking is on biological basis of homosexuality. Is there any evidence on whether it could have evolved as a population control or a gender ratio control that’s of evolutionary benefit to various species?
Andrew King , interesting questions! There was a study recently showing that sex is exhausting and can increase vulnerability to predators..in invertebrates, though 🙂 Here is a news article on this: http://articles.latimes.com/2012/jul/23/science/la-sci-sn-bats-fly-sex-20120723
It would be interesting if it extrapolated to primates!
Re. homosexuality, I recall reading in the popular press of some connection with biological “population control”: apparently highly fertile women with lots of children were more likely to have homosexual offspring. Honestly, I don’t know how valid these studies are, just passing along the info: http://www.medicaldaily.com/articles/10287/20120613/homosexuality-gene-mother-reproduction-evolution.htm
Rajini Rao, thank you for the info and links. I’ve been scientifically curious about this topic for some time, so it’ll be nice reading some articles on it.. My brain’s half asleep just now, but I’m looking forward to reading them first thing tomorrow. Thanks for this interesting post 🙂
Yes, In a heartbeat!
Sure about that, Jorge Albuquerque ? 😉
Rajini Rao hmm, maybe?
Rajini Rao They steal DNA from all over too
Natural GMOs Part 151. Microscopic animals that have stolen one in ten of their genes from other species
Natural GMOs Part 40. Millions of years without natural sex forced these poor little beggars to mate with germs.
Mark Welch D, Meselson M.
Just came across an awesome home-made video from Steven Burke which documents the delicate movements of these little creatures, and sadly, the death throes of one that was stained with methylene blue. Watch the cytoplasm stream out when it lyses at the end 😦
Here is his post (which I will share to the science pages in a bit): http://goo.gl/npn4pE