# A Different Angle on Aphids

**URL:** <https://boards.straightdope.com/t/a-different-angle-on-aphids/372718>\
**Category:** Cecil's Columns/Staff Reports\
**Created:** [September 14, 2006, 6:16pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718 "2006-09-14T18:16:22Z")\
**Posts on this page:** 18\
**Page:** 1

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**Author:** ![SiXSwordS](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@SiXSwordS](https://boards.straightdope.com/u/SiXSwordS)\
**Post date:** [September 14, 2006, 6:16pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/1 "2006-09-14T18:16:22Z")

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Now that I’ve learned all about this thing called [a Joke](http://boards.straightdope.com/sdmb/showthread.php?t=387999), thanks **Khangol** , I have a different question about the [aphids column.](http://www.straightdope.com/classics/a3_223.html)

When [[m]ale and female aphids mate in autumn](http://en.wikipedia.org/wiki/Aphids#Reproduction) is the same… cell (egg?) in the mother fertilized as would, without the intervention of the male, parthenogenetically become a new (female) aphid?  
Also, is there any way a female could parthenogenetically bear male offspring?

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**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\
**Post date:** [September 14, 2006, 7:12pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/2 "2006-09-14T19:12:14Z")

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From Cecil’s column and the Wiki link in the OP, the parthenogenic offspring would seem to be genetically identical to the mother, so no males could result without a father’s participation. However, I’m not an expert on aphid genetics.

I found it odd that neither Cecil nor Wiki mentioned the role **ants** play in the aphid life cycle. In many aphid species, aphids are like cows to the ant colony. In the fall, ants take aphid eggs down into the underground ant nest. In the spring, the ants carry the hatchlings up to the tender new shoots of the plant. The aphids feed on plant juices, and they excrete a sweet, sticky poop. The ants come back and collect the sweet poop as food for the colony.

If you’ve parked under a tree, you probably have seen little spots of aphid poop (nope, it’s not sap) on your car. They start out clear, and then turn dark. You may have seen ants scampering up and down tree trunks, and now you know why.

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<div class="post-metadata">

**Author:** ![SiXSwordS](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@SiXSwordS](https://boards.straightdope.com/u/SiXSwordS)\
**Post date:** [September 14, 2006, 8:21pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/3 "2006-09-14T20:21:02Z")

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[QUOTE=AskNott]  
The aphids feed on plant juices, and they excrete a sweet, sticky poop. The ants come back and collect the sweet poop as food for the colony.  
[/QUOTE]

MMMmmm, aphid feces!

> [@wiki article](#):
>
> At different times of the year, they can be viviparous [live young] or oviparous [laying eggs]  
> and:  
> Sexual females, but also asexual ones, have two sex chromosomes while sexual males only have one.

Leads me to two conclusions.  
Males do not fertilize the same cells that parthenogenetically lead to live offspring. (Not a well founded conclusion.)  
And:  
Females determine the sex of the offspring.

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**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\
**Post date:** [September 14, 2006, 11:19pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/4 "2006-09-14T23:19:33Z")

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Cecil has written more on the subject of [parthenogenesis](http://www.straightdope.com/classics/a991008a.html).

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<div class="post-metadata">

**Author:** ![SiXSwordS](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@SiXSwordS](https://boards.straightdope.com/u/SiXSwordS)\
**Post date:** [September 15, 2006, 3:27pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/5 "2006-09-15T15:27:24Z")

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Thanks for that **Chronos**. I saw Turkeys mentioned in the wiki article and wondered about how that could work. I assumed aphids would be a simpler place to start.

In Turkeys, I assume, the basic process is the same. Cecil even mentions the possibility of a male, um, interacting with a female and the female opting to disregard his input. So to speak.

That leads me to think that the female produces an egg and, let’s say there are no males around or they’re all just to pushy or immature or they’re watching football or they’re Republicans, then the female lays the same egg and, without benefit of intercourse, has a viable offspring.

The process in aphids appears different on the surface. It’s sounds to me as though the females have two reproductive strategies if not different systems. The sexual reproductive system and the parthenogenetic system.

I’ll have to do some more research on virgin birth and whether or not the resultant offspring in Turkeys are always female.

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**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\
**Post date:** [September 17, 2006, 4:58am UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/6 "2006-09-17T04:58:59Z")

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Well, let us know what you unearth, **SiXSwordS.** As I understand the turkey biz in the US, most of the adult turkeys sold are males, as they develop the massive muscles the market desires. I’m beginning to doubt my earlier conclusion about aphids and turkeys producing only females without mating with males.

I already said I was not an expert on aphid genetics, and now I’m looking ignorant about turkey breeding, too. This is not embarrassing. Learning starts with finding out what you don’t know. It’s tempting, but I won’t spring into Rumsfeldic philosophy. I always get dizzy when I do that. 😃

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<div class="post-metadata">

**Author:** ![SiXSwordS](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@SiXSwordS](https://boards.straightdope.com/u/SiXSwordS)\
**Post date:** [September 18, 2006, 2:52pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/7 "2006-09-18T14:52:55Z")

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[QUOTE=AskNott]  
I’m beginning to doubt my earlier conclusion about aphids and turkeys producing only females without mating with males.  
[/QUOTE]

> [@](#):
>
> [One problem is that in parthenogenesis, where a female gives birth without the intervention of the male material, the offspring must be female also since the mother has no Y chromosome to pass on to a male offspring.](http://en.wikipedia.org/wiki/Virgin_Birth)

I think this is true with turkeys, but I’m not sure about aphids. As I quoted earlier, female aphids have two sex chromosomes and males only one. Obviously, the logic quoted above doesn’t apply. However, I think with aphids, the sex chromosome isn’t the point. Without fertilization, the female is reproducing asexually and, I’m guessing here, the offspring has to be identical to the parent.

I think you’re right about one thing. This thread is more a display of my ignorance than a learning tool. Maybe better to let it rest in peace instead of posting the results of my muddleheaded Googling.

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<div class="post-metadata">

**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\
**Post date:** [September 19, 2006, 3:50pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/8 "2006-09-19T15:50:26Z")

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Do turkeys use the same sex chromosone system that mammals do, though? I seem to recall somewhere that in birds, the females are heterozygotic, while the males are homozygotic, contrary to the mammalian system.

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**Author:** ![Caridwen](https://avatars.discourse-cdn.com/v4/letter/c/c89c15/32.png) [@Caridwen](https://boards.straightdope.com/u/Caridwen)\
**Post date:** [September 19, 2006, 4:25pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/9 "2006-09-19T16:25:32Z")

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It’s been awhile but it was always my understanding that through parthenogenesis both aphids and turkeys give birth to female offspring. In the case of aphids they bear live offspring who’s offspring are already forming when they’re born. With turkeys the only way it can be done is a near lethal lab fertalization by cold shock or some sort of injection that causes the # of chromosomes to double, hence female offspring.

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<div class="post-metadata">

**Author:** ![SiXSwordS](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@SiXSwordS](https://boards.straightdope.com/u/SiXSwordS)\
**Post date:** [September 19, 2006, 5:29pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/10 "2006-09-19T17:29:15Z")

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[QUOTE=Chronos]  
Do turkeys use the same sex chromosone system that mammals do, though?  
[/QUOTE]

No, and not only is it different, but it is not entirely understood:

> [@](#):
>
> [In birds, females are the heterogametic sex, with one copy each of the Z and W sex chromosomes. Males are homogametic (ZZ). **However, it is not clear whether it is the presence of the female-specific W chromosome that triggers female development, or the dose of Z chromosome that confers maleness.** An intriguing additional possibility is that both Z and W matter! In marsupials, for example, Y acts as a dominant testis determining chromosome, while the X chromosome determines the choice between pouch and scrotum.](http://www.biology.eku.edu/RITCHISO/avianreproduction.html)

emphasis added

In some discussions of aphid reproduction it is noted that males appear in much greater numbers in the fall and also that it is winged females that start new colonies. (see wikipedia links.) Not that _Jurassic Park_ is going to fly as a cite, but one can imaginie the benefit if a single female or a female only population could propagate a species. If _any_ female (identical or otherwise) could potentially morph into a male, a single female would be able to engender an entire clan.

> [@Caridwen](#):
>
> With turkeys the only way it can be done is a near lethal lab fertalization by cold shock or some sort of injection that causes the # of chromosomes to double, hence female offspring.

I was referring to the “natural” process, rather than the cloning process that might be used in a lab.

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<div class="post-metadata">

**Author:** ![Caridwen](https://avatars.discourse-cdn.com/v4/letter/c/c89c15/32.png) [@Caridwen](https://boards.straightdope.com/u/Caridwen)\
**Post date:** [September 19, 2006, 7:14pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/11 "2006-09-19T19:14:37Z")

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It isn’t a natural process with turkeys as it is with aphids, that’s what I’m saying.  
Aphids and some bees are able to produce offspring parthenogenetically.

[quote]  
If any female (identical or otherwise) could potentially morph into a male, a single female would be able to engender an entire clan

[quote]

Lots of fish are able to change sex.

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<div class="post-metadata">

**Author:** ![SiXSwordS](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@SiXSwordS](https://boards.straightdope.com/u/SiXSwordS)\
**Post date:** [September 19, 2006, 7:20pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/12 "2006-09-19T19:20:56Z")

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[QUOTE=Caridwen]  
It isn’t a natural process with turkeys as it is with aphids, that’s what I’m saying.

[/QUOTE]

[http://www.straightdope.com/classics/a991008a.html](http://www.straightdope.com/classics/a991008a.html)

> [@Cardiwen](#):
>
> Lots of fish are able to change sex.

A cite would help. I’ll try a search in the mean time.

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<div class="post-metadata">

**Author:** ![Caridwen](https://avatars.discourse-cdn.com/v4/letter/c/c89c15/32.png) [@Caridwen](https://boards.straightdope.com/u/Caridwen)\
**Post date:** [September 19, 2006, 7:39pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/13 "2006-09-19T19:39:05Z")

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I don’t have a site, I took embryology in grad school and it’s been awhile.

Lots of fish do though, try looking up salmon. I’ll try to find a site for you.

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<div class="post-metadata">

**Author:** ![Caridwen](https://avatars.discourse-cdn.com/v4/letter/c/c89c15/32.png) [@Caridwen](https://boards.straightdope.com/u/Caridwen)\
**Post date:** [September 19, 2006, 7:43pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/14 "2006-09-19T19:43:41Z")

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Something about Sea Bass

> **[Uncovering Sex-change Secrets Of Black Sea Bass](https://www.sciencedaily.com/releases/2006/04/060412091247.htm)**
>
> David Berlinsky, an associate professor of zoology at the University of New Hampshire, is studying what triggers sex reversal in black sea bass -- and how to prevent it. The sought-after fish is a good candidate for aquaculture on the east coast,...

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<div class="post-metadata">

**Author:** ![SiXSwordS](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@SiXSwordS](https://boards.straightdope.com/u/SiXSwordS)\
**Post date:** [September 19, 2006, 8:51pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/15 "2006-09-19T20:51:36Z")

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I have to admit I’m amazed at how common this is. I found more links than I could even wade through. River Salmon, Reef fish, Sea Bass…

> [@](#):
>
> In fact, reef fish that remain as the same sex for their life span (gonochoristic) are in the  
> minority.
> 
> There are many different patterns for sex-change. Some species will begin life as  
> males and switch to females (protandry), and others switch from female to male  
> (protogyny). Further still, some will change sex in both directions, and others will  
> be both sexes at the same time.

[http://www.bio.davidson.edu/Courses/anphys/1999/Rice/Rice.htm](http://www.bio.davidson.edu/Courses/anphys/1999/Rice/Rice.htm)

Many of the links I looked at mentioned that females become males when there is a dearth of males. In one, the comment was that when the dominant male disappeared, for whatever reason, the dominant female would become male.

Considering [the cost of males](http://www.indiana.edu/~curtweb/Research/cost%20of%20males.html), I have to wonder if aphids, at least, aren’t taking advantage “cloning” females while using sexual reproduction to maintain variable offspring.

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<div class="post-metadata">

**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\
**Post date:** [September 20, 2006, 4:09am UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/16 "2006-09-20T04:09:29Z")

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[QUOTE=SiXSwordS]  
I think this is true with turkeys, but I’m not sure about aphids. As I quoted earlier, female aphids have two sex chromosomes and males only one. Obviously, the logic quoted above doesn’t apply. However, I think with aphids, the sex chromosome isn’t the point. Without fertilization, the female is reproducing asexually and, I’m guessing here, the offspring has to be identical to the parent.  
[/QUOTE]

As you say, sex determination in most aphids is an XX/XO system. Females have two X chromosomes, males have one X (and the single X lacks a partner).

All aphids start out XX, that is, female. Males are produced when one X chromosome is lost during development. A female can give birth to both males and females parthenogenetically.

Furthermore, a male aphid can father only females. Although he could in theory produce X and O sperm, in practice only X sperm are produced. Since both parents contribute an X, only females are produced by sexual reproduction.

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<div class="post-metadata">

**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\
**Post date:** [September 20, 2006, 4:13am UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/17 "2006-09-20T04:13:17Z")

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[QUOTE=SiXSwordS]  
Considering [the cost of males](http://www.indiana.edu/~curtweb/Research/cost%20of%20males.html), I have to wonder if aphids, at least, aren’t taking advantage “cloning” females while using sexual reproduction to maintain variable offspring.  
[/QUOTE]

That’s exactly what they are doing. Cloning is the best way to maximize your reproductive rate, but the disadvantage is that you lose genetic variability and the possibility of adapting to changing conditions. Aphids reproduce sexually after several parthenogentic generations in order to maintain genetic variability within their populations.

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<div class="post-metadata">

**Author:** ![SiXSwordS](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@SiXSwordS](https://boards.straightdope.com/u/SiXSwordS)\
**Post date:** [September 21, 2006, 3:53pm UTC](https://boards.straightdope.com/t/a-different-angle-on-aphids/372718/18 "2006-09-21T15:53:24Z")

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[QUOTE=Colibri]  
\<snip\>All aphids start out XX, that is, female. Males are produced when one X chromosome is lost during development. A female can give birth to both males and females parthenogenetically.  
[/QUOTE]

Thanks **Colibri**. I’ve been away from the computer or I would have said as much earlier.
