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First confirmed hatchings of two California condor chicks from unfertilized eggs

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Re: First confirmed hatchings of two California condor chicks from unfertilized eggs

#81

Post by freeflight »

hadlock wrote: post #62
simiones wrote: post #38

Earlier quoted context omitted.

Most Christians believe that that was not some biological process, but a true miracle where God himself bestowed this child on Mary. It would be technically correct that this was parthenogenesis, but it is a completely different... mechanism. Most non-Christians, even if they believe Jesus was a true historical figure, do not believe that his mother was a virgin.

> Most Christians believe that Do you have any sort of statistics to back this up? A survey of some kind? From my own experience, most people who are Christian subscribe to the lifestyle and teachings, but do not accept 100% of the bible as truth.

How about the fact that over a billion people are members of the Catholic Church? The membership of which requires believing quite a bit of Biblical literalism.

Tbh that whole argument is always kinda weird: If those people don't believe in the whole thing, why are they members in a church about it? That's pretty much the only statistic you need.

[0] https://www.bbc.com/news/world-21443313

Re: First confirmed hatchings of two California condor chicks from unfertilized eggs

#82

Post by pippy »

jaqalopes wrote: post #13

Apologies for the low-effort comment, but this really freaks me out. I had no idea birds could reproduce asexually! That's crazy! Feels like an unanswerable question, but: could we ever see something like this in mammals? A virgin birth, for lack of a better phrase?

There's a great passage about this in Genome by Matt Ridley, which is a great book for anyone interested. In mammals both the male and female gametes imprint their DNA in their sex cells to repress certain genes, if you combine two generic sequences from two males (with no modification) the zygote forms with no brain and too much placenta and dies soon after. If you do the reverse with females, you wind up with a oversized head and no placenta. The working theory is embryonic development is a competitive environment, where males want the best for their offspring at the expense of the female host, and the females 'fight' back by limiting the amount of resources the child has. it's only been recently we've had the technology to remove the epigenetic markers from DNA sequences to allow combinations of same sex strands.

Re: First confirmed hatchings of two California condor chicks from unfertilized eggs

#83

Post by dredmorbius »

nitrogen wrote: post #78
dredmorbius wrote: post #64

For those thinking "Dupe", this specific submission seems to have hit the 2nd chance queue, as the item was submitted 2 days ago. Meaning it's not actually a duplicate. Algolia shows the original submission date, at least for now: https://hn.algolia.com/?dateRange=pastMonth&page=0&prefix=fa...

It appears there was a related story though: https://news.ycombinator.com/item?id=29070133

I tend to discount discussions below a certain threshold.

(What threshold is hard to say, though probably in the 20--40 range. Of course, interesting and salient comments can occur at any level. Perhaps more concentrated in smaller discussions.)

Re: First confirmed hatchings of two California condor chicks from unfertilized eggs

#84

Post by dredmorbius »

bencollier49 wrote: post #6

So in birds, sex chromosome arrangement is a reverse of what we have in humans. Their males are ZZ and the female is ZW. Which is why only males appear from this parthenogenesis.

Right.

From my very shallow understanding:

- The fact that females are defined by unmatched sex chromosomes rather than matched ones means that in haploid parthenogenesis (a split and rejoining of a single half of a genome, rather than fertilisation by male and female sex cells), the resultant sex cells are either ZZ (vialble male) or WW (nonviable "super-female").

- Parthenogenesis in mammals on a similar basis isn't possible as the umatched chromsome is found in males (giving a viable XX female) ... but without an ovum or womb. A self-replicating female egg would be XX.[1] There's ... some research into parthenogenesis in mammals, and at least one apparent observed instance.[2]

- In the case of Avian or similarly Z/W species, parthogenesis is a potentially viable option for resuming sexual reproduction of a population in which all males have been lost. For mammallian populations, not so much. In any case, there'd likely be an extreme genetic bottleneck.

________________________________

Notes:

1. Religious implications for spontaneous mammalian parthogenesis resulting in male offspring are left ... undiscussed.

2. See Google Scholar for a literature overview: https://scholar.google.com/scholar?hl=en&as_sdt=7%2C39&q=par...

Re: First confirmed hatchings of two California condor chicks from unfertilized eggs

#85

Post by mistrial9 »

xxpor wrote: post #72
mistrial9 wrote: post #41

Earlier quoted context omitted.

this is complicated, nuanced and not literal; it is a typical thing for critics to latch on to, so let's be wise-cautious with the exposition here at YNews, please

Not Christian, but as my Rabbi used to say: "When God created the earth 5782 years ago (give or take a few billion years),"

Mel Brooks?

Re: First confirmed hatchings of two California condor chicks from unfertilized eggs

#86

Post by xxpor »

mistrial9 wrote: post #85
xxpor wrote: post #72

Earlier quoted context omitted.

Not Christian, but as my Rabbi used to say: "When God created the earth 5782 years ago (give or take a few billion years),"

Mel Brooks?

It would not shock me in the slightest if that's where he got it.

Re: First confirmed hatchings of two California condor chicks from unfertilized eggs

#87

Post by thaumasiotes »

jaqalopes wrote: post #13

Apologies for the low-effort comment, but this really freaks me out. I had no idea birds could reproduce asexually! That's crazy! Feels like an unanswerable question, but: could we ever see something like this in mammals? A virgin birth, for lack of a better phrase?

> Feels like an unanswerable question, but: could we ever see something like this in mammals? A virgin birth, for lack of a better phrase?

The question is easy to answer. Yes, this is a development that shows up from time to time. Species displaying only asexual reproduction all tend to be evolutionarily young, which implies that adopting the strategy rapidly leads to extinction, but it has short-term benefits which mean that there's usually something around trying it out. (And then there are species with obligatory parthenogenesis and also obligatory sexual reproduction, like aphids, which don't experience the problems that pure-cloning species do.)

By way of examples of sexually-reproducing species shifting to parthenogenesis, there is a species of lizard that can only reproduce that way. We can be certain they originally reproduced sexually since they still engage in a (pointless) simulation of copulation.

Re: First confirmed hatchings of two California condor chicks from unfertilized eggs

#88

Post by RapidFire »

freeflight wrote: post #81
hadlock wrote: post #62

Earlier quoted context omitted.

> Most Christians believe that Do you have any sort of statistics to back this up? A survey of some kind? From my own experience, most people who are Christian subscribe to the lifestyle and teachings, but do not accept 100% of the bible as truth.

How about the fact that over a billion people are members of the Catholic Church? The membership of which requires believing quite a bit of Biblical literalism. Tbh that whole argument is always kinda weird: If those people don't believe in the whole thing, why are they members in a church about it? That's pretty much the only statistic you need. [0] https://www.bbc.com/news/world-21443313

>If those people don't believe in the whole thing, why are they members in a church about it?

Usually they inherit the religion from their parents. They grow up with the church as family so even if they don't believe in the tenets/beliefs they still participate.

Re: First confirmed hatchings of two California condor chicks from unfertilized eggs

#89

Post by InvaderFizz »

simiones wrote: post #42
s1artibartfast wrote: post #23

Earlier quoted context omitted.

If the females are ZW, why can't they make WW or ZW?

ZW is less likely because normally parthenogenesis starts with a haploid egg cell (Z or W) that undergoes meiosis alone, copying its own chromosomes - becoming ZZ if it started as Z and WW if it started as W. WW is normally not viable, just like YY in mammals, so the most likely case of parthenogenesis by far is ZZ, male.

So in this case, the ZZ offspring is a genetic clone of its grandfather? That's the only sense I can make of it.

No, wait, half clone. Yup, I'm fully confused by this turn of events.

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