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Dino-era Mammal the "Jurassic Mother" of Us All? - Comments

Kim Probable's Avatar Comment 1 by Kim Probable

I realize it's a bit pedantic to point this out, but calling it the "great grandmother" is, in effect, the same as calling it the mother. It would still be a part of a direct line.

Thu, 25 Aug 2011 01:02:32 UTC | #863957

Neodarwinian's Avatar Comment 2 by Neodarwinian

A little less than direct, Kim. Plot your family tree from great granny to you. I assume that was more of a literary device than a taxonomic reality.

Still, an old " true beast " found in China. That is one hot site for paleontology lately!

Thu, 25 Aug 2011 02:29:41 UTC | #863987

Sara12's Avatar Comment 3 by Sara12

Yeesh, I need to stop reading comments on other sites' message boards. Frightening. Otherwise, cool find. Especially the bit about the fossil evidence now lining up with the DNA evidence. Sweet!

Thu, 25 Aug 2011 03:52:20 UTC | #864004

JuJu's Avatar Comment 4 by JuJu

Reminds me of the little critter living under some berry bushes in my backyard, little bastard climbs up my apple tree, plucks off an apple, then takes it back to the bushes. Lucky for it, "I" know were distant cousins, or else!

Thu, 25 Aug 2011 06:47:50 UTC | #864024

halucigenia's Avatar Comment 5 by halucigenia

Comment 2 by Neodarwinian :

A little less than direct, Kim. Plot your family tree from great granny to you. I assume that was more of a literary device than a taxonomic reality. Still, an old " true beast " found in China. That is one hot site for paleontology lately!

re-

Although it's unclear if the creature is a direct ancestor of modern placentals, it's "either a great grand-aunt or a great grandmother," the study authors say.

I read that as; it is unclear... but it is either an indirect ancestor like a grand aunt or it is a direct ancestor like a great grandmother. Of course that's not a taxonomic reality (a few more greats would have to be inserted) but is certainly an apt analogy.

In what way would a great grandmother not be a direct ancestor?

Thu, 25 Aug 2011 09:50:35 UTC | #864065

PERSON's Avatar Comment 6 by PERSON

I guess what Neodarwinian was thinking of is that for each creature there have existed more great grandmothers than mothers, i.e. the likely amount of shared genetic material and so relatedness is less between the creature and their grandmothers and the creature and their mothers. That does contradict the assertion made in the first comment. The bit about a "direct line" is correct, but a non-sequitur.

Thu, 25 Aug 2011 11:55:52 UTC | #864094

aquilacane's Avatar Comment 7 by aquilacane

The comments over a National G are a real foxhole battle between pro and no. Wonder why there are so many Christian lurkers on an evolution article. Taking a peak outside the closet, perhaps. still a bit frightened it seems.

Thu, 25 Aug 2011 12:42:05 UTC | #864100

halucigenia's Avatar Comment 8 by halucigenia

Comment 6 by PERSON :

I guess what Neodarwinian was thinking of is that for each creature there have existed more great grandmothers than mothers, i.e. the likely amount of shared genetic material and so relatedness is less between the creature and their grandmothers and the creature and their mothers. That does contradict the assertion made in the first comment. The bit about a "direct line" is correct, but a non-sequitur.

I understand that the wording “calling it the "great grandmother" is, in effect, the same as calling it the mother” is incorrect if taking it out of the context of what I presumed Kim Probable was referring to i.e. the sentence in the article

“Although it's unclear if the creature is a direct ancestor of modern placentals, it's "either a great grand-aunt or a great grandmother," the study authors say.”.

I thought that she read this sentence as saying; it’s unclear if the creature is a direct ancestor (the mother of us all) but if it’s not it is either a great grand-aunt or a great grandmother. In this case it was simply a misunderstanding of what I took to be the meaning of that sentence. So in this context I think that mother and great grandmother do mean the same thing (in my understanding of the sentence) i.e. both being direct ancestors as compared to a great grand aunt being an indirect ancestor.

I replied to Neodarwin because I thought that they had misunderstood Kim Probable’s misunderstanding and was trying to clear up both misunderstandings. Thus, the bit about a "direct line" is correct and not a non-sequitur as I think the misunderstanding was that the article was alluding to a great grandmother not being a direct ancestor while a mother was, in terms of a direct line of ancestry, which as I was trying to explain it was not.

Kim Probable, to clear this up, is that what you thought the article was saying?

Thu, 25 Aug 2011 12:55:30 UTC | #864104

KenChimp's Avatar Comment 9 by KenChimp

Comment 7 by aquilacane :

The comments over a National G are a real foxhole battle between pro and no. Wonder why there are so many Christian lurkers on an evolution article. Taking a peak outside the closet, perhaps. still a bit frightened it seems.

Some faith-heads are just as curious about scientific findings in support of evolution by natural selection as we are. The difference being what motivates their curiosity. For me, I'm curious because I want to know as much about the origins of life today (and in general) as possible. For them, perhaps, they want to know what scientists are finding that contradicts their ridiculous world view.

Speaking of ridiculous, has anyone else here seen the frightening load of posterior dump coming from the "Apostles", a movement of radical evangelicals in the U.S. bent on dominating national political forums, business and social organizations to prepare America for the coming "End Times"?

These deluded would-be tyrants call science a pack of lies, scientists demonic instruments of Satan, and have referred to Oprah Winfrey as "The bitch of Babylon" and "the mouthpiece of the Anti-Christ"!

Un-frackin-believable.

Thu, 25 Aug 2011 12:58:47 UTC | #864107

peanutsplatters's Avatar Comment 10 by peanutsplatters

If this ancestor rat thing came from marsupials which happen to hang out in Australia, does that make Australia birthplace of mammals?

Thu, 25 Aug 2011 13:07:17 UTC | #864109

drumdaddy's Avatar Comment 11 by drumdaddy

untamed mama

Thu, 25 Aug 2011 13:23:17 UTC | #864115

Saganic Rites's Avatar Comment 12 by Saganic Rites

Comment 10 by peanutsplatters :

If this ancestor rat thing came from marsupials which happen to hang out in Australia, does that make Australia birthplace of mammals?

No, just that Australia split from the major land-mass before the placentals reached it; the same reason there are no moles and snakes in Ireland.

Thu, 25 Aug 2011 13:42:10 UTC | #864120

phoffman's Avatar Comment 13 by phoffman

One wonders why popularization articles on science so often do not even include, much less consist of, straightforward, non-technical language which explains the real point in somewhat simplistic, but at least acceptable, form (especially (non-micro-) biology, where that should be easy).

For example, to preclude confusions such as the one (from peanutsplatters) about this little fellow evolving in Australia, one could say: 'What has been discovered is this. If, from any mammal today like us (born into the outside world from a placenta, rather than the other, kangaroo-types or platypus-types born into a pouch or as an egg), we trace back along some line far enough, we come back to that newly-discovered species or a very similar one at around the same time. And any line coming back down from an individual of that species will pass through only mammals like us, though many lines won't make it this far into the future. However, if you go even further back from that species, but not so very far, that different animal will have at least one line which will pass through at least one of those other two types.'

I trust that this is basically what the article is trying to say, but will be very happy to be corrected, if needed. But at least the journal isn't as pathetic as parts of National Geographic TV.

Thu, 25 Aug 2011 14:03:01 UTC | #864124

Schrodinger's Cat's Avatar Comment 14 by Schrodinger's Cat

What I'd like to know, given that convergent evolution exists, is how they know that this species is actually an ancestor of all modern day placental mammals.....and that the placental type did not evolve more than once. If convergence is more common than we think, could we be making past linkages that don't actually exist ?

Thu, 25 Aug 2011 14:19:54 UTC | #864135

DocWebster's Avatar Comment 15 by DocWebster

Comment 4 by JuJu :

Reminds me of the little critter living under some berry bushes in my backyard, little bastard climbs up my apple tree, plucks off an apple, then takes it back to the bushes. Lucky for it, "I" know were distant cousins, or else!

If you really wanted to support your cousin you would pick a nice apple and lay it his or her doorstep so your other cousin, the raptor, doesn't grab and eat it. Wait, does all this familial connection business mean no matter what we eat, if we go back far enough, we are cannibals?

Thu, 25 Aug 2011 14:50:02 UTC | #864144

Sample's Avatar Comment 16 by Sample

@14 Schrodinger's Cat,

I'm on the outskirts of the "oasis" here on this topic but your question is interesting to my ears. I would speculate that you're right, convergence may very well create headaches for taxonomists, certainly in principle.

I can guess why such a challenge does not, however, necessarily mean paleontology is impotent.

Mike

Thu, 25 Aug 2011 15:11:52 UTC | #864152

phoffman's Avatar Comment 17 by phoffman

Perhaps the argument to make convergence unlikely is that many, not just one or two, special things about the skeleton, are shared by all mammals (like us), but not by the other types (see my previous post). It would then seem extremely unlikely that ALL of these would 'converge' more than once, even if one such peculiarity could. But I'm too lazy to get hold of the original article, much less to educate myself sufficiently to be completely confident about that.

Thu, 25 Aug 2011 15:27:57 UTC | #864156

DavidMcC's Avatar Comment 18 by DavidMcC

Comment 14 by Schrodinger's Cat :

What I'd like to know, given that convergent evolution exists, is how they know that this species is actually an ancestor of all modern day placental mammals.....and that the placental type did not evolve more than once. If convergence is more common than we think, could we be making past linkages that don't actually exist ?

Well, all they need to do is show is that all placentas express a certain class of ERVs in their syncitiotrophoblast cells, and they have more-or-less shown that it was not convergence. I don't know that that has been done yet, but it seems likely to be true, because in humans it has been shown that certain HERV-W class genes are fundamental to placental function. This was discussed on an old thread, a few months ago.

Thu, 25 Aug 2011 15:31:03 UTC | #864157

JuJu's Avatar Comment 19 by JuJu

Comment 14 by Schrodinger's Cat

What I'd like to know, given that convergent evolution exists, is how they know that this species is actually an ancestor of all modern day placental mammals

It does seem confusing, But the article does gives this disclaimer:

Although it's unclear if the creature is a direct ancestor of modern placentals, it's "either a great grand-aunt or a great grandmother," the study authors say.

So, when it states:

the newfound fossil species is the earliest known ancestor of placental mammals—animals, such as humans, that give birth to relatively mature, live young—according to a new study.

Its not definitively claiming that it is a direct ancestor, although it could be, I think the article is claiming that its the oldest known placental type creature found so far, which probably had a recent common ancestor with the direct line that lead to modern placentals.

Sure would be nice if DNA fossilized, then we could answer the question more precisely.

Thu, 25 Aug 2011 15:58:52 UTC | #864164

Kim Probable's Avatar Comment 20 by Kim Probable

Comment 8 by halucigenia :

Kim Probable, to clear this up, is that what you thought the article was saying?

I think so. =D I got lost in the various relations.

I was just being a little nit picky and silly. I realize there are a lot of other genetic lines coming into the "mother of all", but was basically just saying that the placental "mother" of the "mother of all" would be the true "mother of all." It's so far back, genetically, that looking back another "generation" or two doesn't really mean much. (I realize we're not talking in true generations, but a much larger scale of time.)

If the article called it a cousin, I would take it to mean that it shared some sort of ancestor with the line that eventually lead to us, but its own genetic line eventually went extinct.

Anyway, overall it wasn't terribly important to the general message of the article. =) I know I would do far worse when it comes to being precise in an interview.

Thu, 25 Aug 2011 17:27:04 UTC | #864185

Mr DArcy's Avatar Comment 21 by Mr DArcy

Without entering into all the nit picking about our ancestors, perhaps we should appreciate that without critters like this one, this discussion might not have happened.

Thu, 25 Aug 2011 17:56:42 UTC | #864196

kev_s's Avatar Comment 22 by kev_s

Is it my imagination or does it look like RIck Perry?

Thu, 25 Aug 2011 18:34:13 UTC | #864208

Agrajag's Avatar Comment 23 by Agrajag

Comment 22 by kev_s

Is it my imagination or does it look like RIck Perry?

No, Perry doesn't look that intelligent!
Steve

Thu, 25 Aug 2011 18:45:35 UTC | #864212

Vicar of Art on Earth's Avatar Comment 24 by Vicar of Art on Earth

Besides giving the employee Darwins' Birthday off, I am having a party to celebrate "Great Grandmother Placenta's Birthday" and while tree climbing will be encouraged, I do think instead of grubs there will be cake in the form of an insect. After a couple "grasshoppers" a spontainious moment of silence for another evolutionary gap being filled may happen.

I am putting forward a late September Friday afternoon, first after the first full moon as it is rather nice to take a day off before Winter. My appolgy to any who support the Indo-European caste system, but if it is good enough for the Queen of England to have an offical birthday for convience, then it is good enough for Great Grandma.

I still believe that England would have stayed a Republic if Cromwell had kept Christmas, I base that on the current political debate in the US on evolution. I guess this may make me a radical "framer" in this circle, but picnics, holiday parties, decorations and dressing up are all old political and religious methods of selling ideas. Yes there is Arbor Day, but planting or hugging a tree is not the same.

Congradulations to the finders and authors.

Thu, 25 Aug 2011 18:49:06 UTC | #864215

Peter Grant's Avatar Comment 25 by Peter Grant

Placentals—including creatures from mice to whales—are all that remain of the so-called eutherian mammals, of which J. sinensis is the oldest known specimen.

The first eutherians evolved from the ancestors of marsupials, which have pouches and give birth to comparatively immature offspring. (A third type of mammal, the monotremes, includes platypuses and lays eggs.)

I just want to get this strait. Are they saying that placentals evolved from egg laying mammals or from mammals with pouches? I can see how a placental could evolve from an egg laying mammal or a marsupial could evolve from an egg laying mammal, but how could something with a pouch evolve into a placental?

Thu, 25 Aug 2011 19:42:52 UTC | #864235

Agrajag's Avatar Comment 26 by Agrajag

Comment 25 by Peter Grant
I can see how a placental could evolve from an egg laying mammal or a marsupial could evolve from an egg laying mammal, but how could something with a pouch evolve into a placental?

Er... a miracle?
;-)
Steve
(PS: "straight")

Thu, 25 Aug 2011 20:17:49 UTC | #864245

Peter Grant's Avatar Comment 27 by Peter Grant

So wouldn't it be better to say that both placentals and marsupials evolved from ancestors which were more like platypuses are today?

Thu, 25 Aug 2011 20:36:53 UTC | #864254

Alan4discussion's Avatar Comment 28 by Alan4discussion

Comment 27 by Peter Grant

I think they are saying that these are two different branches from a common ancestor

Placentals—including creatures from mice to whales—are all that remain of the so-called eutherian mammals, of which J. sinensis is the oldest known specimen.

So the rest of this eutherian group seems to have died out as the evolution of the placentals and marsupials separated.

The first eutherians evolved from the ancestors of marsupials, which have pouches and give birth to comparatively immature offspring.

And that platypuses are another separate branch (as I read it).

(A third type of mammal, the monotremes, includes platypuses and lays eggs.)

Thu, 25 Aug 2011 21:22:10 UTC | #864265

asyouwere's Avatar Comment 29 by asyouwere

"Methinks it is like a weasel."

Thu, 25 Aug 2011 21:47:40 UTC | #864272

Peter Grant's Avatar Comment 30 by Peter Grant

Comment 28 by Alan4discussion

I think they are saying that these are two different branches from a common ancestor

So perhaps these metatherians gave birth to live but still rather immature offspring and had to raise them without the benefit of a pouch. Shouldn't have been a problem for very small mammals, but the larger ones would have been under increased pressure to find a better solution. Marsupials evolved one and eutherians another.

Thu, 25 Aug 2011 22:45:03 UTC | #864292