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She's studying. He's Playing

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She's studying. He's Playing

Postby M. Henri Day » Sat Jun 18, 2005 12:27 pm

Slowly, it is beginning to dawn upon me why we, with such determination, kept women from higher education, etc for so long - afraid of the competition !...

Henri

June 14, 2005

She's Studying. He's Playing.

By
JOHN SCHWARTZ

Little girls watch and learn; little boys goof off and horse around.

At least this seems to be the case with chimpanzees, according to new research.

Chimpanzees like to snack on termites, and youngsters learn to fish for them by poking long leaf spines and other such tools into the mounds that colonies build.

In a paper to be published in the journal Animal Behavior, researchers found that female chimps in the Gombe National Park in Tanzania picked up termite fishing at a mean age of 31 months, more than two years earlier than the males.

The females seem to learn by watching their mothers, said the paper's author, Dr. Elizabeth V. Lonsdorf, director of field conservation at the Lincoln Park Zoo in Chicago.

Dr. Lonsdorf said that typically, when a young male and female are near a mound, "she's really intently termite fishing, and he's spinning himself in circles."

The paper is based on four years of observation and expands on work published last year in the journal Nature.

Dr. Lonsdorf and colleagues are now studying chimpanzees at the zoo with a new, simulated termite mound - or mustard mound, since it is filled with condiments.

Why not termites?

"Our pest-control people would not like that very much," she said.

By the first day, adult females were getting at the mustard and a young female watched carefully and began to pick up the skills, she said. Two young males did not fare as well - one simply sat next to his mother and tried to steal some mustard from her, Dr. Lonsdorf said.

The behavior of both sexes may seem familiar to many parents, she said, adding, "The sex differences we found in the chimps mimic some of the findings from the human child development literature."

She pointed out, however, that at least in the case of chimps, each is doing something important, since the males' play is practice for later dominance behavior.

"They're doing stuff that's really appropriate," she said.

Copyright 2005 The New York Times Company
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Postby KatyBr » Sat Jun 18, 2005 4:40 pm

and how is this different from Homo sap. behavior, he struts while she works.


I saw an interesting documentary once. As a young woman underwent a testosterone injection series-preparory to a sex change, she/ becoming he, was tested each week; her/his intellectual skills became weaker. He got dumber as the testoserone took effect. coincidence? I think not.... (TIC, oc)


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Postby M. Henri Day » Sat Jun 18, 2005 5:11 pm

My point exactly, Katy ! Who says observations of or experiments on (other) animals can't tell us important things about H sap sap ?...

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Postby tcward » Sat Jun 18, 2005 8:53 pm

Well, Happy Fathers Day, anyway, to all you dads and men who are important in the life of some little one...

-Tim
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Postby Apoclima » Sun Jun 19, 2005 7:27 pm

Yes, Happy Father's Day to all the fathers out there!

Henri:
Who says observations of or experiments on (other) animals can't tell us important things about H sap sap ?...


Even from an evolutionary perspective, one cannot generalize one behavior to all "closely related species." One can never be sure that some "adaptive" behavior isn't obscuring a profound difference.

For example, if we studied the vocalizations of human infants, would we want to generalize that behavior to all apes!

"The sex differences we found in the chimps mimic some of the findings from the human child development literature."


What I find irritating about this quote is the idea that something profound and revealing is exposed here. "...mimic some findings.."

The females seem to learn by watching their mothers,


That's just it! Where are the male adults in this study?

We all know that young males without a father or father-figure in their lives (or even one that is aloof or distant) can cause serious developemental problems for a young male. Were these young males ever allowed to see an adult male fishing for termites? Is fishing for termites basically a female activity, like knitting or crochet?

If anything this study shows the attention and discipline problems that young males run into without a male role model.

In conclusion, if we are to take this study seriously, we have to accept the basic difference in learning stages between young females and young males and revamp our ideas about their education, and instead of trying to make little males into effeminized modelers of female behavior patterns. Set them free to learn in their own way, which is apparently, play!

Also, as a passing observation, if little females learn by closely watching their mothers' behavior, then who would have discovered the technique of termite fishing? You got it! It was probably a young male out there just fooling around!

Apo
'Experiments are the only means of knowledge at our disposal. The rest is poetry, imagination.' -Max Planck
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Postby Brazilian dude » Sun Jun 19, 2005 10:33 pm

We all know that young males without a father or father-figure in their lives (or even one that is aloof or distant) can cause serious developemental problems for a young male.

I was raised without a father. Does this explain why I'm like this?

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Postby Apoclima » Mon Jun 20, 2005 12:33 am

Humans are very adaptive, and I am sure that you had some males role models around.

None of us come from a perfectly ideal situation.

Do I think that you (or anyone) does better with a father?

I think that that depends a whole lot on their father and their mother. Some fathers and mothers do a whole lot of damage to their kids.

Benefits of Active Fathering

As they grow, children who have highly involved fathers often do better in some areas of development than children who have less involved fathers. They tend to become better at solving problems and handling frustrations, more socially skilled, more understanding of other’s feelings, and better at dealing with a variety of people. Active fathering also contributes to a child’s sense of humor, attention span, and eagerness to explore and learn.


Do Dads Really Make A Difference?

I would be very proud of the way your mother raised you. I think it may have been easier, if she had a good man to help her, but she should be double proud of you!

I have seen it in many families that when a boy gets to be a teenager, the discipline and authority a mother can provide is not "psychologically enough." I think this often results in a need for a masculine authority, and in the cases where fathers, coaches, pastors and relatives are not enough, youths will often turn to crime, finding gang members and policemen as their (hyper)masculine authority figures, often with not so beneficial an outcome.

It seems to me that you turned out great, BD!

Anyway, I was just making fun of the simplistic idea of studying Apes to study Humans.

Apo
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Postby KatyBr » Mon Jun 20, 2005 2:08 am

BD, young women need a father-figure too, I used to wonder why we even Had a Father's day.

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Postby M. Henri Day » Mon Jun 20, 2005 2:41 am

Alas, it would seem that simple minds are often attracted by simplistic ideas ! But, simple as I am, I do believe that valuable insights on human behaviour can be gained by studying animal models. The point is to avoid the simplistic transfer of behavioural observations from one species to another - the fact that certain types of behaviour are prevalent among P trogolodytes does not, of course, imply that they are necessarily so among a closely related species like H sap sap. But the insights gained in studying the former can be used to inform studies of the latter - thus the fact that chimp fathers are relatively absent in the rearing of their young, both male and female, which leads to a chimp social order very distinct from not only that which obtains among us, but also that obtaining among P paniscus - can help us to create testable hypotheses concerning the consequences of the experiments on social order that we constantly perform on ourselves. But perhaps the distinction between the two approaches is only apparent to simple minds ?...

Henri
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Postby Apoclima » Mon Jun 20, 2005 2:58 am

Are we ever really able to be objective when it comes to studying ourselves?

And, are we able to be objective when we compare and contrast ourselves with other animals?

What exactly have we learned about Humans from this study?

Certainly this study does not say anything about Humans on its own, but only because it "mimics some findings" in human studies.

I find that wording rather odd, by the way. Studies don't mimic each other. Does she mean that she is "aping" child development studies?

I guess we should all grasp intuitively the importance of this study in revealing the true natures of the human sexes.

And how on Earth is a study of animals and their manipulation in such experiments tell us anything about how humans will act or react to social experiments?

Well, at least they are having fun!

Yes, I'm being cynical on this point, not skeptical!

Apo
Last edited by Apoclima on Mon Jun 20, 2005 6:37 pm, edited 1 time in total.
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Postby M. Henri Day » Mon Jun 20, 2005 6:33 am

Apoclima wrote:...

Well, at least they are having fun!

Yes, I'm being cynical on this point, not skeptical!


Apo, I suspect that you, like myself, are also having a bit of fun. Keep up the good work !...

Henri
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Postby Brazilian dude » Mon Jun 20, 2005 9:55 am

It seems to me that you turned out great, BD!

You should see me when I wake up in the morning.

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Postby M. Henri Day » Tue Jun 21, 2005 7:28 am

I reproduce the article below, not merely because of its intrinsic interest, which I find considerable, but also as a backdrop to a query to those who, like Apo, find the «idea of studying Apes to study Humans» simplistic : do you believe the study of other species in order to shed light on our own simplistic not only when the behaviour is the object of study, but also when it is the body (morphology, genetics, etc) ? Do you regard the statement in the article to the effect that «[t]he findings have also attracted scientists to cnidarians as a model to understand the human body» as a priori absurd ; i e, that nothing useful can be learned about the workings of the human body through analysis of animal models ? This by the way, is intended as a real, i e, not a rhetorical question....

Henri

June 21, 2005

Plain, Simple, Primitive? Not the Jellyfish

By
CARL ZIMMER

Jellyfish have traditionally been considered simple and primitive. When you gaze at one in an aquarium tank, it is not hard to see why.

Like its relatives the sea anemone and coral, the jellyfish looks like a no-frills animal. It has no head, no back or front, no left or right sides, no legs or fins. It has no heart. Its gut is a blind pouch rather than a tube, so its mouth must serve as its anus. Instead of a brain, it has a diffuse net of nerves.

A fish or a shrimp may move quickly in a determined swim; a jellyfish pulses lazily along.

But new research has made scientists realize that they have underestimated the jellyfish and its relatives - known collectively as cnidarians (pronounced nih-DEHR-ee-uns). Beneath their seemingly simple exterior lies a remarkably sophisticated collection of genes, including many that give rise to humans' complex anatomy.

These discoveries have inspired new theories about how animals evolved 600 million years ago. The findings have also attracted scientists to cnidarians as a model to understand the human body.

"The big surprise is that cnidarians are much more complex genetically than anyone would have guessed," said Dr. Kevin J. Peterson, a biologist at Dartmouth. "This data have made a lot of people step back and realize that a lot of what they had thought about cnidarians was all wrong."

Renaissance scholars considered them plants. Eighteenth-century naturalists grudgingly granted them admittance into the animal kingdom, but only just. They classified cnidarians as "zoophytes," somewhere between animal and plant.

It was not until the 19th century that naturalists began to understand how cnidarians developed from fertilized eggs, their body parts growing from two primordial layers of tissue, the endoderm and ectoderm.

Other animals, including humans and insects, have a third layer of embryonic tissue, the mesoderm, wedged between the ectoderm and the endoderm. It gives rise to muscles, the heart and other organs not found in cnidarians.

Cnidarians also have a simpler overall body plan. Fish, fruit flies and earthworms all have heads and tails, backs and fronts, and left and right sides. Scientists refer to animals, including humans, with this two-sided symmetry as bilaterians. In contrast, cnidarians seem to lack such symmetry completely. A jellyfish, for example, has the symmetry of a bicycle wheel, radiating from a central axis.

Evolutionary biologists came to view cnidarians as relics from the early days of animal evolution. The first animals were probably spongelike, little more than clumps of cooperative cells. Cnidarians seemed to represent the next stage, having acquired traits like simple tissues and nerves.

The fossil records of animals seemed to back up that hypothesis. Many of the earliest animal fossils resembled jellyfish or other cnidarians. The oldest known bilaterian fossils were younger, appearing in the so-called Cambrian explosion, 540 million years ago.

Some researchers suggested that the bilaterian body plan helped set off the Cambrian explosion. Unlike their ancestors, bilaterians had heads, allowing them to sense their surroundings and control a swimming, or crawling, body.

Recent research undermines that theory. The oldest fossils that can be confidently called cnidarians are just 540 million years old. And Dr. Peterson and his colleagues have made new estimates of the age of cnidarians by studying their DNA.

The DNA mutates at a roughly regular rate over millions of years, a so-called molecular clock. Dr. Peterson estimates that the common ancestor of living cnidarians lived 543 million years ago. In other words, cnidarians did not appear tens of millions of years before bilaterians.

Genetic studies have also challenged conventional theories about cnidarians. Beginning in the 1980's, scientists studying bilaterians uncovered a set of genes that laid out their body plan. Some of the genes established the head-to-tail axis, others distinguished the front from the back.

Humans and insects may look very different, but they share almost identical versions of this genetic tool kit. And the findings suggested that the tool kit had already evolved in the common ancestor of bilaterians.

Dr. Mark E. Martindale of the University of Hawaii and his colleagues decided to look for the genes that build jellyfish and other cnidarians. It took a long time to begin generating results. The team had to find a species that could not only survive life in the laboratory but could produce enough embryos for research.

Dr. Martindale's group chose the starlet sea anemone, a species found along the New England coast. Figuring out how to culture the anemone and investigate its genes demanded great patience. "It's taken 9 or 10 years," Dr. Martindale said, "but it's turned into a gold mine."

Much to their surprise, the scientists found that some genes switched on in embryos were nearly identical to the genes that determined the head-to-tail axis of bilaterians, including humans. More surprisingly, the genes switched on in the same head-to-tail pattern as in bilaterians.

Further studies showed that cnidarians used other genes from the bilaterian tool kit. The same genes that patterned the front and back of the bilaterian embryo, for example, were produced on opposite sides of the anemone embryo.

The findings have these scientists wondering why cnidarians use such a complex set of body-building genes when their bodies end up looking so simple. They have concluded that cnidarians may be more complicated than they appear, particularly in their nervous systems.

"At the molecular level, they have a lot of body regions that aren't recognizable," said Dr. John R. Finnerty, a biologist at Boston University who is collaborating with Dr. Martindale.

Dr. Finnerty expects that the nervous system of cnidarians will turn out to be particularly complex. "The nervous system of a cnidarian is described as a nerve net, but that's a textbook simplification," he said.

He predicts that research will show that this net is divided into specialized regions like the human brain.

These discoveries have prompted Dr. Peterson to reconsider cnidarians' place in the history of life. "It's changed my thinking about early animal evolution," he said.

He now theorizes that cnidarians were not the simple forerunners of the Cambrian explosion, but very much part of it, their evolution driven by the rise of animal food webs.

In a paper to be published in the journal Paleobiology, Dr. Peterson and his colleagues propose that the common ancestor of bilaterians and cnidarians is a crawling worm. This ancient worm, which Dr. Peterson estimates lived 600 million years ago, represented a major advance in animal evolution. Instead of passively filtering tiny bits of food, it was able to graze on larger prey.

"Once they're able to start grazing through those microbial mats, there's nothing to stop them," Dr. Peterson said.

Some of these animals eventually began to eat one another. Animals that could defend themselves were more likely to survive. One way to avoid being eaten was to become bigger. Another way was to loft eggs into the water column rather than leave them to be eaten on the sea floor. Some animals even began to swim as adults in the open water.

Once the water began to fill with animals, cnidarians took on their current form. The earliest cnidarians anchored themselves to the sea floor and grew upward, as sea anemones and corals do today. In the process, they abandoned the bilaterian body plan of their ancestors.

It was also at that time that cnidarians evolved their distinctive weaponry: a cell containing a miniature harpoon called a nematocyte, for paralyzing prey with toxins.

As new lineages of animals moved even higher into the water column, some cnidarians evolved to hunt them as well. Jellyfish are the product of this final stage of evolution, Dr. Peterson argues.

These new insights into cnidarians have prompted major initiatives to understand them better. The starlet sea anemone genome is being sequenced by the Energy Department's Joint Genome Institute, and is expected to be complete this year.

Scientists expect a number of surprises from the genome project. They have already discovered that a number of genes once thought to be unique to vertebrates have turned up in the genomes of cnidarians. It is now clear that these genes did not, in fact, arise in early vertebrates.

They are much older, having evolved in the common ancestor of cnidarians and bilaterians 600 million years ago. Later, they disappeared in branches of bilaterians like insects and nematodes that have been the focus of extensive genome research.

In some ways, cnidarians are a better model for human biology than fruit flies. As strange as it may seem, gazing at a jellyfish in an aquarium is a lot like looking in the mirror.

Copyright 2005 The New York Times Company
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Postby Brazilian dude » Tue Jun 21, 2005 9:45 am

do you believe the study of other species in order to shed light on our own simplistic not only when the behaviour is the object of study, but also when it is the body (morphology, genetics, etc)

There's some word missing here, isn't there? I really don't get it.

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Postby Brazilian dude » Tue Jun 21, 2005 9:47 am

cnidarians (pronounced nih-DEHR-ee-uns).

What if I say nih-DAIR-ee-uns?

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