Darwin re-visited

[Michaelangelica]

Maybe I can fly !

Ananova - Cat grows wings

[Michaelangelica]

I relly enjoyed reading this fascinating article on solar powered sea slugs;) and other animals (?) in the ocean that blur the species line.

Solar Powered Sea Slugs - June - Scribbly Gum - ABC Science Online

Then right at the end it had this

And the dabbling with biological conventions doesn’t end there.

 

Recently, US researchers discovered that for chloroplasts to function, they require instructions from the plant cell nucleus – the chloroplast’s own DNA is not enough.

This raised the question of how they continue to thrive onboard sea slugs in the absence of their parent plant.

The researchers found that in a complex process, some sacoglossans actually absorb the plant DNA into their own cell nucleii then pass the transgenic information on to future generations, which presumably continue adding to the mix.

So how is this decided?

Who pulls the levers?

Not exactly natural selection.

Just selection.

Aint nature Grand?

[Michaelangelica]

Science Daily — Why are there no unicorns?

The problem highlights a general issue in evolutionary biology of what determines the range of plants and animals we see compared to those that might have evolved theoretically.

So it looks like the way genes control development plays an important role in determining what sorts of structure evolve. But the researchers also showed that selection plays a key part in setting the routes that evolution may take within the space of possibilities.

They revealed novel paths, called evolutionary wormholes that link together different inflorescence types, allowing one to evolve into another. Perhaps there are no Unicorns because no evolutionary wormholes exist that connect them to horses, or maybe the wormholes are there but evolution has not had time to go down them.

 

ScienceDaily: Why Are There No Unicorns?

 

Mother Birds 'Engineer' Their Offspring

 

Science Daily — Current research emphasizes the role of maternal effects in fostering the adaptation of organisms to a changing environment. In birds, mothers pass androgens to their eggs, and these hormones have been shown to influence the development and behavior of nestlings. Since these effects may persist in adulthood, it has been suggested that avian mothers may engineer, so to speak, the adult phenotype of their offspring.

. . .

These data provide evidence that facultative maternal effects at the individual level are linked to evolutionary transitions between species, suggesting a role of phenotypic plasticity in supporting adaptative patterns.

ScienceDaily: Mother Birds 'Engineer' Their Offspring

 

'Cultured' Chimpanzees Pass On Novel Traditions

 

Science Daily — The local customs that define human cultures in important ways also exist in the ape world, suggests a study reported online June 7th in Current Biology, a Cell Press publication. Indeed, captive chimpanzees, like people, can readily acquire new traditions, and those newly instituted "cultural practices" can spread to other troops.

A chimp family in a tree. (Credit: iStockphoto/Gary Wales)

 

"We have robust evidence that in chimpanzees there is a considerable capacity for cultural spread of innovations," said Dr. Andrew Whiten of the University of St. Andrews in Scotland. "This strengthens the interpretation of cases of behavioral diversity in the wild as socially transmitted traditions

. . .

The findings have important implications for understanding the ability of primates to adapt over time.

 

"Social learning is important for evolutionary adaptation because it can be so much faster than that which occurs through genetic change; and, unlike learning by one's own efforts--for example, by trial and error--it can be very efficient because one is standing on the shoulders of what previous generations achieved," Whiten said.

This might have a lot of legal and jurisprudential implications.

Brain Chemistry Linked To Aggressive Personality

“Our study provides evidence of an association between brain MAO A level and aggressive personality traits in normal individuals,”

ScienceDaily: Brain Chemistry Linked To Aggressive Personality

[bongo]

I relly enjoyed reading this fascinating article on solar powered sea slugs:cocktail: and other animals (?) in the ocean that blur the species line.

Solar Powered Sea Slugs - June - Scribbly Gum - ABC Science Online

Then right at the end it had this

 

So how is this decided?

Who pulls the levers?

Not exactly natural selection.

Just selection.

Aint nature Grand?

 

 

 

Well said!

[Michaelangelica]

Well said!

thankyou,

but aren't we always trying to poke things into little boxes/categories and nature often refuses to co-operate (EG the flora and fauna living in high temp. sulphuris vents on the sea floor-They shouldn't exist)

 

Natural selection was obviously part of the process here but only part of the story.

WASHINGTON (Reuters) - A battle won by human ancestors against a virus that infected chimpanzees and other primates millions of years ago may have left people today more vulnerable to the AIDS virus, scientists said on Thursday.

. . .

They focused on an ancient virus, known as Pan troglodytes endogenous retrovirus, or PtERV1, to find clues as to why HIV has exacted such a high toll on humanity.

 

"Events that happened millions of years ago have shaped human evolution, in particular susceptibility to modern human infectious diseases," Michael Emerman of the Fred Hutchinson Cancer Research Center in Seattle, Washington, who led the study, said in a telephone interview.

. . .

 

Retroviruses have been infiltrating the genomes of human ancestors and other animals for millions of years. These viruses go into the chromosomes and DNA of the cells they infect and can get passed on from generation to generation.

 

In fact, such vestiges of primitive infections comprise 8 percent of the human genome, Emerman said.

Ancient viral battle left people vulnerable to HIV - Yahoo! News

 

Who need "Natural" selection anymore?

Modified mushrooms may yield human drugs

Mushrooms might serve as biofactories for the production of various beneficial human drugs, according to plant pathologists who have inserted new genes into mushrooms.

 

The researchers then snipped small pieces off the mushroom's gill tissue and added it to a flask containing the altered bacterium.

 

Over the course of several days, as the bacterium goes through its lifecycle, it transfers a portion of its plasmid out of its cell right into the mushroom cell, and integrates the introduced gene into the chromosome of the mushroom.

Modified mushrooms may yield human drugs

[NLN]

Question: how do you know that those with the best immune systems are most vulnerable to the bird flu virus? Please provide a source for this information.

[Michaelangelica]

Question: how do you know that those with the best immune systems are most vulnerable to the bird flu virus? Please provide a source for this information.

Google "cytokine storm, bird flu, influenza, immune system, disease reaction"

or combinations and permutations of these words

and also

the history of the last big bird flu pandemic in 1918-

[NLN]

In order to be taken seriously, you'll need to be more specific than that. References should follow the following format, stating the source, date, and page(s) referenced:

 

[1] J. S. Albus. Outline for a theory of intelligence. IEEE Trans. Systems, Man and Cybernetics, 21(3):473–509, 1991."

 

To see an example, take a look at this typical research paper.

[Michaelangelica]

In order to be taken seriously, you'll need to be more specific than that. References should follow the following format, stating the source, date, and page(s) referenced:

 

[1] J. S. Albus. Outline for a theory of intelligence. IEEE Trans. Systems, Man and Cybernetics, 21(3):473–509, 1991."

 

To see an example, take a look at this typical research paper.

 

Please go away and teach your grandmother to suck eggs.

[NLN]

I'm not necessarily disagreeing with you, Michaelangelica, I'm simply attempting to remind others that the burden of proof rests upon the party making claims. The internet is full of unsupported opinions dressed up as "facts," and we should all make every effort to assure that what we are passing along is the truth. Digging up references in support of our claims is the only defense against the possibility of spreading misinformation.

[Michaelangelica]

YES NLN, the way of "science" ?!

 

Mitey haploids aren't hapless after all

 

Friday, 29 June 2001

 

False spider mites: Diploids don't rule

A truly bizarre species of tiny spider-like creatures that consists entirely of females, has no need for sex and is biologically-speaking "a sandwich short of a picnic" is turning on its head conventional scientific wisdom.

 

Not only do the adults undergo "virgin birth" , but the only time baby boys are produced is when the mother is treated with antibiotics.

 

The false spider mite Brevipalpus phoenicis is the only animal known to exist entirely in the "haploid" state - with only half the full complement of chromosomes, according to a report in today's Science.

News in Science - Mitey haploids aren't hapless after all - 29/06/2001

[Michaelangelica]

Suddenly the old rules of genetics are looking out of date. Instead of being just a vehicle for DNA's commands, as scientists have long held, RNA seems to issue its own commands and alter what genes do in the next generation. "This phenomenon of the white-tailed mouse is just the tip of the iceberg," says Martienssen. And the environmental effects that alter one organism's RNA can apparently be passed down to its descendants almost indefinitely. In another landmark study this year, researchers working with nematode worms tracked a trait initiated with injected RNA over 80 generations. Nobody knows how RNA causes these long-lasting effects. One possibility is that it changes the way DNA is packaged in the cell, thereby permanently shutting down sections of the genome.

 

The implications are powerful. In September Michael Skinner of Washington State University announced that his lab rats inherit, epigenetically, their parents' propensity for a variety of humanlike diseases, including breast cancer, kidney disease, and high cholesterol. His results suggest that a parent's exposure to toxins—or simply bad diet—could harm her children for generations to come; the findings also hint that many seemingly genetic disorders could be treated in ways never before considered. "This opens up a whole new area for medical research and may be a way to combat disease," Skinner says.

 

The nascent field of epigenetic medicine is farthest along with respect to cancer: "Modifications of the genes that cause cancer are much more common than genetic mutations are," says Martienssen. That's good news, as epigenetic modifications—unlike mutations—are in principle reversible.

The Top 6 Genetics Stories of 2006 | Living World | DISCOVER Magazine

Morphic resonance would dictate that any acquired characteristic, whether a behavior or a shape, can be inherited. Acquired-characteristic inheritance is known as Lamarckism, after French biologist Jean-Baptiste de Monet de Lamarck, who proposed the idea in 1809, and is today almost universally rejected in favor of evolution by natural selection of random genetic mutations. Bucking this trend, Sheldrake fills much of his 1988 book The Presence of the Past with experimental evidence for acquired-characteristic inheritance. One example: In 1923, Russian physiologist Ivan Pavlov trained mice to run to a feeding place when an electric bell was rung. The first generation required an average of 300 trials to learn, the second 100, the third 30, and the fourth 10. Pavlov was stumped when a new, unrelated strain of mice did not display the same learning increments, but to Sheldrake, that outcome makes perfect sense.

Heresy | Living World | DISCOVER Magazine

12.11.2006

How Good Genes Go Bad

More ways to mess up your kids.

by Jessica Ruvinsky

 

Environmental toxins can affect gene

expression—for better or for worse.

 

A study in rats suggests that exposure to environmental toxins could be contributing to an inherited vulnerability to common diseases like breast cancer and high cholesterol.

 

Washington State University molecular biologist Michael Skinner had previously shown that sperm abnormalities induced by vinclozolin, a toxic fungicide used on wine grapes, strawberries, and other fruits, can pass from father to son for four generations in rats.

In a new study, he has found that the rats' offspring were inheriting more than just testis troubles.

They also had up to 10 times higher rates of breast cancer, prostate and kidney disease, high cholesterol, and immune abnormalities.

 

The rats, Skinner says, aren't inheriting bad genes so much as their recent ancestors' toxin exposure. In this type of novel inheritance, called epigenetic, changes don't occur in a DNA sequence as they do in a mutation.

Instead, the changes happen to certain chemical markers on the DNA that control how much any particular gene is expressed.

Previous studies in lab rats have shown that this type of nongenetic inheritance can influence traits like fur color and obesity.

Skinner's work shows it could also be crucial for understanding how our parents pass along vulnerability to a wide range of diseases.

How Good Genes Go Bad | Health & Medicine | DISCOVER Magazine

 

To the surprise of scientists, many environmentally induced changes turn out to be heritable. When exposed to predators, Daphnia water fleas grow defensive spines ( above). The effect can last for several generations.

DNA Is Not Destiny | Living World | DISCOVER Magazine

Such results hint at a seemingly anti-Darwinian aspect of heredity. Through epigenetic alterations, our genomes retain something like a memory of the environmental signals received during the lifetimes of our parents, grandparents, great-grandparents, and perhaps even more distant ancestors. So far, the definitive studies have involved only rodents. But researchers are turning up evidence suggesting that epigenetic inheritance may be at work in humans as well.

. . .

The studies by Pembrey and other epigenetics researchers suggest that our diet, behavior, and environmental surroundings today could have a far greater impact than imagined on the health of our distant descendants. "Our study has shown a new area of research that could potentially make a major contribution to public health and have a big impact on the way we view our responsibilities toward future generations," Pembrey says.

. . .

"If you have a generation of poor people who suffer from bad nutrition, it may take two or three generations for that population to recover from that hardship and reach its full potential," Harper says. "Because of epigenetic inheritance, it may take several generations to turn around the impact of poverty or war or dislocation on a population."

DNA Is Not Destiny | Living World | DISCOVER Magazine

The sins of the fathers. . .?

[NLN]

Physicist Mano Singham is currently writing a great series on evolution. Here is his latest entry.

[Michaelangelica]

Did Mendal think of this?

The world is stranger than you think (and evolution could be a LOT quicker.)

The Frog Killing Fungus

The frog killing chytrid fungus, Batrachochytrium dendrobatidis, infects the skin of susceptible amphibians and rapidly kills them. Not identified until 1998, the waterborne pathogen has already been fingered in the extinction of more than 150 species.. . .

./ . .

reveals that the chytrid fungus is reproducing sexually - rather than asexually by cloning itself as had been assumed by experts.

 

The find is significant as it means the fungus is a hardy more persistent species that can survive outside its host and evolve more rapidly than asexual fungi through shuffling its genes.

. ..

"Persistence of the fungus would complicate efforts to reintroduce amphibians" to sites where the fungus had eradicated them

Shuffle anyone?:):hihi:

Origin of frog-killing fungus probed | COSMOS magazine

[maikeru]

YES NLN, the way of "science" ?!

 

 

News in Science - Mitey haploids aren't hapless after all - 29/06/2001

 

I think they can get away with it because of numbers.

 

Look at it this way. Even though being diploid allows you to cover bad mutations, being haploid allows you to expose bad ones, so long as you the species can pay the price (death, disability, or disadvantages incurred) and maintain a large enough population to keep the species going. In fact, exposing bad mutations and weeding out those individuals could help boost the health and variation in a population. Mites are great at this, multiplying to thousands, millions, or billions. Any individuals who would have deleterious mutations would die or forced out through other natural selective pressures. Producing large numbers of offspring also increases the genetic variation in a population gradually simply because there are more individuals out there with mutations creating different copies of genes.

[Freddy]

Did anyone see Meave Leakey's new discovery in Africa concerning human evolution?

 

"A new discovery suggests that Homo erectus may not have evolved from Homo habilis—and that the two may have been contemporaries."

 

A New Discovery in Human Evolution - Newsweek Technology - MSNBC.com

[Michaelangelica]

"A new discovery suggests that Homo erectus may not have evolved from Homo habilis—and that the two may have been contemporaries."

 

]

I have now thanks

That's causing quite a stir eg

BBC NEWS | Science/Nature | Finds test human origins theory

If Homo erectus had evolved from habilis and stayed within the same location ... the small size of the erectus skull suggests that species may not have been ...

news.bbc.co.uk/1/hi/sci/tech/6937476.stm - 40k - Cached - Similar pages -

 

 

Homo erectus and Homo habilis may have co-existed ... discovery of two fossils in Kenya challenges the belief that Homo erectus evolved from Homo habilis. ...

Homo habilis and Homo erectus may have co-existed - 61k

 

Homo habilis & Homo erectus, first stone tool users

Homo habilis is then not necessarily a direct ancestor of H. erectus . as the ... Java lineage ( Homo erectus erectus ) appears to have evolved into the ...

New Fossils Illustrate "Bushiness" of Human Evolution: Scientific ...

Fossils support the separate evolution of Homo habilis and Homo erectus, ... have often assumed that H. habilis evolved into the larger H. erectus, ...

New Fossils Illustrate "Bushiness" of Human Evolution: Scientific American