Darwin re-visited

[Michaelangelica]

Originally Posted by Buffy

Nothing supports Lamarck.
. . .
is environmental stresses causing *random* switches in junk dna, that cause it to be expressed.

Yep I guess so. Pity, it would be a great new way of evolving.

Was Charlie Chaplin's sperm the same at 80 as at 20? do you think?

I was interested in your comments about Societal influences on evolution in another thread. What are your thoughts on this?
Can society influence evolution?

Environmental influences on the fetus we know about ( Hungerwinter & obesity research, iron/nutritional status, drugs etc).
( My mum always said I liked classical music because she played it to me when she was carrying me. Interestingly, though I find it nice to listen to and soothing, but that is about all. I can't stand modern rock and castrated male singers and electric guitars -party next door last night and he has a rock band. What sort of ears are they evolving? I would like the inventor of the amplifier to die a slow, horrible death.)

Family genetics and mutations aside
What happens before conception?
OK if you are male you shouldn't go near too many atomic bombs.
But what about more subtle environmental influence on the egg and sperm before conception?
Where did the rare ability to digest wheat and lactose come from?
How come Tibetans can get more oxygen out of the air than we can?
How does this happen?

I once worked in a Psychiatric ward (40 years ago) with genetically "different" children. Some of the kids were monkey like. I was very young and I found it all a bit shocking and hard to take and felt there was little that could be done to help them develop.
These days they probably would not make it to the birth canal.
"Viable" (most kids had to have continual care) genetic mutations probably happen a lot more than we get to know about

stresses causing spurts of rapid evolution has been around for 30 years.

It is interesting the animals and bacteria that have not evolved at all; Stromatolites in Shark Bay WA, and crocodiles for example.
Shark bay is a Jules Verne 'lost world" of species:-
World Heritage: Shark Bay
Shark Bay - Pilbara
Three billion years is long time to go between chromosome breaks.

Unfortunately, I believe that bats and flying squirells developed in a different branch of the Mammal tree, so I kind of doubt it, but you can always hope!

Hey! What about angels (like Michael, the Top Angel). Don't you read your bible?

Save the cheerleader,
Buffy

LOL
tar
m

[Buffy]

Originally Posted by Michaelangelica

Yep I guess so. Pity, it would be a great new way of evolving.

Sure would, there's just no mechanism that could make it happen. Think about it: why would a behavior like exercise be able to communicate back to the dna in the reproductive system to the exact sequence that had to do with muscle development that it should change *specifically* to enhance muscle development? How would it know? That's a *really* complex operation!

Originally Posted by Michaelangelica

Was Charlie Chaplin's sperm the same at 80 as at 20? do you think?

Any particular sperm cell is subject to mutation at any time, including those that they are split from, so the answer is "probably."

Originally Posted by Michaelangelica

I was interested in your comments about Societal influences on evolution in another thread. What are your thoughts on this? Can society influence evolution?

There are a couple of ways of looking at this. At the individual level, there are many changes in society that dictate the definition of "advantage:" in a society that is rapidly shifting from labor to technology, intelligence becomes more advantageous.

What I find much more facinating is the whole notion that you can take "society"--and there's a good argument for talking about political or social groupings here--to be considered as an "organism" that "reproduces" (generations), and evolves (social rules and organizational behavior). Boerseun started a thread on this a while ago, but I can't find it right now. The comparison is more than a little bit inexact, and in fact can apply to all socially-dependent species including not only primates, but other mammals and even bees.

Originally Posted by Michaelangelica

Family genetics and mutations aside
What happens before conception? OK if you are male you shouldn't go near too many atomic bombs. But what about more subtle environmental influence on the egg and sperm before conception?

Subtle is as subtle does. A mutation is a mutation. Its *location* is what is critical.

Cells have their own built-in mechanism for zapping "bad" mutations: its actually quite hard for mutations to survive. I've said elsewhere that if you think about DNA as being a computer program, the mutation could be in some single statement that causes the program to stop working completely (a bad mutation), but if you think about how computer programs are made modular, and through the use of many layers of abstraction, a mutation made at a very high level would switch from one complex "subroutine" to another similar "subroutine" elsewhere (probably among the vast number of similar copies of sequences that we see in junk DNA: remember, junk DNA is not just random junk, its copies of sequences that are active elsewhere, its just in a location where its *not used*.

Originally Posted by Michaelangelica

Where did the rare ability to digest wheat and lactose come from?

Milk contains fat. Fat is a really good place to get nourishment. Milk is readily available from cows and goats, and if you're hungry, it works, even if it makes you feel horrible. Throw in an environmental shock that makes fruits and vegies scarce while those cows are getting fat and happy on the grasses you can't eat and its going to be a *tremendous* advantage if your genes let you keep that lactose down...

Originally Posted by Michaelangelica

How come Tibetans can get more oxygen out of the air than we can?

Don't you think that most folks with athsma born in Tibet would die at a young age? Getting by with little air is an advantage. Those that have problems with it die or *move*.

Originally Posted by Michaelangelica

It is interesting the animals and bacteria that have not evolved at all; Stromatolites in Shark Bay WA, and crocodiles for example. Three billion years is long time to go between chromosome breaks.

As I mentioned above, its really hard to become a mutation: the DNA has built in mechanisms to get rid of it.

More importantly, as Stephen Jay Gould points out in many of his books, people wrongly think of evolution as a stair step progression when its not. Its just a whole lot of branches. The shark tree has had many of them, but there has never been an environmental shock that makes the *original* (oldest) branch *disadvantageous*, so there's no reason for that branch to go away!

Evolutionarily,
Buffy

[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]

[B]Science Daily — Why are there no unicorns?[B]
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]

Originally Posted by 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

So how is this decided?
Who pulls the levers?
Not exactly natural selection.
Just selection.
Aint nature Grand?

Well said!

[Michaelangelica]

Originally Posted by bongo

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]

Originally Posted by 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.

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.