Darwin re-visited

[HydrogenBond]

I thinking of this the other day and wondered if it enters into evolution. The formation of sperm cells randomly divides the genetic material of the male into roughly halves so each sperm cells get 1/2 DNA.

 

If we go back one generation, the son's DNA is half from his dad and half from his mother. Based on a random split, does that mean that some of this sperm might contain only his father's genes, while the other sperm cell from this same cell division contain only his mother's genes? Random would also imply some sperm can be x% male from the previous generation with the other half from that cell, X% female. We call it all male DNA for that generation, but if we use two generations do some male sperm contain female DNA from the previous generation. It is not clear cut who is giving the male and female genes if we go back many generations.

 

Relative to speciation, this random split suggests a way to concentrate affects into certain sperm and ova. It doesn't have to be 50/50 but can be 100/0 (accumulative genes). If we get two 100/0's from the mother and father, the amount of new genes in the offspring would showed amplified affects. It may not occur often, but would cause a species split without mutations in that generation. It could have been from mutations many generations before, concentrating in a much later generation.

[Moontanman]

Fish migrate too.

Older, bigger fish teach younger fish in schools

When we eat the big fish, the little fish get lost :)

---------------------------------------------------------------------------

 

 

Check out this link on fish size and harvesting small instead of large fish.

 

Want Sustainable Fishing? Keep Only Small Fish, And Let The Big Ones Go

[Michaelangelica]

I can't follow you train of thought HB

[Michaelangelica]

Check out this link on fish size and harvesting small instead of large fish.

 

Want Sustainable Fishing? Keep Only Small Fish, And Let The Big Ones Go

Interesting article thanks. I think all this needs alot more research. Each species/variety/ kind may be different. certainly those that "migrate" from one food source to another may be at risk if the older fish are taken

See also thread "So long and thanks for all the fish"

 

Anyone got an answer to my question?

Does anyone know if mitochondrial DNA is the same in maternal-(monozygotic) twins

I might post is separately

[Symbology]

I thinking of this the other day and wondered if it enters into evolution. The formation of sperm cells randomly divides the genetic material of the male into roughly halves so each sperm cells get 1/2 DNA.

 

If we go back one generation, the son's DNA is half from his dad and half from his mother. Based on a random split, does that mean that some of this sperm might contain only his father's genes, while the other sperm cell from this same cell division contain only his mother's genes? Random would also imply some sperm can be x% male from the previous generation with the other half from that cell, X% female. We call it all male DNA for that generation, but if we use two generations do some male sperm contain female DNA from the previous generation. It is not clear cut who is giving the male and female genes if we go back many generations.

 

Relative to speciation, this random split suggests a way to concentrate affects into certain sperm and ova. It doesn't have to be 50/50 but can be 100/0 (accumulative genes). If we get two 100/0's from the mother and father, the amount of new genes in the offspring would showed amplified affects. It may not occur often, but would cause a species split without mutations in that generation. It could have been from mutations many generations before, concentrating in a much later generation.

 

I'm not sure where you got your genetic training from, but the stuff I got in 7th grade taught me that each offspring gets half of it's chromosomes from the sperm and half from the egg. There aren't any 74/26 splits out there. Though I will admit looking at some children that are spitting images of their parents or grandparents, you might think otherwise.

 

I don't know the details on it, but I am betting that it's a case of dominant traits expressing themselves and the repressive traits just not being visible even though they are being carried along to future generations.

[Pyrotex]

...Does anyone know if mitochondrial DNA is the same in maternal-(monozygotic) twins I might post is separately

I would say, "yes". Mitochondrial DNA is only inherited from the maternal side.

[Galapagos]

The Natural History Museum in London has an interactive Voyage of the Beagle:

 

Darwin - Big idea big exhibition

 

So we can all re-visit Darwin by re-voyaging(??) his voyage :hyper:

Kinda cool..

[HydrogenBond]

Here is what I was saying. Say we take one cell that will become two sperm cells. Each of the two sperm gets half the DNA from the split.

 

Let us go back one generation before that male was born. The DNA that formed that male, who made the two sperm cells above, came from that male's mother (egg) and father (sperm). Each cell in that males body has half the DNA from his mom and half from his dad. His cells all stemmed from half male and half female DNA. If we split that to form two sperm, you can't get two sperm with all male DNA, since his mother gave half the DNA. If we assume a random split of the genes of the base cell, we should get at least a couple of sperm that have only the male's mom's original DNA. I call these female sperm since it ends up with female genes.

[Symbology]

Does anyone know if mitochondrial DNA is the same in maternal-(monozygotic) twins

I might post is separately

 

All offspring of the same mother share the same mitochondrial DNA. I heard an article a decade or two ago that there are only 12 mitochondrial DNA strands in the entire human species. Though I am not currently finding any supporting evidence to that now.

 

Here is the wiki link.

[Michaelangelica]

2009 marks 200 years since the birth of Charles Darwin and 150 years since the publication of The Origin of Species.

[Symbology]

And the public debate on the topic continues to devolve :hyper:

 

Can't we all get along? Do we have to shoot each other over the topic?

 

Oh I forget... survival of the fittest ;)

[Pyrotex]

.... If we assume a random split of the genes of the base cell, we should get at least a couple of sperm that have only the male's mom's original DNA. ....

I don't think so.

The base cell will contain some 100,000 genes. If there is a 50% chance that any given gene may come from the mother, then the odds that ALL the genes come from the mother is:

1 chance out of 2 ^ 100,000. Very roughly (doing logs in my head) this comes out to:

1 chance out of 10 ^ 30,000. Now, let's assume that a (any) base cell splits 10 ^ 10 times in the life of any male human, and there have been in the history of the world, 10 ^ 10 male humans. So, we have had 10 ^ 20 shots at splitting base cells. The odds that there has EVER in the history of the world EVER been a case where ALL the genes came from the mother is:

1 chance out of 10 ^ 29,980.

 

Something this unlikely will almost certainly never happen in the entire life of the universe. Not even in a billion, billion, billion times the life of the universe--a universe which contains a billion, billion, billion Earths. The odds would STILL be very roughly:

1 chance out of 10 ^ 29,900.

 

Pyro the Calculator

[Galapagos]

I don't think so.

[...]

 

Pyro the Calculator

Well put, Pyro!

 

If I understand the question correctly, then even if crossing over didn't occur, what is described in Hbond's post is of vanishingly low probability due to independent assortment.

[Pyrotex]

Yes, that is the conclusion that I also came up with.

 

Kind of reminds me of a debate that occurred online some 12 years ago where this "person" argued that the fastest way to get access to ALL the knowledge and wisdom of the Universe was to generate a database containing EVERY possible PERMUTATION of all the letters (and numbers) that would fit on one page. :) Somewhere in that database was a page describing anti-gravity, another giving the ultimate equation describing space-time, others that quoted every word that Jesus ever spoke, and so on and so on...

 

Assume for simplicity that one "page" may contain 40*50, or 2000 characters; and that your "alphabet" contains 40 characters, numbers and puncts.

 

How many universes would it take to store your database? :)

 

You may assume that one character can be stored on each quark!!!!! :)

[Galapagos]

Assume for simplicity that one "page" may contain 40*50, or 2000 characters; and that your "alphabet" contains 40 characters, numbers and puncts.

 

How many universes would it take to store your database? :)

 

You may assume that one character can be stored on each quark!!!!! ;)

 

According to Quine, it will only require one universe if you change the rules a bit(!) and use binary. :)

 

 

 

In Darwin news, BBC is going to have a "Darwin Season 2009":

http://www.bbc.co.uk/darwin/

To mark the 200th anniversary of Charles Darwin's birth and the 150th anniversary of the publication of 'On the Origin of Species', the BBC is airing a season of landmark TV and radio programmes.

 

Simple yet profound, Darwin's theory of evolution by natural selection is one of the most influential scientific ideas ever conceived. Even today, its conclusions and implications impact religion, politics, economics and art as well as our understanding of the natural world.

 

David Attenborough, Andrew Marr, Armand Leroi and Melyvn Bragg are among the key names who will explore Darwin's extraordinary life and work.

 

And here is a cool interactive evolution timeline on the pbs website:

pbs.org-- Evolution Revolution timeline

[Michaelangelica]

 

In Darwin news, BBC is going to have a "Darwin Season 2009":

BBC - Darwin

And here is a cool interactive evolution timeline on the pbs website:

pbs.org-- Evolution Revolution timeline

good links

Tar

some trivia from an Oz science site

Darwin's room at Christ's College Cambridge - Science Show - 13 December 2008

Darwin's room at Christ's College Cambridge

 

listen now | download audio

 

John van Wyhe takes us on a tour of Darwin's student quarters at Christ's College. He describes college life when Charles Darwin was a student and debunks some of the myths that have arisen around Darwin's life. And Rob Morrison reads a verse from his own poem, celebrating the life and achievements of Charles Darwin.

 

Show Transcript | Hide Transcript

Robyn Williams: And the bicentenary celebrations are already underway, as you'll have heard last Saturday, at the Natural History Museum in Adelaide when Rob Morrison stood to present this poem about Charles Darwin and how lucky we are that he wasn't an Australian and off on a sickie.

 

 

Rob Morrison reads from his poem, Some Australian observations on the nature of Charles Darwin's prolonged illness

 

Financially, a student's life is tough.

The cost of books and union fees and stuff

Means students, as they study to get through,

Must often take a part-time job or two.

 

The same proved true for Darwin, so that he

Forsaking study, took a job at sea

As Beagle's naturalist, in the employ

Of Captain (and creationist!) Fitzroy.

 

 

Seasickness struck him almost straight away,

And as they sailed it cursed him night and day

Until he wondered whether he could bear

The endless agony of mal de mer.

 

Then for a while Australia played the host

To Beagle, as it sailed along our coast,

And Darwin's journal makes us understand

How pleased he was to get his feet on land.

 

As any proper Englishman would do,

He took some walks and hunted kangaroo,

But though we named a city after him

He found Australian customs pretty grim.

 

In January, eighteen thirty six,

Our budding populace and politics

Were bound to seem a little bit uncouth

To Darwin, born and bred a British youth.

 

But colonies like ours were far away

From Britain, and historians today

Remark upon the freedom distance brings,

Which lets us cut our mother's apron strings.

 

Thus British customs, though they might have been

Revered by those who served their British queen,

Were fading here, where men of common sense

Soon recognised the charm of indolence.

 

Thus was the great Australian sickie born

To Aussies, who still contemplate with scorn,

Bewilderment, suspicion and dismay

A man who chooses work instead of play.

 

These days a sickie doesn't mean you're ill,

Condemned to bed, the doctor or a pill.

You "chuck a sickie" for the Melbourne Cup,

To watch the test, or when the surf is up.

 

 

I don't imply all that was going down

In eighteen thirty six in Sydney Town

But, knowing how they lived, one can infer

That goofing off had started to occur.

 

Historians hypothesise that we

Can trace that to our convict ancestry,

When felons in the chain gangs thought it good

To chuck a sickie any way they could.

 

It's hard to know just what Australians thought

Of Darwin, who was quite averse to sport.

Disdaining games and gambling, he averred

Collecting beetles was what he preferred.

 

And so he thought it sad that there should be

Such appetite for inactivity

Among Australians, who he thought were crude

As well as venal, indolent and rude.

 

So back on Beagle, green around the gills

And seasick, Darwin kept applying his skills.

His thoughts were on his specimens and not

Saying "Bugger this!"** and falling in his cot.

 

We who inhabit the antipodes

Are apt to scoff at Englishmen like these.

A seasick Aussie naturally would know

To chuck a sickie and retire below.

 

But Fitzroy saw a stronger man emerge,

For though afflicted by the dreadful scourge

Of sickness, Darwin never tried to shirk

His obligation to perform his work.

 

Such is the British way; to "get a grip!"

To show the world a "stiffened upper lip!"

Two hundred years ago you'd never find

A sickie chucked by Darwin and his kind!

 

 

By now he had accrued a massive store

Of specimens and artefacts galore,

Which would have been enough for some; instead

Ideas began to form in Darwin's head.

 

Five years went past till Beagle had returned

And Darwin started work on what he'd learned,

But even then, although he was ashore,

His illness seemed no better than before.

 

Historians have thought of many ways

By which to diagnose his long malaise,

And experts, citing symptoms, have defined

Rare maladies of body or of mind.

 

Some think that in his travels Darwin might

Have been infected by a parasite,

While others take a very different tack

And swear he was a hypochondriac.

 

Beset by such afflictions, Aussie men

Would have secured a doctor's note by then,

Have chucked a sickie, dropped their work and each

Have packed his fishing gear and hit the beach.

 

But Darwin, steeled with British discipline,

Would never have considered giving in.

Ignoring illness time and time again

He studied corals, earthworms, plants and men.

 

And Darwin's illness lasted twenty years;

Not spent in bed, but thinking up ideas

And arguments until at last he'd solved

The way that plants and animals evolved.

 

Those two decades saw Darwin working out

How natural selection came about,

Until a letter came to him one day,

Perturbing him with what it had to say.

 

 

For Alfred Russell Wallace, so it's said,

While feverish and tossing in his bed,

Despite being ill (and feeling really bad)

Had reached the same conclusions Darwin had.

 

And Wallace, in the letter that he signed,

Revealed, like Darwin, he was disinclined

To chuck a sickie* since he clearly knew,

Though ill, he had important work to do.

 

For Wallace made it absolutely clear

That he and Darwin shared the same idea;

How Nature favoured organisms that

Were best adapted to their habitat.

 

Pity Darwin; what was he to do?

The world, which lacked one theory, now had two,

But who had published first? In his distress

He asked his colleagues to resolve the mess.

 

I'm sure that some of Darwin's friends enjoyed

A brief malicious twinge of Schadenfreude,

But still they rallied round to find a way

To let both theories see the light of day.

 

They all agreed both papers were to be

Read and debated simultaneously,

And so they were, and Wallace did endorse

The "Origin of Species" in due course.

 

But there's a moral that their actions raise

For, while the two are worthy of our praise,

They both would be forgotten now instead

If either had been Aussie born and bred.

 

Such origins would certainly preclude

Egregious shows of British fortitude;

Beset by fever, illness, pain or rash

They would have chucked a sickie in a flash,

 

 

And had they dropped their work while feeling crook

We'd not be celebrating Darwin's book

Or birthday, and it's pretty safe to say

That both the men would be unknown today.

 

The moral's pretty clear; it's simply this,

Next time you've been out late, or on the piss,****

A brief reflection on these blokes should show

A sickie may not be the way to go.

 

So take an aspirin and don't complain,

Just pull your finger out; forget the pain,

Reflect on Darwin, think of Wallace, too;

Imagine what the two of them would do.

 

Should bouts of Mondayitis** come your way,

Or thoughts of working fill you with dismay,

Don't chuck a sickie and remain in bed;

Consider what you might achieve instead.

 

For, just like Darwin, you may find you could

Reject a sickie for the greater good,

And you may then discover, as did he,

Your name revered for all eternity.

 

Robyn Williams: Rob Morrison from Adelaide with a poem we shall hear in full, longer than Paradise Lost or Regained, next year as we celebrate Charles Darwin, 200 years of age, in February 2009.

 

Guests

 

John van Wyhe

Bye-Fellow Christ's College Cambridge Historian of Science University of Cambridge UK

Dr John van Wyhe

INTERPRETATION & TRANSLATION NOTES by medieval Oz translator

*"sickie"= Oz-speake for 'mental-health-day' or 'fishing day' or 'surfs up day'.

Now rare due to feral work contracts and bosses and task centred generation Y or x or one of those.

* "Mondayitis" literally allergy to Mondays. from Mod (Moon day) and itis ('sicknesn' from the Greek suffix such as senioritis[ (rare)) similar to 'sickie' but caused by pathological fear of going to work on Mondays or severe weekend hangover or injuries due to "touch (sic) football"

**"feeling crook" feeling sick, usually self inflicted.

*** "Bugger this!" not used literally as in English parlance especially Navy. More in the sense of "I've had enough" or "given up hope"

**** "Piss" Again not literal; more in the sense of 'strong' or 'copious' amounts of alcoholic beverage(s).

"sickie for the Melbourne Cup". the Melbourne Cup is a semi-quasi-religous celebration involving racing horses. So many Australians "chucked a sickie" to attend this important religious and cultural festival that it is now a holiday in many states. It might as well be in many others due to the long queues placing bets, the prolonged-ritual of the "Office Sweep" (see ibid p 102-104), office arguments about the 'best' horses or how the "sweep" was "rigged" (see note page 1), watching the race and the replay several times etc etc., This often involves contraband office alcohol.(A practice being discouraged by the Work Safety Authorities and those concerned with growing world population)

Please write to publishers for any other translation or academic footnotes required.

[Galapagos]

Darwin's room at Christ's College Cambridge - Science Show - 13 December 2008

 

 

INTERPRETATION & TRANSLATION NOTES

 

Listening to this right now.... lol they are literally describing how the windows were placed in his room, and what color his curtains and cushions were.

 

 

More Darwin news, links, etc:

 

 

Via Pharyngula, Darwin is puttin the moves on the embodiment of Nature:

Darwin is quite a formidable suitor... I wonder if Nature will Select him? buahahha :):)

 

 

Over at NewScientist Magazine:

Darwin's dangerous idea: Top 10 evolution articles - life - 28 December 2008 - New Scientist

Articles include:

• How trees changed the world
  
• Reclaiming the peppered moth for science
  
• Uncovering the evolution of the bacterial flagellum
  
• Evolution: What missing link?
  
• Evolution: 24 myths and misconceptions
  
• Rewriting Darwin: The new non-genetic inheritance
  
• The Ordivician: Life's second big bang
  
• Vestigial organs: Remnants of evolution
  
• Viruses: The unsung heroes of evolution
  
• Freedom from selection lets genes get creative
  

 

Also, I stumbled upon an essay by Dan Dennett, originally written for the college bio textbook "Life" by Purves et al, about how Darwin changed the way we view the world.

 

DRAFT: for LIFE

How has Darwin’s theory of natural selection transformed our view of humanity’s place in the universe?

 

For as long as our ancestors have been making tools, it has no doubt seemed obvious that an excellent artifact can be created only by something even more excellent: a clever artificer. You never see a shoe creating a cobbler; you never see a house making a carpenter. Darwin overthrew that received wisdom.

[...]

We can still be in awe of the "Wisdom in all the achievements of creative skill" while attributing this wisdom not to a single Creator, but distributing it over billions of years in trillions of lineages of replicators, trying their luck in the great tournament of life, mindlessly discovering and rediscovering the brilliant design principles that constitute the diversity of life. Tradition honors the trickle-down theory of value: what we do and think can be valuable only if it derives its value from something even more valuable–only if we are the servants, in effect, of a greater master. Darwin's strange inversion obliges us to rethink what could make something valuable, and then we notice that a bubble-up theory has much to recommend it. There was a time when there was no morality on this planet, and now it has evolved. Just as the air we breathe had to be created as a byproduct of the activities of billions of years of simpler life forms, the very meaning of life on this planet has emerged from the further efforts of the life forms that the atmosphere enabled.