Darwin re-visited

[Michaelangelica]

 

For example, gene variants that improve the digestion of lactose have become more common, presumably since the domestication of cattle provided a ready source of milk. And in some Europeans, genes giving a lighter skin have increased in frequency, as populations have moved north to regions where there is less sunlight to generate vitamin D.

 

You can now get a genetic pathology test to see if you are alergic to gluten, found in many domesticated grass seeds such as wheat

Celiac disease affects approximately 1% of the U.S. population but is highly underdiagnosed, with less than 10% of cases currently detected. In genetically susceptible individuals with the specific markers HLA-DQ2 and HLA-DQ8, ingestion of gluten-containing grains causes inflammation of the small intestine and leads to malabsorption. Symptoms may be gastrointestinal and/or a wide range of other multi-systemic manifestations such as iron-deficiency anemia, chronic fatigue, osteoporosis, dermatitis herpetiformis, and attention-deficit/hyperactivity disorder. Early diagnosis and lifelong treatment with a gluten-free diet is critical to relieve inflammation and symptoms and to reduce the risk for development of secondary autoimmune disorders such as type 1 diabetes. Silent celiac disease, involving inflammation without symptoms, is also important to detect and treat.

Celiac.com Celiac Disease: (Celiac Disease Genetic Testing Awareness Campaign Launched by Kimball Genetics) Gluten-Free

Tibetans ustilise oxgen more efficiently due to a genetic adaptation to low oxygen at high altitudes.

[Tormod]

Very nice. It means small-scale evolution happens in humans, which implies two things: 1) Evolution is an actual process and 2) We are animals, too.

[Michaelangelica]

Very nice. It means small-scale evolution happens in humans, which implies two things: 1) Evolution is an actual process and 2) We are animals, too.

Yes in all that DNA we lug around with us there is probably a bit coding for wings.

 

I wonder how many tall buildings you would have to jump off before the race could learn to fly? :angel: :evil: :Waldo:

[InfiniteNow]

I wonder how many tall buildings you would have to jump off before the race could learn to fly? :angel: :evil: :Waldo:

You would just have to be near your brother, who can fly, so you could acquire his powers...

[Michaelangelica]

You would just have to be near your brother, who can fly, so you could acquire his powers...

Looks good; hope we get it here. I have always loved shows about Superheros, especially bumbling ones, like Spiderman and that Irish Superhero Guy ???

"Heroes" follows the lives of ordinary people who discover they possess extraordinary abilities.

When are the Genetic Engineers going to get serious and start selling us some real Superpowers?

[Michaelangelica]

The Brain is a work in progress (?)

 

One gene, microcephalin appeared 37,000 years ago and is present in 70% of humans

 

Another gene "ASPM" arose only 5,800 yers ago and is present in 30% of humans

 

Do these changes coincide with historical/cultural leaps/events like spread of agriculture (ASPM) or the rise of culturally modern humans (microcephalin) ?

 

Source:

Cosmos 5, Nov. 2005

[Michaelangelica]

Another interesting and practical aspects of genome science is why we all react to drugs differently.

 

There is a new field of science called "Pharmacogeonomics" that address this issue

 

What is Pharmacogenomics (PGx)?

Pharmacogenomics (PGx) is the science of how a person’s genetic make-up influences the way we respond (either positively or negatively) to drugs.

 

We all know examples where some people treated with medication either respond well, while others do not respond at all, while others experience some serious adverse reaction to the medication.

The current paradigm for treating patients with medication is “one size fits all” or as in some cases, medication is based on ’trial and error’.

 

Variable inter-individual responses to certain drugs can be influenced by a number of factors, eg age, sex, pathology, life style or co-medication.However, it is becoming more evident that genetics plays a central role.

In some instances genetics accounts for up to 60% of the patient variation in responses to drugs.

Pharmacogenomics identifies individuals who are at high risk of experiencing adverse drug reactions or those who may not respond to certain medications.

 

Pharmacogenomics is the first step toward ’personalised medication’.

What is PGx Testing?

 

PGx DNA tests look for changes in genes that play a major role in either:

 

1. Drug Clearance

 

Depending upon ethnicity, between 10-25% of the population are genetically known as “poor metabolisers”, that is they do not have the enzymes within their livers to clear specific drugs from their bodies.

As such, they are at increased risk of adverse drug reaction when blood concentrations of drugs increase to toxic level.These individuals require either alternate medication or much lower doses of the drug.

 

On the other hand, between 5-25% of the population are genetically known as “ultra metabolisers”, that is they have multiple copies of genes that code for drug clearing enzymes.Here, these individuals clear the drug so fast that they usually have no effect, therefore require much higher doses than normal.

2. Drug Transport & Action

 

Other genes code for either the drug transporter or drug receptor.

Here individuals with genetic variants may not be able to respond to medication since the level of receptor has changed or it is no longer functioning.

 

Why Is PGx Important Today?

 

Adverse Drug Reactions (ADR):

 

USA

 

* 2.2 million adverse drug reactions per year.

* 4th – 6th leading cause of death.

* Cost of drug related morbidity and mortality $170 billion.

* ADR’s account for 5% of all hospital admissions.

* Overall incidence of serious ADR’s is 7%.

 

UK

 

* 250,000 people per year admitted to hospital with an ADR.

* 6.5% of new hospital admissions

* Estimated healthcare burden of ADRs, over £450 million.

Australia

* 140,000 ADR’s reported each year.

* One in ten GP consultations are patients who have suffered anADR.

CYP2C19metabolises 15% of all prescribed drugs.

It is absent in 20-30% of Asians and 13% of Caucasians

 

A bit (but not a lot) more info here:

Healthscope Molecular News

[Larv]

Michaelangelica,

 

What I read into your post is that alleles and their combinations count for a lot in the field of pharmocogenomics. My own personal guess is that they may count for everything someday, speculating that humans may be entirely genetically predisposed in all categories. The more I study this matter the more I tend to agree. It seems to me, at this stage of our understanding, that environmental factors such as drugs play as much to our genetic complexities as they do to our body chemistry.

 

—Larv

[Michaelangelica]

Michaelangelica,

 

The more I study this matter the more I tend to agree.

 

It seems to me, at this stage of our understanding, that environmental factors such as drugs play as much to our genetic complexities as they do to our body chemistry.

 

—Larv

The people who are selling pharmacogeonomics (phew had to spell)

say one test; and they will know what drugs you will have advese reactions too -for the rest of your life.

If true, this could save our society Billions in health care annually!

 

CYP2D6(cytochrome P450 2D6) is involved in the metabolism of 25% of drugs and is expressed Polymorphically (??)

Drugs metabolised by CYP2D6 include amphetamine, anti-psychoytics, B-blockers, SSRIs etc

 

Many have problems with anti-depressants and ant-psychotics.

Getting this sort of medication right can be a long process, painful and trumatic for many, not just the patient.

IF PMCnomics can work it will be a huge leap forward in medical care for so many

(Plus fewer law suits for the drug companies!)

[Michaelangelica]

Michaelangelica,

 

What I read into your post is that alleles and their combinations count for a lot in the field of pharmocogenomics. My own personal guess is that they may count for everything someday, speculating that humans may be entirely genetically predisposed in all categories. The more I study this matter the more I tend to agree. It seems to me, at this stage of our understanding, that environmental factors such as drugs play as much to our genetic complexities as they do to our body chemistry.

 

—Larv

Bit amazing if it turns out to be true. The pathology company those does the tests and that I got the above info from, seemed to feel there were groups of people with a common gene that had poblems with certain families of chemical The asprin / warfrin lot (which could be deadly) The anti-depression/psychiatric lot (which explains why so a many have so many problems getting this sort of medication right).

I am simplifying but go to their website for details. They also have a newsletter and promotional material. Certainly the tests seem to have the potential of saving countless lives and a lot of money and pain.

 

I wonder how long it will take governments to realise this and start getting everyone tested.

 

It also illustrates my point that evolution is not slow.

It is fast and happening now.

 

 

I mentioned the lactase/ose-digestive 'gene' before but here is a good article on it From 6,000BC to now is not a long time for genetic change. Genes uncover dairy farming origins | COSMOS magazine

: A new genetic analysis of ancient human remains proves that humans were unable to digest milk prior to the spread of agriculture and dairy farming within the last 8,000 years.

. . .

This is some of the best "direct evidence that natural selection is working on human populations" lead author Joachim Burger told Cosmos Online. "It shows that a genotype that is nearly absent 8,000 years ago, can rise to a frequency of more than 70 per cent today, by natural selection."

[Michaelangelica]

Hawks and Cochran, by con*t*rast, ar*gue that the trend “is vis*i*ble even in the last tens of thou*sands of years,” Lahn wrote. It “runs count*er to the feel*ing in some quar*ters that the ev*o*lu*tion of the hu*man phe*no*type [form] has slowed down or even stopped in our re*cent past.”

 

If the study is cor*rect, it raises new ques*tions about how to de*fine the “orig*in” of mod*ern hu*mans—a rath*er ar*bi*trary de*ci*sion in any case, Lahn re*marked.

 

The or*i*gin is “de*fined prob*a*bly more as a mat*ter of con*ven*ience rath*er than re*flect*ing any ac*tu*al wa*ter*shed ev*o*lu*tion*ary event,” he wrote. That is, it’s “use*ful to say that any past crea*tures that are with*in cer*tain lev*els of sim*i*lar*i*ties to us to*day should be con*sid*ered as ‘the same’ as us.”

 

But if the changes that ac*com*pa*nied this event are on*ly a tri*fling part of a wid*er trend, he added, it be*comes rea*son*a*ble to ask wheth*er that fur*ther de*flates the ra*tion*ale for call*ing it an or*i*gin.

 

“In a sense,” he wrote, one could say “the or*i*gin is still on*go*ing.”

 

Research pub*lished in the Sept. 9, 2005 is*sue of the re*search jour*nal Sci*ence by Lahn and col*leagues found that two genes linked to brain size are rap*idly evolv*ing in hu*mans.

Human evolution, radically reappraised

[Michaelangelica]

An interesting TV show on epigenetics.

A bit superficial and didn't really come to grips with the concept but it is interesting that the popular science press is beginning to catch up with the re-invention of Darwin and genetics

Catalyst: Epigenetics - ABC TV Science

Epigenetics

Reporter: Dr Maryanne Demasi

Producer: Belinda Gibbon

Researcher: Dr Holly Trueman

Camera: Dennis Brennan, Geoff Lye, Campbell Miller

 

Sound: Steve Ravich, Chris Coltman, Spiros Maurangelos

 

Editor: Chris Spur

 

Transcript

Related Info

 

19 April 2007

You are what you eat…but science suggests you’re also what your grandmother ate.

 

We’ve always known that the genes of our ancestors are passed on through generations, but could they pass on something more than just their genes?

 

In 2000 the human genome was finally mapped and scientists had cracked our genetic code.

 

But they didn’t bargain on discovering a hidden array of switches that can be turned on, or off, not only by what our bodies experience, but also by what our predecessors got up to.

 

This discovery has opened a brave new world of medical research and has implications for the development of treatments for many diseases including cancer.

[Buffy]

Mike,

 

You do understand that this is expression of recessive traits and not "development of a new trait", right? As such, it does not contradict anything about standard Darwinian theory, and definitely does not support Lamarck. What it *does* show is nice evidence in support of the fact that stresses (and the report is vague on "something grandma ate") can cause mutations in the DNA where a single "switch" can cause major changes in morphology--something that intelligent design advocates claim is impossible....

 

Switches for subroutines,

Buffy

[Michaelangelica]

Mike,

 

You do understand that this is expression of recessive traits and not "development of a new trait", right? As such, it does not contradict anything about standard Darwinian theory, and definitely does not support Lamarck. What it *does* show is nice evidence in support of the fact that stresses (and the report is vague on "something grandma ate") can cause mutations in the DNA where a single "switch" can cause major changes in morphology--something that intelligent design advocates claim is impossible....

 

Switches for subroutines,

Buffy

Yes, thanks Buffy.

I guess "what your mother ate" refers to the 'Hungerwinter' research and other research on obesity and mum's nutrition (I may have posted that in obesity thread)

 

What is clear is that the whole evolution thing is a lot more complex than first thought.

 

What does support Lamarck-sociology? quantum?

 

I have this fantasy, that among the 96% of junk DNA is the gene for wings, and one day. . .

 

Watching too much Heros.

 

Michael

[Buffy]

What does support Lamarck-sociology? quantum?

Nothing supports Lamarck. The "you get strong muscles because your dad built up strong muscles working in a coal mine" has no evidence that supports it at all. What this is about is environmental stresses causing *random* switches in junk dna, that cause it to be expressed.

 

My opinion is that this is not really new in theory, just that we're seeing data to establish it. Gould and Eldredge have been harping on stresses causing spurts of rapid evolution has been around for 30 years. Searhing for segments of junk DNA for useful stuff has only been going on for about 10, and its hard work.

I have this fantasy, that among the 96% of junk DNA is the gene for wings, and one day. . . Watching too much Heros

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! :eek:

 

Save the cheerleader, :)

Buffy

[Michaelangelica]

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! :doh:

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

 

Save the cheerleader, :shrug:

Buffy

LOL

tar

m

[Buffy]

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!

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."

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.

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*.

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...

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*.

 

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.:hihi:

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