Interesting Topics on Evolution

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Jingy

climber
Somewhere out there
Jan 1, 2013 - 02:54pm PT
^^^^ These are the type of "let's limit knowledge and understanding" type folks I was talking about ^^^^
Norton

Social climber
the Wastelands
Jan 1, 2013 - 03:00pm PT
eeyonkee,

wasn't it the other day that you commented that if we could take a newborn from as far ago as 50,000 years or so, and transplant that infant to today, that it would have the same intelligence, learning capacity, as we humans have?

that evolutionarily speaking we would have to go back much further in time to perhaps find homo sapiens of significant difference?
eeyonkee

Trad climber
Golden, CO
Topic Author's Reply - Jan 1, 2013 - 03:03pm PT
continuing breaking of athletic records--production of exceptional "tip of the iceberg" individuals

continuing lengthening of AVERAGE lifespan--production of better average "stock"

continuing identification of those who in past would have been discarded as misfits or disabled and would have been discarded, but are now seen as genius--Einstein, Hawking, Temple Grandin.

Ken, I would argue that none of these are evidence for continuing human evolution. The first could easily be explained by sheer numbers, better nutrition, and better training techniques. The second by better nutrition and education. The third by education and "civilization" of society.

Don't get hung up on the bigger brain = smarter. Although there is clearly a correlation (when normalized for body mass) I just mean genetic-based greater intelligence.

Norton - I referred to 5,000 years, but it might as well have been 50,000, although now I'm not so sure that 50,000 years wouldn't be long enough to show some clear (average) differences.
Norton

Social climber
the Wastelands
Jan 1, 2013 - 03:09pm PT


from wiki:
In the context of human evolution, human vestigiality involves those characters (such as organs or behaviors) occurring in the human species that are considered vestigial—in other words having lost all or most of their original function through evolution. Although structures usually called "vestigial" often appear functionless, a vestigial structure may retain lesser functions or develop minor new ones.[1] In some cases, structures once identified as vestigal simply had an unrecognized function.[2]

The examples of human vestigiality are numerous, including the anatomical (such as the human appendix, tailbone, wisdom teeth, and inside corner of the eye), the behavioral (goose bumps and palmar grasp reflex), sensory (decreased olfaction), and molecular (junk DNA). Many human characteristics are also vestigial in other primates and related animals.

photo not found
Missing photo ID#281721

NOT photoshopped

eeyonkee

Trad climber
Golden, CO
Topic Author's Reply - Jan 1, 2013 - 03:15pm PT
Cool!
moosedrool

Trad climber
lost, far away from Poland
Jan 1, 2013 - 03:20pm PT
Eeyonkee, the direction of human evolution is clearly visible. The people that have the highest number of children dictate that course.

VERY IMPORTANT (Wikipedia)

In biology, and specifically genetics, epigenetics is the study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence – hence the name epi- (Greek: επί- over, above, outer) -genetics. It refers to functionally relevant modifications to the genome that do not involve a change in the nucleotide sequence. Examples of such modifications are DNA methylation and histone modification, both of which serve to regulate gene expression without altering the underlying DNA sequence. These changes may remain through cell divisions for the remainder of the cell's life and may also last for multiple generations. However, there is no change in the underlying DNA sequence of the organism;[1] instead, non-genetic factors cause the organism's genes to behave (or "express themselves") differently.[2] There are objections to the use of the term epigenetic to describe chemical modification of histone since it remains unknown whether or not these modifications are heritable.[3]
One example of epigenetic changes in eukaryotic biology is the process of cellular differentiation. During morphogenesis, totipotent stem cells become the various pluripotent cell lines of the embryo, which in turn become fully differentiated cells. In other words, a single fertilized egg cell – the zygote – changes into the many cell types including neurons, muscle cells, epithelium, endothelium of blood vessels, etc. as it continues to divide. It does so by activating some genes while inhibiting others.[4]
In 2011, it was demonstrated that the methylation of mRNA has a critical role in human energy homeostasis. The obesity associated FTO gene is shown to be able to demethylate N6-methyladenosine in RNA. This opened the related field of RNA epigenetics.[5][6]

Edit: It is unclear for how many generations epigenetics are passed. But it is the fastest mode of pseudo evolution.
Jaybro

Social climber
Wolf City, Wyoming
Jan 1, 2013 - 03:26pm PT
The problem with #1 is that we want to see it as something positive. Like bigger brains, or somehow that we're getting "better," and that's not how it works. We're probably evolving to be more tolerant of pollution and sun exposure, higher temperatures etc, possibly at the expense of what we think of as 'good' qualities.
moosedrool

Trad climber
lost, far away from Poland
Jan 1, 2013 - 03:27pm PT
go-B, I am not sure what you are trying to say...
moosedrool

Trad climber
lost, far away from Poland
Jan 1, 2013 - 03:33pm PT
Are we evolving smarter genes? Sure, but those people would have to breed faster than others to tip the evolution their way.
monolith

climber
albany,ca
Jan 1, 2013 - 03:34pm PT
Please don't let Gobee turn this into an evolution vs anti-evolution thread.
eeyonkee

Trad climber
Golden, CO
Topic Author's Reply - Jan 1, 2013 - 03:46pm PT
Jaybro, you're preaching to the choir with respect to evolution having no "goals". I get that. My point is, even for, say, tolerance to sun, there has to be some differential survival or occurrence rate for the "good" genes to proliferate in a population. Those with the gene have to either survive more or have more babies. I suppose in third world countries with high populations, this sort of thing is likely still happening. In first world countries, it's not so clear (at least to me).
Norton

Social climber
the Wastelands
Jan 1, 2013 - 03:51pm PT
gobee is simply pointing out that deceases such as leprosy can be instantly cured if one just happens to have Jesus show up, take pity, and take care of business.

The problem arises when a leper's path does not cross Jesus's in time for the cure
moosedrool

Trad climber
lost, far away from Poland
Jan 1, 2013 - 04:06pm PT
I think I need to explain my points on evolution.

GENETICALLY driven evolution:
A random mutation in the offspring's DNA (change in the DNA sequence) that gives an advantage to the offspring.

EPIGENETICALLY driven evolution:
The parent develops skills that modify her/his gene expression (no change in the DNA sequence). This skill can be passed to the offspring.

So, the difference between those two:

GENETICALLY driven evolution is random.

EPIGENETICALLY driven evolution is through improving your skills.
eeyonkee

Trad climber
Golden, CO
Topic Author's Reply - Jan 1, 2013 - 04:35pm PT
GENETICALLY driven evolution is random.

Come on, this isn't true. The mutations themselves are random but natural selection is certainly not.

I've go to bone up on epigenetics. I understand the overall concept, but not certain mechanisms and its relative contribution to evolution.
healyje

Trad climber
Portland, Oregon
Jan 1, 2013 - 04:45pm PT
1. Our expression (genetic and epigenetic) and that of our symbionts and endogenic viral load is subject to continual environmental and ecological pressure - whether we're still evolving is not even a question. But I would posit that focusing on, or attempting to point to, behavioral or physical traits which have social currency in our society are largely misguided as most of those [inherent] attributes and capabilities were [fully] expressed in modern humans tens of thousands of years ago. I would similarly be largely skeptical of any too-direct a linkage between behavior and epigenetics.

2. We are no less "social" than ants and I suspect that's due to trade-offs associated with the energy budget of our brain and more to do with the evolution of very early primates in general as opposed anything to do with modern hominids.

3. We exist so 'intelligence' is undoubtably 'common' as sknott relative to the total number of planets in life-hospitable galaxies.
Jan

Mountain climber
Okinawa, Japan
Jan 1, 2013 - 04:58pm PT
I'll focus on # 1 from a biological anthropology point of view.

Of course human evolution is ongoing and there is every reason to think, based solely on numbers, that Europe and America will have little to do with the final direction of the human race. Our future as a species is being determined in Asia, home of over 50% of us. Later, as the population of Africa continues to grow, they will contribute more also. Europe and North America together are only about 6% of the world's total population

Secondly, as has been pointed out, our values cause many less than physically and mentally optimum people to survive and reproduce, thus weakening the biological fitness of the developed societies. Further, we choose to preserve life at all costs at both ends of the human lifespan at the expense of those of reproductive age.

Thirdly, many of our best nourished, healthiest and educated (presumably smarter) people are failing to reproduce or do so only in minimal numbers.

And finally, we have created such comfortable and clean environments that we have reduced much selective pressure. The teeming masses living in the megacities of the world, especially in Asia, are being heavily selected for certain traits, including widespread resistance to both waterborne and airborne microbes, and heavy chemical and particulate pollution of the atmosphere. Those who survive the slums of these cities are definitely superior biological specimens who reproduce more than our pampered citizens.

As for evolution of intelligence, the obstacles that citizens of crowded developing societies face just to survive, demand much more quick and flexible thinking than our spoiled existence which has the luxury to sit around and debate whether evolution even exists or not.
moosedrool

Trad climber
lost, far away from Poland
Jan 1, 2013 - 05:08pm PT
Come on, this isn't true. The mutations themselves are random but natural selection is certainly not.

Of course. Just wanted to show the difference between those two.

The most obvious implication of epigenetics is the speed of this type of evolution. And it is a directional evolution. As opposed to the mutation driven evolution.
healyje

Trad climber
Portland, Oregon
Jan 1, 2013 - 05:16pm PT
And finally, we have created such comfortable and clean environments that we have reduced much selective pressure.

Jan, I believe this is a mistake and one of human-centric social biases. There is no such thing as a "clean and comfortable" environment - there are only 'different' environments with more or less 'novel' attributes. From a microbial perspective, mega slums represent an active competitive environment whereas our "clean and comfortable" environment may be far better suited to the evolution of 'superbugs' given the hostile agents used to achieve these environments. Our first world environments may in fact be be evolutionary 'accelerants'. Similarly, habitat destruction unbalances 'stable' ecologies creating other highly novel incubators.

If a superbug emerges from either our 'clean' environment or a destabilized habitat then it's unlikely mega slum dwellers will be well-suited to survive either other than as more a mutational fluke of pure numbers.
eeyonkee

Trad climber
Golden, CO
Topic Author's Reply - Jan 1, 2013 - 05:31pm PT
Ok, I see where you are coming from, Moosedrool. Great post, Jan. I'm with you. But let's just say that all of Asia and Africa were first world countries, with concomitant very low infant mortality and high life expectancy. Would your answer be the same?

With respect to 3, remember, the setup is the emergence of life on one planet and the liklihood of intelligent life (say, capable of technology)emerging on that planet. I'm not asking about the odds of intelligent life in the universe as a whole, which I would put at extremely high.

Sharks have evolved very little in the last 200 million years. Why? Because they haven't needed to. Evolution doesn't do it's magic just because. And there's certainly no reason to believe that given enough time that sharks would involve intelligence on par with humans.

Healje, (respectfully) the premise that because we are here means that the answer to 3 is high seems faulty to me. It smacks of the creationist premise that because the universe is just right for humans that it must have been designed for them.
Jan

Mountain climber
Okinawa, Japan
Jan 1, 2013 - 05:35pm PT
healeyje-

I'm not sure I understand what you mean. However, if our current sanitary environment makes us more susceptible to superbugs emanating from other continents, and we die off in great numbers, isn't the final effect of that to reduce our role in ongoing evolution even further?

And yes you're right about "clean and comfortable" being an example of social bias. But really, have you ever tried to live in one of those societies? I am always made aware of what a biological weakling I am compared to my Indian and Nepalese friends.
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