Evolutionary Theory

[digibucc]

Evolution is simply a change that is passed down to successive generations, over a long period of time.

These changes are random (genetically), selective (bigger males breed more with willing females), or pressure (no water, lack of water kills the ones that can not live without it).

the mutations are random, or better- based on chance. but selection and pressure
i see as the same thing. what is the difference evolutionarily speaking, of you being
attractive or dying and having water or dying. ?

you either died or not, reproduced or not. evolutionarily speaking, i'd call it
"selective pressure" the pressure to mate or drink, either way.

and again, evolution BY natural selection. for Evolutionary Theory, the selection is
not optional.

 

[pantherx12]

Hey mailman, thought I'd pop in and say sharks can get cancer.

They're much more resistance to it than us and other things mind you, but they can get it.

As cancer is essentially cells growing in a random manner, an organism even one with defence mechanism like a shark may not be able to distinguish the cancerous growth from normal growth.

 

[WhiteLotus]

Cancer talk

Do any of you actually know how cancer is formed?

If you are just saying what your school teacher told you, then go and read this paper

 

[cheesy999]

Do any of you actually know how cancer is formed?

If you are just saying what your school teacher told you, then go and read this paper

do i look like i have moths of spare time?

from my understanding ionizing radiation damages the DNA in the cell and the body fails to shut the cell down before it multiply's

 

[TheMailMan78]

Hey mailman, thought I'd pop in and say sharks can get cancer.

They're much more resistance to it than us and other things mind you, but they can get it.

As cancer is essentially cells growing in a random manner, an organism even one with defence mechanism like a shark may not be able to distinguish the cancerous growth from normal growth.

For the past 100 years, scientists have studied cancerous tumors in sharks. The first chondrichthyes’ (cartilaginous fishes, including sharks) tumor was found on a skate and recorded by Dislonghamcps in 1853 (3). The first shark tumor was recorded in 1908. Scientists have since discovered benign and cancerous tumors in 18 of the 1,168 species of sharks (3). Scarcity of studies on shark physiology has perhaps allowed this myth to be accepted as fact for so many years.

I stand corrected.

However they are FAR less prone to cancer then newer species. That was my point more then anything. Much like man. Education evolves. Let me put it to you this way. The text books I learned from still had Germany divided in two.

 

[WhiteLotus]

do i look like i have moths of spare time?

from my understanding ionizing radiation damages the DNA in the cell and the body fails to shut the cell down before it multiply's

There is WAY more to it than that.

Reactive Oxygen Species can cause cancer, P53, angiogenesis, evasion of apoptosis, the poly A tail not being broken down, cancer going from benign to metastases actually changes the cell type (from epidermal to mesenchymal back to epidermal again), the complete lack of respiration (bar glycolysis), the continual mutations that occur...

and on and on and on.

 

[cheesy999]

There is WAY more to it than that.

Reactive Oxygen Species can cause cancer, P53, angiogenesis, evasion of apoptosis, the poly A tail not being broken down, cancer going from benign to metastases actually changes the cell type (from epidermal to mesenchymal back to epidermal again), the complete lack of respiration (bar glycolysis), the continual mutations that occur...

and on and on and on.

yeah but is there really any need to get that far in depth in a thread about evolution?

The question everyone is asking is DO COMPUTERS CAUSE CANCER

 

[WhiteLotus]

yeah but is there really any need to get that far in depth in a thread about evolution?

The question everyone is asking is DO COMPUTERS CAUSE CANCER

Water can cause cancer... so yes. Why the fuck not.

Humans will not evolve to counter act cancer. In fact we have evolved to live longer and thus are seeing cancer. If we died at 40 like we're meant to, cancer would not even be on our minds.

 

[cheesy999]

Water can cause cancer... so yes. Why the fuck not.

do you read the daily mail?

 

[WhiteLotus]

do you read the daily mail?

Hydrolytic DNA damage, most common is the conversion from Cytosine to Uracil. That's a base change, that's a mutation. Mutations cause cancer.

Though now I think about it, yes that does sound like something that the Daily Mail would report on.

 

[Benetanegia]

All this derailment saddens me since I think this section is on probation time and that kind of things are not going to help keep it open or in TPU rather than on GN. I'm not seeing many mods around which I don't know if that means anything.

 

[sneekypeet]

Ok let me simplify this for all of you. This is TPU not GN. Points and removal of posts has been accomplished up to this point. I am going against my better judgement to reopen this thread to see if TPU actually has some intelligence in masses, and to weed out the trolls with heavier infractions the next time around.

Don't make me have to eat my words for re-opening this thread after the huge amount of time I spent cleaning this to try to save some continuity!!!!

 

[cheesy999]

sorry sneaky - i'll try to be more scientific now (i'd hate it for you guy's too see me as a troll)

anyone actually heard about how darwin came up with the theory, turtle's on beaches etc?

pretty interesting really

 

[LAN_deRf_HA]

What did it flare up again? I thought we rerailed it ourselves. Props us.

 

[digibucc]

What did it flare up again? I thought we rerailed it ourselves. Props us.

yeah when i left it was re-railed and done with. i'm not sure what happened.

 

[pantherx12]

Just to clarify, mailman and I made fappin based posts again. Others may of joined in. Could of been that.

And yeah the Turtle story is brilliant.
One of the species of turtle has an arch/groove in it's shell so it can eat things higher than usual, this trait got passed on as certain types of food became rare to they forced to take advantage of it. And thus the gene for an arch in the shell was passed on. ( simplified version)

By the by, does have to be said, I missed what else happened, but when having discussions ( even scientific ones) there's nothing wrong with throwing out a few jokes, being a bit off topic.
Sometimes I hate forums lol.

 

[sneekypeet]

there's nothing wrong with throwing out a few jokes, being a bit off topic.
Sometimes I hate forums lol.

There sure is, and if you dont get that, dont post! I had to go through and remove over 30 posts from this thread that were just "a few jokes"!!!

 

[cheesy999]

By the by, does have to be said, I missed what else happened, but when having discussions ( even scientific ones) there's nothing wrong with throwing out a few jokes, being a bit off topic.
Sometimes I hate forums lol.

i don't think you realise just how off topic this got

and i think there were birds as well as turtles?

 

[Frederik S]

i have a friend, who is relatively well educated, and
definitely takes science and mathematics seriously.
we were talking awhile ago, and he made the
statement that:

The evolutionary pressure is needed, I agree. Everyone living in a country with decent health care reaches an average age above that of sexual maturity thus Darwin is put out of play, if we negate all the other factors in human reproduction.

Keep in mind that the changes we are seeing could be totally natural. If height is a function your height potential plus food available, then it could just be that more people have access to proper nutrition.

Other types of mutations to the human genome can be caused by the way we live. We are constantly surround by chemicals where we know very little about how they affect us.

Darwin is surprisingly relevant, think of the way we try to remove all bacteria from our lives. The detergents we use only kill off the weakest bacteria leaving more food for the more hardcore ones accelerating their growth. The other scenario is that we clean less and have more of the not so harmful bacteria, and less of the hardcore ones.

 

[streetfighter 2]

Evolution doesn't stop. It's always happening.

Didn't anyone learn from South Park?

and i think there were birds as well as turtles?

The birds are nice but it's really turtles all the way down.

 

[digibucc]

i'm changing this text as people obviously can't be bothered to read past it.

 

[streetfighter 2]

Evolution doesn't halt. It may slow down, but it never stops, pauses or halts*. (The term "pause" works if you mean that it "slows to a crawl".)
Sources:
http://evolution.berkeley.edu/evolibrary/article/evo_54
http://evolution.berkeley.edu/evolibrary/article/evo_51
http://www.pbs.org/wgbh/evolution/library/faq/cat05.html

The absorption of many cultures (the melting pot) along with current medical and hygienic practices are mechanisms driving speciation in the USA.
[unreferenced/conjectural]

*For the purpose of this discussion:
stop = a process/mechanism which is no longer operating
halt = pause = a process/mechanism which has temporarily stopped

Supplementary [uncited] summary:

EDIT:
I also have a very minor personal gripe with the term "Darwin's Evolution". Think of evolution as an art gallery. Darwin told us where to build it and what it should look like. During the last 100+ years scientists actually built it and furnished it with beautiful paintings, sculptures and tapestries. Similar to other galleries, my increasingly metaphorical Darwin Gallery is never complete and some of the works exhibited may not be legitimate.
[unreferenced/conjectural]

 

[Benetanegia]

we've already covered that, that is not true IMO. without selective pressure darwin's evolution halts. it doesn't end, or stop - but it's also not happening. it ... pauses.

There fixed. Evolution happens all the time. You seem to think that evolution is just linked to natural selection, but it's not. Directly from wikipedia:

There are four common mechanisms of evolution. The first mechanism is natural selection, a process in which there is differential survival and/or reproduction of organisms that differ in one or more inherited traits.[1] A second mechanism is genetic drift, a process in which there are random changes to the proportions of two or more inherited traits within a population.[7][8] A third mechanism is mutation, which is a permanent change in a DNA sequence. Finally, the fourth mechanism is gene flow, which is the incorporation of genes from one population into another.

Wether you like it or not, evolution happens when something in the DNA of one species changes (for any reason) and thus is not the same as it was before. No more, no less.

 

[digibucc]

i was using darwin's evolution, to refer to gross evolution, obviously not the same thing.
i was wrong.

of course the processes that lead to what we see as evolution continue to happen, but
they cease to result in evolutionary changes. the kind of changes that determine size,
strength, intelligence, hair, etc, have stopped. without selection pressure, we stop
changing.

so yes, in a strictly technical sense you are right, and i'm an idiot. i should have disclaimed
and prepared for that. but my point has been since my OP that as far as we are concerned,
evolution stopped making any changes with us.


@bene
you are absolutely right. genetic drift (which has no effect with a population the size of
humanity) , gene flow (which has no effect with a population that does not have super-
isolated pockets), and mutation (a change event) also exist. the thing is, they rarely do
much, and never effect the evolutionary change i have been talking about since the
beginning, with the possible exception of mutation, which i already mentioned.

so again, in the most technical definition of everything evolution encompasses, you guys
are exactly right.

but if we are talking about evolutionary change in humans, which is what i thought we had
been talking about, it has stopped occurring. ceased. paused. however. the one time i don't
spend 20 minutes picking my words and i surely regret it.

 

[streetfighter 2]

Are you referring to this?
http://bigthink.com/ideas/26647 (Michio Kaku addressing the direction of contemporary human evolution)

Originally Spoken by Michio Kaku
Evolution is still taking place. But gross evolution, that is, evolution that will give us big brains, big eyes, bald heads and little bodies, that kind of gross evolution is pretty much gone.

Personally I kind of disagree with Michio Kaku. He's a physicist not a biologist after all.
A poster named, Kevin Stone, made the following comment which I think is a compelling argument:

Originally Posted by Kevin Stone
I wish that Mr. Kaku would do a followup video correcting his misconceptions such as his idea that large phenotypic change can no longer take place just because geographic isolation no longer meaningfully exists. First of all despite modern transportation the world is not one unified population. But even if that changes in the future geographic barriers are not solely responsible for reproductive isolation. There are also behavioral factors to consider and they are more effective than you might think. Second, sexual selection is still very much a factor in human evolution and interpersonal pressures in socially complex species like ourselves result in unique forms of sexual selection that we’ve only recently become aware of. Finally, if you’re going to be a futurist regarding evolution you can’t look a couple of hundred years into the future. You have to look tens or even hundreds of thousands of years into the future. THAT’S the scale of evolution. By then advanced transportation systems which Mr. Kaku blames for stagnating human evolution may actually have begun to accelerate it by providing the ultimate geographic barrier possible… planetary colonization! Nothing will accelerate human speciation faster than hundreds of small isolated populations prone to allelic fixation via genetic drift. Far from stagnation, in a hundred thousand years or so human diversity may have skyrocketed, literally.

so yes, in a strictly technical sense you are right, and i'm an idiot.

You're not an idiot.

Here's an example of an idiot I met once:
I was talking to an acquaintance about why she likes to paint. I mentioned that I'm fond of charcoal/pencil drawings because I'm colorblind. She said, "Oh my god, I'm so sorry. Does that mean you're retarded?"
I paused for a brief second and replied solemnly, "Yes."

True story.