|CharlesSmith - 2009-03-15 |
YOU MEAN GUIDED INTELLIGENT DESIGN!
I recently got into a funny debate with an ID proponent who turned me onto their saving grace, Nancy Pearcey.
Pearcey would argue against this as being evidence of evolution because we are merely guiding natural processes, we aren't making new life forms out of building blocks of atoms. She boldly states that we will never be able to make a cell.
She has no scientific background whatsoever. My favorite quote of hers:
"As arch-Darwinian Richard Dawkins said in a recent Salon interview, evolution produces "the illusion of design." The implication for science, as Richard Rorty elaborates so clearly, is that truth is not "out there" to be discovered but is merely a social construction. *Such postmodernist notions threaten to undercut the scientific enterprise.*"
Genes coding for enzymes are hard to mutate, its too easy to break one of these molecular machines, so gene control here would be a light-toggle that sometimes sparks.
But many developmental traits are controlled not so much by protein sequence, but by the timing/amount of their production. Much variation in dog breeds can be accounted for by varying repeats of what was once thought "junk" DNA between the transcribed gene and promoter sequences upstream.
Repetitive DNA is commonly miscopied during meotic crossover, so there's a built-in source of variation that is more akin to a fader than a toggle. Its easy to imagine an isolated population drifting/being selected by "fader" increments till it was behaviorally or physiologically unlikely to interbreed with the parent population, and speciation occurs. If it outcompetes the parent species, voilla the paleontologic punctuated equilibrium is explained.
godot. seems like you're in this field...
Where are we? Can we (current science) make a living cell from a bunch of stuff that we would consider non living ? Can we craft DNA ?
Sorry if this sounds ignorant or is too much for this venue.
|Rodents of Unusual Size - 2009-03-15 |
Dog foxes are cuter. This is scientifically proven.
|Pookles - 2009-03-15 |
This is amazing.
|Simian Pride - 2009-03-15 |
|godot - 2009-03-15 |
To clarify: docility, friendliness to humans, and the "side-effects" of floppy ears, tail wagging, adult barking, coat-changes and loss of the musky "fox smell" all occurred in around 10 generations. The current day population is at 35 generations.
Oops, that's not quite true either. Simian Pride's link above has the scoop.
|fluffy - 2009-03-15 |
Okay, that's pretty surprising.
|facek - 2009-03-15 |
So that connection between melanin and adrenaline explains why blacks are so crazy.
|Tuan Jim - 2009-03-15 |
Cute and interesting. Plus a star for Simian Pride's link.
|mouser - 2009-03-15 |
|papa_november - 2009-03-15 |
So how come these haven't taken off as a trendy new pet?
So, take them on a walk like any other dog.
|Robert DeNegro - 2009-03-15 |
What's the big surprise? This is pretty much how wolves were domesticated to be just about every variety of today's dogs.
The big surprise is:
A) amount of time it took for such a large change to occur in the foxes (less than one human lifetime), and
B) One trait, in this case docility, is linked to many other traits like floppy ears.
Yeah... it's fascinating how prominantly the selected traits show after so few generations.
There are lots of interesting studies about how fast animals are adapting to the intense stressor of humanity - way too fast for random mutation. (But that could easily be due to dormant sequences coming in to play.)
Slightly off topic:
There was a really interesting article in Nature about hive evolution. The basic idea being that a hive must evolve as a hive and that a random mutation in a single ant or bee would not have any advantage. So what is the mechanism of hive evolution ?
Interesting to ponder and I'm fairly drunk.
Only mutations & sexual mixing of the queen's gametes (and those of her consorts) counts. The same is true of a more obvious colony of cells like yourself: mutations in skin & brain cells have no effect on the line. But selection of genes still occurs, as an unfit hive of half-sisters still kills the queen, or reduces her reproductive output.
|Hooper_X - 2009-03-15 |
I wonder what doing the same thing in reverse might get you; breeding for aggressiveness ala certain dog breeds. The groups who want to ban/defend pit bulls/presa canarios/mastiffs/whatever would probably have a field day with this data.
I heard pitbulls were breed for dog fighting... and the dogs that were aggressive to humans were culled. Mostly - and I stress mostly - it's the owners responsible for violent tendencies.
But pitbulls have jaws like a car crusher and once they chomp there is no release.
I'm pretty drunk.
That sounds entirely reasonable, even if you're drunk. (on the other hand, now they are being bred specifically TO attack humans instead of bulls or bears or whatever, so I wonder if that dormant/recessive/whatever gene couldn't switch back on)
|Robin Kestrel - 2009-03-16 |
Especially interesting to me is that in the prior 50 years of non-selective breeding, all they got was foxes better adapted to surviving life in a cage. Despite 50 years of close human contact, they didn't produce tamer foxes until they intentionally selected for that trait, and then that caused a whole slew of other changes in a surprisingly short time.
Great stuff, great comments.
|UnderANeonHalo - 2009-03-16 |
Good video, great comments.
dancingshadow is pretty drunk.
|mcsancherson - 2009-03-16 |
'melanin is connected to adrenaline as well as brain chemicals that modulate behavior'
do i really have to be the first one to say something racist here
|Tuan Jim - 2009-03-16 |
So, if you bred humans for docility, what would they look like after 35 generations?
|glendower - 2009-03-16 |
A fascinating video, but I have a hard time seeing this as some type of parallel to evolution. Here you have one mind selecting which traits get passed on. In nature, there are countless pressures being exerted on a given animal, making the whole process a lot more complex and time consuming.
One can speculate on similar episodes in the geologic past. For example, during the Paleocene-Eocene thermal maximum, when world temperatures spiked 6 degrees C in a few centuries, there was a single focus to natural selection of land species: the ability to dissipate heat. Smaller species, with more surface area/volume, were highly preferred. So, we get an explosion of dwarf mammalian lines in the Eocene like the ancestors to modern horses and primates.
What's important, is that evolution by a single selective factor CAN happen quite rapidly, and that it pulls a LOT of unrelated traits along for the ride.
BTW, current atmospheric carbon levels are rising at a rate only paralleled in the geologic record by the P-E extinction event. Save your baby clothes for future generations.
|dead_cat - 2009-03-16 |
I want one.
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