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Lateral view of a Male Baetis (Baetidae) (Blue-Winged Olive) Mayfly Dun from Mystery Creek #43 in New York
Blue-winged Olives
Baetis

Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.

Dorsal view of a Skwala (Perlodidae) (Large Springfly) Stonefly Nymph from the Yakima River in Washington
This Skwala nymph still has a couple months left to go before hatching, but it's still a good representative of its species, which was extremely abundant in my sample for a stonefly of this size. It's obvious why the Yakima is known for its Skwala hatch.
27" brown trout, my largest ever. It was the sub-dominant fish in its pool. After this, I hooked the bigger one, but I couldn't land it.
Troutnut is a project started in 2003 by salmonid ecologist Jason "Troutnut" Neuswanger to help anglers and fly tyers unabashedly embrace the entomological side of the sport. Learn more about Troutnut or support the project for an enhanced experience here.

This topic is about the Mayfly Species Ephemerella excrucians

For trout (if not anglers), this single species is arguably the most important mayfly in North America. In terms of sheer numbers, breadth of distribution and hatch duration, it has a good argument.

Ephemerella excrucians or Pale Morning Dun usually follows its larger sibling Ephemerella dorothea infrequens with which it shares the same common name. What it often lacks in size by comparison is made up for with it's duration, often lasting for months with intermittent peaks. This close relationship with infrequens has led many anglers to confuse Pale Morning Dun biology with that of the multivoltine Baetidae species, having disparate broods that decrease in size as the season advances. Sharing the same common name has not helped to alleviate this misconception.

Until recently, Ephemerella excrucians was considered primarily an upper MidWestern species of some regional importance commonly called Little Red Quill among other names. Recent work by entomologists determined that it is actually the same species as the important Western Pale Morning Dun (prev.Ephemerella inermis), and the lake dwelling Sulphur Dun of the Yellowstone area, (prev.Ephemerella lacustris). Since all three are considered variations of the same species, they have been combined into excrucians, being the original name for the type species reported as far back as the Civil War. Angler speculation had simmered for some time that the stillwater loving Ephemerella lacustris was much more widespread, inhabiting more water types then previously thought and could account for many large sulfurish ephemerellids found in still to very slow water locations throughout the West. With the revisions, this discussion is now moot.

Ephemerella excrucians variability in appearance, habitat preferences, and wide geographical distribution are cause for angler confusion with the changes in classification. They can be pale yellow 18's on a large Oregon river, creamy orange 14's on western lakes and feeder streams, large olive green on CA spring creeks as well as tiny sulfur ones in many Western watersheds. Then there's the little Red Quill on small streams in Wisconsin. Yet, all are the same species.

Example specimens

Wbranch
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Wbranch on Jan 26, 2010January 26th, 2010, 11:07 am EST
Do any of you entomologist types know the true color of the PMD spinner? Dorothea or excrucians. Where I fish in MT there are huge spinner falls, many spents are on the water in the morning and others fall again at various periods during the day. I'd like to tie some with egg sacks as I saw many in July but forgot what color they were. Thanks.
Catskill fly fisher for fifty-five years.
Taxon
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Taxon on Jan 26, 2010January 26th, 2010, 5:01 pm EST
Matt-

Ernest Schwiebert described Ephemerella dorothea dorothea ova as golden yellow, and Ephemerella excrucians ova as yellowish.
Best regards,
Roger Rohrbeck
www.FlyfishingEntomology.com
Wbranch
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Wbranch on Jan 26, 2010January 26th, 2010, 9:43 pm EST
Roger,

I would of bet my box of PMD's that you would of been the person who answered my question. Thanks for the data.
Catskill fly fisher for fifty-five years.
Wiflyfisher
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Wiflyfisher on Jan 27, 2010January 27th, 2010, 1:09 am EST
E. dorothea of the Upper Midwest have a definite yellowish egg sack. I never looked that closely at the PMDs out West. I was always focused on the big gulping rainbows near me.
Taxon
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Taxon on Jan 27, 2010January 27th, 2010, 5:59 am EST
Roger,

I would of bet my box of PMD's that you would of been the person who answered my question. Thanks for the data.


Matt-

Rather a safe bet, that!
Best regards,
Roger Rohrbeck
www.FlyfishingEntomology.com
Entoman
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Northern CA & ID

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Entoman on Jun 30, 2011June 30th, 2011, 10:12 am EDT
Matt,

The Western Pale Morning Dun complex of species (now reduced to just two) have a wide range of water types they inhabit matched only by their variability in appearance. The method and patterns used are also legion. Generally, their sizes and colors have more to do with variations based on locations and habitat rather than between species. They range from size 12 to size 18, with the largest end of the scale tending to be found in lakes and freestones and the smaller end tending to be found in spring creeks. On some of our larger rivers and tailwaters they have been reported as being larger in the spring tending to smaller sizes as the season wears on. I am dubious that they are the same species through this long cycle as some of these reports seem to imply.

Nymphs run from chocolate brown (almost black) to pale cinnamon with many in the middle of the scale having some degree of variagation. They can also be olivaceous in some habitats.

The duns have earned their reputation in literature for having "illusive shades to describe". Their bodies are creamy with highlights of yellow, orange, or olive green that grow stronger on the dorsal surfaces. The wings are highly variable too, running from the palest gray, creamy or even tannish gray, through medium blue dun. The lower leading edges are often washed in color that matches their bodies.

The spinners are typically colored as follows: Reddish brown, cinnamon (rusty), or ginger. They are also commonly a darker shade of their dun stages. The only universal trait is their hyaline wings.

The egg packets are various shades of yellow.

I have found more variability in this group than any other I can think of. From size 12 sulphurish orange in a few Sierra lakes, #16 olivaceous ones on Fall River, to tiny lemon yellow 18's on the Dechutes, they are literally "all over the map". The most common formula (if such a thing could be said) seems to be creamy yellow with a tinge of pale orange highlighting the dorsal surfaces and light dun wings in size 16. The spinners are rusty cinnamon. This formula can be found in waters as desparate as Poindexter Slough or the Missouri River in Montana to Hat Creek or the Lower Yuba in California.

Regards,

Kurt
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
Oldredbarn
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Oldredbarn on Jun 30, 2011June 30th, 2011, 11:29 am EDT
I am dubious that they are the same species through this long cycle as some of these reports seem to imply.


Kurt,

This is an interesting post to me. I think first off we need to admit that we are still as infants when it comes to really having a handle on what's going on out there with these bugs.

Assuming, just for arguments sake, that it is the same species in the lake, in the stream, larger or smaller versions, variations in shades, emerging as the season progresses, etc...What would account for these differences? Different minerals or food types available? What? We know that different stretches of a stream could show differences in alkalinity, chemical makeup, average temps, and so on...These critters have been around a long, long, time...Could it be that the mayfly has adapted/evolved in a particular way to these different environments? How much from the original does a bug have to change before we classify it as a different species?

I looked up "race" in a Webster's and read the following, "an actually or potentially interbreeding group within a species, also, a taxonomic category(as a subspecies) representing such a group." I'm a Homo sapien according to the folks crafting this puzzle/chart and can travel the globe and mate with other Homo sapiens and father offspring and it doesn't matter if the female is Caucasian, or any other shade, she has buck-teeth, or is shaped or looks like me in any similar way...

I guess what I'm asking then, is this, is this what we are talking about with these variations we find? Something akin to different races? Will it end up something like, for example, E dorothea dorothea central michigani vs E dorothea dorothea UP michigani? (we all know I made this up)...

If we found a species that we considered the same but different (larger, smaller, pinker, bluer, whatever)...Would they be able to mate? Do they mate? Could this lead to even more differences? Or the differences we seem to be observing?

I'm not sure if any of this makes any sense or not and I'm not trying to be funny here...Just wondering how others here reconcile these differences that we all have heard of and you mentioned with the science here...Forget for the moment the angling side of it which tosses a whole other wrench in to the mess.

On a lighter note though regardings Matt's original question about egg sac color...We all know he's going to catch more than his share of trout no matter what color he decides on...:) I may have told the story here before about my step-father dying women's shoes at his shoe repair shop and he is actually color blind...Somehow he would follow a recipe for the color and from the "tone" of the color seemed to always get it right...

I agree with Roger...When in doubt ask Ernie
Ernest Schwiebert described Ephemerella dorothea dorothea ova as golden yellow, and Ephemerella excrucians ova as yellowish.
"You say po-tay-toe and I say po-ta-toe...Let's call the whole thing off!" :)

Spence
"Even when my best efforts fail it's a satisfying challenge, and that, after all, is the essence of fly fishing." -Chauncy Lively

"Envy not the man who lives beside the river, but the man the river flows through." Joseph T Heywood
Entoman
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Entoman on Jun 30, 2011June 30th, 2011, 11:30 am EDT
BTW Matt -

Where in montana? If it's a spring creek, I've had really good luck over the years with a sparse Loopwing Paraquill when imitating the gravid females. Light rusty ginger with a hot yellow egg sack to split the tails. Before they lay their eggs they are still pretty lively, which is why I think the upright wing works better. Of course, being easier to see doesn't hurt either. If they're working the spent ones, I don't think you need to bother with the eggs. I've experimented quite a bit in the past and if anything the patterns sans eggs worked better with the spent patterns. Maybe in keeping with the fact that by the time they're spent they're empty? Speculation, but sounds reasonable.

Kurt
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
Oldredbarn
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Novi, MI

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Oldredbarn on Jun 30, 2011June 30th, 2011, 12:00 pm EDT
Hey...One more thing...Since you have humored me this far...We have all read in the literature where color is usually a ways down the list in terms of importance after size, shape, behavior, etc...I think that with color its an approximation anyway...It's always in some sort of flux...We see a bug floating down the stream and we pick it up and turn it over to observe its color etc...The clock has already begun to tick towards that bugs next moult...There is a living bug trying to get out and away from its old "self"/skin and this changes its shade...Sometimes the color of the female is determined by the eggs in her abdomen and as Kurt said above, once shes deposited them her colors going to change again...

I have had real problems trying to photograph flies I tie to display here on this site so folks can check them out. I don't know if it's the lighting in my tying area, I have the wrong color as a back drop, or what. I tied up some nice parachute Paraleps and after I took a picture of them the abdomen came out this ungodly red that didn't look at all like the fly I was holding in my hand!?

In terms of color...You and I and the next guy percieves it differently. I maybe standing in the river with a freshly hatched dun in my hand on an overcast day and you are observing your dun on a sunny one...Not to mention that the trout views things differntly anyway...His close up is a hell of a lot better than we could ever hope to be...

I guess, bottom line, in my humble opinion, just get it close. :)

I guess it's time for me to come up for air now and I'll leave you all alone...
"Even when my best efforts fail it's a satisfying challenge, and that, after all, is the essence of fly fishing." -Chauncy Lively

"Envy not the man who lives beside the river, but the man the river flows through." Joseph T Heywood
Entoman
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Entoman on Jun 30, 2011June 30th, 2011, 2:28 pm EDT
Hi Spence,

Your speculation on the species stuff is very interesting. So far above my pay grade that I can offer little more than to wonder over the issues with you.

As to color, couldn't agree more. Besides, it's pretty hard to photograph a bug fast enough before they change from what the trout see, regardless how they perceive it. Experiment is always in the cards anyway. One of the Brits favorite colors for fishing Olive hatches is orange! What's up with that? Only the bilingual Datus could have helped us with that one.

Along the same line as to eggs:
For Beatids - I've always done best with jet black
Pale Morning Duns - as bright a yellow as I can find.

Neither one is really all that close to the natural but what can I say?
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
Oldredbarn
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Oldredbarn on Jul 1, 2011July 1st, 2011, 7:51 am EDT
Your speculation on the species stuff is very interesting. So far above my pay grade that I can offer little more than to wonder over the issues with you.


You are funny mister...It was quiet here in the office, the folks have started the holiday early it seems, I had consumed way too much tea, and my poor brain is still somewhere on river time...I guess I was contemplating my navel too intently...:)

This is why I fish...There is more than enough stuff going on "out there" to interest me and fooling a fish from time-to-time is just a cherry on top...No?

Spence

I can see why Mr Lively chose to purchase a cabin on the lower section of the North Branch of the Au Sable...I've been thinking about that portion of our float last Saturday ever since...It's a pleasant reverie...Now the pay back...I'll be trimming trees and cleaning out window tracks this weekend along with mowing the lawn etc...



"Even when my best efforts fail it's a satisfying challenge, and that, after all, is the essence of fly fishing." -Chauncy Lively

"Envy not the man who lives beside the river, but the man the river flows through." Joseph T Heywood
Entoman
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Entoman on Jul 1, 2011July 1st, 2011, 9:23 am EDT
I'll be trimming trees and cleaning out window tracks this weekend along with mowing the lawn etc...


"Requiem to an ex-Hippie Outdoorsman's Life in Suburbia". I sense a short story there Spence. Along the lines of the denial-despair-acceptance grieving principals?...

I have a few thoughts on bug interbreeding after all (surprise, surprise... I've been known to pontificate on popcicle sticks). Being capable of producing offspring is not enough as the offspring must also be able to breed as well. I'm thinking of mules and tiger trout as examples. There is a "genetic wall" in place that prevents "natural Selection" from becoming full blown "evolution". We can breed dogs that are as different as Great Danes and Pekinese, but they remain in the final analysis dogs. I believe current thought is that true evolution takes time plus special circumstances to occur. I remember reading somewhere that human induced "evolution" has allegedly occured in the labratory with very simple organisms (viruses or something) but perhaps the experiment results are dubious. Like claims of achieving "cold fusion", I'm not sure if the results stood up to the test of peer review.

An idea came to me and no, it didn't hurt (at least this time). Put males of Ephemerella dorothea infrequens in a controled but optimal environment with female Ephemerella dorothea dorothea's and see what happens? Perhaps thesis fodder? Of course you'd have to retain the offspring to run the test again to see if they continue the propagation of the "species", assuming there are offspring... You'd also have to figure out a way to syncronize their emergences, which is a whole other can of worms (or would the proper analogy be "can of bugs" in this case). In deference to current social sensibilities (and to obtain funding) you'd probably have to give the bugs access to civil unions so as to avoid accusations of heterosexual bias in your controls as well. Any thoughts from the TroutNut scientific community? Jason, Luke, Dave? I'm in a mood to contemplate my navel today.

Regards,

Kurt
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
Troutnut
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Troutnut on Jul 1, 2011July 1st, 2011, 9:53 am EDT
I believe current thought is that true evolution takes time plus special circumstances to occur.


I don't think that's really true, although it depends what you mean by "true evolution." Evolution can simply refer to a change in allele frequencies within a population over time, in which case it requires no special circumstances at all. In fact, constant subtle evolution probably the rule rather than the exception for most species at any given time. Special circumstances can make it much more rapid and dramatic, of course. You could say speciation usually requires special circumstances, though, as it requires something to cause two parts of a population to become reproductively isolated for a while.

I remember reading somewhere that human induced "evolution" has allegedly occured in the labratory with very simple organisms (viruses or something) but perhaps the experiment results are dubious as I'm not sure if the results stood up to the test of peer review.


There have been several documented examples now of both natural and human-induced speciation, in both the lab and the wild, in both bacteria and macroscopic animals. This has long since passed the test of peer review.

Put males of Ephemerella dorothea infrequens in a controled but optimal environment with female Ephemerella dorothea dorothea's and see what happens? Perhaps thesis fodder? Of course you'd have to retain the offspring to run the test again to see if they continue the propagation of the "species"... Of course you'd have to syncronize their emergences


That would be fun to try. I'm not sure you could get them to actually mate with one another, although I wouldn't put anything past bugs that lay their eggs on a blacktop road thinking it's water. We might be able to manually extract and combine the relevant ingredients from the males and females. That's easy enough to do with fish, but I don't know if it's been done with bugs. Konchu, do you know anything about that?

In a simple world with simple definitions, and if all the taxonomy is right, then the offspring of E. dorothea dorothea and E. dorothea infrequens should be fertile. In reality, who knows.
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
Jmd123
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Jmd123 on Jul 1, 2011July 1st, 2011, 9:54 am EDT
Hmmmm...cross-breeding mayfly subspecies in a controlled environment. That would be a major challenge! First you have to set up an artificial stream - not impossible, the U of MI Bio Station has an artificial stream setup along the Maple River with numerous channels for various manipulations (velocity, substrate type, light intensity, etc.). Then you'd have to collect nymphs of the appropriate subspecies, and able to identiy the NYMPHS to those subspecies - again, probably not impossible if you use Schweibert's Nymphs. But then you have to get them to emerge together AND have a large enough enclosed area that they are comfortable enough to go about their mating and egg-laying activities - ah yes, now it gets more complicated. Light intensity can mess with insect behavior pretty severely. An example is "flicker fusion frequency", in which the fraction-of-a-second on-off pulses (e.g., 60 cycles per second) of artificial lighting can either appear to be continous light (as we humans see it) or flickering like a strobe light (which some insects see it). Imagine trying to go about your normal daily activities under the constant flashing of a damned strobe light! You would go buggy yourself...And any kind of enclosure even in natural daylight could also affect their behavior so that would be something else to work out. Maybe not impossible, but surely not easy.

But you're right, Kurt, it would make a good PhD research project. Too bad I'm too old for that now and have already been there (I was in a PhD program at the U of MO in '96-'97) and don't really want to go back (my advisor was a self-serving a-hole and I have no desire to spend all day, evey day, for years on end hunched behind a microscope picking bugs)...

Jonathon
No matter how big the one you just caught is, there's always a bigger one out there somewhere...
Oldredbarn
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Oldredbarn on Jul 1, 2011July 1st, 2011, 10:01 am EDT
"Requiem to an ex-Hippie Outdoorsman's Life in Suburbia". I sense a short story there Spence. Along the lines of the denial-despair-acceptance grieving principals?...


Think "Crime & Punishment"...:) Maybe Camus' "Myth of Sisyphus"...

My real problem is with me...Surprise, surprise...I have neighbors that are driving me to distraction and I never thought in a million years that I'd find myself in this position! On one side the clover is creeping in to my lawn at record speeds and the guy on the other side, originally from Bagdad, hasn't a clue...His front yard is so full of weeds my friends at Sierra Club will be stopping by soon to give him an award. He's putting up permanent "poles" of some sort in the back yard against the homeowners association guidlines and no one but me cares...:) The association has already told me that they are powerless and I replied, "I'm not. Good luck getting my dues next season."

Anyway! If I was in retirement mode I'd like to try some experiments...Unfortunately the riverkeepers up north are so bogged down in legal fights there's little dough for any kind of studies these days...We used to fund some things with grad students etc but a good deal of that has been put on hold.

I have noticed, and should look into it a little more, that there are floating bug traps in different locations this season along different spots on the Au Sable...Maybe if I can figure out who is behind it there may be a report in it for this site...

Anyway...Happy Independence Day and think of me from time-to-time this weekend as I labor in my own person Gulag! :)

Spence
"Even when my best efforts fail it's a satisfying challenge, and that, after all, is the essence of fly fishing." -Chauncy Lively

"Envy not the man who lives beside the river, but the man the river flows through." Joseph T Heywood
Konchu
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Konchu on Jul 1, 2011July 1st, 2011, 12:57 pm EDT
just a quick response to some of this

evolution means a lot of different things to a lot of different folks. most people think of evolution as a slow process, but aspects of it on various scales are not necessarily so; some of you may have heard of punctuated equilibrium (a.k.a. "evolution by jerks" by its detractors).

yes, mayflies can be experimentally bred in the lab. I have not done it, but know people who do. it is an ok test that yields circumstantial evidence about species. tough, though, because many species do not always require mating for reproduction (asexual or parthenogenetic reproduction) and some combinations may produce progeny that may or may not be fertile themselves and require additional time and tests.

am trying to do some dna work now with colleagues in Canada, exploring Ephemerella and many others. we still need more material to expand the stories we see unfolding before us. lots of surprises. if anybody wants to contribute fresh specimens, especially from the Western USA, PM or email me and we can discuss it. starting to get very specific about what is needed and what is not. several of you already have helped out, and I'm extremely grateful for it. I, or someone, should revive the thread where I initially made a plea for specimens. I'm not doing this to disrupt taxonomy or trying to prove any preconceived notions, just exploring the fascinating world out there and letting the chips fall where they may. if anything I hope that all this increases the stability of the language that we use to identify with our environment.

Hope everyone has a great weekend. Happy Independence Day to my fellow Americans! It's great to have the freedom to blather online and pursue our own curiosities.
Entoman
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Entoman on Jul 1, 2011July 1st, 2011, 1:08 pm EDT
Jason -

Thanks for the input. I was hoping you'd chime in. As far as "true evolution" (putting allele frequencies aside, whatever they are:)) I meant the point beyond natural selection which is really natural "dog breeding". There has to be a point where a critter can breed multi-generations with itself but not with it's source species, right? Or am I being too simplistic.

There have been several documented examples now of both natural and human-induced speciation, in both the lab and the wild, in both bacteria and macroscopic animals. This has long since passed the test of peer review.
Ah.. Figured you'd know about this. Thought it was true but the press is great with the "Frankenstein" sensationalism but not so good at follow -up. I think they also confused the story with gene splicing and chemical soup experiments which are entirely different things, right?

See what you started Spence? Thank goodness you have a key to the Gulag so you can always run up to the river when things get too hairy.:)
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
Entoman
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Entoman on Jul 1, 2011July 1st, 2011, 2:00 pm EDT
Konchu -

some of you may have heard of punctuated equilibrium


Yes, that is the theory I was referring to regarding "special circumstances", though I couldn't remember it's name. There are a few other credible ones too, I seem to at least remember that.

I'm not doing this to disrupt taxonomy or trying to prove any preconceived notions, just exploring the fascinating world out there and letting the chips fall where they may.

Mess with Needham too much Konchu and the pithforks will come out!:)
Seriously though, the search for truth is the search for truth and always woth pursuing, whatever impact it has on our own comfortable little worlds. To do otherwise is to stop thinking, which is tantamount to suicide. I'm hoping for the day when genetic advances provide relative closure. Maybe the lumpers and splitters will have to cancel their taxonomic wrestling contests. Or will they just move to the new genetic venue? Please... Say it 'aint so, Joe!

Ditto you're comments on Independance day. Happy Fourth to all!

Kurt
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
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Troutnut on Jul 1, 2011July 1st, 2011, 2:30 pm EDT
As far as "true evolution" (putting allele frequencies aside, whatever they are:)) I meant the point beyond natural selection which is really natural "dog breeding".


Allele frequencies, basically, represent the prominence of certain traits in the population. For a made-up example, suppose the prominence of brown to blonde hair today is 70% to 30%, and in fifty years it's 60% to 40%. That's a change in allele frequency, and it's a type of evolution.

I'm not sure what "beyond natural selection" would mean. Long-term evolution is simply a combination of natural selection, gene flow, genetic drift, and a few other things acting over a long enough period of time.

There has to be a point where a critter can breed multi-generations with itself but not with it's source species, right? Or am I being too simplistic.


Yeah, that's a basic definition of speciation, the point at which two species are said to have split from one. Of course it gets difficult to determine whether things actually are distinct species when you can't actually try to inter-breed them, or when they reproduce asexually. As with most things in biology, coming up with a definition that always works for every organism is surprisingly hard.

Thought it was true but the press is great with the "Frankenstein" sensationalism but not so good at follow -up. I think they also confused the story with gene splicing and chemical soup experiments which are entirely different things, right?


Yeah, those are totally different.

Yes, that is the theory I was referring to regarding "special circumstances", though I couldn't remember it's name. There are a few other credible ones too, I seem to at least remember that.


Yeah, there's an ongoing "debate" between punctuated equilibrium (this idea that populations undergo short bursts of rapid evolutionary change, in between long periods of stability) and gradualism (the idea that changes mostly accumulate over time). In reality this debate has been over-hyped quite a bit. I think most biologists recognize that the two ideas are compatible, and it's quite clear that both processes are fairly common. The main debate is just a difference of opinion about how much of the world's total biodiversity can be attributed to each process.
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
Konchu
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Konchu on Jul 1, 2011July 1st, 2011, 7:43 pm EDT
just to murky the waters, speciation and differentiation are sometimes separate processes

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