Evolution

[ATM]

HOW DO YOU MENTION BACON AT INGO AND NOT GET A RESPONSE??? WTF

We've seen it. Just not on her.
https://www.indianagunowners.com/forums/114350-post32.html

 

[dburkhead]

So which of those is a new species?

The Talk Origins FAQ link discusses several cases of new species (as defined by biologists) being observed.

The Ring Species discussion was by way of illustrating the mechanism of speciation: A -> B -> C -> D -> E with each consecutive step interbreeding and being, by the "does not interbreed" definition of species, a single species, but the end points (A and E) not interbreeding and so, by that same definition, not the same species. Thus the special term "ring species." Once something happens to "take out" the middle (in the Gulls case, say a plague destroying the Canadian gulls), you've now got two species where you had one before.

The dog example was to show that a single species can develop into a ring species due to selection pressure. Try breeding toys directly with one of the giant breeds. It isn't going to happen. Even with artificial insemination if the bitch is the toy, an attempted cross would most likely lead to a dead bitch (unless she miscarries early. In the bitch is the giant, it also almost certainly won't carry to term.

With dogs, because the various breeds are not geographically separated and there are so many potential breeding paths from toy to giant, the likelihood of something "knocking out" the middle, reproductively isolating the toys from the giants is extremely unlikely. For the arctic gulls, however, it's not at all unlikely (over the long term).

So:

We can observe that mutations happen altering the traits of organisms and sometimes presenting entirely new traits.

We can observe that natural selection occurs, which tends to "weed out" those traits that are particularly unfit for a particular environment.

We can observe that the combination can lead to enough variation within a species to where the extremes are not interfertile--cannot reproduce with each other.

We can observe that environmental changes (which can include geological effects, climate changes from various sources, the arrival of new predators--look at Australia for an example of that, or look at all kinds of examples when the predator that arrives is "man"--and so forth) can decimate large chunks of a population--things entirely capable of taking out the middle of a ring species.

We have seen that simply isolating one population of a species from another leads to differences in the two groups arising over time. Over historical times the changes are usually modest, but there is simply no reason to think that the "drift" will stop over longer time periods.

Summing up:
New traits arising in organisms: observed
Variation within a species reaching a point where some members cannot interbreed with some others: observed
Isolation of one population of a species from other populations: observed
Weeding of various traits out of a species through selection pressure: observed
Such "weeding" sufficiently severe as to seriously threaten the survival of the species (a situation where only the "extremes" are likely to survive): observed.

Everything necessary for speciation has been observed in multiple instances. All of them do take time, however, and pulling the combination together in a single population in sequence (start with one species, see the variation increase or see two subpopulations get isolated and drift away from each other, see the destruction of the middle of a ring species or see the isolated subpopulations drift far enough that they can no longer interbreed, and see the the end result is two distinct species) is rarer but it is seen on occasion in species that have very fast reproduction cycles (which lets you go through the steps quickly).

All the required elements are seen individually pretty much across the board. And the combination leading to speciation is seen in those cases where generations are fast enough to see it happen within recorded time.

 

[rhino]

The true secrets of evolution will only be revealed when the mechanism which caused pigs to evolve the bacon gene is fully understood.

On the other hand, the bacon gene may be what leads to the premature death of almost all domestic pigs . . .

 

[bigg cheese]

Not that I want to get involved... wait.. yes I do .. I feed off of this kind of stuff!

The categorization system today is complete crap. Honestly.

What one needs to focus on is "kinds." A feline will not and has never been shown to bear a non-feline.

*(begin flaming... again, I feed off this kind of discussion )

 

[cce1302]

Not that I want to get involved... wait.. yes I do .. I feed off of this kind of stuff!

The categorization system today is complete crap. Honestly.

What one needs to focus on is "kinds." A feline will not and has never been shown to bear a non-feline.

*(begin flaming... again, I feed off this kind of discussion )

But what about all those links that have been discovered? You know, the half lizard/half bird things, and the half fish/half something else.
Oh. You mean they haven't found them yet? Is that why they're called missing links? Well, no worries. I'm sure they'll find some more good ones, like the Nebraska and Piltdown skeletons.

 

[dburkhead]

Not that I want to get involved... wait.. yes I do .. I feed off of this kind of stuff!

The categorization system today is complete crap. Honestly.

What one needs to focus on is "kinds." A feline will not and has never been shown to bear a non-feline.

*(begin flaming... again, I feed off this kind of discussion )

Ah, the old moving goalposts trick.

The question was whether new species have been observed to evolve.

The answer is "yes."

 

[dburkhead]

But what about all those links that have been discovered? You know, the half lizard/half bird things,

You mean like Archeopterix? Oh, and recent discoveries (skin casts mainly) that show dinosaurs with feathers?

and the half fish/half something else.

Fossil record: Ichthyostega and other proto-amphibians.

Modern day: Walking catfish. Lungfish. Axolotl. Other items that contain features of both fish and amphibians.

Oh. You mean they haven't found them yet? Is that why they're called missing links?

"Missing link" is a misnomer. Lots of "missing links" have been found. Where we had A -> gap -> Z, we now have A -> smaller gap -> M -> smaller gap -> Z or even A -> very small gap -> E -> very small gap -> H -> very small gap . . . and so on.

Scientists keep finding these "missing links," but since it's not a complete, unbroken geneology of "begats" folk who want to believe otherwise keep pointing at those ever smaller gaps as if they had the same significance as no intermediate steps at all.

Well, no worries. I'm sure they'll find some more good ones, like the Nebraska and Piltdown skeletons.

And yet, strangely enough it was scientists working within the scientific method that exposed the hoaxes as hoaxes. One of the big clues that Piltdown was a hoax was that it was completely contrary to the evolutionary evidence of the day. Existing evidence was that in early hominids dentition was becoming more modern while cranial structure was remaining more simian. Then, along comes this "fossil" that completely reversed that trend. Red flags went up all over the place with eventual exposure of the hoax by the scientific community. And even before the hoax was confirmed, it was rapidly seen to fall outside any possible path of human evolution.

As for Nebraska Man. The individual who described that has been himself described as "a first rate administrator and a third-rate scientist." So we had someone trying to make a name for himself jumping the gun and making ridiculous assertions on too little evidence. Do you think that science, biology, and evolution is the only place that happens? I've certainly seen enough of it from sources perporting to criticize or "refute" Evolution.

The key to science, however, is to ask the question "how would I know if this were wrong"? The key to something being a "science" is being able to define situations where "if X happens" (or conversly "if Y does not happen") then my theory is wrong. In physics such a case would be "if I drop a hammer and it fails to fall at thus and so velocity and acceleration (under conditions where we can neglect other forces) then the Theory of Gravity is wrong. In Evolution, an example would be: if someone found a skeleton of a fully formed, modern hominid among a group of dinosaurs (under circumstances which eliminate the possibility of hoax or misinterpretation) then the Theory of Evolution is wrong. There actually have been numerous smaller tests--things that, if they happened, would disprove the ToE--over the course of the last couple of centuries. It's passed all of them. Oh, some of the details have needed to be wrangled out and that work is still ongoing (things like gradualism vs. punctuated equilibrium and what not), but that's normal in science. I mean, we're still learning stuff about gravity and it's presenting us with some surprises. We don't just toss out the Theory of Gravity because there are still unanswered question so I wonder why some people are so insistent that we do that with the ToE.