What is the mechanism that stops genetic differences from accumulating to the point of speciation?

a reply to: GetHyped

And can you ask the question again so one doesn't require an oxford scholar to translate?

If you want my opinion, evolution is a cake mix of cause and effect to put it simply.

a reply to: sycomix

I think that the argument against evolution/speciation falls into two camps:

1) Speciation is entirely possible (after all, it's just accumulated genetic change over a length of time) but there hasn't been enough time for this to occur (because the earth is 6,000 to 10,000 years old)

2) Speciation is impossible because *hand waving*

1) is easily debunked, 2) requires more clarification from the creationist camp than just hand waving to be taken seriously. The purpose of this thread is to explore 2) in more detail/.

a reply to: Thecakeisalie

I hate applying the KISS method to science. It allows for people to misinterpret what it is. People should just accept that science is difficult and complicated. Dumbing it down for someone creates opportunities for people like YECers to create their stupid strawmans against evolution.

Besides, there is nothing wrong with having a large vocabulary and not being adverse to using it. I enjoy being able to use more uncommon words in favor of common ones. The more uncommon ones allow me to be more specific with what I am saying. For instance, I didn't need a thesaurus or a dictionary to understand your first post in this thread. I knew every word.

a reply to: Thecakeisalie

The terminology I've chosen is specific to avoid any dictionary abuse from creationists. However, as you asked, I will break my OP down a bit more:

1) Evolution is genetic change sorted by natural selection

2) If, say, two populations of bear are separated into different environments, the selective pressures needed for the different populations to survive will give rise to different genetic changes (mutations, etc) beneficial to survival and reproduction being selected

3) If these populations are separated for long enough and there's enough environmental pressure to keep adapting and selecting favorable changes, the two populations will be too genetically different to reproduce (a common definition of 'species')

4) Creationists will often argue that small genetic change is possible (microevolution), but large genetic changes is impossible (macroevolution/speciation)

The purpose of this thread is to get creationists to clearly define exactly what, biologically, stops 3) from happening. Where is this barrier? How does this barrier stop genetic changes from adding up too much past some arbitrary point?

a reply to: GetHyped

I think you missed what I said, I didn't say diddly about creationism or evolutionism, I attempted to answer the question posed by the OP. Can species branch off into a new species. I suspect we have evidence that this has happened and will happen again. Maybe the whole RH blood factor thing is a hint of this. We RH- folks look just like anyone else but do not carry this common gene marker, maybe we are on the verge of this speciation???

a reply to: sycomix

I appreciate your answer but it's not really on topic. I accept the evidence for evolution and do not argue that genetic change can't accumulate beyond any line in the sand. My question is to creationists who claim that genetic change can't accumulate beyond any line in the sand. I am asking for them to explain what exactly puts a cap on genetic changes accumulating.

If someone accepts that small genetic changes can take place (which they call microevolution), what stops large genetic changes taking place (which they call macroevolution)?

a reply to: GetHyped

2) If, say, two populations of bear are separated into different environments, the selective pressures needed for the different populations to survive will give rise to different genetic changes (mutations, etc) beneficial to survival and reproduction being selected

it doesnt work like that. genetic mutation is a lottery, essentially. genes dont necessarily mutate to better suit an environment, but if mutation does result in this advantage, then that bear will consequently score better than a bear whose mutations didnt have that result. for every organism that successfully adapts, there are a hundred more who lost the lottery.

as to the actual question...picking fights with theists is generally a fruitless endeavor.

a reply to: GetHyped

Ahh ok, I get ya now. I misunderstood the question I guess.

originally posted by: Krazysh0t
a reply to: Thecakeisalie

I hate applying the KISS method to science. It allows for people to misinterpret what it is. People should just accept that science is difficult and complicated. Dumbing it down for someone creates opportunities for people like YECers to create their stupid strawmans against evolution.

Besides, there is nothing wrong with having a large vocabulary and not being adverse to using it. I enjoy being able to use more uncommon words in favor of common ones. The more uncommon ones allow me to be more specific with what I am saying. For instance, I didn't need a thesaurus or a dictionary to understand your first post in this thread. I knew every word.

Don't get me wrong-Having the the right words to say at the right time is good, but it is intimidating to some. Brian Greene has done a great job of educating us about string theory without overwhelming us with the algorithms. There is nothing wrong with being a wordsmith, but sometimes it can amount to nothing if few can understand what you are trying to say.

a reply to: Thecakeisalie

Look, if the people are willing to learn the more complicated meanings once they understand the simpler ones, then by all means carry on. It's just that all too often I see people taking the dumbed down versions and trying to repeat those as official science cannon.

It's not like I'm endorsing that we teach kids Calculus before Algebra so that they can understand that a line is actually a continuous set of points with a constant rate of change or anything. I'm ok with teaching the Algebra definition of a line first (because it is simpler and easier to understand) then later teaching the Calculus version. But trainee needs to understand that that isn't the end all be all definition as well.

The mechanism that prevents speciasation is constant migration and breeding.

With every pair that mate and have offfspring, the offspring will have a random combination of genes from both parents taking into account dominant and recessive genes as well as some random mutations. Over time, the dominant genes will become a substantial majority of the population. As time goes by, genes will change in length, and those genetic markers used to line up genes will no longer match. Mutations include genes being reversed back-to-front, becoming longer, shorter, swapping locations, or even disappearing. Two adults might try and mate, but they won't have any success.

Ah yes. THE question. The one that no evolution denier will ever answer but they will swear up and down that macro evolution is wrong. I made a thread like this not too long ago called, A challenge for evolution deniers: Explain why changes do not continue to add up over time. It went 17 pages of folks trying to AVOID answering the question and looking for ways to change the subject. I'm assuming this one will do the same, although it is worded far more eloquently than mine was, so hopefully it can bypass the phase where nobody understands what is actually being asked. Good luck!

The premise of this thread assumes that speciation occurs from a build up of genetic mutations. Essentially this is a clone of Barc's thread. I brought up the same issues there which I'm happy to argue about all over again

originally posted by: GetHyped
Furthermore, "species" is nothing more than a man-made construct. It's not a tangible "thing". We could define species in any way we please so this barrier that stops genetic change in populations from accumulating to the arbitrary point of speciation needs to be defined and supported with evidence. Otherwise, the argument is baseless.

You claim the concept of species, and therefore speciation, is an intangible human construct that can be defined in any way we wish.

If that's the case, then :

originally posted by: GetHyped
Can you describe and present evidence for the mechanism that stops genetic differences in populations from accumulating to the point of speciation?

is not a valid question within the context which you've described speciation.

It would help if you can offer your definition of species and how the process of speciation works. If you have studies on hand which have shown conclusively that accumulation of genetic mutations are the sole (or predominant) cause of speciation in both prokaryotic and eukaryotic organisms (vs say, recombination or HGT), I'd be grateful to read them over.

a reply to: GetHyped

1) Evolution is genetic change sorted by natural selection

If this is your view of how evolution proceeds, then I'm sorry, but you're completely off base.

a reply to: hknudzkknexnt

I'm sure there's a biological code that doesn't let ones genetics color outside the lines as a career choice

Why would that be?

It seems as if, for once, I agree with PhotonEffect, who says

(The OP's) is not a valid question within the context which (the OP has) described speciation.

But I have a question. If 'speciation' cannot be rigidly defined, how does one distinguish 'microevolution' from 'macroevolution'?

a reply to: PhotonEffect

I've addressed the definition of speciation here. If anything, the ambiguity further weakens the creationist argument of micro/macroevolution.

a reply to: GetHyped

Yes, that's the point.

a reply to: GetHyped

Good topic. Will make a category in the library. Will post my thoughts later on.
Don't expect much from the other camp. They seem to have a problem with the notion of "evidence".

originally posted by: Titen-Sxull
a reply to: Pistoche

Actually you raise a very good point. The definition of a species is, to some extent, still arbitrary, however most scientists agree that it has to do with infertility between the two populations. As you point out though sometimes species that are still related but would seem on the surface to be quite different can produce hybrids such as the beefalo or liger.

I think the point of this thread, though, is that there is no built-in mechanism that would STOP animals from crossing the species boundary and thus no mechanism that would prevent the tree of life from expanding out further and further branches given long enough. Even if we don't agree 100% on what a species is there is no genetic boundary built in to stop incremental changes from adding up over generations to produce something new and, if that new population is driven far enough it will become a new species.

The fact that we can disagree on where that species line lies shows how long evolution often takes. For example dogs are now a subspecies of wolves while some used to think they were a separate species but either way the variety of breeds is evidence of evolution.

Creationists often reference the Biblical passage that says God created animals after their "kind" which some argue means that animals can evolve but not outside their Genus, they had to admit this after it was shown that new species could emerge. The goalposts of creationism are constantly moving.

Sure they are.

And so are evolutionism, but don't see you complaining about that.

Why not just freaking admit that both of them are a COMPLETE WASTE OF TIME.

I often wonder what part of the brain is it, that gets all wrapped up in processes that are designed to never actually find the truth, but just go on infinitely, and that somehow knowing a flawed useless process is somehow going to tell you something ; but never does,

Exists in the most everyone but not myself ??

Oh, I bet I am just crazy with the full easy realization that science in this matter is so incredibly lacking and controlled that it interests me as much as sitting staring at a blank wall.