New hybrid shark found

[Canuckster1127]

That's a good point Stu. I've heard that raised before and I have to confess, I don't know exactly what the facts are in that regard. As best I understand it, Male Ligers or Tigons as generally sterile and females have been known to bear young when mating with a Lion or Tiger. If that's the case either in whole, or to the degree that such a coupling in the wild (which I also think that Ligers and Tigons are a human engineered cross breed that hasn't happened in the wild but again, I'm open to being corrected on that). That's different from what's happening here with the sharks in that the crossbreed apparently aren't having sterility issues.

From a purely evolutionary viewpoint the process of natural selection wouldn't preclude any number of these cross breeds but the issue is whether such a cross would:

1. Occur naturally without the involvement of man taking the process outside of the normal mechanics of natural selection.
2. Result in offspring that are not sterile or at least fertile enough to generate a continued and sustained population.

There's probably a lot more that could be said. Viewing this in this instance I can understand why observation in the wild of such a case would be a matter of significance for those looking for evidence to support the possibility that such things have happened in the past as well. Maybe only 1 in a thousand or 1 in a million would result in a viable long-term creation of a new species that goes on to independently sustain.

I'm not particular threatened by this in the sense that I resist something because it appears to support the possibility or probability of evolution on a larger scale in the more distant past. Method in this regard (assuming it's reasonable to assume that such events in the past took place as this one has currently been observed with is another question that has to be asked too). My faith in God isn't built upon the need to have unexplainable phenomenon that only God can explain. At best, all science will ever be able to do is to demonstrate how God possibly did some things from a purely material perspective. The issues of first cause and whether there is any direct intervention outside the natural order ultimately cannot be answered by science. Science however, by it inherent nature cannot allow for anything outside of the purely physical and natural because its methods are rooted in that realm and when that method is lifted and applied in realms outside of the physical or natural it carries with it those presuppositions which can circle back and lead to self-perpetuating conclusions.

My thoughts anyway. It's an interesting development and it does seem to be a first of some kind in terms of observation of such a natural occurance without man's direct involvement in bringing it about.

[Stu]

Regarding 2, I'm certainly no expert, but Wiki tells me that there have been (few) Ligers that have been fertile enough to mate, though it seems that is the exception to the rule rather than the norm.

Regards 1, two very different scenario's I would think. Shark species aren't necessarily aggressive toward one another, while the big cats are always at odds. We know that if raised together from a young age big cats are more than capable of co-existing, so all you would need is for a female to adopt a baby (without it dying or getting killed first), or some other freak occurrence.

Not sure if you've seen the one Nat Geo (or some such channel) program of a female lioness that adopts a baby springbok. Weird things happen in nature.

Did you see the size of that thing , apparantly lion / tiger crossbreeds can get huge. Here kitty kitty..

[Ivellious]

The big deal about the sharks in regard to 2 is in fact that the entire new population (or most of it) is fertile and capable of reproducing. Ligers and Tigons, as pointed out, can be fertile, but to my knowledge it is very rare, certainly too rare for a population of them to ever develop in the wild. Even for those that are fertile, I read somewhere that ligers and tigons don't live very long due to a number of genetic problems, so that even further hinders them as a species.

Ligers and tigons can get huge! Though tigers themselves tend to be pretty massive in the wild as well (up to 3.3 meters long and 670 pounds). But yeah, by comparison a zoo in Wisconsin had a 1200-pound liger a while back. Kinda scary haha.

[Danieltwotwenty]

The big deal about the sharks in regard to 2 is in fact that the entire new population (or most of it) is fertile and capable of reproducing. Ligers and Tigons, as pointed out, can be fertile, but to my knowledge it is very rare, certainly too rare for a population of them to ever develop in the wild. Even for those that are fertile, I read somewhere that ligers and tigons don't live very long due to a number of genetic problems, so that even further hinders them as a species.

Ligers and tigons can get huge! Though tigers themselves tend to be pretty massive in the wild as well (up to 3.3 meters long and 670 pounds). But yeah, by comparison a zoo in Wisconsin had a 1200-pound liger a while back. Kinda scary haha.

All this means is that these particular sharks were either really compatible that the chance of infertility and genetic problems was decreased significantly that they have thrived or God intevened.
And as I said before just because an event is unlikely does not make it impossible.

Dan

[Ivellious]

I like that quote, Dan... "And as I said before just because an event is unlikely does not make it impossible."

Which is precisely why bashing the Theory of Evolution based on statistics is a flawed argument.

No offense, just saying haha

[Canuckster1127]

A good illustration I've heard with regard to the statistical analysis in these types of issues is to imagine a plane taking off from Los Angeles and flying to Hawaii. It runs out of gas and is going to go down and hit the ocean. From one statistical perpective, the chances that it's going to hit any particular 100 square foot sector of ocean is remarkably small, maybe 1 in 600,000. The chance however that it's going to hit the ocean is 100%. Sometimes the appeal is made to the miniscule possibility of a particular set of circumstances happening and it seems amazingly small. It's not reasonable however, as in the case of this plane to assume that because the chances are so small, that the plane must therefore continue to fly with no fuel.

[Danieltwotwenty]

I like that quote, Dan... "And as I said before just because an event is unlikely does not make it impossible."

Which is precisely why bashing the Theory of Evolution based on statistics is a flawed argument.

No offense, just saying haha

I have never bashed evolution, I think it is a possibility but not concrete yet.


Dan

[Stu]

I like that quote, Dan... "And as I said before just because an event is unlikely does not make it impossible."

Which is precisely why bashing the Theory of Evolution based on statistics is a flawed argument.

No offense, just saying haha

Well in fact it's all about statistics... neo-Darwinian evolution's mechanism is rooted in and highly dependent on statistics; population size and reproduction rates are key factors in generating possible change.

Statistics are key in point mutations. Sometimes a single mutation is ineffective or even deleterious in which case you require two or even three changes simultaneously in order to be beneficial, but the statistical likelihood of this occurring becomes less and less with each new required mutation. Statistics play a crucial role, because it's not like we are talking about a single event, on the contrary, it's a continual cycle of event after event after event.

Come on if we're throwing statistics out of the equation then what is next. Just because the numbers aren't in favour of neo-Darwinism doesn't mean you get to throw them out.

[Ivellious]

But the argument is typically: "The statistics say it is improbable that evolution would happen this way, so it is impossible." My point is, to argue that improbable=impossible is a bad argument.

[Stu]

But the argument is typically: "The statistics say it is improbable that evolution would happen this way, so it is impossible." My point is, to argue that improbable=impossible is a bad argument.

The trouble is that the more times you require an improbable event (specific point mutations via mutation/selection), then at some point one can safely go on to say it is impossible. Evolution from beginning to end is a series of improbable -- some less (or probable), and many much much more than others -- events.

[sandy_mcd]

Evolution from beginning to end is a series of improbable -- some less (or probable), and many much much more than others -- events.

How does one compute the odds?

[sandy_mcd]

Can anyone say "MICRO" evolution?

I can.

Nothing more than an obvious case of adaptation.

Huh?

I am confused with the article, isn't this just interbreeding between two types of sharks?

I think the unusual feature of this is that the two related species have only recently started to interbreed despite having overlapping ranges. So according to standard theory, two species of similar sharks evolved. Despite sharing (in part) the same area, they did not interbreed. Normally species continue to diverge with time. At some point, they may become too different to interbreed, much less produce viable fertile offspring. But here for some reason, crossbreeding is occurring, even though it hadn't in the past. I looked at the paper and other sources and found no speculation as to why this is happening. So it is, in some respect, backward evolution.

[sandy_mcd]

A good illustration I've heard with regard to the statistical analysis in these types of issues is to imagine a plane taking off from Los Angeles and flying to Hawaii. It runs out of gas and is going to go down and hit the ocean. From one statistical perpective, the chances that it's going to hit any particular 100 square foot sector of ocean is remarkably small, maybe 1 in 600,000. The chance however that it's going to hit the ocean is 100%. Sometimes the appeal is made to the miniscule possibility of a particular set of circumstances happening and it seems amazingly small. It's not reasonable however, as in the case of this plane to assume that because the chances are so small, that the plane must therefore continue to fly with no fuel.

Ah, the evolution of the Tue Jan 05, 2010 2:40 pm argument.

I look at it this way. If you have a plane flying from Los Angeles to Hawaii, and it goes down, the probability of the plane hitting any one small patch of ocean is infintisimally small from one point of view, but the chances of the plane hitting the ocean as a whole is 100%. How you frame the question in many ways determines the conclusion.

Let's run the numbers. Flight distance from L.A. to HI is 2551 miles. At 5280 feet per mile and using the odds of 1 in 600,000, this implies that plane will go almost straight down; it cannot deviate sideways from its flight path by more than 11.25 feet. That's pretty unlikely; I suspect it is more probable that plane will hit a blacktipped shark hybrid.


{Edit} Arithmetic error. Allowable deviation is only 2.2 feet.

[Canuckster1127]

I'm consistent if nothing else ...

My point was on the higher level and not so much the actual numbers working out. I'm actually pointing this out as a counter to some of the arguments I've seen from my Young Earth Creationist "cousins" (they don't want to claim me as a brother in some cases.) When statistics are used as an argument against something having happened in this manner, it's popular in some cases (such as William Dembski work) to tout miniscule probability but then lose sight of the fact that however unlikely a particular outcome may be, there in the end has to be some form of outcome no matter how relatively unlikely it is in comparison with the broad specturm of variable factors.

[sandy_mcd]

When statistics are used as an argument against something having happened in this manner, it's popular in some cases (such as William Dembski work) to tout miniscule probability but then lose sight of the fact that however unlikely a particular outcome may be, there in the end has to be some form of outcome no matter how relatively unlikely it is in comparison with the broad specturm of variable factors.

It is amazing how much misunderstanding there is about statistics.

An extension of your example is this one:

Someone rolls a die 12 times.
Which of the following two sequences is more likely to occur?

112233445566
142116234353



Someone rolled a die 12 times.
Which of the following two sequences (one rolled, one made up) is more likely to have been rolled?

112233445566
142116234353