Social Question

iamthemob's avatar

Does the science of dog breeding provide the best way to explain the genetic mechanisms behind evolution?

Asked by iamthemob (17221points) November 13th, 2010

I have been attempting to figure out a way to explain, particularly to myself, a simple way to determine the genetic explanations behind the most “controversial” mechanisms of evolution.

The genetic nature of dog breeding seems to be the best one, and it explains, for me (1) the introduction of genetic infomation that creates new traits that weren’t there before, (2) the minor amount of genetic change necessary to make big differences, and (3) the ability of the environment to cause sharing of genetic information cross-species.

The “tandem repeats” in the dog’s genome has been correlated to significant physical changes. These are present in all mammals, but not at all to the extent in dogs. This has been shown why they can change so quickly. They also share 99.8% of their genome, but are so physically different. The size of dogs has been linked to changes in a single gene (IGF-1). This explains how we can be so closely related to things that are so different from us, and also how very little change in protein-coding can create so much difference. Finally, the genetic defects brought in through breeding have shown how genetic material can be introduced through shared environments. Doctors have used viral DNA to introduce material that codes for vitamin A into the bloodstream of dogs going blind for lack of it, and have been able to show that the viral DNA attaches to the dog’s to create a new coding mechanism repairing eyesight.

What do people think? And are there any other examples that can show, generally and solidly, the genetic (arguably the more difficult) mechanisms behind diversification?

Observing members: 0 Composing members: 0

66 Answers

LuckyGuy's avatar

I’m not sure if dogs are the “best” example but they are a good example that people can understand and see with their own eyes. The question “When did wild poodles roam the earth?(David Feldman)” is answered by genetics.
Another example is the latest and greatest breed of antibiotic resistant bacteria. It doesn’t take long for the buggers to mutate into something that a particular antibiotic can’t kill. The ones that are bothering us today did not arrive here on the ark. They mutated and evolved to defeat our puny weapons.

iamthemob's avatar

Another example is the latest and greatest breed of antibiotic resistant bacteria. It doesn’t take long for the buggers to mutate into something that a particular antibiotic can’t kill. The ones that are bothering us today did not arrive here on the ark. They mutated and evolved to defeat our puny weapons.

My problem with this example, which I think is good for some aspects of evolution, is that it really goes to selection mechanisms – that’s not something that people necessarily have a problem with, but it’s not difficult to say that isn’t explained by mutation, but rather that bacteria that was resistant already was the bacteria that reproduced, and therefore became a dominant or more common form.

LuckyGuy's avatar

Oh ok. How about the new genetically modified energy crops? Sorghum-Sudan crosses that yield 20 tons per acre? The scientists at Ceres made 100,000 genetic variations and selected crops that were optimized for specific soils and latitudes. That is the BTU equivalent of 500–1000 gallons of oil per acre.

Ooooo!!! The glow bunny! Scientist put the luminescence gene in a rabbit and it glows under UV light.

In the same article above, they mention “South Korean scientists have recently cloned cats that glow red when exposed to ultraviolet rays.”
Looks like Designer pets are possible.

I wonder if they can make certain body parts glow in the dark. Think how much we’d save by not buying romantic candles. “Oh Harry! You are happy to see me!”
“And you, my dear, are chilly!”

nicobanks's avatar

Well, if it works for you, it works for you. But, in general, I wouldn’t say this would be the best way to explain or exemplify evolution because I think most people readily accept and understand microevolution. It’s macroevolution – how a new species can evolve from another; how we could all trace back to single-celled organism – that people have trouble understanding. But maybe I’m just speaking for myself.

cazzie's avatar

You are barking up the wrong tree.

Aqua's avatar

One important point to remember is that evolution is a result of natural selection, and it only happens at the population level. Evolution cannot occur at the individual level. Evolution is a change in gene frequencies from one generation to the next. Artificial selection caused by humans breeding or genetically modifying an organism is not an example of evolution. Evolution is caused when organisms that are better adapted to their environment survive and are able to reproduce better than those without certain traits. Those adaptations are mainly caused by random mutations. It’s also important to remember that evolutionary processes aren’t goal oriented, unlike artificial selection.

iamthemob's avatar

@nicobanks – that’s what I think the dog example addresses, considering the massive changes in a breed with great variety that rest on single genes. As well as the viral DNA example which is fairly concrete (thanks also to @worriedguy for the other example).

Macroevolution was the one I was thinking of, simply because I was stuck on the creation of new genetic information…and the viral DNA and small change examples help show that (1) it doesn’t take much mutation, and (2) new information isn’t new…it’s just repeating old information or adding information from someplace else. If we consider DNA as a strand of information, that information is expressed through the sequence of base pairs. Adding a new base pair – which is “old information” just in a new place, and it’s easy to see how that happens, makes the strand express something new. And understanding how little it takes shows that, over time, the littlest changes add up to very, very big differences.

iamthemob's avatar

@Aqua – I don’t see how either of those are important, though. Considering the analogy is for showing the genetic mutation aspects, and not the selection aspects, of evolution, the ideas that evolution is not goal-oriented and affects populations over time isn’t really addressed.

nicobanks's avatar

But two breeds of dog are still both dogs. They can and will mate with each other. They are the same species. And really, they look pretty much the same. There are striking similarities between even a Great Dane and a Pug. The difference between a fish and a human, on the other hand, is much more difficult to understand. The “great variety” that can rest on a single gene is not really so great at all, in the grand scheme of things: you can’t get a human from messing with a single bonobo gene; you can’t get a rabbit from messing with a single kangaroo gene; etc.

Of course, I understand that “over time, the littlest changes add up to very, very big differences,” but thinking about dog breeding in no way brings that to light. Not for me, anyway.

iamthemob's avatar

@nicobanks – Picture a Great Dane mating with a chihuahua. It might happen, but the biological danger of it is preventative in most cases. The two are separated by only a .2% genetic difference.

If it was a full 1%, do you think, logically, it’s likely for them to still be reproductively compatible?

Aqua's avatar

The point is that the mutation aspects are random, and only the mutations that would cause an organism to reproduce or survive better would be “selected” in nature. I guess artificial selection can be used to show how traits can be passed on and how a species can change on a time scale that we can actually experience, but dog breeding is a better example of genetic variation due to recombination, not mutations. Just remember that it’s not really evolution.

nicobanks's avatar

“If it was a full 1%, do you think, logically, it’s likely for them to still be reproductively compatible?”

But it isn’t a full 1%, is it.

Look, as I said, if understanding the genetics of dog breeding helped you understand evolution, I think that’s great. But you’re asking if it’s a good way to help others understand. I can only speak for myself but my answer is No, it isn’t, it doesn’t help me understand at all, because with dog breeding you’re talking about changes within a single species, and for the most part that is not what we’re talking about when we talk about evolution. The genetics of dog breeding just does not bring evolution to light for me. It just doesn’t, and not because I don’t understand evolution, or the genetics of dog breeding, or your arguments – so there’s really no point in debating this with me. My answer is No and will continue to be No. You’ll just have to accept it: what worked for you will not work for me.

iamthemob's avatar

@Aqua – the thing is, it’s both. For instance, they did an experiment with domesticated wolves and dogs. Dogs appear to be hard-wired to look to humans for assistance when they don’t have all the information. They conducted an experiment to see if this originated in wolves by placing food in two buckets on the right and left side of a human, and put the animals at a distance where they could tell that both buckets had food. They held the animals at a distance, and had the human get their attention, and point to one of the buckets. The dogs automatically paid attention and went to the bucket with food…and the wolves didn’t pay attention at all, and ignored the suggestion.

Among other, it showed that the communicative bond between dogs and humans is hardwired but developed sometime after domestication. Dogs able to communicate, listen, etc. to humans were more likely to be bred, or more likely to breed, etc. Although there’s still an artificial aspect to it, it arose more naturally (e.g., it’s a universal characteristic of dogs, and the breeds are chosen for specific characteristic).

@nicobanks – when you say that it isn’t a full percent, is it…you’re not addressing the question. We could get into a full conversation about the other aspects of it, and talk about it in more detail, but you’d have to be willing to go through it. I can accept that you’re saying it won’t work for you. But…we haven’t really had the full discussion now, have we? ’-)

nicobanks's avatar

“we haven’t really had the full discussion”

I really think we have. By which I don’t mean that you couldn’t possibly have anything more to say on the subject. I’m sure you have more to say, and that’s fine. My point is, I have not: My final answer to your question is “No, not for me,” even though I understand what you’re saying. I realize that last point comes down to you trusting me, and I admit, why should you trust a stranger online? All the same, that’s what I’m asking you to do. And if you don’t, oh well, either way, I’m done.

iamthemob's avatar

Erg…that’s so cryptic! :-)

nicobanks's avatar

Sorry… don’t mean to be :P No hard feelings, I hope.

iamthemob's avatar

It all depends – what did work for you on the explanation front?

nicobanks's avatar

Well, to be honest, nothing. It took a lot of reading, more reading, more reading… slow intake of the information until sufficient understanding came about to be able to take the whole thing for granted. There was never an aha! moment like I’ve had with some other things. Just… eventual, sufficient comprehension.

iamthemob's avatar

@nicobanks – That’s pretty much where I was until I reexamined a couple of the assumptions that I had and realized that I was holding onto them without really having a complete conceptual understanding of them. I just hate that. ;-)

LuckyGuy's avatar

Would you have an “aha moment” if you saw a glow in the dark bunny? The genetic material was introduced from a different species that produced an animal less prone to survival. It glows in the dark for crissake! I’ll bet the neighborhood predators would love that.
What I find interesting is that researchers decided to take one gene out of how many million and swap it to make a new creature. They planned the move in advance, did the science and the successfully executed the plan. That means they have a pretty good understanding of the mechanism.
Genetics will play a larger role in our lives within the next 10 years. The human map is complete. Now it’s time to work the magic.

cockswain's avatar

I think the dog example is a reasonable one, but you’re never going to see much beyond the microevolution scale because a dog’s generation is like 4 years. You need thousands of generations at least to speciate.

I don’t like examples involving bacteria because they reproduce asexually. They don’t get the genetic recombination during meiosis since they reproduce mitotically.

You have to think about the fact that hominids first started appearing from apes roughly 8 million years ago (mya). 7 mya you had pre-australopiths, 4 mya you started getting australopiths, then finally the genus Homo began appearing about 2 mya. Then there were multiple species of them too (H. ergaster, H. erectus, H. heidelbergensis,). Then sapiens began to appear finally only about 100,000 years ago.

That’s not quite what you’re asking, but there just doesn’t seem anything controversial about the science from my perspective. This process takes millions of years for the genes to become substantially different enough to speciate.

What I find really interesting is the fact that cells from animal to animal are generally the same (except the DNA).

@iamthemob , I know that answer doesn’t give you exactly what you’re looking for, but maybe it’s a start. I can recommend a book, “Essentials of Physical Anthropology”, (Jurmain et al, 2009).

I know of no conclusive study involving vertebrates that has monitored the full genetic change from one species to the next across thousands of generations. I don’t know how you could speciate without natural selection factors at play though. Without an ice age to separate early hominids, there wouldn’t have been the separation of populations for a few hundred thousand years that resulted in subtle speciation (Neandertals vs. Sapiens) I hope I stated that historically accurately. While I get you want more proof, there just can’t really be any other explanation. Meiosis, isolation of populations, and genetic drift. What else could cause it?

If you look at mammal fossils, you will see bats, dolphins, reptiles, and humans have distinct similarities in their forelimbs. Specifically, the bones all have 5 “fingers”. But there we are talking about tens and hundreds of millions of years of evolution, not just eight million as with hominids.

In case people didn’t know this, I recently learned modern birds evolved from dinosaurs. Pretty cool. Maybe common knowledge for some, but news to me.

iamthemob's avatar

@cockswain – the funny thing, though, is that the high number of tandem repeats in the dog’s DNA is what really increases the rapid physical change in dogs. It’s why, in many ways, they’re an ideal domesticated animal – we can breed them for physical characteristics we like and we see the results very quickly.

If there’s any mammal species we’re going see speciation in – it’s going to be them.

cockswain's avatar

I didn’t know that, the bit about tandem repeats causing rapid physical change. If you’ve got some handy info about that, I’d like to read it. Otherwise I’ll google it.

But I maintain even if we could intentionally cause a dog to speciate from Canis lupus familiaris to Canis lupus whateverthefuckus, it would take, I don’t know, hundreds of generations of human scientists to study the changes over time. And even then, without a natural selection component (I suppose one could be created), it would probably be slower. Think about species that have existed for millions and millions of years without too much significant change, just because their environment didn’t demand it of them.

iamthemob's avatar

@cockswain – the things is, though – it technically has been going on for thousands of years.

Check out this NatGeo Link. It’s fun.

crisw's avatar

One interesting point about dog breeding and macroevolution that I’ve seen-

Right now, there is only one recognized species of dog, as breeds can and do interbreed.

However, if something were to wipe out every dog except for purebred Great Danes and chihuahuas tomorrow, we would, in effect, have two species of dogs, as there would no longer be any genetic flow between them.

cockswain's avatar

@iamthemob I don’t get what you mean. Dog breeding has been going on for thousands of years? Is that what you mean? If that is what you mean, are you saying we should expect speciation because of that?

iamthemob's avatar

@cockswain – wolves were domesticated, it’s estimated, over 10,000 years ago. As @crisw points out above, the biological flow between breeds would essentially stop if those two were left.

Because we’ve been housing and breeding them for so long, and because of the unique potential they have for significant phenotypical change, it’s possible that we’ll see the difference become so significant that they would qualify as a new species. (I’m not saying in our lifetime, but who knows)

cockswain's avatar

Ah. So what you’re saying is currently many breeds of dogs can combine to produce mutts, but given enough time, perhaps a purebred wouldn’t be able to successfully mate with some other purebred?

iamthemob's avatar

@cockswain – pretty much. although I’m accepting @crisw‘s statement that chihuahua’s and Great Dane’s wouldn’t be considered the same species if all others disappeared. Pretty much the only thing allowing those two to be reproductively bridged are the breeds inbetween.

cockswain's avatar

I agree with that completely. As to whether dogs are the most suitable species for observing this, I don’t know enough about the animal kingdom to say for certain, but you’ve definitely made a reasonable case.

So if all dogs except those two disappeared, we’d have Canis lupus danicus and Canis lupus annoyingashellicus

iamthemob's avatar

My chihuahua is offended. I, on the other hand, pretty much agree.

cockswain's avatar

Wait a second, I just thought of something. I don’t know enough about dog breeding to know if there are breeds that can’t reproduce with each other. Can all Canis lupus familiaris produce viable offspring, regardless of breed?

crisw's avatar

@cockswain

Yes, if you use artificial insemination :>) However, it would have to be a pretty enterprising chihuahua to produce Great Huahuas the old-fashioned way.

Reproductive isolation doesn’t have to be genetic in order to produce a species; it can be physical, behavioral, etc.

lillycoyote's avatar

@worriedguy Too bad. I think I really might have enjoyed the Discovery Channel’s series When Wild Poodles Roamed the Earth.

Edit: I might have enjoyed the follow-up series even more: When Wild AKA Poodle Owners Roamed the Earth.

cockswain's avatar

@crisw It’s true that reproductive isolation should result in speciation, given enough time, right?

Can you give me an example of a two separate species that can produce viable offspring?

Also, as long as one can still use artificial insemination to create fit offspring, they are still the same species right?

Finally, if there came a day that that artificial methods couldn’t produce viable offspring between two breeds of familiaris, wouldn’t we then have to then restructure the genus?

Please confirm or correct my assumptions.

crisw's avatar

@cockswain

“Can you give me an example of a two separate species that can produce viable offspring?”

Oh, lots. Coyotes, wolves and dogs can all interbreed. Grizzly bears and polar bears, zebras and horses, blue and gold and scarlet macaws, bison and cattle, etc. etc.

“Also, as long as one can still use artificial insemination to create fit offspring, they are still the same species right?”

I don’t think so, since you can also use AI with the other species I mentioned and produce animals that would definitely be hybrids.

“Finally, if there came a day that that artificial methods couldn’t produce viable offspring between two breeds of familiaris, wouldn’t we then have to then restructure the genus?”
The genus (Canis)- no. The species- yes. That’s why it’s an example of possible macroevolution.

cockswain's avatar

All those are viable? I didn’t know. I thought hybrids were generally sterile, like mules or ligers. Thanks.

Regarding the genus question, I’m a tad confused still on the taxonomy. Canis lupus and Canis lupus familiaris are both separate species in the Canis genus, right? So if some familiaris couldn’t breed , they would neither be Canis lupus nor Canis lupus familiaris, right? Or is familiaris a subspecies of lupus? If so, then I get your answer. If not, then you’d be adding a new species to the Canis genus, which is what I meant when I said you’d have to rearrange the genus. I guess it isn’t much of a rearrangement on further thought.

I’ve sort of sorted it out a bit as I’ve typed.

crisw's avatar

@cockswain

“All those are viable? I didn’t know. I thought hybrids were generally sterile, like mules or ligers”

“Viable” means “born alive” or “capable of living.” Some of these hybrids are sterile (zebra-donkey crosses, for example) but many are not (wolf-dog crosses, bison-cow crosses, etc).

“Canis lupus and Canis lupus familiaris are both separate species in the Canis genus, right?”

Most taxonomists recognize Canis lupus and Canis familiaris. While some see the dog as a subspecies of wolf, most don’t.

cockswain's avatar

I’m sorry, I was using viable and fit as synonyms, my error. Fit meaning capable of reproducing. Let me back up to are you aware of two separate species that can produce fit offspring?

If two species can produce fit offspring, wouldn’t those two species be the same species? That’s what I’m driving at.

Thanks for the clarification on the taxonomy. So if two familiaris suddenly couldn’t breed, would we have to add those two breeds as two new species in Canis?

I hope I’m not boring you.

cockswain's avatar

Oh man, I just noticed you did list some separate species that do produce fit young. Lame of me, sorry again. Too late to edit my last post.

crisw's avatar

@cockswain

“Species” is a rather fluid concept, and entire books have been written on “the species problem”- what, exactly, is a species?

Species do not, usually, interbreed. But,. as I have mentioned, this lack of interbreeding doesn’t have to be due to genetic incompatibility. This isn’t necessary to define a species. It could be because two species have different ranges in nature, or different breeding seasons, or differently shaped genitalia. So, for example, bison and cattle would not normally interbred because the bison is an American species while cattle originated in Asia. However, put them in the same field and they can breed.,

cockswain's avatar

So that fact is very interesting from an evolutionary standpoint. Using your example of bison and cattle from different continents being able to breed, I am just hypothesizing (through application of the theory) that cattle and bison share a common ancestor. While that may not be a tremendously astute observation on my part, the fact that they can still genetically breed despite speciating on separate continents is interesting to me. This indicates that the ancestor of the bison and cattle lived together on maybe the Asian continent, but at some point in time, maybe due to a glaciation event or something, some population ended up separated and got to America. After enough time, this species evolved into cattle. However, despite these phenotypic changes, and who know how many thousands or millions of years, are still genetically similar enough to the bison to still reproduce.

I don’t suppose if you happen to know if the bison is the ancestor of the cattle, or if they had a common ancestor, do you? Based on hominid dispersal patterns, I’m just guessing the cattle/bison ancestor started in Asia. I’m also guessing the bison is the ancestor because if they had a common ancestor and both speciated, I’d find it very surprising they’d still be genetically similar enough to breed. But the world is full of surprises.

Thanks for helping me understand this. If I’m off base on this cattle/bison ancestor thing, let me know.

crisw's avatar

@cockswain

You are right on target. The common ancestor of the European domestic cow (as well as the bison) was Eurasian, and one species of bison (the wisent) still lives in Europe. The bison and the cow diverged about a million years ago.

The common ancestor of both modern species of bison, Bison priscus, crossed the land bridge into Beringia and evolved into today’s American bison. It went extinct in the late Pleistocene.

By the way, there are actually two species of domestic cattle, which interbred freely. Bos taurus is the sepcies of most European cattle breeds, while Bos indicus is behind the zebu and other Asian/African breeds. They diverged somewhere between 610–850,000 years ago.

cockswain's avatar

Wow, you know your stuff.

You know, that was actually another example of a hypothesis supporting the theory. Thankfully I didn’t have to analyze bison fossils around the world to confirm it.

Thanks again @crisw, you’re a great resource on this topic.

nicobanks's avatar

@worriedguy No, I’ve seen the glow in the dark bunny. It doesn’t work for me for the same reason as dog breeding doesn’t work: a glow in the dark bunny is still a bunny. It doesn’t seem like a new creature at all. Saying it’s a new creature does not resonate with me.

@iamthemob Well, a person simply can’t have complete conceptual understanding of everything they should know. There’s too much knowledge, too much specialized knowledge for that, too much we need to know in order to function and develop successfully in this world. Some things everyone has to accept, to take for granted (not the same things for everyone, of course).

The time for an aha moment is passed. I took my Evolutionary Theory class in undergrad, I went above and beyond in my readings, I continue to read here and there now – it’s over, it’s done. Would the genetics of dog breedings have helped me in my studies? No. Does it help illuminate things for me now? No. Am I missing something? I really don’t think so.

mattbrowne's avatar

It’s one of several. Volcanic islands in the Pacific are pretty powerful too. Especially the more remote ones. Then take seasonal influenza and multi-drug-resistant bacteria. And finally, use comparative genomics. Here we go. Pretty hard to refute.

iamthemob's avatar

@mattbrowne – my only problem with those examples is that they address the in-species diversity issues rather than speciation in the sense that there are major physical changes like @nicobanks mentions. Comparative genomics is more helpful – but that’s an area of study, rather than a specific example that clarifies the issue.

Because of the unique relationship we have with dogs, as well as the nature of their genetic structure, as well as our full mapping of it, I feel as if it’s a good concrete example that can be taken through to explain various aspects. Multiple examples can confuse laymen, and bring up the question “well, okay, but that’s a bacteria…what about…” and “yeah, but we don’t see change at this level…” etc.

mattbrowne's avatar

@iamthemob – Lots of speciation going on on Pacific islands. There are species transported by cyclones and tsunamis to new islands far away. The new environments created enormous pressure on these species. There are also cases of prehistoric humans carrying animals along with them on their boats. And more modern humans as well. Even Hawaii has got great examples.

iamthemob's avatar

@mattbrowne – but that isn’t really the speciation that people think of when they think “new species.” It’s more about “how does a lizard and a horse come from the same thing.”

mattbrowne's avatar

@iamthemob – Recently I saw the BBC documentary called

http://en.wikipedia.org/wiki/South_Pacific_(TV_series)

It gives numerous speciation examples over a short period of time. Isolation has enabled the region’s wildlife to evolve in unusual ways. On Hawaii, the most isolated archipelago of all, the caterpillars have turned carnivorous. Before the arrival of humans, fewer than 500 species colonised Hawaii in 30 million years. Once established, they evolved into countless new varieties. The differing bill shapes of Hawaii’s honeycreepers are used to illustrate how one colonising species can evolve into many specialists.

The fifth programme looks at the unusual animal life of the South Pacific. Species have evolved new behaviour to take advantage of ecological niches. On New Guinea, kangaroos such as the dingiso have become arboreal, taking the place of monkeys. The lack of predators on the ground has resulted in more flightless birds than anywhere else on Earth, including the kagu from New Caledonia.

If you don’t know the series, get the DVDs. They are excellent !

iamthemob's avatar

I didn’t – I shall explore it!

Again, my problem with those examples is that most people who haven’t been completely indoctrinated into a creationist mentality get that species can develop into specialized versions of themselves. Changing characteristics is often not the issue. What I like about the dog example is that it shows how, in complex organisms:
(1) large physical changes are associated with small changes in a single gene, and therefore show that tiny mutations can have significant effects that would account for major developmental shifts rather than small ones.
(2) tandem repeats demonstrate that there is no need for “new genetic information” be introduced into an organisms system in order for there to be physical change, but rather information that was already held in the genome can account for noticeable changes simply through how often it is repeated, answering questions regarding how changes happen if the information for x or y characteristic did not exist before.
(3) the small genetic difference between breeds shows the small difference creating large changes, and this has happened over a few thousand years only. Span that over billions, and the idea that a 1% change becomes reasonably definite, and 10% change becomes reasonably probable even for the doubtful, mathematically – and this shows the genetic difference between pretty much all mammals.

When you combine (1), (2) and (3), you can see how beneficial mutations or changes can pass to multiple members of a population without being expressed, and therefore discounting a general notion that a mutation has to be expressed and beneficial in a single member of the group and passed on, and increasing the perceived likelihood of shared mutations or changes. Then, you add

(4) Viral DNA sharing in treatment of the genetic defects caused by inbreeding.

This shows how that different organisms in the environment can have genetic material transferred between them, allowing for characteristics that are beneficial to be transferred between populations.

Differentiation and specialization are rarely the problems for people in terms of being able to conceptualize the mechanisms of evolution. It’s the “Yeah, but how did an eye happen” or “Lizards AND people?” questions. Much of this is almost completely theoretical.

cockswain's avatar

the caterpillars have turned carnivorous

Now there’s a good concept for a horror movie.

iamthemob's avatar

@cockswain – there’s Mothra…plus this

mattbrowne's avatar

@iamthemob – I think there are examples of significant single gene changes for species brought to new Pacific islands. But of course we know a lot more about dogs and investigating this is cheaper than traveling to remote areas in the Pacific.

Maybe lactose tolerance (a “gene defect”) in humans is a good example too. Check this out:

http://en.wikipedia.org/wiki/Lactose_intolerance#History_of_genetic_prevalence

iamthemob's avatar

But of course we know a lot more about dogs and investigating this is cheaper than traveling to remote areas in the Pacific.

Yeah, that’s why I like it as an example.

crisw's avatar

This is an interesting non-dog article about imminent speciation that is occurring in a species of mosquito that carries malaria. I think it’s also something people can relate to.

mattbrowne's avatar

@crisw – Excellent article. I think content like this should be part of the mandatory biology curriculum in 10th grade! There’s still this myth out there that evolution is just about fossils and because no one was alive during the time of the dinosaurs we can’t be sure.

You know what happens when a thief steals from the Creationism Museum in Kentucky?

Sorry guys, says the police, but since no one saw the thief, there’s nothing we can do. You don’t want us to search for forensic evidence in your museum, do you?

iamthemob's avatar

@mattbrowne – Best…joke…ever.

cazzie's avatar

Isn’t there a breed of birds that have gone around the world and met itself again and has become so different that it can’t or won’t mate with itself?

The possum in New Zealand is now a bigger and meaner animal than their counterparts in Australia, where they came from in the 1900’s. They brought over a few specimens to Australia to see if their Australian counterparts would find them appealing, but it was apparent that the New Zealand variety had changed so much, the Australian cousins were ‘not that into them.’.

crisw's avatar

@cazzie

“Isn’t there a breed of birds that have gone around the world and met itself again and has become so different that it can’t or won’t mate with itself?”

Several, although the most well known are gulls of the genus Larus,. They are called ring species.

Schroedes13's avatar

In short, the inherent difficulty with the evolutionary theory is that it is just that. A theory. The reason it is so hard to try and understand and come to terms with animal A and a animal B coming from the same common ancestor is that there are very few and even less valid examples of this at present. Even the idea of apes to humans is thin at best, with many of these pre-human species being extrapolated from a single bone or a set of 2 or 3 bones. That is why some forms of science take just as much faith to believe in as the various religion’s creation theories.

cockswain's avatar

just gonna go ahead and leave that one alone

crisw's avatar

Especially since this question’s nearly a year old…

@Schroedes13

If you really want to discuss evolution (and not just preach) ask a question about it or respont to a more recent discussion.

Schroedes13's avatar

@crisw I just joined Fluther yesterday, so I haven’t had the luxury of seeing the question before that point in time. I’d love to discuss evolution. I was just stating my belief in the topic. I thoroughly believe in the process of microevolution, but I find evolution and the science behind it very flimsy.

cockswain's avatar

Honestly, and I don’t say this condescendingly, I’d suggest taking a physical anthropology class or at least reading a textbook on the subject. My experience has been that folks that don’t accept the theory of evolution aren’t familiar enough with the genetic evidence and the fossil record. No problem with that, it’s just important to study it before a discussion. But certainly, like @crisw said, start a new thread and people will jump in. I’m personally very comfortable explaining it, and @crisw is several times better than I.

iamthemob's avatar

@crisw – wow…this question is almost a year old. ... ..... Now I feel old…

Answer this question

Login

or

Join

to answer.
Your answer will be saved while you login or join.

Have a question? Ask Fluther!

What do you know more about?
or
Knowledge Networking @ Fluther