Disappointment Ahead: This is not actually about poop.
I believe Evolution is true. But... I have a question.
Say there's a dinosaur. And millions of years later, his descendants are birds. Okay, fair enough. I can understand why a species might evolve the ability of flight. But why start down that path if it takes millions of years to get there? What practical advantage is a dinosaur with a few sparse feathers? What advantage in natural selection does an animal have that, for example, has evolved feathers but not flight? Do its genes just say "well, that's okay, we're going for flight and we'll get there eventually, for now all we have are feathers..." ?
I think it's more a matter of "this tree-dwelling creature's fluffy protective covering that resembles scales has an interesting side-effect of slowing them down when they fall out of trees, if they spread their forelegs out. Oh look, that means that the ones with long forelegs and better fluff-scales are more likely to survive and breed. etc"
Feathers are good for insulation. Birds got feathers, mammals got fur, same purpose originally, but feathers turned out to be useful for the flying thing later on.
Feathers may also have been useful for attracting mates.
Evolution is all step-wise - cumulative small changes that have beneficial or at least neutral effects. AFAIK polymers don't have the ability to form long term plans.
A leading hypothesis concerning the development of feathers is that they provided insulation. Feathers trap a layer of air near the skin of the animal, keeping it warmer. (This is part of how oil spills fuck up birds - the oil penetrates into the zones where air would be and destroys that insulating property.)
After you get feathers, ideas are that wings and proto-wings helped animals that jump a lot. For example, a predator that leaps onto its prey could "steer" a little if bit its forelimbs could provide small amounts of drag and/or lift where necessary. For that, you really need a bipedal predator - cats jump, but their forelimbs are tied up in walking. You need a creature that has powerful hind legs for leaping and for speed, low body weight, and arms that aren't particularly crucial for anything else: a raptor-like dinosaur.
Remember that insect flight had occurred long before feathered flight - so animals that hunt insects could greatly increase their food supply if they could catch flying insects. Jumping is like artificial height here - if you can jump an extra foot you can reach higher flying insects as if you were a foot taller, but you don't have to feed a a larger body that actually is a foot taller.
More info:
http://en.wikipedia.org/wiki/Origin_of_avian_flight
(also look at the "Flying and gliding animals" and "Insect Flight" links.)
Quote from: vexati0n on May 06, 2010, 11:43:31 PM
Disappointment Ahead: This is not actually about poop.
I believe Evolution is true. But... I have a question.
Say there's a dinosaur. And millions of years later, his descendants are birds. Okay, fair enough. I can understand why a species might evolve the ability of flight. But why start down that path if it takes millions of years to get there? What practical advantage is a dinosaur with a few sparse feathers? What advantage in natural selection does an animal have that, for example, has evolved feathers but not flight? Do its genes just say "well, that's okay, we're going for flight and we'll get there eventually, for now all we have are feathers..." ?
Okay, before addressing your question, I have a few points. Semantics, mostly, but in science it's important to be precise with words.
1. Better to say that you accept the theory of evolution, rather than believe. Accepting as an explanation means it's easier to change in the light of new evidence.
2. "Dinosaurs" is not a natural grouping of organisms. Its a common term, like daddy longlegs, which could talk about any number of things. Better to talk about Avemetatarsalis, or a particular group of Theropods from which the Class Aves branches.
3. Since we can't know descendent-ancestor relationships, and we can't test them, it is better not to use words like "descended from". It gets put to use in the popular parlance but it's scientifically untestable. Better to say that Class Aves is within the clade Avialae, which is the sister taxon to the Deinonychosauria, both of which are considered to be in the Clade Umaniraptora. Notice that while we can say all the Umaniraptora share a common ancestor, we can't say that a particular species in the fossil record is the ancestor.
Okay, to your question: Why do flightless Theropods have feathers?
Now, we can address this at two levels, the proximate and the ultimate level.
At the
proximate level, this question means, what is the mechanism for feathers? What causes feathers to occur? What are feathers derived from? These sorts of things. Proximate questions (even if they are worded as why) really have to do with HOW, the direct mechanism. This might be developmental or physiological as well as plainly morphological.
At the
ultimate level, this question means, why do they have feathers, what is the thing being selected upon, what are the evolutionary benefits of feathers. Ultimate questions address why at the level of survival of individuals and lineages to reproduce.
So, using strong inference, I'm going to lay it out for you. Strong inference is the best method for addressing scientific questions, in which one produces multiple hypotheses and designs one or more crucial experiments to eliminate all but one of those hypotheses. By parsimony, that will be the most likely answer.
So, at the proximate level I can lay out various hypotheses about how feathers develop, what tissues feathers develop from. If I watch, for example, the development of birds, I can see that the cells that grow into feathers are homologous to the cells that develop into scales in other Diapsids (ex. snakes, turtles, crocodilians). So, we can conduct observational experiments with various epidermal tissues to show that scales and feathers show a common embryological origin. So, at the proximate level, feather cells and scale cells are derived from the same tissue. Feathers might even be a modified scale, though I don't know off the top of my head any way of testing that.
So, why DO flightless Theropods have feathers? Obviously we can't just go find living specimens and conduct experiments upon them, so we have to settle for living and non living models.
I'll post part two of this tomorrow. With all of this, I'm trying to show you how this doesn't have to be a just so story, you can really answer these questions with satisfaction.
AWESOME, Kai! I'm looking forward to part two.
Quote from: The Lord and Lady Omnibus Fuck on May 07, 2010, 04:54:13 AM
AWESOME, Kai! I'm looking forward to part two.
This!
It's almost making up for the thread not really being about poop.
Quote from: vexati0n on May 06, 2010, 11:43:31 PM
But why start down that path if it takes millions of years to get there? What practical advantage is a dinosaur with a few sparse feathers? What advantage in natural selection does an animal have that, for example, has evolved feathers but not flight?
Because the LORD YOUR GOD wanted it to be that way.
\
:oilpig:
Feathers are completely inferior to fleshy, wretched wings.
(http://rlv.zcache.com/i_concur_tshirt-p235089396038200982t5hl_400.jpg)
In testing evolutionary hypothesis, all of them really come down to five reasons.
1. Predators/Parasites/Pathogens
2. Nutrition
3. Fecundity
4. Abiotic Factors
5. Competition
And when I say all I mean every trait with selection pressures, those pressures come down to one of the five above reasons. And so, ultimate level hypotheses always address at least one of those reasons.
So, here are my example hypotheses for "Why do flightless theropods have feathers".
1. Flightless theropods have feathers to thermoregulate body temperature and increase survival. (Abiotic factors)
2. Flightless theropods have feathers as a mating display which increases mating success (Fecundity).
3. Flightless theropods have feathers for territorial displays to reduce competition and increase survival (competition).
4. Flightless theropods have feathers as a protection against pathogens and parasites, increasing overall survival (predators/parasites/pathogens).
Of course, the problem we run into now is that the original flightless theropods have been extinct for millions of years now. We can use models to test abiotic factors such as thermoregulation (you can probably dream up an experiment gluing feathers to surfaces under different conditions etc), but for the others we really need a live model. There is a saying in biology, that for every question there is a perfect model to test that question upon (known as Krough's Law or Principle after August Krough).
How about....ostriches and their kin? They're large flightless birds, relatively easy to raise in captivity, and apparently they're running wild and escaped in the American Southwest. This seems to me to be the perfect living model to test the above hypotheses upon, at least initially.
The underlying issue for the reason for feathers comes down to adaptation and exaptation. Adaptation is a novel trait that comes about due to selection pressures. Exaptation, on the other hand, is when an adapted trait is later coopted for a new use, and receives further adaptation due to this use. The same issue of which came first is central to the origin of flight in insects as well as birds. Did wings/feathers/lobes originate to provide some sort of gliding support and then over time they were selected to become full wings, OR were feathers and wing lobes originally for some other purpose, and they later became exapted for flight?
Maybe there will be a part three later.
:awesome:
I read an article saying that much of the recent fossil finds from the China desert show that a majority of the late "dinosaurs" were feathered and much of our past conception was flawed (look back @ any dino book for kids written pre 1970, you don't even get coloration changes, which were the big thing around when Jurassic Park was written).
Quote from: Telarus on May 07, 2010, 05:19:04 PM
:awesome:
I read an article saying that much of the recent fossil finds from the China desert show that a majority of the late "dinosaurs" were feathered and much of our past conception was flawed (look back @ any dino book for kids written pre 1970, you don't even get coloration changes, which were the big thing around when Jurassic Park was written).
Yeah, most of our knowledge of feathered theropods (specifically Umaniraptors) comes from fossil finds in China. And it's not like we're talking a single fossil here. There are tones of feathered Umaniraptor fossils.
I feel an In Those Days coming on.....
So has the fossil record produced evidence for a complete transition from one species to another? Forgive my ridiculous questions, I'm just looking to fill in some gaps in my understanding of evolutionary theory.
Plus some bastard infected my brain with a bunch of this crap which is undoubtedly rooted in some kind of twisted Creationist plot to undermine my understanding of science.
But even after looking through wikipedia and other more reliable sources of information it would appear that the fossil record contains lots of evidence that there have been different species, but not as much evidence for those species evolving from one to another. Like a species exists in the fossil record and then died out, and another species that descended from the first shows up in the next epoch, but transitional species between the two are difficult to find for some reason.
Or is that just horse shit? I'd sleep better if I knew it was.
Edit: Or do I just have some fundamental misunderstanding of it? Using my own brain instead of repeating what I read on some website, I'd guess that every species is transitional in some lineage. Since the fossil record can hardly be expected to preserve every animal that ever lived, we have to use logic to infer that the species that showed up in the Jurassic didn't come out of nowhere spontaneously, and must therefore have ancestors in the Cretaceous, even though none of the animals in the Cretaceous belonged to that species.
Homo Erectus to Homo Sapiens Sapiens is really really well documented.
Quote from: vexati0n on May 07, 2010, 08:22:35 PM
So has the fossil record produced evidence for a complete transition from one species to another? Forgive my ridiculous questions, I'm just looking to fill in some gaps in my understanding of evolutionary theory.
Plus some bastard infected my brain with a bunch of this crap which is undoubtedly rooted in some kind of twisted Creationist plot to undermine my understanding of science.
But even after looking through wikipedia and other more reliable sources of information it would appear that the fossil record contains lots of evidence that there have been different species, but not as much evidence for those species evolving from one to another. Like a species exists in the fossil record and then died out, and another species that descended from the first shows up in the next epoch, but transitional species between the two are difficult to find for some reason.
Or is that just horse shit? I'd sleep better if I knew it was.
Edit: Or do I just have some fundamental misunderstanding of it? Using my own brain instead of repeating what I read on some website, I'd guess that every species is transitional in some lineage. Since the fossil record can hardly be expected to preserve every animal that ever lived, we have to use logic to infer that the species that showed up in the Jurassic didn't come out of nowhere spontaneously, and must therefore have ancestors in the Cretaceous, even though none of the animals in the Cretaceous belonged to that species.
Okay, so,
First of all, it is impossible to determine whether one species gave rise to another from the fossil record. It is untestable, unless you invent a time machine that can go back and watch the speciation.
In modern systematics and evolutionary biology, since incidence of one species turning into another within a single lineage (anagenesis) is untestable, we work only with testable hypotheses of relationship by branching or splitting of lineages (cladogenesis). We know that sister lineages must share a common ancestor, but whether one of those lineages is the ancestor of the other is untestable, so we just work with relationships.
We discover these relationships by homology, what I have referred to before as "the key to the heart of biology". Homology is not just similarity, but special similarity that is a hypothesis of a common origin. The forelegs of a mammal, a bird, and a salamander both in the sense of their location and constituant parts would be examples of a homology. By mapping homologies on different species and lineages, we arrive at a tree like diagram of hypothetical relationships. The most informative type of branching is dicotomous, since it has the least assumptions.
Here (http://en.wikipedia.org/wiki/Therapoda) there is a cladogram of the Therapoda, a tree diagram that maps the relationships between different Therapod lineages. Note the dicotomous branching, and that higher groups, like Eumaniraptors, are distinguished by nodes where all members of that group stem from the node, indicating a common ancestor.
Now, the media often talks about transitional fossils. In the true sense, all fossils are transitional, just like all species are transitional (unless they have become extinct). Usually what they mean is some sort of inbetweeness in form between two markedly different lineages. An example would be
Archaeopterix, which has many characters shared by Deinonychosauria, the sister group to the group that contains the modern birds, but also has feathered wings, a uniquely shared character of all members of Avialae. Looking here (http://en.wikipedia.org/wiki/Avialae) you can see a cladogram of the Avialae. Since Archeopterix is related to the rest of the Aves clade, but not as closely related to the rest as they are to each other, it is put at a "basal" position on the cladogram. As I said above, it is transitional in the sense of morphology, but since we cannot test for ancestors and descendents, we use a branching pattern.
Clear as mud?
Quote from: Requia ☣ on May 07, 2010, 09:01:50 PM
Homo Erectus to Homo Sapiens Sapiens is really really well documented.
How? Did you go back in time and show that the Homo erectus fossils we have gave birth to the ancestors of Homo sapiens? It's completely untestable. All we can say is there is some common ancestor to both; whether one is the ancestor of the other is unknowable.
We actually have a little bit of recent evidence of current evolution happening:
http://news.nationalgeographic.com/news/2006/07/060714-evolution.html
http://www.pbs.org/wgbh/evolution/library/01/6/l_016_01.html
This gets picked at by the creationists, due to it not being a 'radical' enough change.
Quote from: Kai on May 07, 2010, 09:06:39 PM
Quote from: Requia ☣ on May 07, 2010, 09:01:50 PM
Homo Erectus to Homo Sapiens Sapiens is really really well documented.
How? Did you go back in time and show that the Homo erectus fossils we have gave birth to the ancestors of Homo sapiens? It's completely untestable. All we can say is there is some common ancestor to both; whether one is the ancestor of the other is unknowable.
I'd doubt that most of the fossils are our ancestors, given that they y'know, died horribly (if I remember right most of the fossils became fossils by way of being leopard food first), but we have representations of the gradual changes.
Quote from: Requia ☣ on May 07, 2010, 09:49:47 PM
Quote from: Kai on May 07, 2010, 09:06:39 PM
Quote from: Requia ☣ on May 07, 2010, 09:01:50 PM
Homo Erectus to Homo Sapiens Sapiens is really really well documented.
How? Did you go back in time and show that the Homo erectus fossils we have gave birth to the ancestors of Homo sapiens? It's completely untestable. All we can say is there is some common ancestor to both; whether one is the ancestor of the other is unknowable.
I'd doubt that most of the fossils are our ancestors, given that they y'know, died horribly (if I remember right most of the fossils became fossils by way of being leopard food first), but we have representations of the gradual changes.
That is what we call a just so story.
"These fossils show that H. erectus is our ancestor!"
"How is that?"
"Well, because they look like they're somewhere in the middle!"
Yeah....doesn't work for scientists. The stories are colorful and fun but not the least bit scientific.
Quote from: Telarus on May 07, 2010, 09:24:33 PM
We actually have a little bit of recent evidence of current evolution happening:
http://news.nationalgeographic.com/news/2006/07/060714-evolution.html
http://www.pbs.org/wgbh/evolution/library/01/6/l_016_01.html
This gets picked at by the creationists, due to it not being a 'radical' enough change.
That is the sort of thing you can judge ancestor-descendent relationships from, and very cool might I add.
Can't do that with fossils. Otherwise Darwin wouldn't have spent 500 pages trying to convince people.
I'm not talking about proving decent.
Quote from: Kai on May 07, 2010, 09:04:37 PM
Quote from: vexati0n on May 07, 2010, 08:22:35 PM
So has the fossil record produced evidence for a complete transition from one species to another? Forgive my ridiculous questions, I'm just looking to fill in some gaps in my understanding of evolutionary theory.
Plus some bastard infected my brain with a bunch of this crap which is undoubtedly rooted in some kind of twisted Creationist plot to undermine my understanding of science.
But even after looking through wikipedia and other more reliable sources of information it would appear that the fossil record contains lots of evidence that there have been different species, but not as much evidence for those species evolving from one to another. Like a species exists in the fossil record and then died out, and another species that descended from the first shows up in the next epoch, but transitional species between the two are difficult to find for some reason.
Or is that just horse shit? I'd sleep better if I knew it was.
Edit: Or do I just have some fundamental misunderstanding of it? Using my own brain instead of repeating what I read on some website, I'd guess that every species is transitional in some lineage. Since the fossil record can hardly be expected to preserve every animal that ever lived, we have to use logic to infer that the species that showed up in the Jurassic didn't come out of nowhere spontaneously, and must therefore have ancestors in the Cretaceous, even though none of the animals in the Cretaceous belonged to that species.
Okay, so,
First of all, it is impossible to determine whether one species gave rise to another from the fossil record. It is untestable, unless you invent a time machine that can go back and watch the speciation.
In modern systematics and evolutionary biology, since incidence of one species turning into another within a single lineage (anagenesis) is untestable, we work only with testable hypotheses of relationship by branching or splitting of lineages (cladogenesis). We know that sister lineages must share a common ancestor, but whether one of those lineages is the ancestor of the other is untestable, so we just work with relationships.
We discover these relationships by homology, what I have referred to before as "the key to the heart of biology". Homology is not just similarity, but special similarity that is a hypothesis of a common origin. The forelegs of a mammal, a bird, and a salamander both in the sense of their location and constituant parts would be examples of a homology. By mapping homologies on different species and lineages, we arrive at a tree like diagram of hypothetical relationships. The most informative type of branching is dicotomous, since it has the least assumptions.
Here (http://en.wikipedia.org/wiki/Therapoda) there is a cladogram of the Therapoda, a tree diagram that maps the relationships between different Therapod lineages. Note the dicotomous branching, and that higher groups, like Eumaniraptors, are distinguished by nodes where all members of that group stem from the node, indicating a common ancestor.
Now, the media often talks about transitional fossils. In the true sense, all fossils are transitional, just like all species are transitional (unless they have become extinct). Usually what they mean is some sort of inbetweeness in form between two markedly different lineages. An example would be Archaeopterix, which has many characters shared by Deinonychosauria, the sister group to the group that contains the modern birds, but also has feathered wings, a uniquely shared character of all members of Avialae. Looking here (http://en.wikipedia.org/wiki/Avialae) you can see a cladogram of the Avialae. Since Archeopterix is related to the rest of the Aves clade, but not as closely related to the rest as they are to each other, it is put at a "basal" position on the cladogram. As I said above, it is transitional in the sense of morphology, but since we cannot test for ancestors and descendents, we use a branching pattern.
Clear as mud?
Ok, I think I get it... species are identified, and then, according to their characteristics and their place in the geological record, they are said to be "somewhere on the path" of a given lineage, but no claims are made about whether or not specific species that are found are directly descended from other specific species.
Being the 21st century and all, though, is there still no way of finding enough prehistoric DNA to calculate actual descendants?
Quote from: vexati0n on May 07, 2010, 11:56:06 PM
Quote from: Kai on May 07, 2010, 09:04:37 PM
Quote from: vexati0n on May 07, 2010, 08:22:35 PM
So has the fossil record produced evidence for a complete transition from one species to another? Forgive my ridiculous questions, I'm just looking to fill in some gaps in my understanding of evolutionary theory.
Plus some bastard infected my brain with a bunch of this crap which is undoubtedly rooted in some kind of twisted Creationist plot to undermine my understanding of science.
But even after looking through wikipedia and other more reliable sources of information it would appear that the fossil record contains lots of evidence that there have been different species, but not as much evidence for those species evolving from one to another. Like a species exists in the fossil record and then died out, and another species that descended from the first shows up in the next epoch, but transitional species between the two are difficult to find for some reason.
Or is that just horse shit? I'd sleep better if I knew it was.
Edit: Or do I just have some fundamental misunderstanding of it? Using my own brain instead of repeating what I read on some website, I'd guess that every species is transitional in some lineage. Since the fossil record can hardly be expected to preserve every animal that ever lived, we have to use logic to infer that the species that showed up in the Jurassic didn't come out of nowhere spontaneously, and must therefore have ancestors in the Cretaceous, even though none of the animals in the Cretaceous belonged to that species.
Okay, so,
First of all, it is impossible to determine whether one species gave rise to another from the fossil record. It is untestable, unless you invent a time machine that can go back and watch the speciation.
In modern systematics and evolutionary biology, since incidence of one species turning into another within a single lineage (anagenesis) is untestable, we work only with testable hypotheses of relationship by branching or splitting of lineages (cladogenesis). We know that sister lineages must share a common ancestor, but whether one of those lineages is the ancestor of the other is untestable, so we just work with relationships.
We discover these relationships by homology, what I have referred to before as "the key to the heart of biology". Homology is not just similarity, but special similarity that is a hypothesis of a common origin. The forelegs of a mammal, a bird, and a salamander both in the sense of their location and constituant parts would be examples of a homology. By mapping homologies on different species and lineages, we arrive at a tree like diagram of hypothetical relationships. The most informative type of branching is dicotomous, since it has the least assumptions.
Here (http://en.wikipedia.org/wiki/Therapoda) there is a cladogram of the Therapoda, a tree diagram that maps the relationships between different Therapod lineages. Note the dicotomous branching, and that higher groups, like Eumaniraptors, are distinguished by nodes where all members of that group stem from the node, indicating a common ancestor.
Now, the media often talks about transitional fossils. In the true sense, all fossils are transitional, just like all species are transitional (unless they have become extinct). Usually what they mean is some sort of inbetweeness in form between two markedly different lineages. An example would be Archaeopterix, which has many characters shared by Deinonychosauria, the sister group to the group that contains the modern birds, but also has feathered wings, a uniquely shared character of all members of Avialae. Looking here (http://en.wikipedia.org/wiki/Avialae) you can see a cladogram of the Avialae. Since Archeopterix is related to the rest of the Aves clade, but not as closely related to the rest as they are to each other, it is put at a "basal" position on the cladogram. As I said above, it is transitional in the sense of morphology, but since we cannot test for ancestors and descendents, we use a branching pattern.
Clear as mud?
Ok, I think I get it... species are identified, and then, according to their characteristics and their place in the geological record, they are said to be "somewhere on the path" of a given lineage, but no claims are made about whether or not specific species that are found are directly descended from other specific species.
Being the 21st century and all, though, is there still no way of finding enough prehistoric DNA to calculate actual descendants?
Even in the cases where you have DNA, like in the last 100,000 years, you can only show relationship. There are a number of genes, both nuclear and mitochondrial, that get used for systematic analysis on a regular basis. You compare the genes between specimens by lining their sequences up manually, and then running either a regular parsimony analysis to find homologies or (ugh) an overall similarity or model analysis like baetsian or maximum likelyhood, disrespectfully. This will show special or overal similarity, but theres no way you could calculate that this bone fragment comes from an organism that is the ancestor of humans, only that they are related to one another. Remember, these sequences aren't from species, they're from individuals, and individuals within species vary. You can calculate ancestor decendant relationships between generations in humans, but much more than that and you're showing similarity and not "who is spawn of who".
Quote from: Telarus on May 07, 2010, 09:24:33 PM
We actually have a little bit of recent evidence of current evolution happening:
http://news.nationalgeographic.com/news/2006/07/060714-evolution.html
http://www.pbs.org/wgbh/evolution/library/01/6/l_016_01.html
This gets picked at by the creationists, due to it not being a 'radical' enough change.
That study is really interesting because it validates catastrophic evolution, where extreme pressures cause evolution to occur very rapidly. I've always thought there was a lot of potential in that theory.
Quote from: The Lord and Lady Omnibus Fuck on May 08, 2010, 01:25:09 AM
Quote from: Telarus on May 07, 2010, 09:24:33 PM
We actually have a little bit of recent evidence of current evolution happening:
http://news.nationalgeographic.com/news/2006/07/060714-evolution.html
http://www.pbs.org/wgbh/evolution/library/01/6/l_016_01.html
This gets picked at by the creationists, due to it not being a 'radical' enough change.
That study is really interesting because it validates catastrophic evolution, where extreme pressures cause evolution to occur very rapidly. I've always thought there was a lot of potential in that theory.
I tend to hold with Gould's ideas that evolution is neither completely gradual nor completely catastrophic; evolution is a punctuated equilibrium.
I always assumed that was the consensus. It makes the most intuitive sense to me.
Quote from: Kai on May 08, 2010, 05:50:31 AM
Quote from: The Lord and Lady Omnibus Fuck on May 08, 2010, 01:25:09 AM
Quote from: Telarus on May 07, 2010, 09:24:33 PM
We actually have a little bit of recent evidence of current evolution happening:
http://news.nationalgeographic.com/news/2006/07/060714-evolution.html
http://www.pbs.org/wgbh/evolution/library/01/6/l_016_01.html
This gets picked at by the creationists, due to it not being a 'radical' enough change.
That study is really interesting because it validates catastrophic evolution, where extreme pressures cause evolution to occur very rapidly. I've always thought there was a lot of potential in that theory.
I tend to hold with Gould's ideas that evolution is neither completely gradual nor completely catastrophic; evolution is a punctuated equilibrium.
I like that phrase, and yes, it makes perfect sense that it would be. Gradual change punctuated by fits, starts, and dead-ends.
Quote from: The Lord and Lady Omnibus Fuck on May 08, 2010, 06:21:43 AM
Quote from: Kai on May 08, 2010, 05:50:31 AM
Quote from: The Lord and Lady Omnibus Fuck on May 08, 2010, 01:25:09 AM
Quote from: Telarus on May 07, 2010, 09:24:33 PM
We actually have a little bit of recent evidence of current evolution happening:
http://news.nationalgeographic.com/news/2006/07/060714-evolution.html
http://www.pbs.org/wgbh/evolution/library/01/6/l_016_01.html
This gets picked at by the creationists, due to it not being a 'radical' enough change.
:)
That study is really interesting because it validates catastrophic evolution, where extreme pressures cause evolution to occur very rapidly. I've always thought there was a lot of potential in that theory.
I tend to hold with Gould's ideas that evolution is neither completely gradual nor completely catastrophic; evolution is a punctuated equilibrium.
I like that phrase, and yes, it makes perfect sense that it would be. Gradual change punctuated by fits, starts, and dead-ends.
Quote from: vexati0n on May 06, 2010, 11:43:31 PM
Disappointment Ahead: This is not actually about poop.
I believe Evolution is true. But... I have a question.
Say there's a dinosaur. And millions of years later, his descendants are birds. Okay, fair enough. I can understand why a species might evolve the ability of flight. But why start down that path if it takes millions of years to get there? What practical advantage is a dinosaur with a few sparse feathers? What advantage in natural selection does an animal have that, for example, has evolved feathers but not flight? Do its genes just say "well, that's okay, we're going for flight and we'll get there eventually, for now all we have are feathers..." ?
Evolution is purposeless. There are no goals. There are traits that allow a species to survive and pass on their genes.
The trait may be very stupid. Take something like sexual selection. For example: female birds think a male bird with plumage that is so ridiculous that it actually makes them more vulnerable to predators are more attractive, so the entire species begins to take that trait on. Evolution is does not have an end-game or design. If you're really interested in learning more about this, check out The Blind Watchmaker by Richard Dawkins.
Yes, I realize someone may have already answered this. No, I don't care.
Quote from: Vladimir Poopin on May 08, 2010, 08:44:45 PM
Quote from: vexati0n on May 06, 2010, 11:43:31 PM
Disappointment Ahead: This is not actually about poop.
I believe Evolution is true. But... I have a question.
Say there's a dinosaur. And millions of years later, his descendants are birds. Okay, fair enough. I can understand why a species might evolve the ability of flight. But why start down that path if it takes millions of years to get there? What practical advantage is a dinosaur with a few sparse feathers? What advantage in natural selection does an animal have that, for example, has evolved feathers but not flight? Do its genes just say "well, that's okay, we're going for flight and we'll get there eventually, for now all we have are feathers..." ?
Evolution is purposeless. There are no goals. There are traits that allow a species to survive and pass on their genes.
The trait may be very stupid. Take something like sexual selection. For example: female birds think a male bird with plumage that is so ridiculous that it actually makes them more vulnerable to predators are more attractive, so the entire species begins to take that trait on. Evolution is does not have an end-game or design. If you're really interested in learning more about this, check out The Blind Watchmaker by Richard Dawkins.
Yes, I realize someone may have already answered this. No, I don't care.
It's not stupid if it works. Take plumage. The obvious plumage makes them more vulnerable to predators, but if the male can survive with that obvious plumage it shows other traits good for avoiding predation.
It's also, as I said already, a matter of adaptation and exaptation.
Well, after all that, I would just like to say that I find it extremely awesome that birds are actually dinosaurs. I've always thought it was really sad that all the dinosaurs died, but now I know that at least one family of them ended up surviving after all. Sure they're not really the ravenous predators they once were (I guess they're kind of the Russia of evolutionary history that way), and some of them have even become downright cute, but still it's a relief to know that the only class of animal that ever really deserved to exist on this planet isn't completely gone.
Quote from: vexati0n on May 10, 2010, 03:35:02 AM
Well, after all that, I would just like to say that I find it extremely awesome that birds are actually dinosaurs. I've always thought it was really sad that all the dinosaurs died, but now I know that at least one family of them ended up surviving after all. Sure they're not really the ravenous predators they once were (I guess they're kind of the Russia of evolutionary history that way), and some of them have even become downright cute, but still it's a relief to know that the only class of animal that ever really deserved to exist on this planet isn't completely gone.
If you've ever had chickens, you might feel differently. Those fuckers will eat anything they can catch. If they had any size on 'em they'd be dangerous as fuck.
good thread, Kai!
thx.
I love that we have people on here with, like, actual expertise in stuff.
Quote from: vexati0n on May 10, 2010, 03:35:02 AM
Well, after all that, I would just like to say that I find it extremely awesome that birds are actually dinosaurs. I've always thought it was really sad that all the dinosaurs died, but now I know that at least one family of them ended up surviving after all. Sure they're not really the ravenous predators they once were (I guess they're kind of the Russia of evolutionary history that way), and some of them have even become downright cute, but still it's a relief to know that the only class of animal that ever really deserved to exist on this planet isn't completely gone.
Yeah, the class Aves is the last extant lineage of the Theropods, and is sister to a group that includes genera like
Utahraptor,
Velociraptor, and
Deinonychus. Since all the other Theropods are extinct, the closest living relatives of birds are crocodilians. Weird, huh?
Is there a prevailing hypothesis about whether all modern birds descend from a single therapod, or whether different bird species have lineages that date to different pre-avian dinosaurs?
Quote from: vexati0n on May 10, 2010, 07:38:51 PM
Is there a prevailing hypothesis about whether all modern birds descend from a single therapod, or whether different bird species have lineages that date to different pre-avian dinosaurs?
Aves seems to be monophyletic, indicating a single common ancestor. There is no evidence to suggest that the group has multiple origins.
Quote from: The Lord and Lady Omnibus Fuck on May 10, 2010, 05:47:05 PM
Quote from: vexati0n on May 10, 2010, 03:35:02 AM
Well, after all that, I would just like to say that I find it extremely awesome that birds are actually dinosaurs. I've always thought it was really sad that all the dinosaurs died, but now I know that at least one family of them ended up surviving after all. Sure they're not really the ravenous predators they once were (I guess they're kind of the Russia of evolutionary history that way), and some of them have even become downright cute, but still it's a relief to know that the only class of animal that ever really deserved to exist on this planet isn't completely gone.
If you've ever had chickens, you might feel differently. Those fuckers will eat anything they can catch. If they had any size on 'em they'd be dangerous as fuck.
The only real difference I can see between the earlier Archeopteryx and other basal Avialae is the long tail, and teeth. There are actually some birds still around today that retain the "finger" on the edge of the wing.
Edit: Like the Hoatzin: http://en.wikipedia.org/wiki/Hoatzin
Nigel,
there is still hope that we can have chickens with teeth:
http://www.eurekalert.org/pub_releases/2006-02/cp-btm021506.php
It's interesting that, out of all the lineages of Archosaurs that ever existed, only two lineages remain extant, one, aquatic and confined to tropical and subtropical fresh and estuarine waters, the other cosmopolitan, primarily terrestrial, with most species possessing the ability of flight. Strange.
Crappy world, with crappy "dinosaurs" that don't get any bigger than a bird or a crocodile.
I feel ripped off.
Quote from: Doktor Howl on May 10, 2010, 08:25:16 PM
Crappy world, with crappy "dinosaurs" that don't get any bigger than a bird or a crocodile.
I feel ripped off.
Somehow, I don't think a meteor explains this completely.
Quote from: Kai on May 10, 2010, 08:29:01 PM
Quote from: Doktor Howl on May 10, 2010, 08:25:16 PM
Crappy world, with crappy "dinosaurs" that don't get any bigger than a bird or a crocodile.
I feel ripped off.
Somehow, I don't think a meteor explains this completely.
Mother Nature is a tard.
I want big fucking lizards. Great big bastards. I want to have to carry an elephant gun in my truck, and I want downtown Tucson swarming with velociraptors.
Also, giant/colossal squid: Not giant/colossal enough. Should also prey on shipping.
Dok,
Could have offered some useful hints.
Quote from: Doktor Howl on May 10, 2010, 08:31:28 PM
Dok,
Could have offered some useful hints.
"offered hints"?!
wtf?
i've been operating under the impression that you were fully engaged in the DIY bio scene, working towards making this a reality!
what kind of mad scientist are you to 'offer hints'?
:wink:
Quote from: Iptuous on May 10, 2010, 08:37:19 PM
Quote from: Doktor Howl on May 10, 2010, 08:31:28 PM
Dok,
Could have offered some useful hints.
"offered hints"?!
wtf?
i've been operating under the impression that you were fully engaged in the DIY bio scene, working towards making this a reality!
what kind of mad scientist are you to 'offer hints'?
:wink:
I don't do bio, first of all.
Second of all, wtf, Ippie?
You know, if I could, the first thing I would do is make chickens about 15 feet tall, and then let 200 of them loose in Disneyland.
OK, maybe not Disneyland. Too many kids. Maybe Las Vegas.
Quote from: The Lord and Lady Omnibus Fuck on May 10, 2010, 08:57:23 PM
You know, if I could, the first thing I would do is make chickens about 15 feet tall, and then let 200 of them loose in Disneyland.
OK, maybe not Disneyland. Too many kids. Maybe Las Vegas.
No, Dollywood. For starters.
Quote from: The Lord and Lady Omnibus Fuck on May 10, 2010, 08:57:23 PM
You know, if I could, the first thing I would do is make chickens about 15 feet tall, and then let 200 of them loose in Disneyland.
OK, maybe not Disneyland. Too many kids. Maybe Las Vegas.
Hmmm... Lets think about the allopatric growth here. A chicken 15 feet tall would be....about the size of the largest Tyrannosaurs. You'd need to make the bones not hollow (flight wouldn't be a possibility) to hold up the mass, and a tail might be necessary to balance. A large, toothless, feathered Tyranosaur that will eat anything.
That's fucking scary.
Quote from: Kai on May 10, 2010, 09:04:21 PM
Quote from: The Lord and Lady Omnibus Fuck on May 10, 2010, 08:57:23 PM
You know, if I could, the first thing I would do is make chickens about 15 feet tall, and then let 200 of them loose in Disneyland.
OK, maybe not Disneyland. Too many kids. Maybe Las Vegas.
Hmmm... Lets think about the allopatric growth here. A chicken 15 feet tall would be....about the size of the largest Tyrannosaurs. You'd need to make the bones not hollow (flight wouldn't be a possibility) to hold up the mass, and a tail might be necessary to balance. A large, toothless, feathered Tyranosaur that will eat anything.
That's fucking scary the future I want to see.
Fixed.
Quote from: Doktor Howl on May 10, 2010, 08:50:09 PM
I don't do bio, first of all.
Second of all, wtf, Ippie?
sry, just being dumb. :)
you could at least contract out some bio madness to stick in the desert...
or make the ostriches a little more dinosaur-like. scale up those razors that they stick on fighting cocks, or something...
the hardest part about that would be getting the tranquilizer gun.
well, maybe releasing it in a populated area without getting caught would be a little tricky, too....
but think of the
headlines!
ok.
and now back to our regularly scheduled decent thread material...
Quote from: Iptuous on May 10, 2010, 09:08:57 PM
Quote from: Doktor Howl on May 10, 2010, 08:50:09 PM
I don't do bio, first of all.
Second of all, wtf, Ippie?
sry, just being dumb. :)
you could at least contract out some bio madness to stick in the desert...
or make the ostriches a little more dinosaur-like. scale up those razors that they stick on fighting cocks, or something...
the hardest part about that would be getting the tranquilizer gun.
well, maybe releasing it in a populated area without getting caught would be a little tricky, too....
but think of the headlines!
ok.
and now back to our regularly scheduled decent thread material...
1. Kai is in charge of bio. You'll have to get him onboard.
2. I just take :wink: as an "I'm not laughing
with you" kind of condescension. Call me crazy.
Quote from: Doktor Howl on May 10, 2010, 09:10:36 PM
1. Kai is in charge of bio. You'll have to get him onboard.
2. I just take :wink: as an "I'm not laughing with you" kind of condescension. Call me crazy.
i figured you would be more likely to pervert Nature for your sadistic pleasure than he, though.
oh. i'm misusing it then... i meant it as in silent acknowledgment of shared joke kinda thing.... of course an inline image loses the subtlety of an actual wink, so....
(ftr, i try to go out of my way to antagonize in almost all cases. i try to be everybody's friend.... :sad: can't help it.)
Quote from: Iptuous on May 10, 2010, 09:19:59 PM
Quote from: Doktor Howl on May 10, 2010, 09:10:36 PM
1. Kai is in charge of bio. You'll have to get him onboard.
2. I just take :wink: as an "I'm not laughing with you" kind of condescension. Call me crazy.
i figured you would be more likely to pervert Nature for your sadistic pleasure than he, though.
No, I'm in the "We have to kill nature before it kills us" camp, most of the time. Except for huge fucking lizards.
Quote from: Iptuous on May 10, 2010, 09:19:59 PM
(ftr, i try to go out of my way to antagonize in almost all cases.
Why?
Quote from: Doktor Howl on May 10, 2010, 09:21:35 PM
Quote from: Iptuous on May 10, 2010, 09:19:59 PM
(ftr, i try to go out of my way to antagonize in almost all cases.
Why?
dunno. upbringing?
maybe because i was a military brat and moved around continuously. gotta make new friends. gotta make new friends. gotta make new friends.
as far as corrupting nature, isn't the best way to kill nature by displacing it with the patently
unnatural?
giant lizards could be just the beginning.
perhaps it's some latent thanatos, or something, but i favor large predatory animals that could give humans a run for their money. it's not just a megafauna fixation, i like the vicious ones...
Quote from: Iptuous on May 10, 2010, 09:31:42 PM
Quote from: Doktor Howl on May 10, 2010, 09:21:35 PM
Quote from: Iptuous on May 10, 2010, 09:19:59 PM
(ftr, i try to go out of my way to antagonize in almost all cases.
Why?
dunno. upbringing?
maybe because i was a military brat and moved around continuously. gotta make new friends. gotta make new friends. gotta make new friends.
What's antagonizing people got to do with that?
Honestly curious, here.
Quote from: Doktor Howl on May 10, 2010, 09:33:49 PM
Quote from: Iptuous on May 10, 2010, 09:31:42 PM
Quote from: Doktor Howl on May 10, 2010, 09:21:35 PM
Quote from: Iptuous on May 10, 2010, 09:19:59 PM
(ftr, i try to go out of my way to antagonize in almost all cases.
Why?
dunno. upbringing?
maybe because i was a military brat and moved around continuously. gotta make new friends. gotta make new friends. gotta make new friends.
What's antagonizing people got to do with that?
Honestly curious, here.
to a great degree, being friends with someone consists of avoiding pissing them off. being there when they need you seals the deal, but it's all contingent on simply not pissing them off...
so, i'm speculating that's why i have this conflict avoidance drive.
or, maybe i'm just a pansy that's good at rationalizing?
i dunno. no skin off my back, either way... :)
Quote from: Iptuous on May 10, 2010, 09:37:47 PM
Quote from: Doktor Howl on May 10, 2010, 09:33:49 PM
Quote from: Iptuous on May 10, 2010, 09:31:42 PM
Quote from: Doktor Howl on May 10, 2010, 09:21:35 PM
Quote from: Iptuous on May 10, 2010, 09:19:59 PM
(ftr, i try to go out of my way to antagonize in almost all cases.
Why?
dunno. upbringing?
maybe because i was a military brat and moved around continuously. gotta make new friends. gotta make new friends. gotta make new friends.
What's antagonizing people got to do with that?
Honestly curious, here.
to a great degree, being friends with someone consists of avoiding pissing them off. being there when they need you seals the deal, but it's all contingent on simply not pissing them off...
so, i'm speculating that's why i have this conflict avoidance drive.
or, maybe i'm just a pansy that's good at rationalizing?
i dunno. no skin off my back, either way... :)
Did you mean you go out of your way to NOT antagonize, then?
Quote from: Doktor Howl on May 10, 2010, 09:10:36 PM
Quote from: Iptuous on May 10, 2010, 09:08:57 PM
Quote from: Doktor Howl on May 10, 2010, 08:50:09 PM
I don't do bio, first of all.
Second of all, wtf, Ippie?
sry, just being dumb. :)
you could at least contract out some bio madness to stick in the desert...
or make the ostriches a little more dinosaur-like. scale up those razors that they stick on fighting cocks, or something...
the hardest part about that would be getting the tranquilizer gun.
well, maybe releasing it in a populated area without getting caught would be a little tricky, too....
but think of the headlines!
ok.
and now back to our regularly scheduled decent thread material...
1. Kai is in charge of bio. You'll have to get him onboard.
2. I just take :wink: as an "I'm not laughing with you" kind of condescension. Call me crazy.
I think it would be cool to design some imitation
T. rex, but first I'd like to get the bigger issue of biodiversity under control. The more species we have to work with, the more weirdness we can engineer. And the prettier the planet will be.
I'd probably start with ostriches, btw. Get them some tails and teeth, then scale up the size, morph the wings into some claws...
Quote from: Doktor Howl on May 10, 2010, 09:38:49 PM
Did you mean you go out of your way to NOT antagonize, then?
yeah...
:oops:
So, Doc... something like this then?
(http://www.disc0rd.com/images/chicken%20rex%20doc.png)
YES.
Quote from: Kai on May 10, 2010, 10:13:53 PM
Quote from: Doktor Howl on May 10, 2010, 09:10:36 PM
Quote from: Iptuous on May 10, 2010, 09:08:57 PM
Quote from: Doktor Howl on May 10, 2010, 08:50:09 PM
I don't do bio, first of all.
Second of all, wtf, Ippie?
sry, just being dumb. :)
you could at least contract out some bio madness to stick in the desert...
or make the ostriches a little more dinosaur-like. scale up those razors that they stick on fighting cocks, or something...
the hardest part about that would be getting the tranquilizer gun.
well, maybe releasing it in a populated area without getting caught would be a little tricky, too....
but think of the headlines!
ok.
and now back to our regularly scheduled decent thread material...
1. Kai is in charge of bio. You'll have to get him onboard.
2. I just take :wink: as an "I'm not laughing with you" kind of condescension. Call me crazy.
I think it would be cool to design some imitation T. rex, but first I'd like to get the bigger issue of biodiversity under control. The more species we have to work with, the more weirdness we can engineer. And the prettier the planet will be.
I'd probably start with ostriches, btw. Get them some tails and teeth, then scale up the size, morph the wings into some claws...
Make sure they can take riders, Enrico needs them for the ostrich cavalry.
Quote from: Kai on May 09, 2010, 02:34:51 PM
Quote from: Vladimir Poopin on May 08, 2010, 08:44:45 PM
Quote from: vexati0n on May 06, 2010, 11:43:31 PM
Disappointment Ahead: This is not actually about poop.
I believe Evolution is true. But... I have a question.
Say there's a dinosaur. And millions of years later, his descendants are birds. Okay, fair enough. I can understand why a species might evolve the ability of flight. But why start down that path if it takes millions of years to get there? What practical advantage is a dinosaur with a few sparse feathers? What advantage in natural selection does an animal have that, for example, has evolved feathers but not flight? Do its genes just say "well, that's okay, we're going for flight and we'll get there eventually, for now all we have are feathers..." ?
Evolution is purposeless. There are no goals. There are traits that allow a species to survive and pass on their genes.
The trait may be very stupid. Take something like sexual selection. For example: female birds think a male bird with plumage that is so ridiculous that it actually makes them more vulnerable to predators are more attractive, so the entire species begins to take that trait on. Evolution is does not have an end-game or design. If you're really interested in learning more about this, check out The Blind Watchmaker by Richard Dawkins.
Yes, I realize someone may have already answered this. No, I don't care.
It's not stupid if it works. Take plumage. The obvious plumage makes them more vulnerable to predators, but if the male can survive with that obvious plumage it shows other traits good for avoiding predation.
It's also, as I said already, a matter of adaptation and exaptation.
If it doesn't work, it is stupid.
Then again, the species dies off so I guess the problem takes care of itself. Still, if it were intelligent then species wouldn't die out because of counter-productive adaptations.
If it doesn't work, then the lineage goes extinct yes.
Which means nothing we have today is in essence stupid, because it's worked. Because if it didn't work, it wouldn't be here.
It sounds tautological but it's really just simple.
I lol every time I see this thread in the queue :mrgreen:
Quote from: Kai on May 11, 2010, 01:12:06 AM
If it doesn't work, then the lineage goes extinct yes.
Which means nothing we have today is in essence stupid, because it's worked. Because if it didn't work, it wouldn't be here.
It sounds tautological but it's really just simple.
Yes...Of course, what works can and will change.
Quote from: Kai on May 11, 2010, 01:12:06 AM
If it doesn't work, then the lineage goes extinct yes.
Which means nothing we have today is in essence stupid, because it's worked. Because if it didn't work, it wouldn't be here.
It sounds tautological but it's really just simple.
that makes me wonder about domesticated animals. particularly the ones that are so fucked up for meat purposes or aesthetic purposes, that they couldn't live without human care. i guess that still counts, but it's certainly strange in that context....
Quote from: Iptuous on May 11, 2010, 03:46:49 AM
Quote from: Kai on May 11, 2010, 01:12:06 AM
If it doesn't work, then the lineage goes extinct yes.
Which means nothing we have today is in essence stupid, because it's worked. Because if it didn't work, it wouldn't be here.
It sounds tautological but it's really just simple.
that makes me wonder about domesticated animals. particularly the ones that are so fucked up for meat purposes or aesthetic purposes, that they couldn't live without human care. i guess that still counts, but it's certainly strange in that context....
Well, that's just artificial selection, as opposed to natural selection.
is there a difference in this context?
isn't it just another cooperative biological relationship?
i mean it's weird that having ridiculous amounts of wrinkles because some other species has selected it for you is technically an advantage, but nobody said nature makes sense....
Quote from: Iptuous on May 11, 2010, 04:26:37 AM
is there a difference in this context?
isn't it just another cooperative biological relationship?
i mean it's weird that having ridiculous amounts of wrinkles because some other species has selected it for you is technically an advantage, but nobody said nature makes sense....
haha, ok. I see what you mean
yes, breeding is pretty weird
It should be noted that I received this in response to a comment I made about birds being dinosaurs:
Quotelol.. thats like saying people are monkeys,...... although a close relation is obvious, closest living relative to the t-rex is a chicken. but how far back in your family do you go before your grandparents were monkeys?... lol.. i am no monkey.... and if dinosaurs evolved into birds, why do turtles and crocodiles not fly?... they have no wings,... hummmm evolution didnt work so well there... they are close relatives... if you really look at dna of any animal and any other they are similar,... we come from the same building blocks.. like legos,... then they classify the groups to seperate them more,,... so u are a monkey.,,... almost 90% monkey,... if i made you a ham sandwich that is 90% balogna you cant really say its a ham sandwich... you are a monkey, birds are dinosaurs,.. we are different,.. in the same family,.. the theory of evolution,.. is just that,... a theory that has been proven wrong,.. birds that migrate to the same place 1000s of miles would not have ever made the first journey, it would have been to far to fly, without knowing were to go, they are not suicidal,.. they would have stopped somewere nice that is alot closer,.. same with lots of other animals,.. so using correct terminology like the avian dinosuars, people are nothing more than domesticated monkeys,.. scientist test them all the time, and even tought them to use currentcy,.. they even figured out to stock up when u offer 2 for 1 specials,..and use the currentcy to pay for sex,.. so i find it totally awsome that you guys made it out of the tree,.. but im thinking person that realizes that monkeys are related to people,.. but i am no monkey,.. nor cave man,... it was proven that people lived at the same time as cave people in one area,.. not evolved from,... they lived at the same time,.. and competed for food and everything else,.. i wonder why they died out?... cause we eliminated the bigger stronger species by outsmarting them,.. not born from them,.. 2 different things, that are related,.. are not the same. hippos are not horses,.. although they are related,.. and related to the same prehistoric animal, not evolved from it,... yes i beleive in god,... and sciene,,, science is just fact,.. just because its fact, doesnot mean that it was not created,... the world is to complexly connected not to come from the plan,,.. it wouldnt have worked,... and i believe in aliens and bigfoot also,.. and think god made them also,..,, expanding universe grows constatly,.. no reason why,.. but it is fact,... it keeps being made,.. not evolved,.. what makes it?... it has nothing to evolve from..
Quote from: Iptuous on May 11, 2010, 03:46:49 AM
Quote from: Kai on May 11, 2010, 01:12:06 AM
If it doesn't work, then the lineage goes extinct yes.
Which means nothing we have today is in essence stupid, because it's worked. Because if it didn't work, it wouldn't be here.
It sounds tautological but it's really just simple.
that makes me wonder about domesticated animals. particularly the ones that are so fucked up for meat purposes or aesthetic purposes, that they couldn't live without human care. i guess that still counts, but it's certainly strange in that context....
Artificial selection is a different sort of process, although it works under the same principles. Domesticated animals and plants are obligate mutualists with humans, and probably would not be able to survive without us.
Vex, that quote is ridiculous. :lulz:
No biologist today doubts that birds are the last of the theropod lineage. The evidence is overwhelming.
Kai, do you know of any other species that have a mutual relation with another where they impede or promote selective breeding in some way? even in some rudimentary way?
Vex, regarding your friends rambling response....
i thought I overused ellipses!
Does the bolded statement causing confusion? does he understand what speciation is? would he expect all life, assuming that it arose from a common source, to change in unison for all time?
I dunno. I just told him to shut up if he can't at least speak in complete sentences.
Quote from: Iptuous on May 11, 2010, 01:35:09 PM
Kai, do you know of any other species that have a mutual relation with another where they impede or promote selective breeding in some way? even in some rudimentary way?
Yeah, lots of them. Obviously not conscious, but theres a whole field of biology devoted to studying coevolution, where two or more species engage in a selective arms race with each other. Insects and plants are the most prominent examples, where the plants are constantly being selected for by insect herbivory to produce better and better defensive chemicals and the insects are being heavily selected for by the plants to develop novel ways of avoiding those chemical defenses.
Or, think of parasites and hosts. While the parasite may not be causing selection pressures on the host, thus not being coevolution, the host is causing strong selection pressures on the parasite. Think crab lice. They have those giant claws to grasp the thick hairs in the pubic region. This adaptation is a selection force by the host.
Or, social parasites, in ant colonies. Or, really, any case where selection is being caused by living things rather than abiotic factors. Humans just go about it consciously (and unconsciously, for that matter). It's not even so much a matter of forcing the best animals to breed, but rather
selecting out animals with undesirable traits. Works no different than any other type of selection, in that sense.
This is why I say humans have been doing genetic engineering for at least 12000 years.
hm....
the arms race type situation seems to be pressures that cause selection set in opposition.
is there any situation, for instance, where an animal that eats a certain plant will kill off specimens that do not produce suitable fruit? or an animal that predates on another will kill off malformed young of their prey, or something?
something that could be rudimentary shaping of the other species to make it more amenable as a food source, rather than acting passively as a selective pressure for the other to build defenses against?
Quote from: Iptuous on May 11, 2010, 02:20:17 PM
hm....
the arms race type situation seems to be pressures that cause selection set in opposition.
is there any situation, for instance, where an animal that eats a certain plant will kill off specimens that do not produce suitable fruit? or an animal that predates on another will kill off malformed young of their prey, or something?
something that could be rudimentary shaping of the other species to make it more amenable as a food source, rather than acting passively as a selective pressure for the other to build defenses against?
No. But if the plant depends on suitable fruit to bribe animals into spreading it's seeds then a plant without suitable fruit will be by default eliminated from the lineage.
Humans are the only species with the foresight to consciously direct selection, AFAIK.
hm....
we'll have to change that with the megachickens.
teach them to corral humans and kill off the ones that aren't plump enough.
maybe just have them cue in on the ones holding comfort wipes as 'keepers'...
Not counting the sharks with lasers on their heads.