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I get what you're asking. You want a testable account of how any given species went from what we would call species X to what we would call species Y. There is

I get what you're asking. You want a testable account of how any given species went from what we would call species X to what we would call species Y. There is probably never going to be such a level of resolution in our analysis that would satisfy even the staunchest naysayer. To really comprehend evolution requires an imagination capable of extrapolating a given set of principles into a framework that entails the very minuscule available data we do have under one encompassing theory. That theory is evolution. It is not something that can be fully understood in isolation. This doesn't directly answer your question, but this was a key insight that finally made the entire picture click in my mind. Your question of wanting hard evidence of cross-species evolution is a red-herring and a distraction to your understanding. The concept of species is not a biological reality. Any definition we can come up with for a species, we can find many instances that break the definition. What we see as a species is just groups of individuals who have exchanged genes in recent history. There is no demarcation to delineate a transition between one species and another: (in the case of sexual reproduction) at every point a child can mate with its parents, with no exceptions (except for degenerate cases). This is true for every species that sexually reproduces, going all the way back to the origin of sexual reproduction. The reason groups of animals that represent a unified gene pool look so different is that groups of individuals fall into stable states with their environmental niche, while other groups fall into other stable states for other niches. Animals appear to be delineated by clear species simply as a function of our perspective from a single time slice. If we could observe gradual change over millions of years, we would see many splitting branches and merging branches, branches that get further apart and then seed an explosion of many smaller branches (i.e. when say land animals split from birds), etc etc. But in reality, every individual is a single branch on this tree. What we judge as a species are just branches that are 'close together' in this tree such that they look like a single unit.

noonespecial 12y ago
A good way to think about it is to imagine a prism's dispersion of white light. There is clearly red and clearly orange but it gets tricky finding the place where "red becomes orange". The closer you look, the harder it is to choose a spot.
nyrulez 12y ago
Thanks - your answer is reasonable. What I was really looking for is a mechanism that demonstrates this: "Animals appear to be delineated by clear species simply as a function of our perspective from a single time slice. If we could observe gradual change over millions of years, we would see many splitting branches and merging branches, branches that get further apart and then seed an explosion of many smaller branches (i.e. when say land animals split from birds), etc etc." The idea of gradual change is fine to me - and the term species seems to create too much confusion. But the fact that gradual change over time can create seemingly distinct states (lets not call them species) still boggles me mind when I try to conceive of the mechanism. Is asking that question a red-herring or completely unreasonable ? In fact that is the part I find most fascinating. The fact that the change was gradual doesn't preclude from the fact that this gradual change did lead to states which were observed to be quite distinct. One doesn't preclude the other. To explain more of where I am coming from: As a person who writes reasonably complex software for a living, I am amazed by the "software" in the brain if you will i.e. its remarkable cognitive capacity for many tasks that we are still in the process of replicating in AI. I find it hard to understand how this could arise as a step by step gradual change purely aided by a favorable set of environmental properties. So something to that effect would be really cool to understand (And even emulate or copy in our software development practices). I am a bit disappointed that there are no simulations that can be done or we don't understand the mechanisms well enough to do this. For a very specific example, it would be cool to simulate "This is how the eye came into being.". Not just enumerating the commonalities between eyes of different species - I find the "commonality" argument as being "factual evidence" of origin of the eye very weak personally. I know its been accepted as fact by most or everyone else but something that would demonstrate the underlying "gradual" principles at work to evolve an eye for example would be uber-cool and satisfying in my book. I don't understand why this question is stupid or or unscientific.
- splawn 12y ago
  If you just want to play with something that uses a genetic algo, there is this: http://boxcar2d.com/ http://boxcar2d.com/ You can handcraft a simple starting point and let it gradually evolve in different environments. Note how the different environments bring out different traits even tho the starting point is the same. I don't know how many hrs I lost playing with this. :)

noonespecial 12y ago

A good way to think about it is to imagine a prism's dispersion of white light. There is clearly red and clearly orange but it gets tricky finding the place where "red becomes orange". The closer you look, the harder it is to choose a spot.

nyrulez 12y ago

Thanks - your answer is reasonable. What I was really looking for is a mechanism that demonstrates this: "Animals appear to be delineated by clear species simply as a function of our perspective from a single time slice. If we could observe gradual change over millions of years, we would see many splitting branches and merging branches, branches that get further apart and then seed an explosion of many smaller branches (i.e. when say land animals split from birds), etc etc." The idea of gradual change is fine to me - and the term species seems to create too much confusion. But the fact that gradual change over time can create seemingly distinct states (lets not call them species) still boggles me mind when I try to conceive of the mechanism. Is asking that question a red-herring or completely unreasonable ? In fact that is the part I find most fascinating. The fact that the change was gradual doesn't preclude from the fact that this gradual change did lead to states which were observed to be quite distinct. One doesn't preclude the other. To explain more of where I am coming from: As a person who writes reasonably complex software for a living, I am amazed by the "software" in the brain if you will i.e. its remarkable cognitive capacity for many tasks that we are still in the process of replicating in AI. I find it hard to understand how this could arise as a step by step gradual change purely aided by a favorable set of environmental properties. So something to that effect would be really cool to understand (And even emulate or copy in our software development practices). I am a bit disappointed that there are no simulations that can be done or we don't understand the mechanisms well enough to do this. For a very specific example, it would be cool to simulate "This is how the eye came into being.". Not just enumerating the commonalities between eyes of different species - I find the "commonality" argument as being "factual evidence" of origin of the eye very weak personally. I know its been accepted as fact by most or everyone else but something that would demonstrate the underlying "gradual" principles at work to evolve an eye for example would be uber-cool and satisfying in my book. I don't understand why this question is stupid or or unscientific.

splawn 12y ago
If you just want to play with something that uses a genetic algo, there is this: http://boxcar2d.com/ http://boxcar2d.com/ You can handcraft a simple starting point and let it gradually evolve in different environments. Note how the different environments bring out different traits even tho the starting point is the same. I don't know how many hrs I lost playing with this. :)