Bambu what you cite is exactly what reproductive isolation is. In an extremely short period of time these flies went from randomly assorted mating to highly exclusive. That is exactly how allopatric speciation is suppose to occur.
This exclusivity occurred in 35 generations which is less than 1 year. If this level of change can occur in behavior in such a short time what do you posit will slow this change over 5 years or 50 years or 500 years. Further physical changes occurred as well since the starch based flies developed midgut changes to handle the food source.
It is obvious you accept change can occur, you keep showing pretty pictures illustrating it, but what do you think holds that change in check over time. If you accept that changes can occur to the fruit flies over time what force holds those changes in check to keep a fruit fly a fruit fly?
Imagine a time machine allowing you move through two special environments populated by 2 groups of fruit flies. This environment has everything the flies need to live. Now move your time machine forward in time by 1000 years. You would expect to see slight difference in the populations. The average size might have shifted or coloration. It might be slight but it is present. Now move that time machine forward 10000 years changes continue to accumulate, but you would still think you are looking at a fruit fly. At 100,000 years though you might have to say the changes are enough that you can not call what you are looking at a fruit fly. Move forward 1,000,000 years, if you think small simple changes can occur in less than 1 year then what do you call something that has seen millions of small changes. Do you honestly think these 2 populations of flies separated for a 1,000,000 years would still be so similar you would consider them the same species?
What force or mechanism to you offer to counter-act the ever-present change in the genetic make up of a population over time?
This exclusivity occurred in 35 generations which is less than 1 year. If this level of change can occur in behavior in such a short time what do you posit will slow this change over 5 years or 50 years or 500 years. Further physical changes occurred as well since the starch based flies developed midgut changes to handle the food source.
It is obvious you accept change can occur, you keep showing pretty pictures illustrating it, but what do you think holds that change in check over time. If you accept that changes can occur to the fruit flies over time what force holds those changes in check to keep a fruit fly a fruit fly?
Imagine a time machine allowing you move through two special environments populated by 2 groups of fruit flies. This environment has everything the flies need to live. Now move your time machine forward in time by 1000 years. You would expect to see slight difference in the populations. The average size might have shifted or coloration. It might be slight but it is present. Now move that time machine forward 10000 years changes continue to accumulate, but you would still think you are looking at a fruit fly. At 100,000 years though you might have to say the changes are enough that you can not call what you are looking at a fruit fly. Move forward 1,000,000 years, if you think small simple changes can occur in less than 1 year then what do you call something that has seen millions of small changes. Do you honestly think these 2 populations of flies separated for a 1,000,000 years would still be so similar you would consider them the same species?
What force or mechanism to you offer to counter-act the ever-present change in the genetic make up of a population over time?
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