Using this definition, wolves and dogs were considered to be separate species, despite the fact that they interbreed in nature. Many bird species are capable of interbreeding, and will do so in nature and in captivity. As an example, check out web resources on breeding conures, where there is a great deal of concern about losing species to hybridization.
What is clear is that reproductive isolation is a concept that is less about science than it is about philosophy. It gives evolutionary theory a tremendous boost, but causes tremendous scientific problems otherwise.
As another example, check out this story about how global warming is causing grizzlies and polar bears interbreeding
Polar bears face a new threat besides melting ice — male grizzly bears are moving into their territories, competing for food and are even mating with their females.
Scientists have already discovered one case of a hybrid “grolar” bear and are circulating requests to hunters and polar tour operators to look out for more...
Scientists suggest that the white coat of polar bears evolved because paler creatures would have had an advantage in hunting seals.
In genetic terms, however, such differences are superficial. In captivity polar bears and grizzlies can interbreed, with their offspring also being fertile — a sign that their DNA is similar. :
Grizzlies and polar bears mate in the wild when they are in contact during mating season. They've always fit the classical definition of species, and now they fit Mayr's as well.
So, why should we care about whether biologists calls these animals one species or two?
Well, it points out something that many on the left would like us to forget: scientists are people too. They have their own prejudices, biases, and yes, agendas. The data they gather is viewed through the lens of their expectations, and once they've built a model for a process, they are extremely reluctant to revise it, even in the face of overwhelming data. Definitions are changed to make observed data fit a predetermined model, rather than changing the model to fit the data.
It's not a conspiracy, or a plot; it's usually just human nature.
We've all heard the stories of global warming activists exaggerating to 'raise awareness." Al Gore won an Oscar for that. We've also heard about "mistakes" like NASA's Goddard Institute for Space Studies using September climate data to claim that October 2008 was the hottest October ever recorded. That incident was particularly interesting as the GISS initially denied the error, making up reasons for the findings before coming clean about the error.
While these incidents, and the dozens like them are embarrassing for the Climate Change crowd, things just got a whole lot worse.
Hackers recently released hundreds of emails and data files, including computer models used to determine climate trends. There are multiple instances in these files of scientists openly planning to alter data to fit the desired outcome. There are comment remarks in computer code that are even more blunt, saying that data will be adjusted to match "the real temperature."
Most of us assume that the data would be the real temperature, and any manipulation would introduce error, but we don't think like scientists.
Again, I'm not claiming a global scientific conspiracy here, just normal, human tunnel vision. These men and women have invested thousands of man hours and billions of dollars of other people's money into climate change research. The models they built represented the sum of all that effort, time, and expense. When the data didn't fit, it's a very human failing to want to explain away the data instead of going to the guy who pays your check and say, "Well, we were wrong." So they naturally look for ways to throw out the data that doesn't fit. They invent plausible sounding reasons for doing so, and they publish their "enhanced" results. Other groups working in the field are now under pressure to corroborate the findings, and adopt the same "enhancements."
It's human nature, and each and every one of us has experienced exactly the same reaction, and done the same thing. Remember, scientists are not priests; they are not unbiased or impartial, no matter what the stereotype is.
The difference is that there are unscrupulous politicians applying very real pressure to these research institutes to come up with the "right" answers, right being defined as the answer which gives the government the most control.
The bottom line is that science is not the clean, neat, theoretical process we have pictured in our minds. Scientists are not dispassionate robots, acting solely on logical analysis of the data. Science is messy, confusing, and contradictory, and scientists are just as subject to pettiness and corruption as any other human being.