Falsifiable Theories, Speed of Evolution and Diversity of species

Falsifiable Theories
What is evolution? The standard definition in science is:

  1. A change in the relative frequency of alleles in the gene pool of a population.
  2. A change in the adaptation norm of a population.
  3. A change in the diversity of populations of organisms via speciation.
These changes take place over time. The amount of change is dependant on the amount of time and the change in the environment. The theory of evolution claims that these things change in a population because of environmental factors. A falsifiable test would be to take two groups of fruit flies, and change the environment of one, but not the other. The alleles will change. The adaptive norm will change. Given time and genetic separation (A LOT of time), these two groups will become different species. These are easy things to test, and they have been done.

Speed of evolution
It is hard to judge the relative speed of something without knowing the entire process. Claiming changes over 1000 years has a very different view if one believes the Earth is 6000 something years old vs. 4,000,000,000 years old. The radioactive dating of rocks is an accepted practice. Given a known rate of decay from one element to another it is possible to make estimations of the age. These estimations have been proven to be accurate.

So how fast is evolution occurring? There are evolutionary processes that take millions of years. Others take less time. Corn has been bread from its original grass over a few thousand. Evolution happens with speed according to how fast the environment is changing - as does extinction. The mass extinctions of the past have caused great spurts of evolutionary change because many species went extinct and lots of ecological niches were opened up. Humans have been changing the environment of the planet for a few thousand years, and rather quickly at times - is it any surprise that species are changing quickly along with that?

Diversity of Species
And why shouldn't there be a great diversity of species? There are a great diversity of different ecologies. In the Santa Cruz mountain range there are species that can't survive on the sunny side of the valley, and others that have adapted to it, yet can't survive in the shaded side. There are different thousands if not millions of variables for a particular micro-ecology and different species will be best suited to each one of those. A polar bear couldn't survive in the same places that a grizzly bear does. Different combinations of plants surviving means different animals surviving. Even though a species of plants may be able to live in a climate does not necessarily mean that it can survive there - if its form of pollination and seed dispersion does not work. Likewise, even if an animal can survive in a climate, its food source may not be able to.

One good example of this is the humming bird, bees, and the flowers. Two species of flowers - identical in all aspects other than color. One is red, the other is blue. Hummingbirds are attracted to the red flower, bees attracted to the blue. While the flowers can grow in either climate, only the red ones grow where humming birds and no bees are and only the blue ones grow where bees are with no humming birds.

Diversity needs no explanation other than this. It has predictable consequences too. Left to nature, if you plant the red species where there no humming birds, after a generation of flowers goes by, they won't reproduce and flourish.

The above gives adequate explanation for what is happening. What else could be happening?