So you don't understand how evolution actually works?
Everything that reproduces does so with variation. Every individual organism has around 60 completely unique mutations in its genetic code. Most of these mutations produce little difference in the life or survivability of that organism, but a very small number will produce benefits and will increase either the likelihood of survival to reproduce or an improvement in reproductive potential overall. This improvement is largely determined by the environment a population lives in, which naturally sets the conditions under which certain mutations will be "successful" over others. From this point on, those organisms more likely to survive and/or thrive will tend to do so and produce more copies of themselves, which will proliferate into subsequent generations. Over time, this will affect the overall allele frequency in a population, or create a separate population altogether (leading to such things as ring species). This is how a single population of organisms diversifies or changes over time, and how new populations - and even new species - arise out of old ones, and this is how evolution works.
Pakicetus was not a dog, and it was certainly not "one generation from a whale". Pakicestus were around about 48-49 million years ago, and the earliest whales didn't appear until around 34 million years ago.
SOURCE:
Evolution of cetaceans - Wikipedia
Then you don't know what a "species" is. Ring species is a clear and observed instance of a single population of organisms diverging and becoming two separate and distinct species, and proves that there is no genetic barrier at the level of "species" that prevents evolution beyond that level.
I've already given you two links which list observed instances of speciation.
Like I said, this is an odd request considering the information would be exactly the same, and further considering that posts have a word limit. Here are just a couple of examples from the links I already provided:
From Observed Instances of Speciation:
5.4.2 Selection for Geotaxis with and without Gene Flow
Soans, et al. (1974) used houseflies to test Pimentel's model of speciation. This model posits that speciation requires two steps. The first is the formation of races in subpopulations. This is followed by the establishment of reproductive isolation. Houseflies were subjected to intense divergent selection on the basis of positive and negative geotaxis. In some treatments no gene flow was allowed, while in others there was 30% gene flow. Selection was imposed by placing 1000 flies into the center of a 108 cm vertical tube. The first 50 flies that reached the top and the first 50 flies that reached the bottom were used to found positively and negatively geotactic populations. Four populations were established:
Population A + geotaxis, no gene flow
Population B - geotaxis, no gene flow
Population C + geotaxis, 30% gene flow
Population D - geotaxis, 30% gene flow
Selection was repeated within these populations each generations. After 38 generations the time to collect 50 flies had dropped from 6 hours to 2 hours in Pop A, from 4 hours to 4 minutes in Pop B, from 6 hours to 2 hours in Pop C and from 4 hours to 45 minutes in Pop D. Mate choice tests were performed. Positive assortative mating was found in all crosses. They concluded that reproductive isolation occurred under both allopatric and sympatric conditions when very strong selection was present.
Hurd and Eisenberg (1975) performed a similar experiment on houseflies using 50% gene flow and got the same results.
5.7 Speciation in a Lab Rat Worm, Nereis acuminata
In 1964 five or six individuals of the polychaete worm, Nereis acuminata, were collected in Long Beach Harbor, California. These were allowed to grow into a population of thousands of individuals. Four pairs from this population were transferred to the Woods Hole Oceanographic Institute. For over 20 years these worms were used as test organisms in environmental toxicology. From 1986 to 1991 the Long Beach area was searched for populations of the worm. Two populations, P1 and P2, were found. Weinberg, et al. (1992) performed tests on these two populations and the Woods Hole population (WH) for both postmating and premating isolation. To test for postmating isolation, they looked at whether broods from crosses were successfully reared. The results below give the percentage of successful rearings for each group of crosses.
WH × WH - 75%
P1 × P1 - 95%
P2 × P2 - 80%
P1 × P2 - 77%
WH × P1 - 0%
WH × P2 - 0%
They also found statistically significant premating isolation between the WH population and the field populations. Finally, the Woods Hole population showed slightly different karyotypes from the field populations.
From Some More Observed Speciation Events:
Here is a short list of referenced speciation events. I picked four relatively well-known examples, from about a dozen that I had documented in materials that I have around my home. These are all common knowledge, and by no means do they encompass all or most of the available examples.
Example one:
Two strains of Drosophila paulistorum developed hybrid sterility of male offspring between 1958 and 1963. Artificial selection induced strong intra-strain mating preferences.
(Test for speciation: sterile offspring and lack of interbreeding affinity.)
Dobzhansky, Th., and O. Pavlovsky, 1971. "An experimentally created incipient species of Drosophila", Nature 23:289-292.
Example two:
Evidence that a species of fireweed formed by doubling of the chromosome count, from the original stock. (Note that polyploids are generally considered to be a separate "race" of the same species as the original stock, but they do meet the criteria which you suggested.)
(Test for speciation: cannot produce offspring with the original stock.)
Mosquin, T., 1967. "Evidence for autopolyploidy in Epilobium angustifolium (Onaagraceae)", Evolution 21:713-719
Example three:
Rapid speciation of the Faeroe Island house mouse, which occurred in less than 250 years after man brought the creature to the island.
(Test for speciation in this case is based on morphology. It is unlikely that forced breeding experiments have been performed with the parent stock.)
Stanley, S., 1979. Macroevolution: Pattern and Process, San Francisco, W.H. Freeman and Company. p. 41
Example four:
Formation of five new species of cichlid fishes which formed since they were isolated less than 4000 years ago from the parent stock, Lake Nagubago.
(Test for speciation in this case is by morphology and lack of natural interbreeding. These fish have complex mating rituals and different coloration. While it might be possible that different species are inter-fertile, they cannot be convinced to mate.)
Mayr, E., 1970. Populations, Species, and Evolution, Massachusetts, Harvard University Press. p. 348
Observation is not a matter of opinion.
You should throw out your crystal ball.
