A bit OT, but linked in with reproduction from a single 'kind'.
News | CIRES
"We step on soil every day, but few people realize that 'dirt' supports a complex community of microorganisms that plays a critical role on Earth, he said. "The number of bacterial species in a spoonful of soil is likely to exceed the total number of plant species in all of the United States."
http://www.sdearthtimes.com/et0998/et0998s8.html
The group, led by microbiologist William B. Whitman, estimates the number to be five million trillion trillion that's a five with 30 zeroes after it. Look at it this way. If each bacterium were a penny, the stack would reach a trillion light years. These almost incomprehensible numbers give only a sketch of the vast pervasiveness of bacteria in the natural world.
http://www.cropchoice.com/leadstry9f94.html?recid=633
To put this in its context Jack Heinemann of Canterbury University pointed out that it is extremely difficult to simply detect HGT as at present scientists are only aware of 10 million species of bacteria which is only 1% of the total number of bacteria species i.e. we don’t have clue about the other 99%. On top of this of the species of bacteria that are known not all of them are able to be studied in the lab as they cannot be cultured for analysis. Put in a global context bacteria hold as much carbon in them as all the plants on the planet and ten times the amount of nitrogen than plants. While virus species out number bacteria by 10-100 times.
So if we are to believe the Flood (and Noah`s cruise) happened in the last six millenia,those critters have been doing some diversifying ever since.