speciation - Evolution in 37 years, is it possible?

I am confused, can evolution ( speciation ) really occur in such a short time ?

In 1971, biologists moved five adult pairs of Italian wall lizards from their home island of Pod Kopiste, in the South Adriatic Sea, to the neighboring island of Pod Mrcaru. Now, an international team of researchers has shown that introducing these small, green-backed lizards, Podarcis sicula, to a new environment caused them to undergo rapid and large-scale evolutionary changes."

Here is a short video featuring the scientist.

Two related articles:

Edit: I asked a similar question previously about two people having 44 chromosomes and their possibility of creating a new species. You might like to read/answer that as well:

Can two humans with 44 chromosomes produce viable offspring?

Answer

I am confused, can evolution ( speciation ) really occur in such a short time?

Well, Evolution and Speciation are not the same. Evolution is the adaptation of an existing species to an environment over generations. Speciation is the development of a new species, and the definition of "species" can vary depending on who you talk to - but a very commonly accepted one is that two individuals cannot produce fertile offspring.

However, the answer is still Yes. Evolution can occur in as little as two generations because that's all the time it takes for a change in the DNA to be exhibited in the newest generation. For instance, Lactase Persistence - which allows the bearers to ingest dairy products without digestive stress into adulthood - has evolved at least twice in humans in separate groups. Both are the result of either one or two point mutations (single changes in a Nucleotide within the DNA). The result is that at one point in time for each appearance of lactase persistence, a child was born that could drink milk into adulthood while their parents and cousins could not.

That is evolution; the child was better adapted to the resources available, and because lactase persistence either...

• Provided a significant advantage over their kin in the environment (which is likely, as being able to digest milk in an agrarian society opens up a new source of energy)...

or

• Didn't hinder the child's ability to grow and produce fertile offspring of their own...

...it has persisted in the populations where it initially evolved.

Speciation is a little trickier, but that's because there isn't a known qualitative way to differentiate species at the genetic level quite yet. It could be a few key gene changes, it could be a whole genome difference of 10%, or a million other factors. Practically speaking, though, Speciation is simply the result of accumulated genome changes that at some point prevent the members of one group from producing fertile offspring with their ancestral group.

Because we simply don't know how much of or where the genome has to change, it's certainly possible that speciation could occur in the same time period as it takes to evolve: Two generations.

Since I'm doubting the wall lizards have a generational time of >37 years (don't mistake it for lifespan, humans can reproduce in our teens - even if we live into our 80's), it's definitely possible that the wall lizards could evolve (and potentially speciate) in such a short amount of time.

With organisms that have a very, very short generational time - like E. coli or other bacteria - you can observe the Evolution of populations in days or hours.