And someone's response to the above:
Whoa, man. This guys' conclusions are all wrong. There is absolutely no reason why Noodleous Doubleous should be construed as a separate species, when it should be patently obvious that the Penne and Rigatoni are simply conducting their mating ritual.
Let's examine each pasta's physical characteristics.
The Penne is small, has a smooth carapace, and two pointed ends: all features designed to facilitate penetration.
The Rigatoni is larger (so to protect her brood, similar to the red-tailed hawk), has a ribbed outside to ward off wayward Penne (since it would be evolutionarily unfavorable to pass on such incompetent genes), and is just the right size to sheath the Penne.
The Rigatoni is oriented vertically, while the Penne is at a 45° angle. This allows the Rigatoni to remain in place and conserve nutrients for the gestation period, while the more aerodynamic Penne needs to come to the female, undoubtedly a goal attained only after fighting off all other competing Penne in the area. The fact that all Rigatoni were oriented the same way (and likewise the Penne) suggests the pasta have either a genetic or societal aversion to same-sex relations, as such unions would not bear offspring. The bubbles coming from the dorsal end of the Rigatoni clearly indicates the Rigatoni's willingness to mate and serves much the same purpose as cats caterwauling, or cows balling.
Further, let's examine the conditions under which the conjoining occurs.
The two pastas need to be mixed together in a suspending liquid. This is obviously necessary, as intercourse cannot happen with the species separated; also, as they do not have any self-locomotive ability, they need the support and mobility provided by the water.
The water needs to be boiling. This is in clear opposition to the Kinsey/Cole Porter assertion that 'every average man...much prefers to play his favorite sport when the temperature is low;' however, such an occurrence is not out of the question. These pastas may well be extremophiles much like the Pompeii worm or antarctic krill, who can only function under very high or very low temperatures. Their apparent inactivity when in boxes on store shelves supports this.
Also, when the act is occuring, the water covers over with a white froth; a froth which serves both as protective camouflage, and also allows the demure pasta some measure of privacy. The observation that no unions take place while the pasta was being directly observed supports the hypothesis of the pasta's modest nature.
The investigators found that the pasta were engorged and tender after boiling, as shown in Figure 4. I trust I don't need to draw parallels to humans' similar condition post-coitus.
The investigators' extremely low calculated probability of insertion was no doubt correct. However, their conclusion that such a low probability leads to Intelligent Design doesn't take all the facts into account. If they had simply researched the birth rates of Penne & Rigatoni, they would have found that one mating yields upwards of 10^44 pasta spores. This high spore:mating ratio indicates that even such a low insertion probability as 2.05x10^-32 is more than enough to perpetuate the species. The few Penne who do manage to woo the female into mating are clearly the most powerful; an assertion that indicates the pasta's high standards of genetic preservation. The fact that Rigatoni and Penne remain largely unchanged over thousands of years evidences this careful quality control.
The researchers' conclusion of Intelligent Design is just poor science.
And on a personal note, I find their dissection of the mated pair in Figure 5 personally distasteful and wholly unnecessary.