Chapter 30

Bad Design—Sharks Get More Reproductive Options, Too

Sharks are famous for their poor social skills. In fact, they sometimes eat each other.

Figure 30.1 TV news footage of a great white shark savaged by another shark, probably another great white.

Some sharks have poor social skills.

They are so aggressive that they will even bite people before they are born. I’m not joking. A marine biologist was once inspecting a pregnant female shark, and had his hand in her uterus. One of the unborn pups bit the marine biologist on the thumb.69

Now that’s aggression.

It gets worse. Sharks are so aggressive that they will not only eat other sharks after they are born, they are so aggressive that they will eat each other before they are born.

Sand tiger sharks (Carcharias taurus),70 also known as grey nurse sharks (Carcharias taurus),71 have pups so aggressive that they eat their siblings while in the womb. By the time they are born, there is only one pup per womb.

Sharks also tend to have solitary lifestyles. This means that sharks can sometimes have a hard time finding a mate. You would too under the circumstances.

So sometimes, sharks have to get creative if they’re going to reproduce.

One thing that sharks have got going for them, that we haven’t, is that female sharks can breed without males.72, 73 That’s right. If no male sharks show up that the female wants to breed with, she can reproduce all by herself!

Think of the convenience! If no good males are available, a female shark can create young all by herself. If they are, she can reproduce in the usual sexual way. Think of how many human women suffer because of a lack of good mates, or suffer at the hands of bad mates. Sharks don’t have to put up with this, and they can still reproduce without one.

So sharks find it easier to breed than humans do. Maybe the Creator is a shark after all.

69. George H. Burgess, “Shark Conservation in the Western North Atlantic: A Perspective,” Florida Museum of Natural History, http://www.flmnh.ufl.edu/fish/organizations/ssg/regions/region12/conservation.htm.

70. Demian D. Chapman et al., “The behavioural and genetic mating system of the sand tiger shark, Carcharias taurus, an intrauterine cannibal,” Biology Letters, 9 (3), June 23, 2013, DOI 10.1098/rsbl.w013.0003.

71. John Platt, “Artificial uterus could save grey nurse shark from extinction,” http://blogs.scientificamerican.com/extinction-countdown/2009/02/18/artificial-uterus -could-save-grey-nurse-shark-from-extinction/.

72. Demian D. Chapman et al. “Parthenogenesis in a large-bodied requiem shark, the blacktip Carcharhinus limbatus.” Journal of Fish Biology, 2008, 73 (6), 1473, DOI 10.1111/j.1095–8649.2008.02018.x.

73. Stony Brook University, “‘Virgin Birth’ By Shark Confirmed: Second Case Ever,” ScienceDaily, http://www.sciencedaily.com­/releases/2008/10/081010173054.htm#.