| The distribution of singletons, doubletons, and other variants among the continents was investigated. |
| Of these, 75 are singletons, two are doubletons, and one is present in three sequences. |
| It transpires that in this region of our galaxy, binary and multiple star systems are more common than singletons like our Sun. |
| Thus the difference in susceptibility to RDS in premature singletons and multiples may depend on the size of the conceptus. |
| Women pregnant with multiples are more likely than those with singletons to suffer premature delivery, toxemia, and hemorrhage. |
| Concordant with this result, Tajima's test and Fu and Li's tests indicated an excess of singletons as expected under the rapid growth hypothesis. |
