Bulbs have evolved repeatedly in several lines and occur among many members of Asparagales.
We also find unanticipated allelic heterogeneity at Tyrp1 and Sox10, indicating that color variants evolved repeatedly though mutations in the same genes.
Given that the same habitat specialist types have evolved repeatedly on the islands, we might also expect them to occur on the mainland.
Ovules are basically crassinucellate (with ample nucellar tissue), but the tenuinucellate condition (without a parietal cell) has evolved repeatedly within several families.
Fishes have been in existence for more than 450 million years, during which time they have evolved repeatedly to fit into almost every conceivable type of aquatic habitat.
These groups have evolved along parallel lines, and features such as highly projectile tongues, loss of lungs, and loss of fifth toes have evolved repeatedly, even within the same family.
A critical question for the subject is whether a set of adaptations arose once and has simply been retained by all species descended from a common ancestor having those adaptations or whether the adaptations evolved repeatedly because of the same environmental factors.
A new genetic study of peacocks and closely related pheasants found that this trait appears in some birds but not others, which suggests that it independently evolved repeatedly.
There is more [technological] capability that exists than [the federal government] takes advantage of". A division of Raytheon until the end of 1999, 16-year-old Savi had expertise in Washington contracting, but that wasn't enough, and the company, now privately owned, has had to evolve repeatedly, Fritts said.
Thus, divergent genomic GC content has evolved repeatedly in widely separated bacterial taxa.
