Often taxonomists prefer to use phylogenetic analysis to determine whether a population can be considered a subspecies. Phylogenetic analysis relies on the concept of derived characteristics that are not shared between groups, usually applying to populations that are allopatric (geographically separated) and therefore discretely bounded. This would make a subspecies, evolutionarily speaking, a clade – a group with a common evolutionary ancestor population. The smooth gradation of human genetic variation in general tends to rule out any idea that human population groups can be considered monophyletic (cleanly divided), as there appears to always have been considerable gene flow between human populations. Rachel Caspari (2003) have argued that clades are by definition monophyletic groups (a taxon that includes all descendants of a given ancestor) and since no groups currently regarded as races are monophyletic, none of those groups can be clades.
What analysis method are taxonomists fond of using in considering a population?
phylogenetic

Seabird migration is similar in pattern to those of the waders and waterfowl. Some, such as the black guillemot Cepphus grylle and some gulls, are quite sedentary; others, such as most terns and auks breeding in the temperate northern hemisphere, move varying distances south in the northern winter. The Arctic tern Sterna paradisaea has the longest-distance migration of any bird, and sees more daylight than any other, moving from its Arctic breeding grounds to the Antarctic non-breeding areas. One Arctic tern, ringed (banded) as a chick on the Farne Islands off the British east coast, reached Melbourne, Australia in just three months from fledging, a sea journey of over 22,000 km (14,000 mi). Many tubenosed birds breed in the southern hemisphere and migrate north in the southern winter.
Which bird sees more daylight than any other during migration?
The Arctic tern

Victoria's self-imposed isolation from the public diminished the popularity of the monarchy, and encouraged the growth of the republican movement. She did undertake her official government duties, yet chose to remain secluded in her royal residences—Windsor Castle, Osborne House, and the private estate in Scotland that she and Albert had acquired in 1847, Balmoral Castle. In March 1864, a protester stuck a notice on the railings of Buckingham Palace that announced "these commanding premises to be let or sold in consequence of the late occupant's declining business". Her uncle Leopold wrote to her advising her to appear in public. She agreed to visit the gardens of the Royal Horticultural Society at Kensington and take a drive through London in an open carriage.
What private estate did Victoria aquire with Albert in 1847?
Balmoral Castle