The phrase "a pair of ancestral" is correct and usable in written English.
It can be used when referring to two items or entities that are related to one's ancestors or heritage.
Example: "She inherited a pair of ancestral rings that had been passed down through generations."
Alternatives: "two ancestral items" or "a duo of ancestral artifacts".
Then there is a pair of ancestral portraits that Touhami commissioned for a show at the Mori Museum in Tokyo to celebrate the 30th anniversary of Hello Kitty.
A pair of ancestral images called ana deo from the eastern island of Flores -- animated wood carvings of a man and a woman -- would have acted as links between the villagers and the spirit world.
Mammalian sex chromosomes evolved from the degeneration of one homolog of a pair of ancestral autosomes, the proto-Y.
Identical KALX and KALY sequences were located on a pair of ancestral chromosomes before the cessation of recombination in stratum 4. Both KALX and KALY were subjected to mutations following the establishment of stratum 4.
Statistically supported incongruities between a gene family phylogeny and that of vertical descent can be interpreted as an HGT between a pair of ancestral lineages assuming the descendant of the donor lineage is sampled (see previous section).
We can also use the ensemble of parsimonious histories encoded by our method to compute a probability for the relative duplication order of a pair of ancestral proteins u and v. Let where denotes the set of ancestors of a protein.
Their sex chromosomes are called the Z and W, with males having two Z's and females a Z and a W. The Z and W are derived from a different pair of ancestral chromosomes than the X and Y, a team led by Daniel W. Bellott and Dr. Page report in the current issue of Nature.
The ancestral tRNAs reconstructed from the phylogenetic trees of Bacteria, Archaea and Eukarya [ 24] strongly confirmed this finding (depicted in Table 1 for all pairs of ancestral tRNAs with complementary anticodons).
Such reconstruction is often performed under a hidden Markov model (HMM) with the latent state being the pair of ancestral origins at a locus, where the transition probability of ancestral origins between two loci, or the two-locus diplotype (two-haplotype) probabilities are required.
Because we are calculating the substitutions by comparing each members of a pair of paralogs to their common ancestral state reconstruction, alignment lengths L1 and L2 do not have to be equal due to paralog-specific indels.
Molecular evolutionary studies in recent years have established that the mammalian sex Chrs originated from a pair of ordinary autosomes, and most ancestral genes on that pair were still maintained on the X Chr but degenerated on the Y Chr due to the lack of recombination [ 23- 25].
