Sentence examples for originated once from inspiring English sources

This implies two possible scenarios for the origin of asexuality in the genus: 1) asexuality originated once, with subsequent radiation of asexuals and at least two independent reversals to sexuality or 2) asexuality originated multiple times (at least seven times; Figure 5).

We use these data to unravel the history of the North American reticulate complex and to determine whether the sexual polyploids appear to have arisen via hybridization or introgression, whether such taxa have originated once or multiple times, and whether such origins require the existence of the missing diploid "D.

Analysis of word sounds suggests that language originated once, in central and southern Africa.

Fungiculture in attine ants originated once approximately 50 million years ago while the transition to fungal cultivation using fresh plant material appears to have arisen about 40 million years later [8].

To determine if the genes originated once in cyanobacteria and from what kind of eukaryote they might be derived, phylogenetic analyses were performed to determine the position of the cyanobacterial genes relative to eukaryotic class I FBAs.

Whereas mitochondria originated once and have apparently never been lost [ 3- 5], plastids have spread between eukaryotic lineages several times in events referred to as secondary and tertiary endosymbioses.

In our pIns-MycER TAM mice, where mature β-cells are normally highly sensitive to the pro-apoptotic activity of c-Myc [ 9], invasive β-cell tumours only originate once apoptosis is prevented, in this case by constitutive over-expression of the protein BclxL.

It also implies, though does not prove, that modern language originated only once, an issue of considerable controversy among linguists.

If we agree that life originated only once, then the evolutionary relationships among all living things can, in principle, be expressed on a single, huge clade.

We also consider the role of members of the AGAMOUS subfamily in the development of the pistil, a character that originated only once.

The shapes of phylogenetic trees and networks suggest that the protective E-2 haplotypes (Figure 3 and Table S4, green) originated only once: they group on a single branch of the tree.