The arrival to the
The Africanized honey bee (AHB) is a New World amalgamation of several subspecies of the western honey bee (
- NSF-PAR ID:
- 10368657
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Ecology and Evolution
- Volume:
- 12
- Issue:
- 2
- ISSN:
- 2045-7758
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
more » « less
Abstract U nitedS tates of theA fricanized honey bee, a hybrid betweenE uropean subspecies and theA frican subspeciesA pis mellifera scutellataA frican andE uropean lineages in a feral population inS outhT exas. An 11‐year survey of this population (1991–2001) showed that mitochondrial haplotype frequencies changed drastically over time from a resident population of eastern and western European maternal ancestry, to a population dominated by theA frican haplotype. A subsequent study of the nuclear genome showed that theA fricanization process included bidirectional gene flow between European and Africanized honey bees, giving rise to a new panmictic mixture ofA . m. scutellata‐A. m. scutellata maternal ancestry, and three were of western European maternal ancestry. No colonies of eastern European maternal ancestry were detected, although they were present in the earlier samples. NuclearDNA revealed little change in the introgression ofA . m. scutellata -
The 17th-century colonization of North America brought thousands of Europeans to Indigenous lands in the Delaware region, which comprises the eastern boundary of the Chesapeake Bay in what is now the Mid- Atlantic region of the United States.1 The demographic features of these initial colonial migrations are not uni- formly characterized, with Europeans and European-Americans migrating to the Delaware area from other countries and neighboring colonies as single persons or in family units of free persons, indentured servants, or tenant farmers.2 European colonizers also instituted a system of racialized slavery through which they forcibly transported thousands of Africans to the Chesapeake region. Historical information about African- descended individuals in the Delaware region is limited, with a population estimate of less than 500 persons by 1700 CE.3,4 To shed light on the population histories of this period, we analyzed low-coverage genomes of 11 individuals from the Avery’s Rest archaeological site (circa 1675–1725 CE), located in Delaware. Previous osteological and mitochondrial DNA (mtDNA) sequence analyses showed a southern group of eight individ- uals of European maternal descent, buried 15–20 feet from a northern group of three individuals of African maternal descent.5 Autosomal results further illuminate genomic similarities to Northwestern European refer- ence populations or West and West-Central African reference populations, respectively. We also identify three generations of maternal kin of European ancestry and a paternal parent-offspring relationship between an adult and child of African ancestry. These findings expand our understanding of the origins and familial relationships in late 17th and early 18th century North America.more » « less
-
Population genomics of divergence among extreme and intermediate color forms in a polymorphic insectmore » « less
Abstract Geographic variation in insect coloration is among the most intriguing examples of rapid phenotypic evolution and provides opportunities to study mechanisms of phenotypic change and diversification in closely related lineages. The bumble bee
Bombus bifarius comprises two geographically disparate color groups characterized by red‐banded and black‐banded abdominal pigmentation, but with a range of spatially and phenotypically intermediate populations across western North America. Microsatellite analyses have revealed thatB. bifarius in the USA are structured into two major groups concordant with geography and color pattern, but also suggest ongoing gene flow among regional populations. In this study, we better resolve the relationships among major color groups to better understand evolutionary mechanisms promoting and maintaining such polymorphism. We analyze >90,000 and >25,000 single‐nucleotide polymorphisms derived from transcriptome (RNA seq) and double digest restriction site associatedDNA sequencing (ddRAD ), respectively, in representative samples from spatial and color pattern extremes inB. bifarius as well as phenotypic and geographic intermediates. Both ddRAD andRNA seq data illustrate substantial genome‐wide differentiation of the red‐banded (eastern) color form from both black‐banded (western) and intermediate (central) phenotypes and negligible differentiation among the latter populations, with no obvious admixture among bees from the two major lineages. Results thus indicate much stronger background differentiation amongB. bifarius lineages than expected, highlighting potential challenges for revealing loci underlying color polymorphism from population genetic data alone. These findings will have significance for resolving taxonomic confusion in this species and in future efforts to investigate color‐pattern evolution inB. bifarius and other polymorphic bumble bee species. -
more » « less
Abstract Among the three main divergent lineages of gray wolf (Canis lupus), the Holarctic lineage is the most widespread and best studied, particularly in North America and Europe. Less is known about Tibetan (also called Himalayan) and Indian wolf lineages in southern Asia, especially in areas surrounding Pakistan where all three lineages are thought to meet. Given the endangered status of the Indian wolf in neighboring India and unclear southwestern boundary of the Tibetan wolf range, we conducted mitochondrial and genome-wide sequencing of wolves from Pakistan and Kyrgyzstan. Sequences of the mitochondrial D-loop region of 81 wolves from Pakistan indicated contact zones between Holarctic and Indian lineages across the northern and western mountains of Pakistan. Reduced-representation genome sequencing of eight wolves indicated an east-to-west cline of Indian to Holarctic ancestry, consistent with a contact zone between these two lineages in Pakistan. The western boundary of the Tibetan lineage corresponded to the Ladakh region of India’s Himalayas with a narrow zone of admixture spanning this boundary from the Karakoram Mountains of northern Pakistan into Ladakh, India. Our results highlight the conservation significance of Pakistan’s wolf populations, especially the remaining populations in Sindh and Southern Punjab that represent the highly endangered Indian lineage.
-
more » « less
Abstract Members of genetically admixed populations possess ancestry from multiple source groups, and studies of human genetic admixture frequently estimate ancestry components corresponding to fractions of individual genomes that trace to specific ancestral populations. However, the same numerical ancestry fraction can represent a wide array of admixture scenarios within an individual’s genealogy. Using a mechanistic model of admixture, we consider admixture genealogically: how many ancestors from the source populations does the admixture represent? We consider African-Americans, for whom continent-level estimates produce a 75–85% value for African ancestry on average and 15–25% for European ancestry. Genetic studies together with key features of African-American demographic history suggest ranges for parameters of a simple three-epoch model. Considering parameter sets compatible with estimates of current ancestry levels, we infer that if all genealogical lines of a random African-American born during 1960–1965 are traced back until they reach members of source populations, the mean over parameter sets of the expected number of genealogical lines terminating with African individuals is 314 (interquartile range 240–376), and the mean of the expected number terminating in Europeans is 51 (interquartile range 32–69). Across discrete generations, the peak number of African genealogical ancestors occurs in birth cohorts from the early 1700s, and the probability exceeds 50% that at least one European ancestor was born more recently than 1835. Our genealogical perspective can contribute to further understanding the admixture processes that underlie admixed populations. For African-Americans, the results provide insight both on how many of the ancestors of a typical African-American might have been forcibly displaced in the Transatlantic Slave Trade and on how many separate European admixture events might exist in a typical African-American genealogy.
