scholarly journals Mating systems and population structure in two closely related species of the wheat group I. Variation between and within populations

Heredity ◽  
1973 ◽  
Vol 30 (2) ◽  
pp. 141-167 ◽  
Author(s):  
Joseph Hillel ◽  
Marcus W Feldman ◽  
Giora Simchen
Keyword(s):  
Population Structure ◽  
Related Species ◽  
Mating Systems ◽  
Closely Related Species ◽  
Group I ◽  
Wheat Group

Interspecific Mating and Cytological Studies of Closely Related Species of Ips DeGeer and Orthotomicus Ferrari (Coleoptera: Scolytidae)

1966 ◽  
Vol 98 (2) ◽  
pp. 175-188 ◽  
Author(s):  
Gerald N. Lanier
Keyword(s):  
Related Species ◽  
Group Iv ◽  
Sperm Transfer ◽  
Interspecific Mating ◽  
Closely Related Species ◽  
European Species ◽  
Group Iii ◽  
Group I

AbstractInterspecific pairing of closely related species of Ips and Orthotomicus was undertaken to test their degree of breeding isolation. Pairings of the following species frequently resulted in sperm transfer but no eclosion: Ips mexicanus × I. concinnus (group I), confusus × montanus (group IX), plastographus (group III) × pini (group IV) and Orthotomicus latidens × O. sabinianae.Mating was generally unsuccessful when the more distantly related species, confusus × plastographus and confusus × pini, were paired.Individuals which produce all-female broods were discovered in a population of O. latidens. About 50% of the eggs deposited by these females hatched, whereas 92% of the eggs from “normal” females produced larvae.Cytological investigations revealed no constant differences between the karyotypes of I. mexicanus and concinnus (7AA+Xyp), O. latidens and sabinianae (9AA+Xyp), or between I. confusus and montanus (15AA+Xyp). I. pini (oregonis) and plastographus also have karyotypic formulae of 15AA+Xyp, but both are easily distinguished from confusus and montanus and an atypical chromosome in pini (oregonis) distinguishes it from plastographus. The mexicanus and concinnus karyotype and that of O. latidens and sabinianae can be directly derived from each other by fusion or fission. Their relationship to the karyotype of the European species O. proximus (6AA+Xy), is plausible but their karyotypes are composed of a remarkably different number of autosomal arms from those known for other species of Ips.

scholarly journals Genomic compatibility occurs over a wide range of parental genetic similarity in an outcrossing plant

2005 ◽  
Vol 272 (1570) ◽  
pp. 1333-1338 ◽  
Author(s):  
Yvonne Willi ◽  
Josh Van Buskirk
Keyword(s):  
Mate Choice ◽  
Inbreeding Depression ◽  
Related Species ◽  
Genetic Similarity ◽  
Mating Systems ◽  
Hybrid Breakdown ◽  
Offspring Performance ◽  
Closely Related Species ◽  
Wide Range ◽  
Broad Scale

The theory of inbreeding and outbreeding suggests that there is a hump-shaped relationship between the genetic similarity of sexually reproducing parents and the performance of their offspring. Inbreeding depression occurs when genetic similarity is high, whereas hybrid breakdown is expected when genetic similarity is low. Between these extremes, the effect of genetic similarity on fitness is unclear. We studied the shape of this relationship by crossing 65 target genotypes of the clonal, self-incompatible Ranunculus reptans with partner genotypes spanning a broad scale of genetic similarity, ranging from crosses within populations to between-population crosses and hybridisation with a closely related species. Offspring were raised in outdoor tubs. Results revealed a quadratic relationship between parental genetic distance and offspring performance, with the clonal component of fitness more strongly hump-shaped than the sexual component. Optimal genetic similarity encompassed a broad range of within-population and between-population crosses. This pattern of genomic compatibility has important implications for the evolution of mating systems and mate choice.

Do Closely Related Species Influence Each Other's Sexual Size Dimorphism?

2018 ◽  
Author(s):  
Chloe Boynton
Keyword(s):  
Body Size ◽  
Related Species ◽  
Species Interactions ◽  
Sexual Size Dimorphism ◽  
Birds Of Prey ◽  
Closely Related Species ◽  
Size Dimorphism ◽  
Group I ◽  
Males And Females ◽  
Range Overlap

Size differences between males and females (sexual size dimorphism) are often seen in a variety of species. In birds of prey in particular, a phenomenon occurs where the female is larger than the male. One of the main hypotheses attempting to explain sexual size dimorphism in birds of prey is that the female and male differ in size to partition resources, like prey. There is also evidence that predator and prey body size are correlated, so predators of similar size may be in direct competition. It has been shown that when two closely related species interact in the same area, they are likely to be in competition for similar resources, like prey. This study is looking at sexual size dimorphism and closely related species interactions, which has never been looked at before in birds of prey. I am using the subfamily Buteoninae (Buteo Hawks) as my focal group. I will be using sexual size dimorphism ratios, estimates of genetic distance between closely related species and proportion of range overlap between different closely related lineages within the subfamily. I am expecting to see that if species are closely related and inhabit the same area they will have a decreased sexual size dimorphism. This is because both species are likely to be competing for the same resources, and to avoid competition the species will diverge in body size from one another. This will cause the male and female of each species to converge in size, reducing their sexual size dimorphism.

A review of the systematics and distribution of Chydorus ventricosus Daday, 1898, with the first description of the male and redescription of the species

1986 ◽  
Vol 64 (4) ◽  
pp. 818-832 ◽  
Author(s):  
R. Rajapaksa ◽  
C. H. Fernando
Keyword(s):  
Population Structure ◽  
Sri Lanka ◽  
Critical Review ◽  
Related Species ◽  
Accurate Diagnosis ◽  
Review Of The Literature ◽  
Comprehensive Description ◽  
Closely Related Species ◽  
Oriental Region ◽  
Type Series

Based on the study of the type series and material from Sri Lanka, a comprehensive description of Chydorus ventricosus Daday is given including the first description of the male. The detailed morphology of all instars of females and males, population structure, and some biological notes are also provided. This species was considered a tropicopolitan species based on previous records from Asia, America, and Africa. However, a detailed study of populations from a wide area of the Oriental region and material previously designated as Chydorus ventricosus from America and Africa, and a critical review of the literature indicates that it is very probably restricted to the Oriental region. Chydorus ventricosus closely resembles an undetermined number of taxa. Only a detailed study will determine their status. We have compared it with the only two well-described, closely related species. The present study has characterized all stages of Chydorus ventricosus. This will enable accurate diagnosis of this species.

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