OBSERVATIONS ON THE BIOLOGY OF <i>TYLENCHUS DIPSACI</i> (KUHN) BASTIAN, AND ON THE OCCURRENCE OF BIOLOGIC STRAINS OF THE NEMATODE

Hodson, W. E. H.

doi:10.1111/j.1744-7348.1926.tb04265.x

Cited by 16 publications

(6 citation statements)

References 3 publications

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“…Gulf of CA to southern Colombia (Keen, 1971) n/a n/a n/a n/a T. matarucana a Panama, Colombia, Venezuela (Hodson, 1926) n/a n/a n/a n/a (Hodson, 1926) n/a n/a n/a n/a…”

Section: T Mariana = T Radulamentioning

confidence: 99%

Protoconch enlargement in Western Atlantic turritelline gastropod species following the closure of the Central American Seaway

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Allmon

et al. 2019

Ecology and Evolution

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The closure of the late Neogene interoceanic seaways between the Western Atlantic (WA) and Tropical Eastern Pacific (TEP)—commonly referred to as the Central American Seaway—significantly decreased nutrient supply in the WA compared to the TEP. In marine invertebrates, an increase in parental investment is expected to be selectively favored in nutrient‐poor marine environments as prolonged feeding in the plankton becomes less reliable. Here, we examine turritelline gastropods, which were abundant and diverse across this region during the Neogene and serve as important paleoenvironmental proxies, and test whether species exhibit decreased planktotrophy in the WA postclosure as compared to preclosure fossils and extant TEP species. We also test for differences in degree of planktotrophy in extant sister species pairs. Degree of planktotrophy was inferred by measuring the size of protoconchs, the species' larval shell that represents egg size. Protoconch size was compared between extant postclosure WA and TEP species and preclosure fossil species. To compare extant sister species, we reconstructed the phylogeny of available WA and TEP species using one nuclear (H3) and three mitochondrial markers (12S, 16S, and COI). Compared to the preclosure fossils, protoconch size increased in WA species but remained the same in the TEP species. In the two extant sister species pairs recovered in the phylogenetic analysis, the WA species are inferred to be nonplanktotrophic while the TEP species are planktotrophic. This suggests that decreased nutrient availability and primary productivity in the WA may have driven this change in developmental mode, and was the primary selective force resulting in postclosure turritelline extinctions.

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“…Gulf of CA to southern Colombia (Keen, 1971) n/a n/a n/a n/a T. matarucana a Panama, Colombia, Venezuela (Hodson, 1926) n/a n/a n/a n/a (Hodson, 1926) n/a n/a n/a n/a…”

Section: T Mariana = T Radulamentioning

confidence: 99%

Protoconch enlargement in Western Atlantic turritelline gastropod species following the closure of the Central American Seaway

Sang

Friend

Allmon

et al. 2019

Ecology and Evolution

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“…No case of attack on strawberry is ever seen, while heavy infestation of the bulbs is common. I n another bulb area Hodson (1926) records that oat, a well-known host of this eelworm, is frequently grown in the vicinity of infested bulb fields, and even on ground which probably ceased to grow bulbs because of the depredations of this pest, yet no case of infestation of oats is ever seen. Yet again oat fields which are very severely attacked may contain clover, another favourite host, in flourishing condition; thus, in one instance, a field of "abundant" oats, so badly infested as to yield only 8 bushels per acre instead of 45, was followed in the autumn by a good crop of red clover which, according to Hodson, showed no sign of attack either then or subsequently.…”

Section: ( D ) Nematodesmentioning

confidence: 99%

Biological Races in Insects and Allied Groups

Thorpe

1930

Biological Reviews

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Discussion and Summary. Turning now to a consideration of the general significance of these numerous examples, the question which first presents itself is: Do they really represent the commencement of evolutionary change? In other words: Are they species in the making? A large number of workers (e.g. Schroder, Pictet, Cuénot, Nuttall, Harrison, Adkin and Sandground, to mention only a few) have answered in the affirmative with regard to the particular case with which each was concerned1. It seems worth while now to consider the question as a whole. If these races are indeed nascent species, then we must assume that their characteristics are sooner or later germinally fixed and that there is some degree of isolation, physiological or habitudinal, which ensures their continuance. How much evidence is there for these assumptions? It seems to the writer that perhaps the most important consideration in this connection is that of isolation. As has long been realised, the great difficulty in regarding mutations or any other inheritable variations produced in small numbers, as the starting point of new species, is that of accounting for the spread of such throughout a population. If the differences which serve to distinguish one species from another were of a kind likely to be of immediate survival value, then the problem would be simpler, but this does not appear to be the case with the general run of specific characters, still less of varietal ones. The importance of geographical isolation in fostering such variations is undoubted, but in many cases it is unlikely that this factor can come into play until a comparatively late stage in the process; the first steps in the spread of a new variant are little assisted by geographical barriers. If, however, there is some form of physiological isolation such as is provided by various small biological differences and by a repugnance for cross‐mating, then the process seems much easier to comprehend. Charles Darwin saw this clearly, as is evinced by his great interest in Bates' statement (Trans. Linn. Soc.23, 501): “The process of the creation of a new species I believe to be accelerated in the Ithomiae and allied genera by the strong tendency of insects, when pairing, to select none but their exact counterparts.” As Carpenter (1913, Proc. Ent. Soc. p. lxxxviii) points out, Darwin (Life and Letters, 2, 392) wrote to Bates regarding this generalisation: “I look upon this fact as very important”; but later rather severely criticised him for making the statement in general terms without sufficient evidence. That the evidence even now is far from being as extensive as could be wished is made clear by Richards (1927, pp. 345–347). As has already been seen in this review, in the few instances among naturally occurring biological races in which the matter of selective mating has been put to the test, the results have been positive, although not always, it must be said, on a scale large enough to be very convincing. There is here a big field for further work of a very great importance, ...

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“…Gulf of CA to southern Colombia (Keen, 1971) n/a n/a n/a n/a T. matarucana a Panama, Colombia, Venezuela (Hodson, 1926) n/a n/a n/a n/a T. nodulosa Baja, CA, to Southern Gulf of CA, to south of Ecuador (Keen, 1971)…”

Section: T Gonostomamentioning

confidence: 99%

“…T. rubescens San Francisco Island, Gulf of CA, to Gorgos Island, Colombia (Keen, 1971) (Hodson, 1926) n/a n/a n/a n/a…”

Section: T Gonostomamentioning

confidence: 99%

Protoconch Enlargement in Western Atlantic Turritelline Gastropod Species Following the Closure of the Central American Seaway

Anderson

2018

Geological Society of America Abstracts With Programs

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OBSERVATIONS ON THE BIOLOGY OF TYLENCHUS DIPSACI (KUHN) BASTIAN, AND ON THE OCCURRENCE OF BIOLOGIC STRAINS OF THE NEMATODE

Cited by 16 publications

References 3 publications

Protoconch enlargement in Western Atlantic turritelline gastropod species following the closure of the Central American Seaway

Protoconch enlargement in Western Atlantic turritelline gastropod species following the closure of the Central American Seaway

Biological Races in Insects and Allied Groups

Protoconch Enlargement in Western Atlantic Turritelline Gastropod Species Following the Closure of the Central American Seaway

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