MORTALITY
The end of life is ever more close. But it isn't of great concern when you truly believe you go on in a better way in the hereafter. In about thirteen years I will be 100. I keep getting warnings the end is near.
Eight years ago I had a case of shingles in the right trigeminal nerve region. Fortunately, my eye escaped the damage it often causes. Blood work at the time showed some immune deficiencies and a marrow sample indicated I had the same disease that Carl Sagan had died from about six months after a successful bone marrow transplant.
One or two shots a week at the local cancer/blood diseases center have maintained neutrophils at low levels, but high enough that they seem to prevent infections. But an accompanying low level of platelets means a minor accident could be fatal- hence my internist son wants me to promise not to drive when schools are closed and roads are icy.
A FINAL POST
I've given some thought to a final post so a daughter could click on the publish button after I am gone. Because of the mix of topics I'd like to cover, I probably should write separate ones. If I mention God, half my readers are likely to tune out. If I mention evolution, the other half are likely to tune out. I have already tried to discuss why the two concepts are not mutually exclusive. It appears to me that some teachers in Europe and Asia have focused on a few evolution posts to have classes access them; it is just my guess based on peaks in page views.
POPULAR EVOLUTION POSTS
A February 27, 2015 post, on Evolution: the body cavity, covers a topic presumably given very little attention although it is important in understanding physiology and evolution. The content could help you understand why I think the biggest gap in the origin of coelomate animals can be filled by an ancestor of nemerteans.
The May 2, 2014 post, on Evolution of Macromolecules, when applied to cell physiology, can help one understand the natural selection biochemical features of cells had as most of the important underpinnings developing before the origin of multicellularity.
The April 8, 2015 post, Cnidaria: nematocyst origin, provoked renewed interest in the July 19, 2013 post on Acoelomate evolution, 2, cnidarians. They should be helpful in understanding the sponge-cnidarian-flatworm sequence of early evolution that had to be completed in the Pre-Cambrian before the protonemertean-polychaete-pogonophoran sequence led to hemichordates, then chordates.
OVERLOOKED POSTS OF IMPORTANCE
In order to understand the major errors infecting current evolutionary theory attempting to determine the "Tree of Life", the errors made in proposing the Ecdysozoa and Lophotrochozoa need to be seen. The post of May 31, 2013, Science Screw-Up No. 1 points out the errors that should have been seen by reviewers and stopped the publications involved. There are many other posts that provide a more rational answer to explain the "Tree of Life". It is necessary to understand the ecology of the deep sea to see how the pogonophorans have answered many important unasked questions about evolution.
ECLECTIC OR CHAOTIC?
My interests had jumped around in animals of interest over the years, as well as thinking of moon origin and the early environment on earth, continental drift, and unfortunately, or fortunately, not in a well-planned way. Without my chaotic background, I doubt I would have arrived at the role of pogonophorans and extreme longevity answering major questions of evolution. I accumulated a stack of mostly unpublished papers that I looked at and thought I should assemble them in a book. I think I picked the title, "Animal Evolution: A Serial Symposium" to accommodate my eclectic collection. That was almost thirty years ago when I started printing it out on a dot-matrix printer. The files saved on floppies, hard disks, and tape never got fully transferred to CDs and thumb drives before the old hard drives were corrupted; probably a good thing they are not swamping me with redundant data.
When I retired nineteen years ago, I was going to write the book that turned out to be "Evolution Insights", my 2010 unpublished manuscript. That might never have been done if I hadn't had the health problems noted above warning me time was limited. This blog was conceived of when it was apparent publishers were not looking for such books from new (though ancient) authors in 2010. Again golf and other things became distractions until other health problems jarred me in to getting a blog going. So I thank Google for their support of this blog and hope that it will survive my demise - whether tomorrow or ten years from now. This is not meant to be morbid, but you start to think about such things when you return from a memorial service for a WMU colleague first met about 51 years ago.
So while I work on my final post I will probably continue posting.
Joseph G. Engemann Kalamazoo, Michigan November 9, 2015
Monday, November 9, 2015
Saturday, October 24, 2015
EVOLUTION: THE POGONOPHORA LINK
THE LINK
Pogonophora are the previously unknown link in the evolutionary sequence connecting annelid worms to vertebrates via the hemichordates. Some items of evidence not mentioned in earlier posts on this topic include information compiled by Libbie Hyman and presented in her 1959 volume on The Invertebrates, volume V, 1959. The link status demonstrates the error of the widely assumed evolutionary separation of deuterostomes from advanced protostomes.
The confusion of the features of pogonophorans blending features of protostomes and deuterostomes was easily dismissed as caused by lack of adequate availability of well preserved specimens or some such estimation of the recently discovered group.
On page 59, she noted that, prior to the recognition of the pogonophorans as a phylum, one was described as "a vermiform animal with a crown of tentacles and was considered by its describer to be a polychaete annelid of the family Sabellidae".
Also, on page 59 she says "These outstanding studies by Ivanov have shown that the pogonophores are closely related to the hemichordates and belong among the Deuterostomia."
Webb's (1964) discovery of the segmented posterior of a pogonophoran helped endorse their annelid origin. Later, the contrary view was demonstrated by Gans and Northcutt (1983) affirming their connection to the deuterostomes despite the obvious annelid connection demonstrated by the generally unknown work of Webb.
So, Gould's (2002) contention that the evidence for elimination of the annelid theory should be dismissed means that the annelid theory should be reinstated as a leading explanation for the inversion of annelid features shown in the chordates. [ http://evolutioninsights.blogspot.com/2013/06/evolution-protostome-deuterstome-link.html and http://evolutioninsights.blogspot.com/2015/05/evolution-annelids-to-chordates-middle.html ] The second of the two posts just mentioned illustrates the larval similarity of pogonophoran larvae to solitary hemichordates. Hyman, on page 219, notes Caullery's 1944 observation that one pogonophoran's developing young "strikingly resemble young stages of the buds of Cephalodiscus", a colonial hemichordate.
I have tried to clarify the protostome-deuterostome connection demonstrated by the pogonophorans in numerous posts on this blog. By the time I realized the connection existed when provoked by the 1983 assertions of Gans and Northcutt, I had already published two revisions of Hegner's invertebrate zoology text, one in 1968 the other in 1981.
THE EMBRYOLOGICAL SHIFT FROM PROTOSTOME TO DEUTEROSTOME
The stumbling block for accepting the link is the drastic change in embryology that occurs. I might not have realized how it occurred if I had not revised Hegner's Invertebrate Zoology for its second edition (1968). In the process I had to deal with the proper classification of pogonophorans and realized the affinity that seemed impossible.
I tend to think there are answers for everything. I did not have the answer, but the needed facts were already in my background. As a result of the book preparation I had come to the conclusion that pogonophorans were extremely long-lived. [ http://evolutioninsights.blogspot.com/2015/05/abyssal-ocean-environment-and-extreme.html ] I did publish that conclusion in a 1978 abstract (Engemann, J. G., Indirect evidence shows deep-sea benthos may reach extreme ages as individuals. Am. Zoologist, 18:666).
My 1963 doctoral thesis at Michigan State University made me aware of the extreme affects environment can have on selection and evolution. I had not made much attempt to publish bits of the thesis because they were not greatly different from many other studies. But it made me aware of some necessary bits of information that helped explain the way embryological shift had been expedited.
The peculiar egg appendage of the isopod Asellus had been illustrated in Sar's work on the crustacea of Norway in the 1800's. K. H. Barnard had studied phreatoicid isopods in South Africa in the early 1900's and noted a bulge in embryos in a homologous position with the egg appendage that persisted briefly after the embryo hatched. My sections of phreatoicid eggs showed a thin-walled, yolk-filled homologue of the appendage existed before hatching as described in - http://evolutioninsights.blogspot.com/2014/06/egg-appendages-of-michigan-isopod.html .
The big thing to take from the above is that embryological features can evolve separately from the rate of adult features. Thus the old presumption that the earliest features in the evolution of the embryology of an organism correspond to the older ancestral stages in its evolution is not always true.
The thesis comparison of Tasmanian and Michigan isopods from comparable latitudes but quite different ecological circumstances in temporary pools showed drastically different rates of development and how r- and K- selection can work before the theory was described (MacArthur, R. H., and E. O. Wilson. 1967. The Theory ofIsland
Biogeography. Princeton Univ. Princeton , N.J.
THE MOLECULAR DATA
The exquisite work molecular biologists can do is remarkable. But it is limited and not easily applied to discovering ancestral relationships at the phylum level. Those limitations have been discussed in the post - http://evolutioninsights.blogspot.com/2013/05/science-screw-up-no-1.html .
My understanding of the slow rate of DNA changes in the pogonophora was confirmed by seeing how they showed up in phylogenetic studies among clusters of disparate groups due to little change in the over half-billion year old group almost in suspended animation in the abyssal sediments. Unfortunately, the generation time error affecting molecular clocks has not been considered in most work on molecular phylogeny.
MISSING LINKS
What do you call a missing link, such as the pogonophorans, once they are discovered?
CREDITS
I never expected to have work on an obscure invertebrate lead to the above understanding. But, in retrospect, I realize that much credit goes to unknown biologists and scientists of the past as well as many known ones. Thanks to Dr. V. Hickman of the University of Tasmania for calling the phreatoicid isopod to my attention, Dr. T. W. Porter of Michigan State University and the rest of my doctoral committee for keeping me focused on the comparative thesis study, the U. S. Fulbright Agency for the award for study at the University of Tasmania, Western Michigan University for allowing me to teach a ridiculous range of classes whose subject matter provided some needed insights, and the Macmillan Publishing Company for contracting with me to revise their texts. A book would be needed to explain how students, family, friends and strangers contributed to my development under the guidance of the same Creator that made evolution a reality.
Joseph Engemann Kalamazoo, Michigan October 24, 2015
Pogonophora are the previously unknown link in the evolutionary sequence connecting annelid worms to vertebrates via the hemichordates. Some items of evidence not mentioned in earlier posts on this topic include information compiled by Libbie Hyman and presented in her 1959 volume on The Invertebrates, volume V, 1959. The link status demonstrates the error of the widely assumed evolutionary separation of deuterostomes from advanced protostomes.
The confusion of the features of pogonophorans blending features of protostomes and deuterostomes was easily dismissed as caused by lack of adequate availability of well preserved specimens or some such estimation of the recently discovered group.
On page 59, she noted that, prior to the recognition of the pogonophorans as a phylum, one was described as "a vermiform animal with a crown of tentacles and was considered by its describer to be a polychaete annelid of the family Sabellidae".
Also, on page 59 she says "These outstanding studies by Ivanov have shown that the pogonophores are closely related to the hemichordates and belong among the Deuterostomia."
Webb's (1964) discovery of the segmented posterior of a pogonophoran helped endorse their annelid origin. Later, the contrary view was demonstrated by Gans and Northcutt (1983) affirming their connection to the deuterostomes despite the obvious annelid connection demonstrated by the generally unknown work of Webb.
So, Gould's (2002) contention that the evidence for elimination of the annelid theory should be dismissed means that the annelid theory should be reinstated as a leading explanation for the inversion of annelid features shown in the chordates. [ http://evolutioninsights.blogspot.com/2013/06/evolution-protostome-deuterstome-link.html and http://evolutioninsights.blogspot.com/2015/05/evolution-annelids-to-chordates-middle.html ] The second of the two posts just mentioned illustrates the larval similarity of pogonophoran larvae to solitary hemichordates. Hyman, on page 219, notes Caullery's 1944 observation that one pogonophoran's developing young "strikingly resemble young stages of the buds of Cephalodiscus", a colonial hemichordate.
I have tried to clarify the protostome-deuterostome connection demonstrated by the pogonophorans in numerous posts on this blog. By the time I realized the connection existed when provoked by the 1983 assertions of Gans and Northcutt, I had already published two revisions of Hegner's invertebrate zoology text, one in 1968 the other in 1981.
THE EMBRYOLOGICAL SHIFT FROM PROTOSTOME TO DEUTEROSTOME
The stumbling block for accepting the link is the drastic change in embryology that occurs. I might not have realized how it occurred if I had not revised Hegner's Invertebrate Zoology for its second edition (1968). In the process I had to deal with the proper classification of pogonophorans and realized the affinity that seemed impossible.
I tend to think there are answers for everything. I did not have the answer, but the needed facts were already in my background. As a result of the book preparation I had come to the conclusion that pogonophorans were extremely long-lived. [ http://evolutioninsights.blogspot.com/2015/05/abyssal-ocean-environment-and-extreme.html ] I did publish that conclusion in a 1978 abstract (Engemann, J. G., Indirect evidence shows deep-sea benthos may reach extreme ages as individuals. Am. Zoologist, 18:666).
My 1963 doctoral thesis at Michigan State University made me aware of the extreme affects environment can have on selection and evolution. I had not made much attempt to publish bits of the thesis because they were not greatly different from many other studies. But it made me aware of some necessary bits of information that helped explain the way embryological shift had been expedited.
The peculiar egg appendage of the isopod Asellus had been illustrated in Sar's work on the crustacea of Norway in the 1800's. K. H. Barnard had studied phreatoicid isopods in South Africa in the early 1900's and noted a bulge in embryos in a homologous position with the egg appendage that persisted briefly after the embryo hatched. My sections of phreatoicid eggs showed a thin-walled, yolk-filled homologue of the appendage existed before hatching as described in - http://evolutioninsights.blogspot.com/2014/06/egg-appendages-of-michigan-isopod.html .
The big thing to take from the above is that embryological features can evolve separately from the rate of adult features. Thus the old presumption that the earliest features in the evolution of the embryology of an organism correspond to the older ancestral stages in its evolution is not always true.
The thesis comparison of Tasmanian and Michigan isopods from comparable latitudes but quite different ecological circumstances in temporary pools showed drastically different rates of development and how r- and K- selection can work before the theory was described (MacArthur, R. H., and E. O. Wilson. 1967. The Theory of
THE MOLECULAR DATA
The exquisite work molecular biologists can do is remarkable. But it is limited and not easily applied to discovering ancestral relationships at the phylum level. Those limitations have been discussed in the post - http://evolutioninsights.blogspot.com/2013/05/science-screw-up-no-1.html .
My understanding of the slow rate of DNA changes in the pogonophora was confirmed by seeing how they showed up in phylogenetic studies among clusters of disparate groups due to little change in the over half-billion year old group almost in suspended animation in the abyssal sediments. Unfortunately, the generation time error affecting molecular clocks has not been considered in most work on molecular phylogeny.
MISSING LINKS
What do you call a missing link, such as the pogonophorans, once they are discovered?
CREDITS
I never expected to have work on an obscure invertebrate lead to the above understanding. But, in retrospect, I realize that much credit goes to unknown biologists and scientists of the past as well as many known ones. Thanks to Dr. V. Hickman of the University of Tasmania for calling the phreatoicid isopod to my attention, Dr. T. W. Porter of Michigan State University and the rest of my doctoral committee for keeping me focused on the comparative thesis study, the U. S. Fulbright Agency for the award for study at the University of Tasmania, Western Michigan University for allowing me to teach a ridiculous range of classes whose subject matter provided some needed insights, and the Macmillan Publishing Company for contracting with me to revise their texts. A book would be needed to explain how students, family, friends and strangers contributed to my development under the guidance of the same Creator that made evolution a reality.
Joseph Engemann Kalamazoo, Michigan October 24, 2015
Monday, October 12, 2015
EVOLUTION: INSECT SPECIATION
ISOLATING MECHANISMS
Insects have numerous isolating mechanisms that enable sub-populations of species to avoid hybridization and take different evolutionary routes to formation of new species. Darwin found the isolation of finches on different Galapagos islands may have been responsible for enabling them to evolve specializations leading to different species. Island populations of insects may produce new species by a similar mechanism.
Geographic isolation and population size
These two factors interact. In the island populations of finches in the Galapagos Islands. The ancestral finches that first reached the islands after their volcanic origin presumably were few in number and consequently had fewer variations in the total "gene pool" than the larger continental populations from which they originated. When new genes or combinations arose, that were better suited to survival on the various islands with varied conditions, selection might act more rapidly than in enormous potentially interbreeding continental populations. Such selection can also operate on small semi-isolated populations of continental populations on the periphery of the species range.
Lock and key genitalia
Insect species have an effective way of preventing interbreeding between previously interbreeding populations. Because of the need for, or value of, internal fertilization for reproduction of terrestrial adults there has been the evolution of specialized male organs for introducing sperm into the reproductive system of the females. Selection has made the male and female genital openings of the semi-rigid exoskeleton match up in a "lock and key" arrangement of various shapes dependent on species.
The lock and key relationship of male and female genitalia presumably becomes better established over time so closely related species can no longer have cross-fertilization possible. Other mechanisms may have helped the reproductive isolation occur. Geographic isolation is not the only spatial mechanism to facilitate reproductive isolation.
Micro-habitat isolation
Some butterfly species in tropical forests isolate themselves from other similar species living in the same region, but at different elevations from the ground, some near the ground, other high in the canopy, and still others at an intermediate height. Other insects may isolate themselves by their preference for a single species of plant species. Many animals have parasitic species of insects found only on their species. Various environmental conditions are often required by small organisms, sometimes in very small patches within what is a generally similar habitat by casual inspection; moisture, nutrients, soil particle size and texture, and chemical factors are features of micro-habitats that determine suitable environment for small organisms.
Imprinting
Lorenz discovered imprinting when he found that young geese responded to the first large moving animal they see after hatching as the object to follow. They would follow him instead of the mother goose if they saw him first. Imprinting of various types may occur at other times in the life cycle
A similar phenomenon occurs with the imprinting of the olfactory cues of a stream being imprinted on young salmon as guides to return to the same stream to breed. It is thought that some insects preferentially lay eggs on the same plant type they fed upon as larval insects; a few times of use of a different plant variety could lead to separate evolutionary lines of the same species.
Temporal isolation
When the breeding season is extended over time it is possible for new species to evolve from populations separated by time of breeding. I think this may have been a factor in evolution of species of isopods in Tasmania when the life cycle took three years for production of a new brood. Cross-breeding would be less likely and three new species could evolve, especially when adults did not survive for a second breeding season. Some intertidal populations of invertebrates have pairs of closely related species with separate reproductive seasons. Many marine species have external fertilization and would benefit from a short breeding season giving specialized predators less time to prey upon them.
Pheromones
Chemical signals species give off include sex attractants given off by the females to facilitate their being found by the opposite sex. Some tortricid moth species have been found to have sex attractants composed of two or three chemical components; ratios of the different compounds were different in each species and males only responded to the ratio characteristic of the species.
Pheromones of insects include other behavioral controls. Formic acid is an alarm pheromone common to most species of ants; in fact, their family name, Formicidae, is based on that fact.
Beetle speciation
Beetles have more species than any other order of animals. Their especially thick exoskeleton made the lock and key genitalia more effective in preserving the genetic isolation of new species once other adaptions became specialized. The appearance of the new species may be almost identical to related species, something less common among related vertebrate species. The hardened first pair of wings of beetles adapts them for survival without damage to their underlying membranous wings when crawling in forest floor debris.
Genetic factors in speciation
The important role of the genes in controlling development and function of organisms may be complicated by the complex life cycles of those with complete metamorphosis from larvae to pupae to adult. It would seem that a lesser sequence of shifting controls would be found in insects with a gradual metamorphosis from wingless stages otherwise similar but preceding the adult stage. The hormones regulating such changes have some parallels with vertebrate hormones.
Population size may affect the rate of evolutionary change although the loss of a better gene can occur by chance from mortality unrelated to a gene's value. Local and/or broad scale catastrophes can ignore the fitness of a genome. Barring loss of all with a better gene, it will probably become the most prevalent gene in a small population sooner than in a large population; if it is not lost, it will eventually be the norm in both.
The advantage of a complex life cycle
Most insects have a sequence of stages from egg, to larva, to pupa to adult. The complexity might seem like a disadvantage exposing them to many different hazards during the course of their life cycle. But consider the different ways they have developed to survive winter in temperate regions. A species may overwinter in the egg stage, hidden away from predators and not a target food item for birds or other predators specializing on eating the adult or larval stage.
The sequence of stages through the year are less likely to enable excessive buildup of a predator population specialized to feed on one or two of the the stages. When all stages are present at the same time, their different requirements may isolate them from competition with the other stages in feeding; it may also enable species survival by providing replacements if a particular stage has excessive predation.
An advantage of proper timing of stages of the insect species occurs when growth of the individual and its food organism, whether plant or animal, is at an optimal stage of growth. Many insects feed on dead and/or decaying organisms that are present in accumulations soil or aquatic sediments. Termites utilize wood effectively because they have symbiotic protozoans and bacteria in their gut that enable them to utilize cellulose, a plant material not digestible by large animals without such symbionts.
Speciation
Speciation is undoubtedly continuing among insect groups. Most orders and families are quite ancient in their origin. Fossils of insects much like those today have been found that are as ancient as the dinosaurs.
The previous post, http://evolutioninsights.blogspot.com/2015/10/evolution-insect-size.html , gives a probable reason insects have remained small. Their small size has been a factor for their successful speciation into the largest number of species of any group of comparable sized organisms, with numbers of individuals far exceeding those of vertebrates and advanced invertebrates.
It is amazing that such diversity can be packed into the same adult body format- a head with compound eyes, antennae, and mouthparts; a thorax of three segments, three pair of legs and often two pair of wings; and an abdomen of about ten segments usually lacking appendages but bearing the genitalia.
There is great diversity in the specialization that insects have evolved for survival. It is a topic that could provide information for many interesting posts.
Joseph G. Engemann Kalamazoo, Michigan October 12, 2015
Insects have numerous isolating mechanisms that enable sub-populations of species to avoid hybridization and take different evolutionary routes to formation of new species. Darwin found the isolation of finches on different Galapagos islands may have been responsible for enabling them to evolve specializations leading to different species. Island populations of insects may produce new species by a similar mechanism.
Geographic isolation and population size
These two factors interact. In the island populations of finches in the Galapagos Islands. The ancestral finches that first reached the islands after their volcanic origin presumably were few in number and consequently had fewer variations in the total "gene pool" than the larger continental populations from which they originated. When new genes or combinations arose, that were better suited to survival on the various islands with varied conditions, selection might act more rapidly than in enormous potentially interbreeding continental populations. Such selection can also operate on small semi-isolated populations of continental populations on the periphery of the species range.
Lock and key genitalia
Insect species have an effective way of preventing interbreeding between previously interbreeding populations. Because of the need for, or value of, internal fertilization for reproduction of terrestrial adults there has been the evolution of specialized male organs for introducing sperm into the reproductive system of the females. Selection has made the male and female genital openings of the semi-rigid exoskeleton match up in a "lock and key" arrangement of various shapes dependent on species.
The lock and key relationship of male and female genitalia presumably becomes better established over time so closely related species can no longer have cross-fertilization possible. Other mechanisms may have helped the reproductive isolation occur. Geographic isolation is not the only spatial mechanism to facilitate reproductive isolation.
Micro-habitat isolation
Some butterfly species in tropical forests isolate themselves from other similar species living in the same region, but at different elevations from the ground, some near the ground, other high in the canopy, and still others at an intermediate height. Other insects may isolate themselves by their preference for a single species of plant species. Many animals have parasitic species of insects found only on their species. Various environmental conditions are often required by small organisms, sometimes in very small patches within what is a generally similar habitat by casual inspection; moisture, nutrients, soil particle size and texture, and chemical factors are features of micro-habitats that determine suitable environment for small organisms.
Imprinting
Lorenz discovered imprinting when he found that young geese responded to the first large moving animal they see after hatching as the object to follow. They would follow him instead of the mother goose if they saw him first. Imprinting of various types may occur at other times in the life cycle
A similar phenomenon occurs with the imprinting of the olfactory cues of a stream being imprinted on young salmon as guides to return to the same stream to breed. It is thought that some insects preferentially lay eggs on the same plant type they fed upon as larval insects; a few times of use of a different plant variety could lead to separate evolutionary lines of the same species.
Temporal isolation
When the breeding season is extended over time it is possible for new species to evolve from populations separated by time of breeding. I think this may have been a factor in evolution of species of isopods in Tasmania when the life cycle took three years for production of a new brood. Cross-breeding would be less likely and three new species could evolve, especially when adults did not survive for a second breeding season. Some intertidal populations of invertebrates have pairs of closely related species with separate reproductive seasons. Many marine species have external fertilization and would benefit from a short breeding season giving specialized predators less time to prey upon them.
Pheromones
Chemical signals species give off include sex attractants given off by the females to facilitate their being found by the opposite sex. Some tortricid moth species have been found to have sex attractants composed of two or three chemical components; ratios of the different compounds were different in each species and males only responded to the ratio characteristic of the species.
Pheromones of insects include other behavioral controls. Formic acid is an alarm pheromone common to most species of ants; in fact, their family name, Formicidae, is based on that fact.
Beetle speciation
Beetles have more species than any other order of animals. Their especially thick exoskeleton made the lock and key genitalia more effective in preserving the genetic isolation of new species once other adaptions became specialized. The appearance of the new species may be almost identical to related species, something less common among related vertebrate species. The hardened first pair of wings of beetles adapts them for survival without damage to their underlying membranous wings when crawling in forest floor debris.
Genetic factors in speciation
The important role of the genes in controlling development and function of organisms may be complicated by the complex life cycles of those with complete metamorphosis from larvae to pupae to adult. It would seem that a lesser sequence of shifting controls would be found in insects with a gradual metamorphosis from wingless stages otherwise similar but preceding the adult stage. The hormones regulating such changes have some parallels with vertebrate hormones.
Population size may affect the rate of evolutionary change although the loss of a better gene can occur by chance from mortality unrelated to a gene's value. Local and/or broad scale catastrophes can ignore the fitness of a genome. Barring loss of all with a better gene, it will probably become the most prevalent gene in a small population sooner than in a large population; if it is not lost, it will eventually be the norm in both.
The advantage of a complex life cycle
Most insects have a sequence of stages from egg, to larva, to pupa to adult. The complexity might seem like a disadvantage exposing them to many different hazards during the course of their life cycle. But consider the different ways they have developed to survive winter in temperate regions. A species may overwinter in the egg stage, hidden away from predators and not a target food item for birds or other predators specializing on eating the adult or larval stage.
The sequence of stages through the year are less likely to enable excessive buildup of a predator population specialized to feed on one or two of the the stages. When all stages are present at the same time, their different requirements may isolate them from competition with the other stages in feeding; it may also enable species survival by providing replacements if a particular stage has excessive predation.
An advantage of proper timing of stages of the insect species occurs when growth of the individual and its food organism, whether plant or animal, is at an optimal stage of growth. Many insects feed on dead and/or decaying organisms that are present in accumulations soil or aquatic sediments. Termites utilize wood effectively because they have symbiotic protozoans and bacteria in their gut that enable them to utilize cellulose, a plant material not digestible by large animals without such symbionts.
Speciation
Speciation is undoubtedly continuing among insect groups. Most orders and families are quite ancient in their origin. Fossils of insects much like those today have been found that are as ancient as the dinosaurs.
The previous post, http://evolutioninsights.blogspot.com/2015/10/evolution-insect-size.html , gives a probable reason insects have remained small. Their small size has been a factor for their successful speciation into the largest number of species of any group of comparable sized organisms, with numbers of individuals far exceeding those of vertebrates and advanced invertebrates.
It is amazing that such diversity can be packed into the same adult body format- a head with compound eyes, antennae, and mouthparts; a thorax of three segments, three pair of legs and often two pair of wings; and an abdomen of about ten segments usually lacking appendages but bearing the genitalia.
There is great diversity in the specialization that insects have evolved for survival. It is a topic that could provide information for many interesting posts.
Joseph G. Engemann Kalamazoo, Michigan October 12, 2015
Thursday, October 8, 2015
EVOLUTION: INSECT SIZE
INSECT EVOLUTION, SIZE LIMITATION CAUSES
There may be several reasons insects are all rather small. But the principle reason limiting size of insects is the design of their respiratory system. A clue to this may be found in comparison of insects and crustaceans.
Crustaceans also have an exoskeleton that must be shed for growth to occur, but they can be many times larger than any insect. There are no truly marine species of insects beyond shoreline regions. But large crustaceans are found in the ocean, in freshwater, and upon land. So molting and the support provided by living in water are not the answer.
Both have blood in the body cavity. Blood enters the heart and is pumped out through arteries, bathing the organs in the body cavity as it returns to be pumped out again. In the crustaceans the blood entering gills or flattened appendages is oxygenated as carbon dioxide is discharged. That respiratory exchange takes place in the interior of the insect as the blood passes around the smaller tubules of the tracheal system.
The tracheal system is a system of tubules with openings on the surface of the insect. The interior surface of the tracheal tubes and tubules is continuous with the outer chitinous exoskeleton layer covering the insect. The tubules are closed on the end inside the insect. The finer terminations may be water filled when the insect is inactive. Increased numbers of solute molecules due to metabolic activity can cause water to leave the tubules and assist movement of oxygen into the blood. The highly branched system's fine terminations in all parts of the body substitute for the need for a capillary network of a circulatory system.
The main factor for size limitation
Two facts may be responsible for limiting the insect size due to tracheal system function. 1- large size means greater hydrostatic pressure on the tubules may collapse them and inhibit respiration. 2 - large size means greater length of tubules may slow diffusion of oxygen into the regions more distant from the spiracle on the exterior surface.
The limitations of the circulatory and respiratory system and the resultant small size may also be a factor in preventing warm-blooded insects from developing. Some larger insect such as certain bees and moths have larger bodies and ability to sustain a warmer temperature than the environment by "furry" bodies and a high rate of activity.
It is of interest that even aquatic insects have air-filled tracheal systems. Several different mechanisms are used in different aquatic insects to oxygenate those tracheal systems.
It is likely that a crustacean ancestor, perhaps now extinct, gave rise to insects.
Small organisms have the advantages- of finding more hiding places, needing less food per individual, reaching adult size more rapidly, higher reproductive potential, and as is evident around us - having more species and specializations exist in a small area.
Joseph G. Engemann Kalamazoo, Michigan October 8, 2015
There may be several reasons insects are all rather small. But the principle reason limiting size of insects is the design of their respiratory system. A clue to this may be found in comparison of insects and crustaceans.
Crustaceans also have an exoskeleton that must be shed for growth to occur, but they can be many times larger than any insect. There are no truly marine species of insects beyond shoreline regions. But large crustaceans are found in the ocean, in freshwater, and upon land. So molting and the support provided by living in water are not the answer.
Both have blood in the body cavity. Blood enters the heart and is pumped out through arteries, bathing the organs in the body cavity as it returns to be pumped out again. In the crustaceans the blood entering gills or flattened appendages is oxygenated as carbon dioxide is discharged. That respiratory exchange takes place in the interior of the insect as the blood passes around the smaller tubules of the tracheal system.
The tracheal system is a system of tubules with openings on the surface of the insect. The interior surface of the tracheal tubes and tubules is continuous with the outer chitinous exoskeleton layer covering the insect. The tubules are closed on the end inside the insect. The finer terminations may be water filled when the insect is inactive. Increased numbers of solute molecules due to metabolic activity can cause water to leave the tubules and assist movement of oxygen into the blood. The highly branched system's fine terminations in all parts of the body substitute for the need for a capillary network of a circulatory system.
The main factor for size limitation
Two facts may be responsible for limiting the insect size due to tracheal system function. 1- large size means greater hydrostatic pressure on the tubules may collapse them and inhibit respiration. 2 - large size means greater length of tubules may slow diffusion of oxygen into the regions more distant from the spiracle on the exterior surface.
The limitations of the circulatory and respiratory system and the resultant small size may also be a factor in preventing warm-blooded insects from developing. Some larger insect such as certain bees and moths have larger bodies and ability to sustain a warmer temperature than the environment by "furry" bodies and a high rate of activity.
It is of interest that even aquatic insects have air-filled tracheal systems. Several different mechanisms are used in different aquatic insects to oxygenate those tracheal systems.
It is likely that a crustacean ancestor, perhaps now extinct, gave rise to insects.
Small organisms have the advantages- of finding more hiding places, needing less food per individual, reaching adult size more rapidly, higher reproductive potential, and as is evident around us - having more species and specializations exist in a small area.
Joseph G. Engemann Kalamazoo, Michigan October 8, 2015
Tuesday, September 15, 2015
ADVISING POPE FRANCIS
Progress
It is refreshing that the legalism Christ decried in synagogue officials that seemed to have reappeared in the church hierarchy and almost made the pope a captive of the Curia may be lifted due to the efforts of Pope Francis. His call for fresh input from clergy and laity for consideration in an upcoming Synod of Bishops will no doubt be answered with abundant contributions representing many viewpoints. I appreciate his willingness to consider topics with wide input beyond the tunnel vision of others such as the view of Cardinal Schonborn noted in the post at http://evolutioninsights.blogspot.com/2014/10/god-evolution-and-pope.html .
The problem of whether or not to ordain women was dealt with in the post - http://evolutioninsights.blogspot.com/2014/11/god-women-priests.html - , but the implementation of bringing women in to the priesthood might be easier if the church was not so world encompassing, not only geographically, but culturally.
The environment
A post - http://evolutioninsights.blogspot.com/2015/06/pope-francis-and-global-warming.html - dealt with climatic aspects of his recent encyclical..
In remarks related to environmentalism, and our role as caretakers of our world, he made a comment involving reproduction and rabbits that was not too well received. But it is refreshing that he does not look at human reproduction as demanding large families. The command in Genesis to "increase and multiply and fill the earth" has already been fulfilled. In fact it is more than filled if a sustainable world is desired. When the coffee cup is full, you don't need to keep pouring and overflow it.
In spite of such considerations, families should be the ones that determine their own family sizes. Realistic knowledge of appropriate numbers could go a long way toward providing societal norms as a guide. We don't need to have starvation, disease, and war as implements of population control.
Marriage and family
A post [ http://evolutioninsights.blogspot.com/2014/04/evolution-and-marriage.html ] included comments suggesting the rights of those with alternative life-styles could be better served with legislation and/or judicial decisions providing contractual rights without calling it marriage and impinging on religious freedom. In Matthew 10, Jesus talks about marriage and notes some are born, others develop, into states presumably incompatible with participating in a traditional marriage of bisexuals.
Christ made clear statements forbidding divorce. But he also was generous in forgiving those failing in doing what was the ideal way. It seems a reasonable approach would be to recognize that and extend forgiveness if a wrong has been done. Blame would not have to be established. Let all parties move on and act according to their consciences.
Birth control normally involves two people. When they have conflicting view of what is acceptable, it would seem that a loving relationship could lead to compromise in some instances. I don't see how abortion could be an acceptable compromise, although forgiveness is up to God. But other forms may be of different degrees of errors in moral behavior.
A spectrum of behavior from virtual to sinful, or vice versa
The degrees of good or bad are not easily defined by clergy accustomed to thinking in terms of theological truth. The previous pope railed against relativism. But the circumstances may be part of the definition of an act. Yes, there is an objective ideal that could be determined for an act involving morality. But it would be much worse if it was done with relish, whereas there might be no moral fault if it was done to accommodate their families need in some way. To sever your relationship with God, you need to know that what you are doing is a serious violation of God's law, and it must be done with full consent of the will. It seems like that would take a very evil person to do such a thing.
A positive view of God
If you have a hard time realizing God made us and loves us, I encourage you to read a brief post - http://evolutioninsights.blogspot.com/2013/06/god-and-people.html - and especially concentrate on the last two paragraphs. It is worth reading even if you don't know the implications of John 3:16. If you have an interest in how to find God, you might get an idea of how simple it is from reading the post - http://evolutioninsights.blogspot.com/2014/05/finding-god.html
I don't expect Pope Francis will read this post. If you get any inspiration from it and want to tell the pope, please pass it on.
Joseph G. Engemann Kalamazoo, Michigan September 15, 2015
It is refreshing that the legalism Christ decried in synagogue officials that seemed to have reappeared in the church hierarchy and almost made the pope a captive of the Curia may be lifted due to the efforts of Pope Francis. His call for fresh input from clergy and laity for consideration in an upcoming Synod of Bishops will no doubt be answered with abundant contributions representing many viewpoints. I appreciate his willingness to consider topics with wide input beyond the tunnel vision of others such as the view of Cardinal Schonborn noted in the post at http://evolutioninsights.blogspot.com/2014/10/god-evolution-and-pope.html .
The problem of whether or not to ordain women was dealt with in the post - http://evolutioninsights.blogspot.com/2014/11/god-women-priests.html - , but the implementation of bringing women in to the priesthood might be easier if the church was not so world encompassing, not only geographically, but culturally.
The environment
A post - http://evolutioninsights.blogspot.com/2015/06/pope-francis-and-global-warming.html - dealt with climatic aspects of his recent encyclical..
In remarks related to environmentalism, and our role as caretakers of our world, he made a comment involving reproduction and rabbits that was not too well received. But it is refreshing that he does not look at human reproduction as demanding large families. The command in Genesis to "increase and multiply and fill the earth" has already been fulfilled. In fact it is more than filled if a sustainable world is desired. When the coffee cup is full, you don't need to keep pouring and overflow it.
In spite of such considerations, families should be the ones that determine their own family sizes. Realistic knowledge of appropriate numbers could go a long way toward providing societal norms as a guide. We don't need to have starvation, disease, and war as implements of population control.
Marriage and family
A post [ http://evolutioninsights.blogspot.com/2014/04/evolution-and-marriage.html ] included comments suggesting the rights of those with alternative life-styles could be better served with legislation and/or judicial decisions providing contractual rights without calling it marriage and impinging on religious freedom. In Matthew 10, Jesus talks about marriage and notes some are born, others develop, into states presumably incompatible with participating in a traditional marriage of bisexuals.
Christ made clear statements forbidding divorce. But he also was generous in forgiving those failing in doing what was the ideal way. It seems a reasonable approach would be to recognize that and extend forgiveness if a wrong has been done. Blame would not have to be established. Let all parties move on and act according to their consciences.
Birth control normally involves two people. When they have conflicting view of what is acceptable, it would seem that a loving relationship could lead to compromise in some instances. I don't see how abortion could be an acceptable compromise, although forgiveness is up to God. But other forms may be of different degrees of errors in moral behavior.
A spectrum of behavior from virtual to sinful, or vice versa
The degrees of good or bad are not easily defined by clergy accustomed to thinking in terms of theological truth. The previous pope railed against relativism. But the circumstances may be part of the definition of an act. Yes, there is an objective ideal that could be determined for an act involving morality. But it would be much worse if it was done with relish, whereas there might be no moral fault if it was done to accommodate their families need in some way. To sever your relationship with God, you need to know that what you are doing is a serious violation of God's law, and it must be done with full consent of the will. It seems like that would take a very evil person to do such a thing.
A positive view of God
If you have a hard time realizing God made us and loves us, I encourage you to read a brief post - http://evolutioninsights.blogspot.com/2013/06/god-and-people.html - and especially concentrate on the last two paragraphs. It is worth reading even if you don't know the implications of John 3:16. If you have an interest in how to find God, you might get an idea of how simple it is from reading the post - http://evolutioninsights.blogspot.com/2014/05/finding-god.html
I don't expect Pope Francis will read this post. If you get any inspiration from it and want to tell the pope, please pass it on.
Joseph G. Engemann Kalamazoo, Michigan September 15, 2015
Monday, September 7, 2015
INVERTEBRATE ZOOLOGY
INVERTEBRATE ZOOLOGY IS FUNDAMENTAL TO UNDERSTANDING EVOLUTION
Understanding the story of animal evolution is very dependent on knowledge of invertebrates. Vertebrates are recent (ok, the last half billion years), but very important, contributors to understanding the evolutionary history of animals. Darwin mostly used vertebrate examples in explaining his understanding of natural selection, Darwin's finches being the primary example. His studies of domestication of vertebrates also helped. But he also contributed to our understanding of invertebrates such as coral reefs, barnacles, and earthworms.
What make invertebrate zoology so useful?
There are many species representing different parts of the evolutionary tree of life. They provide steps along the transition from simple to complex structure and diversity. As research subjects many of them have the advantages of
1 short life cycles
2 small size
Together it greatly simplifies getting adequate data in studying many phenomena. It keeps costs down for care of subjects and allows varied approaches to be used in a short time. The ethical problems of care of subject animals seems less, but should not be ignored.
3 abundant numbers are usually available in nature for field observation.
4 many extinct species have left fossils; their small size often providing intact fossils.
Examples of contributions of invertebrate zoologists
E. O. Wilson observed social behavior of ants and other insects and conceived the sub-discipline of ecology and/or animal behavior termed SOCIOBIOLOGY.
Paul Ehrlich developed his understanding of population ecology, in part, from his studies of lepidopterous insect populations, and applied it to his concerns for overpopulation by humans in an influential book, The Population Bomb.
Alfred Kinsey transferred from years of studying wasps to studies of human sexuality.
Libbie Hyman [ http://evolutioninsights.blogspot.com/2015/03/abandoned-theories-and-libbie-hyman.html ] studied hydras and planarians and stayed mostly an invertebrate zoologist of great breadth.
Robert Pennak was my hero for his excellent book on aquatic invertebrates of the United States. It has an excellent introductory discussion of the the transition of marine groups to fresh water.
Robert Barnes wrote an excellent invertebrate zoology text, especially in coverage of his specialty, polychaete worms. If he had put insects and parasites in his first edition I would probably never have undertaken the revision of Hegner's invertebrate zoology text. Meglitsch produced an impressive invertebrate zoology text that never received the recognition of Barnes' text which had largely been adopted by invertebrate zoologists.
A two volume text by Beklemishev (translated from the Russian) was a remarkable comparative anatomy of invertebrates. Its value as a reference is somewhat marred by his belief that animals should be grouped according to the extent of their segmentation.
As invertebrate zoology becomes a minor part of biological education in today's universities, it is unlikely that it will attract authors to update the subject to the extent it was done in the past. The digital age has made it unlikely that many will read the specialty journals and be exposed serendipitously to insights inspired by seemingly unconnected topics. On the other hand, I have seen some weird results produced by search engines, so maybe there is hope.
Why did I become an invertebrate zoologist?
The reasons are somewhat lost in time. But my first application for graduate school was to a botany department. I had actually had more interest in invertebrates from using Hegner's Invertebrate Zoology text. The variety was amazing, there were so many species, I thought maybe I could become the world's expert in some obscure group (I don't think I was very competitive). I had been a little put off by the extreme need for grades motivating pre-Med student friends. Plants were soon eliminated along with vertebrates due to sneezing and wheezing triggered by pollen and animal dander, factors seldom a problem with aquatic animals.
I had some vague notion that I might make some momentous discovery studying an obscure invertebrate. I knew that was unrealistic. Even so, dabbling in varied topics, I seem to be the only zoologist who realizes the abandoned annelid theory should be reinstated with modification to include the role of the pogonophorans as a central part of the theory. The evidence that abyssal animals can live extremely long lives [ http://evolutioninsights.blogspot.com/2015/05/abyssal-ocean-environment-and-extreme.html ] and provide reason molecular phylogenies need reworking is something I hope to make others understand.
Joseph G. Engemann Kalamazoo, Michigan September 7, 2015
Understanding the story of animal evolution is very dependent on knowledge of invertebrates. Vertebrates are recent (ok, the last half billion years), but very important, contributors to understanding the evolutionary history of animals. Darwin mostly used vertebrate examples in explaining his understanding of natural selection, Darwin's finches being the primary example. His studies of domestication of vertebrates also helped. But he also contributed to our understanding of invertebrates such as coral reefs, barnacles, and earthworms.
What make invertebrate zoology so useful?
There are many species representing different parts of the evolutionary tree of life. They provide steps along the transition from simple to complex structure and diversity. As research subjects many of them have the advantages of
1 short life cycles
2 small size
Together it greatly simplifies getting adequate data in studying many phenomena. It keeps costs down for care of subjects and allows varied approaches to be used in a short time. The ethical problems of care of subject animals seems less, but should not be ignored.
3 abundant numbers are usually available in nature for field observation.
4 many extinct species have left fossils; their small size often providing intact fossils.
Examples of contributions of invertebrate zoologists
E. O. Wilson observed social behavior of ants and other insects and conceived the sub-discipline of ecology and/or animal behavior termed SOCIOBIOLOGY.
Paul Ehrlich developed his understanding of population ecology, in part, from his studies of lepidopterous insect populations, and applied it to his concerns for overpopulation by humans in an influential book, The Population Bomb.
Alfred Kinsey transferred from years of studying wasps to studies of human sexuality.
Libbie Hyman [ http://evolutioninsights.blogspot.com/2015/03/abandoned-theories-and-libbie-hyman.html ] studied hydras and planarians and stayed mostly an invertebrate zoologist of great breadth.
Robert Pennak was my hero for his excellent book on aquatic invertebrates of the United States. It has an excellent introductory discussion of the the transition of marine groups to fresh water.
Robert Barnes wrote an excellent invertebrate zoology text, especially in coverage of his specialty, polychaete worms. If he had put insects and parasites in his first edition I would probably never have undertaken the revision of Hegner's invertebrate zoology text. Meglitsch produced an impressive invertebrate zoology text that never received the recognition of Barnes' text which had largely been adopted by invertebrate zoologists.
A two volume text by Beklemishev (translated from the Russian) was a remarkable comparative anatomy of invertebrates. Its value as a reference is somewhat marred by his belief that animals should be grouped according to the extent of their segmentation.
As invertebrate zoology becomes a minor part of biological education in today's universities, it is unlikely that it will attract authors to update the subject to the extent it was done in the past. The digital age has made it unlikely that many will read the specialty journals and be exposed serendipitously to insights inspired by seemingly unconnected topics. On the other hand, I have seen some weird results produced by search engines, so maybe there is hope.
Why did I become an invertebrate zoologist?
The reasons are somewhat lost in time. But my first application for graduate school was to a botany department. I had actually had more interest in invertebrates from using Hegner's Invertebrate Zoology text. The variety was amazing, there were so many species, I thought maybe I could become the world's expert in some obscure group (I don't think I was very competitive). I had been a little put off by the extreme need for grades motivating pre-Med student friends. Plants were soon eliminated along with vertebrates due to sneezing and wheezing triggered by pollen and animal dander, factors seldom a problem with aquatic animals.
I had some vague notion that I might make some momentous discovery studying an obscure invertebrate. I knew that was unrealistic. Even so, dabbling in varied topics, I seem to be the only zoologist who realizes the abandoned annelid theory should be reinstated with modification to include the role of the pogonophorans as a central part of the theory. The evidence that abyssal animals can live extremely long lives [ http://evolutioninsights.blogspot.com/2015/05/abyssal-ocean-environment-and-extreme.html ] and provide reason molecular phylogenies need reworking is something I hope to make others understand.
Joseph G. Engemann Kalamazoo, Michigan September 7, 2015
Wednesday, August 12, 2015
GOOGLE and SCIENCE
A THANK YOU FOR GOOGLE
A TV business news item said Google was going to do some genetic engineering of mosquitoes to control pest populations. Why the thank you?
The technology for doing such work is over thirty years old. But business in general will not fund such biological control projects because once they are in place they tend to be self-sustaining and not a source of continuing profits.
Such projects should be funded by government research and other grants because they can benefit all in much greater proportion than their cost. But in our anti-taxing environment there is no one to effectively compete with other research that is more likely to benefit big business.
So Google deserves a big thank you from all of us for putting money into an important project with small monetary reward. It gets money put to good use a little quicker than waiting for the owners to fund good projects with their estates.
Notice that pharmaceutical companies go to great lengths to produce new drugs to keep their profits high from non-generic versions that may be no better than generic drugs.
An example of the biological control of pests is the introduction of milky spore bacteria into soil where Japanese Beetles are established. One treatment is likely to give long lasting control keeping populations very low. The chemical companies probably prefer you use a pesticide that need repeated applications.
The genetic modification of mosquitoes is almost assured to only control the species modified. Chemical controls are seldom so well targeted. Environmental modification can help. In Michigan, malaria is no longer naturally occurring due largely to screened windows, drained swamps, and perhaps some other measures. But draining swamps has made it difficult for some populations of fish, birds, amphibians, and perhaps others to resist extinction.
The techniques likely to be used for mosquito control do not include the introduction of genes hazardous to other organisms or ourselves. Most genetically modified organisms are not a hazard when incorporated in the food chain. Some that use genes for toxins would need to be further studied.
The likely approach for mosquito control will introduce genes into the male that will cause the female they fertilize to only produce male offspring with the same engineered feature. Male mosquitoes don't feed on blood, only the female does. A variety of parasites are transmitted by mosquitoes, malaria is the major worldwide threat.
Thanks again, Google
Joseph G. Engemann Kalamazoo, Michigan August 12, 2015
A TV business news item said Google was going to do some genetic engineering of mosquitoes to control pest populations. Why the thank you?
The technology for doing such work is over thirty years old. But business in general will not fund such biological control projects because once they are in place they tend to be self-sustaining and not a source of continuing profits.
Such projects should be funded by government research and other grants because they can benefit all in much greater proportion than their cost. But in our anti-taxing environment there is no one to effectively compete with other research that is more likely to benefit big business.
So Google deserves a big thank you from all of us for putting money into an important project with small monetary reward. It gets money put to good use a little quicker than waiting for the owners to fund good projects with their estates.
Notice that pharmaceutical companies go to great lengths to produce new drugs to keep their profits high from non-generic versions that may be no better than generic drugs.
An example of the biological control of pests is the introduction of milky spore bacteria into soil where Japanese Beetles are established. One treatment is likely to give long lasting control keeping populations very low. The chemical companies probably prefer you use a pesticide that need repeated applications.
The genetic modification of mosquitoes is almost assured to only control the species modified. Chemical controls are seldom so well targeted. Environmental modification can help. In Michigan, malaria is no longer naturally occurring due largely to screened windows, drained swamps, and perhaps some other measures. But draining swamps has made it difficult for some populations of fish, birds, amphibians, and perhaps others to resist extinction.
The techniques likely to be used for mosquito control do not include the introduction of genes hazardous to other organisms or ourselves. Most genetically modified organisms are not a hazard when incorporated in the food chain. Some that use genes for toxins would need to be further studied.
The likely approach for mosquito control will introduce genes into the male that will cause the female they fertilize to only produce male offspring with the same engineered feature. Male mosquitoes don't feed on blood, only the female does. A variety of parasites are transmitted by mosquitoes, malaria is the major worldwide threat.
Thanks again, Google
Joseph G. Engemann Kalamazoo, Michigan August 12, 2015
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