Carpenter Ants Drywood Termites Unlike the Subterranean termite, dry wood termites do not require any contact with the soil. They live in undecayed wood with a low moisture content.
A look at cichlid fish in Lake Victoria This is the first in what I hope to be a series of postings. In the series I hope to accomplish two things, establish that evolution is an active branch of mainstream science and that there is indeed an overwhelming amount of evidence in favor of the idea of evolution.
Note that no single post is meant to be a proof, just another piece of evidence that supports the theory of evolution. In the October 11th issue of Nature, Meyer et. If they all share a recent common ancestor in that lake or came from separate lineages that invaded the lake. In their paper they sequenced a bp part of the cytochrome b gene and a bp segment of mitochondrial DNA from what is called the control region.
They sequenced these genes from several species of fish in the lake and a few species from relatively nearby lakes. What they found was the sequences in the Lake Victoria species of fish were all very similar, but they were different from the sequences of fish in nearby lakes.
All the sequences are listed in the paper. They came to the conclusion that this indicated the cichlid species of Lake Victoria all derive from a recent common ancestor in the lake.
They estimate the time of divergence at aboutyears ago based on a model that assumes mutations are relatively constant over time. The lake, incidentally, had been independently dated to be-years old The News and Views section of that issue has an overview of the paper written by John Avise.
Also, the cover photo of this issue consists of a picture of several of these fish. As I said in part one, I have two goals in for this series.
One, to show that evolution is an accepted branch of mainstream science. And two, that contrary to the continual assertions of creationists, there is an overwhelming amount of data in favor of the theory of evolution.
Again, note that no single post is intended as a stand alone proof. This post is divided into two section, an introduction the part you are reading to provide a bit of background, and the actual summary of the paper discussed.
Speciation occurs when two or more possibly subsets of a formerly interbreeding population become reproductively isolated. For many years, speciation theorists thought that virtually all speciation occured when the two subsets of the population where separated by geographical boundaries. Reproductive isolation followed physical isolation as the two, now separate lineages, diverged.
This could occur for many reasons, for example mating rituals grew different or chromosome numbers changed etc. In any case the end result would be that the two lineages could no longer interbreed if they encountered each other. Incidentally this type of speciation is called allopatric speciation.
A second type of speciation, sympatric speciation, occurs when two lineages of a formerly interbreeding population diverge to the point of reproductive isolation while still residing in the same locale.
This was first demonstrated to occur by Guy Bush working on the Apple maggot fly Rhagoletis pomenella.
The paper I will outline here is one found in the August 9, issue of Nature. I will continue this discussion in my next post. Isolation mediated by microorganisms In the paper outlined here Breeuwer and Werren, the authors examine two species of wasps living sympatrically in the same area.In the s, Louis Pasteur found that microorganisms caused food spoilage, The third domain Eukaryota includes all multicellular organisms and many unicellular protists and protozoans.
the protists are most commonly unicellular and microscopic. This is a highly diverse group of organisms that are not easy to classify.
Entamoeba gingivalis and Trichomonas tenax are the main protozoans found in the oral cavity. Wet smears can be prepared using fresh specimens to observe the morphology and mobility of the protozoans. Entamoeba gingivalis are commonly found inhabiting the gingival tissues surrounding the teeth and Microorganisms in the mouth and throat.
BIOL Nutrition for Life (2 Hours). Designed for students who wish to apply nutrition information to their lives, this course explores how food selection affects body size, body composition, performance, disease resistance, impact on the environment, and longevity.
Protozoa are a very diverse group of organisms that vary widely in size, shape, features and habit. This page gives an overview of some commonly found freshwater protozoa.
The protozoa have been grouped by their major features. example, one type of bacteria that is commonly found living in soil produces the antibiotic streptomycin.
Many diseases in humans and animals can be treated with antibiotics. Millions of bacteria live on your skin and all other parts of. Bacteria Protists, and Fungi protozoans.
3. A comprehensive account many of the main commonly used methods for the collection, Read full chapter. Role of Zooplankton in Aquatic Ecosystems. R.W. Sterner, in Encyclopedia of Inland Waters, Protozoa.
Protozoans are unicellular or colonial organisms with the capacity for phagotrophy. Like most microorganisms, protozoa have very.