Special Effects Of Mutation In The Evolutionary Biology Of Dogs

Special Effects of Mutation in The Evolutionary Biology of Dogs.

Mutations in the Coding Regions of Two Genes Affect the Size and Shape of the Dog Skull and Jaws.

ABSTRACT

This paper aims at investigating the special effects of mutation in the evolutionary biology of dogs. Specifically, the paper aims at analyzing a thorough research on whether mutation affects the size and shape of the dog skull together with the jaws when the mutation occurs in the coding regions. Mutation is one factor of evolution beside other factors such as gene drift, speciation, adoption and gene flow.

SPECIATION

Speciation as I have indicated in the above is a gradual process of evolution. In this process, new species arise because of biological evolution. Speciation can occur naturally through biological evolution when the organisms try to adapt to new climatic conditions that they were not used to before. Again, the induction of speciation can be done in the laboratory following genetically controlled mechanisms. Various methods of evolution exist depending on the period of isolation. These include peripatric and parapatric.

MUTATION

Mutation is the alteration or change in the arrangement and sequence of genetic material of living organisms. This can occur during cell division or it can be caused by natural calamities

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

such as diseases and nuclear weapons if used at war. This occurs beside isolation and speciation. Mutations generate variations in the gene pool. The less constructive mutation are outnumbered in the gene pool by natural selection, while more favored and beneficial mutations continue to accumulate, leading to evolutionary change.

GENE CODING

Gene coding is a process of translating DNA portions into amino acids in the regions that would code for amino acid linkage. This process happens in the body whereby there is transcribing small portions of DNA into messenger RNA before converting them into proteins.

TABLE OF CONTENTS

Introduction

Aim

Literature review

Methodology that include data type, data source, data collection and analysis of data,

Executive results

Hypothesis

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

Discussion

Recommendation according to the data

Conclusion

Reference

Introduction

Isolation and speciation are the main cause of genetic change. Speciation takes place when a population becomes isolated from another. This leads to transformation and great change in the morphological appearance of the organisms when mutation and adaptation occur due to changing ecological conditions. The parent organisms become gradually lost and replaced by the newly evolving species. After the replacement of the old parents, the growing new species diverge as they increase in population.

LITERATURE REVIEW

Dogs like other animals can adapt to various climatic conditions. The genetically change can happen after a given period of time whereby phenotype and genotype features become visible. Depending with the environmental conditions and isolation, detectable morphological transformation shows how a certain creature has gradually changed after a given period of evolution.

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Historically, wild dogs and domestic dog’s diverged long time ago even before man migrated and traded on them. This is estimated to be more than 16,000 years ago. In the day-to-day life, dogs occur in different shapes, sizes and behaviors. Wolves have a different behavior from domesticated dogs.

Generally, in order to come up with reliable results, various dogs have to be investigated depending on the size and the topographical regions they occupy. In the study, a comparative morph metric and genomic research will be carried out. The study of dogs’ shapes and size indicates that dogs occur in various sizes from small to big ones. In addition to that, dogs have different shapes of snout, jaws and skull sizes. Therefore, the researchers are interested in knowing genes involved in causing the traits.

The recognition and description of those genes that causes the difference shapes and size is of great importance toward the scientific discovery since this gene also occur in human being.

Literature on dog evolution shows that dogs evolved in North America about 39.9 million years ago. By then, the first dog looked like a creature between a weasel and fox. Borophagines were the second generations of dogs that evolved 33.9 million years ago. These dogs were looked like hyena but had huge jaws, muscles and sturdy teeth. They became vanished 2.4 million years ago. Canines were the third group of dogs that flourished. This third generation existed only in North America about 7 million years ago, when some dog species were migrated to Asia and other continents.

A table showing Canid species, how they are distribution and the composition of chromosome number

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

Canid species

Common name

Geographic range

2n

Wolf-like canids Small (6 -11 kg)

Canis aureus

Golden jackal

Old World

a

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

77

Canis adustus

Side-striped jackal

Subsaharan Africa

Canis mesomelas

Black-backed jackal

Subsaharan Africa

77

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

Large (12-31 kg)

Canis simensis

Simien jackal

Ethiopia

77

Canis lupus

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

Gray wolf

Holarctic

77

Canis latrans

Coyote

North America

77

Canis rufus

Red wolf

Southern US

77

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

Cuon alpinus

Dhole

Asia

77

Lycaon pictus

African wild dog

Subsaharan Africa

77

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

Canids from South American

Speothos venaticus

Bushdog

Northeast S. America

75

Lycalopex uetulus

Hoary fox

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

Northeast S. America

75

Cerdocyon thous

Crab-eating fox

Northeast S. America

75

Chrysocyon brachyurus

Maned wolf

Northeast S. America

76

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

Canids similar to Red fox

Vulpes aelox

Kit fox

Western US

50

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

Vulpes vulpes

Red fox

Old and New World

37

Vulpes chama

Cape fox

Southern Africa

Alopex lagopus

Arctic fox

Holarctic

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

50

Fennecus zerda

Fennec fox

Sahara

64

Other canids

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

Otocyon megalotis

Bat-eared fox

Subsaharan Africa

72

Urocyon cinereoargenteus

Gray fox

North America

66

Nycteruetes procyonoides

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

Raccoon dog

Japan, China

42

b

a represents Diploid chromosome number.

b represents variable number of B-chromosomes.

AIM

To investigate whether mutations in the coding regions of two genes affect the size and shape of the dog skull and jaws

METHODOLOGY DATA TYPE, DATE SOURCE, DATA COLLECTION, ANALYSIS OF DATA,

1) The first procedure was to analyze the genetic coding from 15 small breeds and 8 large dog breeds.

2) The second step was to investigate the arrangement of genes in the genetic code of both small and big dogs (gene variant).

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This number included dogs in various shapes and sizes and from different topographical regions.

3) This research included more than 460 dogs with 142 breeds among them. This was aimed at giving out the sequence variant of specific genes.

4) The examination of more than 142 breeds was carried out to investigate the numbers of tandem that probably controlled the skull size and jaws.

5) A comparison of small and large dogs was carried out.

6) Portuguese dogs were used for genotyping analysis whereby there was physical observation of sizes and shapes of waterdogs. Again, x-ray imaging, radiation and DNA sequencing was carried out.

7) Finally, a cross-examination and manipulation of SNPs that is connected to small size in dogs was carried out through SNP genotyping in and around the IGF-1 gene in 460 Portuguese water dogs. This research was repeated with 520 dogs from 15 small breeds and 8 large dog breeds.

Hypothesis

Null hypothesis: mutations in the coding regions of two genes affect the size and shape of the dog skull and jaws

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Alternative hypothesis: mutations in the coding regions of two genes do not affect the size and shape of the dog skull and jaws

EXECUTIVE RESULTS

Having formulated the statistical analysis of the data, the available results indicated that null hypothesis is very true according to the probability of the significant level results.

According to the research experimental design, it was found that this occurred often up to 75% of the time, I can conclude that our results support our experimental prediction that mutations in the coding regions of two genes affect the size and shape of the dog skull and jaws

After performing the above experimental research, it was found that insulin-like growth factor 1 is the main determinant of size and shape variations. This IGF-1 codes for the above-mentioned protein. Hence, it was named after that insulin hormone. The resulted indicated that this gene is involved in controlling the skeleton and size of small dogs. This was confirmed to all dogs that were investigated (Elaine A.O).

According to NHGRI’s reports, this gene can cause similar effects in human beings. From the research, it was found that 16 of the 18 genes tested showed a multiple alleles varying in length of their repeats showing that almost all the dogs under investigation shared this determinant gene.

According to the article for gene coding by Belinda Edmonds, single nucleotide polymorphism

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gene that occurs in Insulin-Growth like factor 1 is the precursor for different sizes and shapes in water dogs. This was confirmed after SNP genotyping in and around the IGF-1 gene in 460 Portuguese water dogs.

This research exposed that variation in dog body size appeared to be linked to infinitesimal genetic variations. This variation was termed as single nucleotide polymorphisms (SNPs), in the IGF-1 gene.

According to Dana S. there is a significant similarity in whippets. This is caused by a myostatin mutation and racing routine. Actually, whippets that had homozygous erasure or deletion expressed a remarkable body shape. This included physical features such as broader head and legs that were shorter.

This heterozygous and homozygous mutation was not detected in other dogs that were more masculine such as boxers and mastiffs (Heidi G, 2007). The suggestion is that this myostatin protein mutation does not happen often in cross relatives due to differences in racing. [1] Accord ing to Dana S myostatin gene mutation causes an increase in muscle mass in heterozygous dogs and this leads to racing performance among the breeds of dogs.

DISCUSSIONS

After a repeat of several researches on mutation and the effects in dogs, a reliable answer is almost to be adopted by scientists (Quinton, 2007); there is still a room to improve on the hypothesis. However, there are some limitations to this research. In the first place, the research is focused on a number of dogs. In the process of confirming or inducing mutation, scientists can interfere with the genetic composition of the dog. This can lead to misleading results. It is not known how vital this form of evolutionary transformation is under less synthetic or artificial conditions (Garner, 2004).

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

RECOMMENDATION

The scientific manipulation and correlations are the determining factors toward the desired results. Direct operation of the Q/A ratio of the Runx-2 gene in a collie might be interfered with. This might not reflect the expected answer. Therefore, it is a noble idea and scientifically valid to see developmental studies of the patterns of Runx-2 and Alx-4 gene expression in dog embryos to learn accurately how these variations occur.

Conclusion

To investigate whether mutations in the coding regions of two genes affect the size and shape of the dog skulls and jaws was the main purpose of this research. The main purpose of this study was to investigate whether mutation in the coding regions of two genes affect the morphological appearance of the dogs skull and jaws. From the genomic analysis, I can conclude that mutation in the coding regions of two genes do affect the size and shape of the dog skull and jaws beside other factors such as speciation and gradual evolution. This was proved by the significant level of the data analysis.

Again, the small sizes and different shapes of dogs are as a result or diversification and adaptation to the new environments that man introduced them. The small size for dogs could have contributed toward domestication and confining of dogs in crowded places and cities. Again, they were able to carry and migrate with them during war and when trading.

REFERENCE

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Special Effects of Mutation in The Evolutionary Biology of Dogs.

A journal of International Society for Computational Biology (ISCB) available at www.genetics.p losjournals.org/

Christensen O.F and Hobolth A (2007), Genomic relationships and speciation of dogs compared to human and primates, PLoS Genet 3(2): edition 7,

Dogs genome and evolution, retrieved on 30th November 2007, available at www.ncbi.nlm.nih. gov/

Dogs’ genome and discovered variant determining gene, retrieved on 30 November 2007, available at www.genome.gov

.E. Hastert and W.R. Rice (1993), Laboratory research on speciation, Evolution 47: 1637-1653.

G.W. Salt and Rice, W (1988), Speciation and disruptive selection, American Naturalist 131 journal pg 911-917

Joseph Boxhorn (2006), Instances of dogs Speciation, Miller New York

Molecular genetic pools and evolution tree on dog family, retrieved on 30th November 2007,

available at www.eur ekalert.org/

Mosher DS and Quinton (2007), increase in muscle due to mutation in myostatin genes in dogs, University Academic Press

Nowak, R. (1999) walker mammal animals of the earth 6th edition, Johns Hopkins University Press

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Niles Elbridge and Stephen Jay (2006), insulin growth factor 1, Oxford University press

Neil, M. (1987) Molecular Evolutionary Genetics, Columbia University Press

P, Bustamante and Mellersh (2007), myostatin transmutation and muscle mass in Heterozygote Dogs.

Pavlicek and Jurka, J. Biology Direct journal 2006, 1: 15.

Raymond M. (2006), Dogs exhibit the greatest diversity in body size of any mammalian species,

Ridley, M. (2003), Speciation and mutation adapted from Evolution 3rd edition (Boston:

Blackwell Science)

Robert T. K. (2004), Molecular evolution of the dog family, Oxford University Press.

V. Ravine and Kirkpatrick, M (2002), models on speciation by natural speciation and sexual selection, The American Naturalist journal pg159

Wayne, R.K. and Benveniste R.E (1989), Carnivore Behavior, Ecology and Evolution, Cornell University Press

[1] Mosherl and Pascale (2007), greyhound dogs have more tolerance because of longer races (900 meters vs. 300 meters for greyhounds and whippets respectively).

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