1. Comparative anatomy—Closely related organisms share anatomical similarities. American deer, bears, and men have bone structure and musculature that are remarkably similar. Apes and humans are even closer. Molecular biological studies have confirmed the direct correlation of many structures in related species even over very extensive periods of evolutionary history.
2. Artificial Selection—Perhaps the most obvious evidence of evolution is the process of breeding of agricultural plants and animals. A multitude of different rices, wheats, apples, dogs, cattle, horses, etc. have had their interbreeding intentionally controlled and modified by human intervention to produce offspring that fit a purpose desired by the human. This process is a relatively rapid and predictable one.
3. Ecology-Biogeography—Isolated populations such as sparrows in the Americas have taken on the characteristics that helped them to adapt to their surroundings. Northern sparrows, adapting to shorter seasons, less easily available food, and colder winters are larger and darker than their southern counterparts. Male fish living in waters with heavy predator fish populations tend to live near the bottom of the waterway and to be less colorful since predators are attracted to more brightly colored males. Recently (2003) discovered “little people”, Homo floresciensis, found on the eastern Indonesian island of Flores, 300 miles east of Java, by paleoanthropologists Mike Morwood and Peter Brown demonstrate the effects of isolation on evolution.
   

   original fossils of Pithecanthropus erectus (now Homo erectus) found in Java in 1891 (Photo credit: Wikipedia)

   The nine specimens discovered in Liang Bua cave, age-dated to only 18 KYA, included children and an adult female one meter tall with a head the size of a grapefruit. The dwarf hominids (3 meter tall adults with 380 ml braincase size) have all of the characteristics, other than size, of Homo erectus, an extinct humanoid. They made small, sophisticated tools and used fire. The island was isolated by surrounding water 2.6 million years ago, and the animals, including the hominids, left there adapted. Animals larger than rabbits became smaller like the people. An extinct pygmy elephant species called, Stegodon, adapted to become smaller due to a lack of food and an absence of predators. Animals smaller than rabbits adapted to be able to obtain more food by becoming larger, e.g. Komodo dragons, giant lizards, and giant turtles. Isolation and species limitation is the common experience; it is unusual to find a single species widely spread throughout the world. On the contrary, there is a truly remarkable diversity of species. continued…

In my novella, Book 5 of the Sybil Norcroft series entitled Decisions, my main character, Sybil Norcroft, M.D., PhD., F.A.C.S. makes an impassioned plea to have the United States protect its young athletes. She goes so far in the book to launch a fight against head injuries and concussion to get rid of football in high school. In an announcement on May 29, 2014, President Obama made a sweeping presentation of what his administration will do to protect our youth. Since I belief in what my protagonist had to say—so, guess who put the words into her mouth—I feel somewhat vindicated. The information quoted below comes from White House Concussion Summit Puts Focus on Youth Sports, Emily Lea Berry, May 29, 2014:

“President Barack Obama announced today [May 29, 2014] several new partnerships that will put around $86 million toward funding new research and development in the prevention, diagnosis, and treatment of traumatic brain injury, especially in young athletes. The Healthy Kids & Safe Sports Concussion Summit at the White House was attended by members of Congress and senior leadership from the National Collegiate Athletic Association (NCAA), Major League Soccer, the National Hockey League, US Soccer, and the National Football League (NFL), as well as brain experts and physicians from across the United States.

Official photographic portrait of US President Barack Obama (born 4 August 1961; assumed office 20 January 2009) (Photo credit: Wikipedia)

“We [at the White House] decided, Why not use our convening power to help find more answers” to many questions posed by parents and coaches, as well as the military, Obama said. The new partnerships announced include:

• The NCAA and Department of Defense will commit $30 million for concussion education and a study that Obama called “the most comprehensive clinical study of concussion ever,” involving up to 37,000 college athletes.
• The NFL will give $25 million during the next 3 years to test strategies such as creating health and safety forums for parents and to get more trainers at high school games.
• The National Institutes of Health, in its partnership with the NFL, will dedicate $16 million of the NFL’s previous donation to studies and clinical trials on the chronic effects of repetitive concussions.
• The National Institute of Standards and Technology will invest $5 million during the next 5 years to explore the development of lighter, more responsive equipment to protect athletes.
• New York Giants Chairman Steve Tisch will personally donate $10 million to expand the BrainSPORT Program at the University of California, Los Angeles, which does research on treating sports concussions in youth.

Obama said the leaders of the concussion summit can agree on 2 things: Sports are vital to the United States, and it is their responsibility as leaders to make sure young people play sports safely.

“Bravo,” says Carl Douglass.

1. Homologies—Related organisms that share similarities that are derived from common ancestors. Comparative anatomical studies of cells and embryological development reveal characteristics that most probably derive from more ancient forms. Examples include plants with modified or adapted leaves such as the pitcher plant with leaves that form pitchers which catch insects, the Venus Flytrap with leaves that are modified into jaws that catch insects, the Poinsettia with its bright red leaves that superficially resemble flower petals to bring insects to its pollen, and the cactus with leaves that have evolved into spines.

Another area in which homologies are found is in the forelimb of tetrapods. Creatures as diverse as frogs, birds, rabbits, lizards, and humans all have apparently different forelimbs adapted to different modes of living. However, all of these tetrapods share the same set of bones including the humerus, radius, and ulna. All of these same bones are seen in fossils of the extinct transitional animal, Eusthenopteron. All of those disparate animals have a common ancestry.

While it is common to castigate belief in evolution because it suggests that man descended from monkeys, the more accurate concept is that Homo sapiens descended through multiple adaptations–most of which became extinct–from the great apes or more recently from a common ancestor to chimpanzees, bonobos, and humans. Humans, chimpanzees, and great apes have homologous chests that are broader than they are deep, with shoulder blades flat in back which permits the ability to suspend themselves by using the upper arms, indicative of a common ancestor that was able to do so. Monkeys and other quadripeds with their different modes of locomotion have narrow, deep chests with shoulder blades situated at the sides.

As dissimilar as they appear, baleen whales and humming-birds have tetrapod skeletons inherited from a common ancestor. Although some bones have been lost during the lengthy and complicated process of adaptation, nearly every bone in their limbs corresponds to an equivalent bone in the other—humerus, radius, ulna, phalanges, ribs, hind limb parts, and skull, and these homologies showing convincing relatedness could only have come from a process of evolution.

Developmental biology has revealed homologies such as currently living snakes having hind limb buds in developmental embryological stages that are comparable to fossil ancestral snakes, like the Cretaceous snake, Pachyrhachis problematicus, that had hind limbs that included an ilium, pubis, femur, fibula, calcaneum, and astragalus.

More generally, all living things have fundamental molecular and cellular similarities, best explained by common ancestry. At the molecular level DNA changes, on average, by point mutation accumulation of 1-2% per 5 million years, and multiple remarkably different appearing species, share genetic homologies based on those regular changes. For example, time scale evaluations reveal differences of alpha and beta chains of hemoglobin which differ by 65% in any vertebrate; and when traced backwards through the fossil record, the two chains are found to be descended from a single common ancestral gene that existed 600 million years ago. Gorillas and men share almost identical alpha chains excepting only one amino acid.

Roundworms share 25% of their genes with humans which are only slightly different from each other. DNA and RNA coding is a shared four base code that constitutes the pattern of reproduction and function of all living things. Transferal of genetic material from one living cell to another results in the recipient following the new genetic instructions as if they were its own. On the cellular level, all organisms are made of cells; all cells have membranes filled with water containing genetic material, proteins, lipids, carbohydrates, salts and a myriad of other substances similar from species to species. Most cells use sugar for fuel and produce proteins as building blocks and information messengers. Animal and plant cells have only three components that are unique to one or the other.

Vestigial structures were described previously in blogpost 8. We revisit the subject here because of it being a clear evidence of evolution, and the process which results in the retention of a vestigial structure is a fairly readily apparent piece of evidence.

4. Vestigial structures—Are evidence of the homologies described above and are a clear indication of shared evolutionary genes. Vestigial structures have lost most or all of their original function present in earlier animals through evolution—disuse or altered use. These vestigialities may present as anatomical structures, behaviors, and biochemical pathways. The characters can all be traced to the genes that code for such characters in the animal under study, including humans, and match with the genetic codes of more ancient animals. The process of vestigiality may extend so far as to match genes that have no function at all–so-called junk genes–which are genetic and evolutionary relics.

One thing to be clear about is that vestigiality is not the same as exaption in which a structure originally used for one purpose is modified to perform a new one. The wings of penguins, although small and apparently degenerative, are in fact modified for underwater loco-motion as opposed to flying. It is not a necessary part of vestigiality that the structure be entirely useless. The human vermiform appendix is a remnant of the large cecum of herbivore ancestors which evolved to breakdown cellulose. In humans, the appendix apparently serves a limited purpose of acting as a reservoir for symbiotic microbes that contribute to digestion.

According to later versions of Robert Wiedersheim’s list of 86 human organs that are vestigial, there may be as many as 180 known examples. In addition to the appendix, such examples include the coccyx, a remnant of a lost tail which is regularly seen in embryos and which rarely actually forms in a newborn infant–23 instances recorded in the medical literature since 1884–the plica semilunaris on the inside corner of the eye is a remnant of the nictitating membrane of lower animals–such as birds, reptiles, fish, monotremes, and marsupials–muscles in the ear and by the coccyx and other parts of the body which no longer perform a function despite their physical presence–humans and other primates compensate by their ability to turn their heads in the horizontal plane, an ability not common among monkeys–male nipples, tiny non-functioning sperm ducts that lie behind the ovaries of women, the formation of “goose bumps” under stress which is a vestigial reflex used in pre-human ancestors to raise their hair in times of stress to frighten away predators and to enhance warmth, wisdom teeth, and the transitory infantile grasping reflex wherein a baby can support its own weight by hanging from a rod harking back to the ancestral primate infant clinging to its mother’s considerable hair.

There are vestigial molecular structures in humans which are no longer in use. One such molecule which is indicative of common ancestry with other species is L-gulonogama-lactone oxidase, or GULO produced by a gene that is functional in most mammals to produce an enzyme that can make L-ascorbic acid (vitamin C). A mutation inactivated the gene in a common ancestor of primates, and it now remains dormant in the human genome so that biosynthesis is missing in man, and only a vestigial gene sequence remains, i.e., it is a pseudo-gene, a molecular vestigial compound.

Other animals have vestigial organs: whales, dolphins, and snakes have vestigial feet buried deep in their backs that are sometimes externally evident in adults. The wings of emus, ostriches and other flightless birds are vestigial remnants of their flying ancestors’ wings. Boas and pythons have vestigial pelvis remnants which are visible externally as two small anal spurs on each side of the cloaca. In most snakes, the left lung is greatly diminished in size or absent altogether. Amphisbaenians, which independently evolved limblessness, also retain vestiges of the pelvis including the pelvic girdle and have lost their right lungs. Crabs have small tails tucked between their rear legs that are no longer in use. The functional version of such tails is found in lobsters, the close crustacean relative of crabs. Flightless beetles have wings sealed under wing covers that never open. Some moths (e.g. the Gypsy moth) have flightless females which nevertheless possess small wings. In other moths, females utilize the wings to fly. Sightless moles have functionless vestigial eye structures. Horses and some other animals stand on a single toe but have vestigial toes evident in x-rays of their hooves. These toes rarely become evident on the horses’ hooves. Plants also have vestigial parts. Dandelions and other asexually reproducing plants produce unneeded flower petals which in more primitive flowering plants that reproduce sexually, the petals are crucial for attracting insects to affect pollination.

The existence of vestigial structures is attributable to changes in the environment and behavioral patterns of animals that produce selection pressure. As the function of the trait is no longer important or even beneficial for survival or for enhanced procreative ability, or even proves to be detrimental, it is likely to be phased out or removed entirely, but there may remain remnant gene sequences, and degenerative or rudimentary structural evidence of the evolutionary connection with ancestors for whom the structure or function had value. In some instances, the vestigial gene, structure, molecular change, or behavior may persist because its total removal or destruction by a mutation would result in serious adverse effects for the animal and the species. continued…

Evidence for evolution by natural selection includes several areas of observation and inquiry including:

1. Fossil evidence—Examination of ancient species reveals many that are no longer in existence or that have been dramatically altered, e.g. dinosaurs. This area of study also allows for comparison of life forms occurring before and after a given fossil and has resulted in a complex body of knowledge related to evolutionary progress.

The study of fossil evidence is tedious and frustrating by its nature. Many species do not evolve and either remain stagnant or become extinct. Most plants and animals decompose and disappear at death leaving no trace. Others are buried beyond retrieval inside layers of nearly impenetrable rock. Soft tissue does not fossilize for the most part. It is obvious that the fossil record is woefully incomplete. The total number of species that ever lived on earth is estimated to be between 17 million and 4 billion. The number is more likely than not to approach the high end of that estimation given that 10 million species live on the earth today. Only some 250,000 fossil species have been found, about 0.1-1.0% of all species that have lived. Imagine how many arks it would have taken just for the fossil species we know about, let alone the great mass that are unknown to us. (See stratigraphy)

2. Transitional forms—There has been a widely voiced contention against the theory of evolution that “missing links” or intermediate life forms between ancestral creatures and that of the presumed descendants have not been found despite long arduous efforts by zealous scientists. That is incorrect. Here are several clear-cut examples:

            Ten specimens of Tiktaalik roseae, were discovered in 2004 on Canada’s Ellesmere Island by Neil Shubin and Ted Daeschler who sought for a transitional form specifically in sedimentary rock of an age (approximately 375 million years old) predicted by evolutionary theory that such a transitional animal should be found. Tiktaalik is a creature that seems to have the head of a crocodile and the body of a fish. It is a 375 million year old fossil form which was technically a fish with a jaw, scales and gills, but had unusual fins. The fins had thin ray bones suitable for paddling like fishes but they also had sturdy interior bones that enabled it to prop itself in shallow water and to use its limbs for support as most four-legged animals do to crawl out onto dry land. It had a flattened head with eyes and nostrils on top of its head which would have allowed it to live in shallow water and peer above the surface. Tiktaalik is an immediate precursor to the amphibians that first left a predominately aquatic life to live on land. It had a neck like early amphibians. Its skull, neck, ribs, and pectoral fin are like the earliest tetrapods. The sturdy pectoral fin has the precursors of the humerus, radius, and ulna of tetrapod arms with a bendable elbow and an extendible proto-wrist. It is, therefore, a transition form between ancient fishes and their descendants, all the four-legged vertebrates including amphibians, dinosaurs, birds, and mammals like humans. Eusthenopteron and Acanthostega were other, less definitive examples.

The primitive aquatic nymph was found in fossils dated 300 MYA. This simple creature had a significant feature—wing-like structures on all thoracic and abdominal segments. The wing-like nature of those structures is reflected in the pattern of canals on the appendages, which is altogether similar to the pattern of veins in winged insects. However, this fossil is of an aquatic animal, and the structures are not wings, but gills similar to those found on the aquatic nymph larval stages of dragonflies and mayflies. The most likely scenario, therefore, for the origin of wings is that the wings of adult terrestrial insects evolved in animals that also had gills in their larval stages, another example of ontology recapitulating phylogeny and the tinkering of old genes to make new structures and functions.

A transitional ant that lived 92 MYA was found preserved in amber. The earliest known snake–one that lived 90 MYA–had a small pelvic girdle and reduced hind legs. The earliest known chordate–an animal that lived 530 MYA–called Haikouella lanceolata, was found in China. This inch long, eel-like fish had a frilly dorsal fin. The interesting thing about this creature was that it had a head and a circulatory system. The fascinating thing and that which makes Haikouella a crucial find, is that it had a brain and a cartilaginous bar along its back—the first known notochord. It was a true chordate, and chordates gave rise to all vertebrates, which eventually gave rise to mammals, which ultimately gave rise to human beings.

Genetic evidence clearly links the modern hippopotamus and modern whales evolutionarily. 60 MYA, there were no fossils of modern whales and none appeared until 30 million years later. However, 10 million years later than the period where there was no indication that deep sea mammals lived, fossil evidence began to appear. Intermediates include Pakicetus (52 MYA) which had simple teeth and whalelike ears, Ambulocetus (50 MYA) “the walking whale” which had reduced but robust limbs with hooves and could waddle on land like a seal, the partially aquatic Indohyus (48 MYA) with special features of teeth and ears found only in whales and their ancestors. Rodhocetus (47 MYA) had a more elongated skull and nostrils further back on its skull and was still more aquatic having a reduced pelvis and smaller limbs so that walking on land would have been awkward and difficult but was a good swimmer. Next came Basilosaurus and Dorudun (40 MYA) with short necks and blowholes on top of their skulls The next intermediate or transitional form clearly accepted as a “link” is Aetiocetus.(25 MYA). Aetiocetus had its nostrils at the middle of its skull unlike Pakicetus with its nostrils at the front of its skull. The Beluga whale’s (23-5.33 MYA with a fossil dating to 7-10 KYA found in the US) nostrils are located at the top of its skull, and it has a highly flexible neck. The Beluga is the modern counterpart of Aetiocetus. As they now exist, whales are stretched out land animals whose forelimbs have become paddles, and whose nostrils have moved atop their heads. Evolution tinkered with the parts of land creatures and ended up with whales; whales did not just appear de novo in completed form.

An ancient slope-faced ape, Pierolapithecus catalaunicus, informally nicknamed Pau, may be the last, or at least the latest found, common ancestor of the great ape family—gorillas, chimpanzees, orangutans, and humans. 12.5-13 million year old fossils were found in northeastern Spain including complete remains totaling 83 bone fragments. Pau weighed between 66 and 77 pounds and stood upright almost four feet tall. Evolutionary reconstructions indicate that great apes branched off from the larger primate family tree between 11-12 MYA, but there has been a relative void of fossils from that period; so, this find is the first good evidence from that transitional era. Pau had a broad sloping face, wide rib cage and a flexible wrist suitable for tree climbing, characteristics of apes and humans. He also had small hands with straight fingers that were monkey-like similar to more ancient primates. He was transitional in that, although he could live in trees and hang there, he was unable to swing from branch to branch like later apes, an adaptation that probably evolved independently in chimpanzees and orangutans long after these two groups diverged. Man came much later from the more immediate pre-chimpanzee line.

Reptiles preceded birds. The Maniratoa, reptile progenitors of the pterodactyl, Archaeopteryx, had full teeth, a furucula (wish-bone), a flat sternum, aiglon fossil belly ribs, wings, three curved claws on its wings, wing feathers, tail feathers, and reduced fingers—suggestive as characteristics of modern birds. Archaeopteryx lithographica, which lived about 150 MYA, is considered by many to be the first bird having bird feathers including tail feathers and reptile teeth, and was the size of a European magpie, but had enough reptilian characteristics for it to be considered more likely an intermediate “missing-link” form. Researchers found a 120 MYA sparrow sized pterodactyl in China’s Liaoning province, a region that was forested at the time the reptile, called Nemicolopterus crypticus, lived. Unlike Archaeopteryx, this small reptile had curved claws and attachment sites on bones for muscles that would have facilitated clinging to tree branches. Also, unlike most pterodactyls, it lacked teeth and probably ate insects. Modern birds appeared about 100 MYA during the Mesozoic Age with flat claws that facilitated terrestrial rather than arboreal living.

Another example is found in the evolution of horse feet which appeared in the fossil record. 55 MYA. Hyracotherium had four toes; more recently Miohippus and Parphippus had three; and more than 6 MYA came a primitive single toed animal, Pliohippus. 4 MYA Equus, the direct progenitor of the modern horse with its well developed single toe, appeared. This fossil record is more complex than that of Aetiocetus because of a multi-branched horse evolutionary tree, and the line given above is not a direct one. In each of these cases it is reasonable to presume that paleontologists will find still more intermediate forms, but the effort and expense required is immense given the vastness of the earth, the difficulty of finding and extracting fossil material from amidst mountains of rock, and the fragility of the creatures that resulted in permanent loss of many individuals and whole genuses, and the staggering costs involved in such painstaking and time consuming research.

Finally, consider Australopithecus afarensis, a recognizable forerunner of humans. The diminutive creature was a mix of human and ape-like characteristics. It was small with a chest having a chimpanzee-like funnel shape rather than the human-like barrel shape. It had long arms and hooked fingers adapted for hanging from branches, but its mid-skull foramen magnum, pelvis, and stiff feet which were definitely human-like in that they were adapted for a life of standing and walking on two legs including fast locomotion, unlike the apes with their posteriorly positioned foramen magnum, short bent legs and flexible feet that were (and still are) so remarkably adapted for tree living and so clumsy when running on flat ground. continued…

1. Adaptive maturation of the immune response. Virtually every aware person is familiar with the effects of the immune response, from immunizations to allergies. During the immune response, a remarkable and rapid adaptive evolution of antibody molecules occurs. During this adaptive evolution, the genes coding for the antibody secreted in response to a specific antigen–like ragweed–accumulate successive mutations which progressively increase the affinity for antigen. That is, the initial exposure may produce no symptoms; but successive exposures result in increasing runny nose, sneezing, and watering eyes.

When an organism is exposed to an antigen and mounts an immune response, a complex sequence of events ensues which binds antigen to immature antibody secreting B cells. Those B cells, whose antigen receptors, each with the same specificity as the antibody it will later secrete, form the best match to the invading antigen; and they proliferate most rapidly. This leads to a selected antibody accumulation which better matches the antigen than any other potential antibody. Prior to the antigen exposure, the protein antibody was not present in its specific chemical form. After several exposures, even more specificity and quantity of the antibody is produced and more quickly than the time before. If the antigen is a hormone, the peptides involved may bind to its receptor and antagonize, agonize, modulate, or simulate the hormone. This process is crucial in seeking candidate drugs for experimentation in human disease. The process of adaptive maturation of the immune response is a clear demonstration of the type of biochemical processes that are the underpinnings of evolutionary selection. A striking example is found in the development of bacterial resistance to anti-microbial agents.

2. Bacterial resistance to antibiotics is related to easy genetic selection in many bacteria. Extended spectrum ß lactamases, are enzymes that make Escherichia Coli–among others–resistant to most antibiotics. For example, TEM₁ makes E. Coli resistant to Ampicillin causing at least one-half of the urinary tract infections around the world to be resistant to that antibiotic. By changing a single amino acid in that enzyme, the ß lactamase can change the bacteria from susceptible to resistant to the drug cephtazamine in a matter of days. The powerful antibiotic, Vancomycin, requires the annealing of multiple gene products into a single structure or cluster. It took forty years for the first resistant strain to occur in enterococci. This is genetic selection that occurs within the lifetime of most of us. Similarly, soil bacteria develop the ability to survive on, then thrive on, and finally become obligate to, formerly toxic environments. This adaptability is such that the soil bacteria can rapidly evolve to cope with another new change in its environment frequently, as it must for the species to survive and persist. In many instances, the evolutionary process is clearly understood. Consider the precision of one selected article by Beckler, D.R., Elwasila, S., Ghobrial,G., Valentine, J.F., and Naser, S.A., from the Department of Molecular Biology and Microbiology, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Correlation between rpoB Gene Mutation in Mycobacterium Avium Subspecies Paratuberculosis  and Clinical Rifabutin and Rifampicin Resistance for Treatment of Crohn’s Disease, World Journal of Gastroenterology, 14: (17) 2723-2730, May, 2008. The researchers tested the two named drugs against the mycobacterium over time and recorded an increase in the minimum inhibitory concentration of the drug required to eradicate the bacteria by 30 fold. They traced the resistance to a mutation: By molecular biological methods, the mutation was identified as a small nucleotide substitution between nucleotides 1363 and 1443. The authors were able to refine that locus to a novel rpoB mutation C1367T which caused an amino acid change Threonine 456 to Ile 56 in the drug’s binding site. No other significant mutations were found.

3. Originally, the Hawthorne maggot fly (Rhagoletis pomonella) fed only on that plant. About 100 years ago, it underwent a mutation–with six out of thirteen alozyme loci becoming different–that caused it to adapt to feed on apples; and shortly thereafter, it became a major threat to apple farming in the northern United States. Apple flies take less time to mature. There is little evidence of interbreeding—a documented 4-6% hybridization rate—which is an example of a species undergoing speciation during the lifetime of individual people.

4. Yaws is a childhood skin infection whose existence is clearly dated from ancient times and is caused by a bacterium, Treponema pallidum which is transferred person-to-person by skin contact. In 1492 Columbus and his crews encountered Amerindians who were known to have yaws and carried the infection back to Europe. In Europe conditions known to foster the emergence and propagation of sexually transmitted diseases existed in near perfect form—over-crowding, high level of promiscuity in conditions of filth and anonymity, and a relatively high level of mobility.

Syphilis–also caused by Treponema pallidum–was almost unknown until the fifteenth century A.D. In the bacterial stew pot of medieval Europe, the previously rare occurrence of sexual transmission of Treponema pallidum reached a critical mass of frequent and multiple partner sexual intercourse, and the bacteria mutated into a dominant and virulent form. Instead of being transmitted as the benign form yaws, it emerged as syphilis which was first recorded during the Franco/Italian war beginning in 1495, an infection that reached epidemic proportions. Spanish sailors regularly returned to the Americas after their first visit. During the fifteenth century, Amerindian populations were decimated by the sexually transmitted disease.

5. In the savanna country of eastern and southern Africa, Apis mellifera scatellata bees developed into a highly defensive and aggressive bee, commonly known as African Killer Bees. They were intentionally introduced into Brazil in 1956; by 1990 they had advanced northward and invaded Sinaloa, Mexico producing large numbers of pure and also feral and hybrid colonies. In 1994 Africanized bees arrived in Blythe, California. By 1996 there were 21 established colonies found in the Imperial Valley. These insects are true killers of humans, livestock, and other bees. On the other hand, European honey bees are ordinarily quite docile, benign, and useful because they produce large quantities of honey for storage.

The process of Africanization is a straightforward example of evolution in action. The African bees have several characteristics that allow them to become dominant over European honey bees. They are extremely defensive and are more easily agitated. They very rapidly swarm to attack a presumed threat. They are more aggressive by nature and attack and take over honey bee hives. The African bees produce far more drones, and these drones rapidly invade honey bee hives and drive out the queen bee’s protectors and drones and then dominate the breeding process producing hybrids that become full blown African bees in a matter of only a few generations. The Africanized queens produce more offspring more rapidly—with gestation periods of three days as opposed to the seven days required for honey bees. Although Africanized bees produce much more honey than honey bees, they do not store it, but instead, they use the honey for rapid colony reproduction. The Africanized bees are more efficient foragers and fly faster, thereby bringing more pollen back to the hive to use as fuel for the manufacture of honey. When the hives become too large, or the weather cools to the point of intolerability, queens and their attendants move on, in an inexorable march in all directions repeating their predations, rapid procreation, and evolution.

6. Nylon eating bacteria: A Pseudomonas aeruginosa, strain POA, now exists which required new enzymes to digest a material efficiently that never existed until the modern age. The gene, however, did exist and served other functions; but when nylon became available, a simple gene frame shift occurred that allowed the bacteria to consume and digest nylon, a kind of plastic. The bacteria responded by being able to reproduce faster and more plentifully on a diet of nothing but nylon, a fiber produced only by man. The newly evolved enzyme’s crystal structure has been studied with high resolution x-ray which revealed that the amino acid replacements in the catalytic cleft of a pre-existing esterase (an enzyme) with a ß lactamase fold resulted in the evolutionary change.

7. Perhaps the most obvious, evident, and factual demonstration of natural selection resulting in a species change is found in the human immune virus—HIV. The virus is a weak construction of two RNA strands which are strung with genes, and the strands are held together by a sugar-based encapsulation. When HIV enters a cell it uses cellular parts to transform to DNA; and the process is made possible by an enzyme, reverse transcriptase. Using that enzyme, HIV produces some 10 billion new viruses a day. Mutational processes in cells ordinarily have mutations so infrequently that only three or four occur in a person’s life time, and most of those come to naught. HIV reverse transcriptase is highly inaccurate and capricious. It produces some 10,000 mutations every day. Because of this demonstrable capacity to mutate, anti-HIV medications become ineffective very quickly.

Scientists and drug companies rush to produce ever newer medications to keep up with the demands caused by this clear example of natural selection. It is a huge problem world-wide of which physicians are well aware, and even third-world victims of HIV infections become rather quickly aware. For example, the highly touted and relatively inexpensive drug, Nevirapine, has been given as a single daily dose to tens of thousands of infected pregnant African women to prevent mother-to-fetus transmission of HIV. Initially, it was remarkably effective. However, now–most of time–drug resistance occurs rendering the treatment useless. Effective multiple drug regimens are available with a much lower rate of developing resistance, but these regimens are out of reach for individual Africans and even their countries because of the great cost.

8. The elucidation of the rapid evolution of the enzyme ß galactosidase is a particularly good example of the evolution of protein differentiation. Evolved ß galactosidase has been shown repeatedly to code for a protein capable of evolving ß galactosidase activity. The wild type protein appears to have some activity toward an analogue of lactose, but very little activity toward lactose itself. Mutations which result in the capacity to catalyze lactose breakdown include strains that grow rapidly on lactose, but not on the disaccharide lactulose. Other strains grow slowly on lactose but somewhat more rapidly on lactulose and have a wider range of activity in general. The wild, unmutated gene does not allow galactose-arabinoside to be used as a sole carbon source, but both types of mutated bacteria permit limited ability to use the new sugar source. Double mutants–two different sites–are significantly more capable of growing on galactose-arabinoside than the wild bacteria or either of the two mutants alone. continued…

Early reviewers of the newest set of Carl Douglass books, The Trojan Horse in the Belly of the Beast Trilogy, challenge the author because of the gritty, even frightening, reality of the subject matter. A dominant theme in the first book of the trilogy, Though They Come From the Ends of the Earth, is the gross maltreatment of women—specifically the infliction of FGM [Female Genital Mutilation]—on girls in the Middle-East and Africa. It was the author’s purpose to bring the subject to light in a striking way. In that book, the protagonist is a single victim, and the horrors of the practice are starkly presented in that one fictional girl’s experience. Even if she were the only victim of the practice–which is carried out in the name of religion—it would be heart wrenching enough. But, the fact is there are some 148 million women living in the world today who have been victims. We have become inured to such mistreatment. After all, it happens “over there” to “people not like us”, and we do not like to think about it; so, we turn our eyes and ears away. There was a time when we acted as a nation similarly to the barbarism of slavery and accepted the platitudes offered by the slave owners. Similarly, the people of the United States were largely aware of the evils of polygamy and entered into a quasi-acceptance of the religious rights excuses underpinning the practice. As recently as 2014, the Supreme Court of the United States told us that polygamy—as long as it does not include more than one actual legal marriage certificate—is all right, one more example of our growing resignation to and acceptance of a level of preventable mistreatment of a subsection of our population—women.

In the next BLOGPOST, the author will present a brief exposition on what is probably the most egregious current example of this descent into acceptance of a manifest evil: elective abortion. continued…

The possession of vestigial organs is regarded as evidence of evolution.

21. Vestigiality and Atavisms: Vestigial organs are special features of animal heredity which only make sense by recognizing that they represent remnants of traits that were once useful in an evolutionary ancestor. Atavisms are bodily structures that occasionally occur in animals which recapitulate an ancestral trait, such as a demonstrable leg extending from the body of a whale. That leg is an atavism, because whale ancestors had legs. If a human baby is born with a fifth leg, that is a birth anomaly, not an atavism, because human ancestors never had five legs.

Examples include:

1. ~Ostrich wings are vestigial in that the flightless birds descended from flying ancestral birds, and the ostrich is left with definite wings that are too small to allow flight. The wings are now useful for maintaining balance while running, an evolutionary co-option of the small wing remnants—new tricks for old genes.
2.  ~Other flightless birds are: the South American rhea, the New Zealand Kiwi with wings only a few inches long, and flightless rails, grebes, ducks, wood rails, teals, moorhens, the extinct dodo, and the penguin whose flightless wings have evolved into flippers which allows swift underwater swimming. All of these birds have wings; they are just remnants of the powerful wings of flying ancestors. They all have the same wing bones as their flying counterparts. Some of the wings are functional, i.e., they have evolved to perform a function, often a significantly reduced one, other than the original one of flying; some are nonfunctional. Vestigial organs can be either; the crucial issue is that the vestigial structure no longer functions as it did in the ancestor.
3. ~Vestigial eyes are present in several species and are relatively common. An example is the Eastern Mediterranean blind mole rat whose eyes are miniscule, less than a millimeter across and hidden beneath a layer of skin. The eyes are incapable of seeing. Evolution towards loss of sightedness began 25 million years ago from sighted rats. True moles independently lost their sight, also retaining only a vestigial remnant. Blind cavefish, some spiders, salamanders, burrowing snakes, salamanders, shrimp, and beetles lost their eyesight, and some even their eyes completely by prolonged–evolutionarily long–lack of access to light.
4. ~Whales have vestigial pelves and leg bones imbedded in their tissues. They were once part of an ancestor’s skeleton, but that connection is now represented only by string-like connective tissues.
5. 5. ~The human vermiform appendix is of only minimal usefulness, and some human babies are born without one at all. The structure was of significance to an herbivorous ancestor as the cecum, and both the cecum and the appendix decreased in size as the size of the degree of reliance on an herbivorous diet decreased.
6. ~The human coccyx remains to tell us of our long ago ancestors who had long, useful tails. The rare baby is born with an actual tail. Many humans have a specific tail muscle, the extensor coccyges, which is identical to the muscle found in monkeys and other mammals that lifts the tail. In them it is of real function. In humans, it is present and has no tail to extend. The presence of the coccyx and certainly of the tail, is undeniable evidence of evolution in humans—the genetic capacity to produce a tail is there in our genome, but, for most of us has become a relic of the dim past. Arrector pili, the tiny muscles at the base of every hair that cause hairs to stand up during cold or attack have no real function in relatively hairless humans who tend to use their brains rather than their fangs and claws for defense. Humans also have three ear pinna muscles which, for most people, are useless, but for some, a vestigial function for vestigial muscles can be seen in those who can wiggle their ears.
7. ~Atavistic whale legs occur about once in 500 births with many of them having the full complement of the Bauplan tetrapod limb. Some go so far as to have feet and toes. Atavisms are considered by experts to be re-expressions of genes that have lain dormant after having been expressed in ancestors. The whale genome contains degraded genes that have evolved to be relics of past DNA because–by natural selection–they were no longer needed and fell into disuse.
8. ~Modern horses have one toe, the middle ancestral one. However, horse embryos start out with three toes. Rarely, the other two toes continue to grow to become atavistic toes complete with hooves which are very nearly identical to the ancient horse predecessor, Merychippus, which lived 15 MYA [million years ago].

The material presented here and the definitions discussed in these first eight blogspots on evolution give the reader a direction and a set of definitions to use in understanding the next several blogs which delve into the supporting evidence for the theory of evolution. Aspects of natural selection can be taken as observable facts which occur so recently as to be seen by people of today on a fairly regular basis. Others include recent historical observations. The following blogspot will present eight examples that can only be explained by the process of evolution.

continued…

Stephen Hawkings and Leonard Mlodinow, writing in their book, The Grand Design, published August 25, 2010, defined a model [or theory, for the present purposes] this way: “A model is a good model if it:

1.  Is elegant (i.e., is the most clear, concise, and complete statement that explains observable phenomena).
2.  Contains few arbitrary or adjustable elements.
3.  Agrees with and explains all existing observations.
4.  Makes detailed predictions about future observations that can disprove or falsify the model if they are not borne out.”

In every particular, the Darwinian Theory of Evolution, is in agreement with the definitions of those two famed theoretical physicists and their colleagues in the biological sciences. That leads us to Darwin’s theory.

20. The Darwinian Theory of Evolution: The theory has been modified since Charles Darwin and Alfred Russel Wallace first articulated it in 1858, and Darwin presented his thesis in 1859—The Origin of Species. The theory of evolution or natural selection holds that measurable change in animals and plants over time comes from the changes in heritable traits as measured by allele frequency of a population through successive generations—Mendelian transmission genetics. Natural selection is, therefore, the process by which species–not individuals–adapt to their environment in small incremental steps over time, usually, a long period of time. In addition, branching phylogenes result in branching speciation expressed in hierarchal patterns. The process leads to relentless and directed evolutionary change wherein individuals with certain characteristics have a greater survival or reproductive rate than other individuals in a population and pass on those heritable genetic characteristics to their offspring. An evolutionist put it this way, “variation proposes, and selection disposes”.

While mutations occur at random and by chance, the process of natural selection is far from directionless. The direction is not pre-designed, but once a mutation has occurred and survives, selection is driven by environmental pressures and developmental constraints to produce an organism and a population that can adapt and survive. DNA can accurately be said to exert power over its own future which expands, diversifies, becomes more complex, and uses the changes wrought to advance still further and sometimes faster. The structures, organs, and bodies that develop become instruments of DNA’s power to continue to produce salutary advancements. The embryological developmental constraints–and therefore an element of direction to evolution–come from the channeling of genetic mutations, or by filtering them, through mechanisms of development that favor the emergence of some phenotypes. Some structures may be impossible for embryos to develop; others are likely to emerge and to persist in the DNA; so, they can be passed on to successive generations. Natural selection, therefore, chooses not from an entirely random selection, but from a structured set that is determined–or at least biased–by the mechanisms of development. Evolution is constrained by diverse physical principles, by rules of construction and good design, and by some scaling rules. The result of these constraining influences of development and principles of construction is to drive the direction of evolution and to hasten the evolution of a certain structure or characteristic at a pace that exceeds what would be predicted by mathematical statistical expectations alone.

Evo-devo [evolutionary development] scientists tend to accept the concept that natural selection is the most prominent determinant of who thrives and who dies or fails to reproduce, no matter how constrained development might be. They also stress that development itself is subject to descent with modifications, i.e. evolution. Successfully adapted populations achieve an additive and persistent rather than subtractive and destructive overall evolutionary progress. Opportune moments in evolutionary history such as the Cambrian Explosion (543-490 MYA) occurred. The environmental conditions during the Cambrian era led to the production of a plethora of new marine forms when the glaciers receded, and a long period of global warming followed. Evolutionary history is punctuated by conditions in the environment along with an organism living on the edge of mutation which occasionally result in definitive leaps forward.

A specific example of selective forces is one that gave a mighty push to our own class, mammalia. The end of the Cretaceous era, about 65 ±0.3 MYA saw a rapid and severe extinction of many—over 90%–of life forms including large dinosaurs. It was a dark and difficult time to be on earth, and there was a progressive decline in bio-diversity during the late periods suggesting an ecological crisis. On the tail of the Cretaceous Era, there came the Cenozoic age of opportunistic new life. Mammals diverged from a few small, simple, furtive, generalized forms hiding in holes and in the branches of trees into a diverse collection of terrestrial, marine, and flying animals; birds evolved substantially in the Cenozoic as well. Mammals grew and flourished from then until the present to become the dominant animals on earth.

There are trillions of molecules in complex organisms, and the possibility of their being present as a result of pure chance is all but impossible. A sense of such improbability can be gained by considering the odds that–by chance alone–each of four players could receive a complete suite of cards in a single deal during a game of bridge. The odds against that happening are an unfathomable 2,235,197,406,895,366,368,301,599 to 1 (2+ septilion or more than 2 billion billion to 1). And that is dealing with the permutations and combinations involving only 52 entities. The difference produced by natural selection is that over the eons of geologic time, changes occur and accumulate which favor survival of animals and plants with more adaptable characteristics, and those characteristics are passed on to future generations. The process is then directional, and continues to be driven by the requirements of the environment, and not just chance. Complex structures and organ systems such as eyes, hands, and brains did not occur by random gene drift, but by a process driven by mutation, natural selection, and time.

“Survival of the fittest”, as natural selection is often termed, is an inadequate and misleading slogan, an oversimplification of a much more complex process. The phrase suggests some sort of match between gladiators, but natural selection is a far more subtle power of selection which depends on very small differences in overall survival and fecundity. Some changes result in a better adaptation to different parts of the environment and location and reproductive success may depend on that adaptation. Other genetic changes may produce a truly fitter, more aggressive, or more enduring sub-species that in time dominates. For example, primitive creatures such as flatworms have photosensitive cells that could have been present in primordial life forms and which evolved into the complex eyes of animals of today–at all stages, of definite survival value. Natural selection is primarily a matter of reproductive success that includes the ability to survive to the age of reproduction (improvement in differential mortality), increased fertility (differential fertility), or may involve a sub-group that has an enhanced physical or chemical ability for successful union of gametes, or may be a matter of size or color or scent that enhances the attraction of the opposite sexes to each other (sexual selection). Colors and scents of flowers attract bees to ensure pollination and propagation of the species of flowers. An interesting example is that of the Malaysian Rafflesia kerri flower. Spikes at the center of the flower help disperse its characteristic odor of rotting meat throughout its jungle habitat. This attracts carrion flies that pollinate the plate sized bloom. Ecological selection occurs when organisms that survive and reproduce increase the frequency of their genes in the gene pool over those that do not survive in a given location. continued…

This is an opinion my main character in the Sybil Norcroft series of novellas would get excited about and would publish it far and wide using her bully pulpits—the position of Chief Medical Consultant for Wolf News Network and later as the Surgeon General of the United States. In late April, 2014, the CDC (Centers for Disease Control) released its Threat Report 2013 with an in depth discussion of the scientific evidence regarding the prevalence of allergy to penicillin in America. Of the more than 300 million Americans, 10%–nearly 30 million people—self-report that they are allergic to penicillin. The CDC reports—on the contrary—that 28.5 million of those people are wrong. When carefully evaluated 19 out of 20 of them do not have a true allergy to penicillin and its family of medications.

It is reasonable to ask if it matters if people wrongly think that they are allergic and for that reason avoid using penicillin and its congeners. The answer is emphatically that it does matter a great deal. The misconception about penicillin allergy results in over usage of other, far more broad-spectrum antibiotics; and that leads to our mounting crisis of antibiotic resistant infections. This is hazardous to the health of individuals and to the nation and is extremely expensive. Penicillin is cheap; newer broad spectrum antibiotics still under patent are inordinately expensive. The mistaken belief that people are allergic to penicillin but are not leads to prolongation of hospital stays, significantly more antibiotic usage, and increased incidence of MRSA (Methicillin Resistant Staphylococcus Aureus), VRSA (Vancomycin Resistant Staphylococcus Aureus), VRE (Vancomycin Resistant Enterococcus), C-Diff (Clostridium difficile), and fungal infections. Almost all of those infections are significantly more injurious and lethal than the original penicillin sensitive infections.

The CDC reports that more than two million such infections and 23,000 deaths occur each year in the U.S. Choice of antibiotics is becoming increasingly more limited throughout the country and people die as a direct result of antibiotic failures. Many of those failures are avoidable by physicians determining whether or not their patients are in fact allergic; and if not, returning to the use of older, but still effective, simple penicillin. The study included 50,000 hospitalized patients and found that 20% of patients admitted to hospitals report being allergic to penicillin, and they are the most vulnerable to antibiotic resistant infections. Skin testing for penicillin allergy, use of penicillin as the first line drug, and the avoidance of broad spectrum antibiotics is a cheaper and more effective way to deal with individual infections and the nation’s antibiotic resistance problems.

Similarly, Lake Victoria in Zimbabwe is home to hundreds of species of cichlid fish, many of which are similar in most respects with the key exception of color pattern. Female cichlids use color pattern to identify mates of their own species, preventing them from mating with the wrong species. Because they exhibit this form of behavioral isolation, the many species of cichlid fish in the lake will not mate with one another, and their reproductive isolation remains fixed, generation after generation.

Natural selection, however, aside from the chance aspects of mutations, is not entirely a random process, but is instead predictable and is the core mover of establishing new forms and more complicated and successful forms and of design and order throughout nature from the sub-atomical to the macro-universe. Better adapted genotypes will tend to persist and to reproduce and to determine the direction and design of future generational development. The cumulative process of myriad small changes over time is directed by nonrandom survival and proceeds in the direction of increased complexity, specialization, and more successful function. Understanding the effect of natural selection was the paramount contribution of Charles Darwin to the world’s understanding of the process of evolution.

Darwin, however, was wrong about one aspect of evolution with regards to speciation. He admitted to confusion and ignorance about the process but presented the opinion that new species arose to fill empty niches in nature. A mass of research has established that–to the contrary–speciation occurs as an evolutionary accident. Species do not arise to increase diversity nor to provide balanced ecosystems. They are simply the result of genetic barriers that arise when spatially isolated populations evolve in separate directions. This is known formally as the theory of geographic speciation. This process is somewhat comparable to the establishment of different languages when populations with the same proto-language separate, then develop different linguistic language selections, then even more distinct language differences over time to the point that the languages are more than just dialects of the same language, but become mutually unintelligible. Consider the examples of sister tongues Latin→ Italian→ Spanish→ French or German→ English.

Diagram of mutation and selection in evolution. (Photo credit: Wikipedia)

The finding of naturally occurring separated species arising from the same ancestor is a requirement of verification of the theory of geographic speciation. A dramatic example exists in the case of Panamanian snapping shrimp. Each side of the Isthmus of Panama harbors seven species of the shrimp in shallow waters. The remarkable thing about these seven species is that the closest genetic relative of each species is its counterpart on the opposite side of the isthmus—Atlantic and Pacific Ocean snappers. This came about when the isthmus was formed by rising from the sea bed three million years ago. Once separated, each of the seven species formed both an Atlantic and a Pacific species that has persisted successfully over that period of time.

Mutations occur at random, but with expected frequency, and most of them come to naught. Natural selection is more involved with preventing evolutionary change than driving it which results in a rather long process of microevolutionary alteration due to environmental changes and species adaptations to achieve macroevolutionary change, especially speciation–roughly 100,000 to 5,000,000 years to evolve two reproductively isolated descendants. It is appropriate to ask if there has been enough time in earth’s existence and especially whether there has been enough time when the earthly environmental conditions were compatible with life to develop the known ±10 million species on earth today or especially the estimated 100 million potentially unknown species. Mathematically, starting with a single species 3.5 billion years ago and allowing for a split into two descendants only every 200 million years, there would have been plenty of time to achieve even the possible 100 million living species and even taking into account the myriads of species that have become extinct during that period of time.

Evolution Blogspot 7. Expanded Definitions, Part VI

The theory or law of evolution is often disparaged by the statement that it is “only a theory” by those who fear the implications of the science involved. They are correct that it is a theory, although they evidently are unaware of or choose to ignore the scientific definition of a theory. They would be more disparaging and even less accurate if the referred to Darwin’s concepts as an “hypothesis” meaning that it is little more than a hunch or a guess. The purpose of this blogspot is to set the record straight, at least insofar as science is concerned.

19. Theory: The National Academy of Science has defined a scientific theory as, “a well substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses”. In this definition, a theory is a more advanced, better tested, and more firmly established explanation than a guess, conjecture, or hypothesis. In science a theory such as the Theory of Evolution is a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence. The theory of gravity posits that forces of attraction exist that can be proved by mathematics and observable consequences–such as sending a space vehicle to orbit the earth or the moon. The law of gravity is considered to be a well established working theory of science despite the fact that it cannot be touched, heard, or seen directly. Physicists have studied extensively and understand the atom in great detail, but the fundamental nature of gravity still eludes them. Most educated people accept gravity as a given, but cannot bring themselves to accept evolution by natural selection. Nonetheless, evolution occupies in biology a position of acceptance on the order of the acceptance of gravity in physics. In brief, a scientific theory–a key to any scientific advance–in the words of physicist and Nobel Laureate, Jean Perrin, “is to be able to explain the complex visible by a simple invisible.” continued….