A Lesson in Science About Gregor Mendel

Gregor Mendel (1822–1884)
Pioneer in Genetics

Wisdom is supreme; therefore get wisdom. Though it cost all you have, get understanding. —Proverbs 4:7

Gregor Mendel’s early life is a tale of struggle and sacrifice, culminating in his acceptance as an Augustinian monk and his subsequent discovery of the three laws of genetics known as Mendalian laws. Although he died thirty years before his extraordinary work was noticed by the scientific community, his name today is synonymous with genetics.

Named Johann Mendel at birth, Gregor was born into a family of sturdy peasants. His father, Anton, acquired and improved lands that had been allowed to decay during the Napoleonic wars. A gifted gardener, Anton taught his son the arts of grafting and husbandry. These techniques impressed Johann and would intrigue him for the rest of his life. The boy, in turn, impressed the local schoolmaster, Thomas Makitta, with his capacity for learning. Makitta urged the family to give the boy higher education, and they agreed.

Yet they were so poor that they could not support his years of high school at Leipnik and Troppau. Johann was placed on half-rations by the school and was always hungry and malnourished. Several times his health broke, and he became despondent. Each time he returned home, where peasant cooking and outdoor work revived him. He attempted to teach pupils, but was largely unsuccessful because he was so quiet and shy.

In the midst of these trials matters became worse. Anton was seriously injured while working in the corvée or unpaid labor gang. No longer able to exert himself fully, he was forced to deed his farm to his son-in-law. Johann agreed to the move, though as an only son the farm was rightfully his. He preferred to become a teacher. His younger sister Theresia, deeply sympathetic to her brother’s plight, made a bold sacrifice—she gave up her dowry to put him through school. She would not hear his protests, and he finally yielded. Theresia, attractive and vivacious, eventually enjoyed a happy marriage regardless.

After completing high school, Mendel again became ill, possibly in sheer frustration over his inability to find a job. A local priest with whom the young man sought counsel recommended he enter the Augustinian monastery of St. Thomas at Altbrünn.

This appealed to Mendel. The monastery had a well-earned reputation for cultural and scientific achievement. It boasted a library, botanical gardens, a clock tower, and a museum of Moravian flora. Its monk-scholars were in many cases authorities in their fields. Among them were Cyril Franz Napp, the prelate of St. Thomas and a noted Old Testament scholar. Peter Thaler, one of the monastery’s most brilliant minds, had developed extensive mineralogical and botanical collections. The community was active in music, discussion of art, literature, and research. Mendel was accepted on condition he learn Czech.
At his induction, Mendel adopted the name Gregor. Before being allowed to teach, he was required to complete four more years of study in Greek, Hebrew, pedagogical methods, and theology. At the end of the second year he took his vows as a monk. His instructors lavished praise on his high-quality work.

Delegated to parish work, Mendel found it excruciatingly difficult. He had no intuitive understanding of people, yet found himself empathizing with their miseries to the point of fretting himself sick. He would lie awake for nights, unable to sleep for tenderheartedness. In order to survive his own deeply involved reactions, he had to remove himself from his work. He could not communicate well in his clumsy Czech. As a result, Prelate Napp transferred him to a teaching position in the town of Znaim.

Mendel quickly took to his new duties, teaching elementary Greek and math. Unlike most teachers of the day, he was not severe and quickly won his pupils’ hearts. A friend urged him to take a teaching exam. Against his better judgment he was persuaded to test in the sciences, where he had much aptitude but little foundation. As a result he failed. He continued to teach but only as a “substitute.”

One good result of the exam was that one of his examiners, the influential teacher Andreas Baumgartner, admired the young man’s fire and pulled strings to have him admitted to the University of Vienna. Among his new teachers was Doppler (1803–1853), the experimental physicist for whom the Doppler effect is named. Doppler wakened in Mendel a desire to contribute original research of his own.

Having earned his degree, Mendel returned as a supply (substitute) teacher to the Brünn Modern School. He was a supply teacher in name only; his supervisors quickly recognized his worth and retained him in full capacity for years. He went above the call of duty, tutoring slow pupils in his own hours without demanding extra fees. His presentations were extremely clear.
When he tried a second time to pass the teaching exam, he withdrew in the midst of it, having encountered intense opposition from a committee that resented his independent thought. This double failure preyed on his mind, but his career was soon to take a turn for the better.

Mendel’s famous experiments were about to begin. Intrigued by the inability of hybrids to remain true when reproducing, he looked at the challenge with a physicist’s eye, determining to quantify the problem and see what would emerge. He may have guessed what the results would be for his experiments indicate he had a clear idea of the course he intended to follow even before he began.

For two years Mendel bred pure strains of peas. Then for eight more years he crossbred and self-pollinated patches of peas, painstakingly identifying and testing them for seven selected traits. These traits included such basic features as tall or short vines and wrinkled or smooth peas.

His choice of the garden pea was perfect for his experiments. Not only does it self-pollinate well, but it is easily grown, has a short season, and is not readily contaminated with outside pollens.

As a result of his studies, he discovered dominant and recessive characteristics. The gene for tallness, for example, was dominant over that for shortness. He found that all hybrids share identical characteristics the first year. If tall and short plants are bred together, all plants are tall the first year. The next year, when self-pollinated, one-quarter of the peas revert to their original types. The ratio of dominant to recessive at this point is 3 to 1. The succeeding year, the short, or recessive varieties produce only more of their own kind. But the dominant, or tall, varieties produce both short and tall, again following a 3 to 1 ratio.

From this Mendel deduced that two genes were involved in producing each characteristic that he studied, one from the ova and one from the gamete. When the genes combined, they united in four patterns: tall tall, tall short, short tall, and short short. A mathematical pattern could be observed: A + 2Aa + a. Since talls dominated, all combinations with a tall came out tall. That explained why three talls were produced for each short and why self-breeding the talls again produced some shorts from the hidden (recessive) short genes. Clearly, dominant seeds actually carried recessive genes in many cases. When bred the following year, recessives united with recessives in one-fourth of the instances, obeying the laws of probability.

Mendel derived three laws from his experiments. The first declares that the egg and sperm each carry only one of the matching pair of factors (genes), for example, either tallness or shortness, not both. The second law states that traits are inherited independent of each other. For example, in the garden pea, color of blossoms is inherited without regard to tallness or shortness. (Later researchers discovered that some traits are linked). The final law, the law of dominance, states that when sperm and cell come together, each provides one factor (gene) to each inherited trait. One gene will always be dominant over its matching gene. Originally developed for plants, Mendel’s laws were soon shown to be true for animals too, making them powerful theories for interpreting the genetics of all living things.

This was brilliant work, but no one yet understood its importance. Nageli (1817–1891), a well-known scientist whom Mendel contacted, expressed interest but never did anything with the priest’s work.

Fortunately for posterity, Mendel’s work was noted in a bibliography. Three researchers, DeVries (1838–1935), Correns, and Tschermak, rediscovered it at about the same time. Mendel’s ideas were then quickly taken up and widely disseminated. Valuable results, such as Nilsson-Ehle’s breeding of a new strain of wheat able to survive in Scandinavia, flowed directly from Mendel’s three laws. Unfortunately, Mendel did not live to see his vindication.

In the meantime, Mendel went on to other things. In Brünn he helped form the Society for the Study of Natural Science. He communicated with other scientists and did additional work on hybrids. Although he read Darwin, he did not accept many of his theories, believing that God had created the world and that blind chance could not be responsible for the outcome.

In 1868 Prelate Napp died, and Mendel was elected abbot in his stead. He left the Brünn school, but could not say good-bye to his pupils, as he disliked sentimental scenes. Characteristically, he gave his remaining salary to help needy students. From his new income he distributed help to those in need and repaid his sister for her dowry by educating his nephews.

As his administrative thoroughness became apparent, more and more jobs were thrust upon him. Yet he maintained his cheerful humor, exhibiting gentleness and modesty throughout his life. To escape his ever-increasing burdens, he began vacationing in the Alps. He grew heavy and humorously noted that “long walks and especially hill climbing are very difficult for me in a world where universal gravitation prevails.”

Mendel’s last battle was with the government. In 1875 a tax law that singled out religious establishments was passed. Mendel stubbornly resisted this encroachment on religious freedom. Those who joined him in the fight soon lost heart, and they fell away when the Moravian government confiscated monastic lands. The government offered compromises, but Mendel remained firm. He began to smoke heavily and grew sick. When he could no longer perform his duties, others stepped in and negotiated a resolution, conceding the government’s authority to levy the tax. The government waived the back taxes, but secular authority had triumphed.

When Mendel died on January 6, 1884, Catholics, Jews, and Protestants alike came to pay him homage. All loved him for his kindness, generosity, and strength of character. But none who attended the funeral yet knew the importance of the work in genetics with which his name is indissolubly linked.

About the Author of Scientists of Faith

Dan Graves recieved his undergraduate degree from John Wesley College and a M.S. in Library Science from Western Michigan University. An avid, life-long reader, Graves became interested in the topic of apologetics from reading C.S. Lewis and Francis Schaeffer, which led to a focus on the personal histories of various scientists of the faith.

For more information about Scientists of Faith, visit the Kregel Web site at www.kregelpublications.com.

A Lesson About Eusebius

From the new paperback edition of Eusebius!

Eusebius in Greek means one who is reverent, pious, or devout—a proper name (nearly equivalent to Pius in Latin) that was shared by a half dozen other famed figures in Christian history. A geographical suffix distinguishes them from one another. Just as Jesus of Nazareth differentiated him from the twenty other Jesuses in biblical times, so Eusebius of Caesarea designates the church historian.

Although there were also a number of Caesareas in an-tiquity—all named in honor of Augustus, the first Roman emperor—Eusebius’s is Caesarea Maritima, the famous city of Palestine constructed by Herod the Great on the Mediterranean shore, at a site previously called Strato’s Tower. This Caesarea is mentioned frequently in the New Testament as the Roman capital of Judea, the headquarters of Pontius Pilate, Cornelius, Herod Agrippa, Felix, and Festus, as well as the place where Paul was imprisoned for two years. Here, too, the riot broke out in a.d. 66 that led to the great Jewish War against Rome and the destruction of Jerusalem. The last only enhanced the importance of Caesarea, and by the third century it was virtually the capital of Syria, a very large, cosmopolitan city with a Jewish, Greek, Samaritan, and Christian populace.

Eusebius was probably born around 260. His biography, written by Acacius, his successor as Bishop of Caesarea, has not survived to provide more exact detail. His ancestry and the story of his youth are unknown. His education may be adduced from the fact that the great Eastern scholar-theologian Origen spent his later years in Caesarea, dying several years before Eusebius was born. Origen’s influence persisted strongly in the theological school founded there by the learned Pamphilus, presbyter in the church at Caesarea, who taught Eusebius and influenced him most. Eusebius joined Pamphilus in writing a defense of Origen, made use of his great library, and wrote a Life of Pamphilus (now lost), whom he valued so highly that he was often known as Eusebius Pamphili. In the final Great Persecution of the Christians under Diocletian, Pamphilus was imprisoned and martyred in 310.

Upon the death of his mentor, Eusebius went to Tyre in Phoenicia and Alexandria in Egypt, where he was imprisoned in the Diocletianic persecution but released shortly afterward. Many years later an opponent accused him of having gained his release by pagan sacrifice, but no evidence for this was adduced at the time or since. Had such evidence existed, it surely would have been used in the theological turmoil of the day. Just after Constantine’s edict of toleration was issued in 313, Eusebius was elected Bishop of Caesarea, where he remained until his death, despite being offered (and declining) the patriarchate of Antioch in 331.

About 316, he gave the dedicatory address at the new cathedral in Tyre, which he published in Book 10 of his Church History. Two years later the Arian controversy exploded in Eastern Christendom, and Eusebius soon found himself embroiled in it. He favored a mediating position between the theological extremes of Arius, presbyter in Alexandria (“Jesus is more than man but less than God, who existed before the Son”), and Alexander, Bishop of Alexandria (“Jesus is God, of the same essence and co-eternal with the Father”). Although Eusebius did not endorse the full subordinationism of Arius, he was somewhat sympathetic to the Arian cause, for which the Council of Antioch provisionally excommunicated him and two others in 324. His case, however, was transferred to the great Council of Nicea the following year, where he sat at Constantine’s right hand and served as a prominent theological adviser, delivering a panegyric in honor of the emperor.

As leader of the moderate party at the council, Eusebius presented the creed used by his church at Caesarea and was exonerated of any heresy. Constantine stated that the creed reflected his own views, and it seems to have served as basis for that adopted at Nicea, but this creed was adopted only after important addenda had been made by the Alexandrian party, including Jesus being defined as homoousios (“of one substance” or “essence”) with the Father. Although Eusebius finally voted with the overwhelming majority for what would emerge as the Nicene Creed, he wrote a letter to his church explaining his hesitations and voicing concerns that the Alexandrian party was verging on Sabellianism, a heresy that claimed unity over trinity (i.e., that the Son of God was only God acting in a saving mode or capacity).

This concern followed Eusebius to the Council of Antioch in 331, which deposed Eustathius, a leading anti-Arian, and to the Synod at Constantinople in 336, which condemned Marcellus, Bishop of Ancyra (modern Ankara), for extreme anti-Arianism. This does not, however, mean that Eusebius remained a pro-Arian. Eusebius’s orthodoxy later in life is confirmed by his rejection of two cardinal principles of Arianism: that there was a time when the Son of God was not and that he was created out of nothing.

Just after the Synod of Constantinople, Eusebius was chosen to deliver an oration on the tricennalia of Constantine, the celebration marking his thirtieth year as emperor. Constantine died in the following year (337), and Eusebius two years after that, most probably on May 30, 339, a date known with considerable certainty from the Syriac martyrology of the fourth century. Nothing is known of Eusebius’s two final years, other than that he published a Life of Constantine in four books, a panegyric rather than a strict history.

For more information about Eusebius, visit Kregel's Web site at www.kregelpublications.com