My 14 year old daughter is in Grade 9 in a public school in Edmonton, Alberta. I have had the chance to look over her science textbook (Science in Action 9. Published by Addison Wesley, Copyright 2002 Pearson Education Canada Inc.) during the Christmas season to see just what it says about evolution.
Unit A covers ‘Biological Diversity’ and it is broken down into four sections:
1. Biological diversity is reflected in the variety of life on Earth.
2. As species reproduce, characteristics are passed from parent to offspring.
3. DNA is the inherited material responsible for variation.
4. Human activity affects biological diversity.
Looking at these sections, it would seem that the subject of evolution is inescapable. I move on to the first section to see just how the single most important concept in Biology is presented in this unit.
1.Biological diversity is reflected in the variety of life on Earth (pg.8) opens by examining what diversity means. The amount of organisms identified today is mentioned (over 1.5 million species of animals and 350 000 plants), a definition of species is given (a group of organisms that have the same structure and that can reproduce with one another), ecosystems are discussed, with the diversity within ecosystems, diversity within species and species distribution mentioned. All good headings that should include the word evolution or natural selection – but no, it is not mentioned. It then moves on to ‘Classification’. Linnaeus is mentioned and the need to classify animals in a consistent manner based on their structural relationships. ‘Interdependence’ discusses how predator and prey relationships affect populations. Then a subsection called ‘Variation Within Species’. Surely this subsection on variation will mention evolution? ‘Variability and Survival’! I have found it, one of the essential elements of natural selections. Sure enough…protective coloration…bacterial resistance…banded snails… but no mention of evolution, or Darwin.
Finally, a chapter heading called ‘Natural Selection’! Here is where they introduce Darwin…but no, no mention. I move to the index, perhaps I missed it…but no ‘Darwin’. No ‘Evolution’.
That is it. No mention is made of species formation, evolution or Darwin. Some review questions follow and the section ends. Perhaps the word that unites all of biology will be mentioned it the next section:
2. As species reproduce, characteristics are passed from parents to offspring (pg.26) opens by examining variation as it can be found in plants in a greenhouse. Then a chapter heading, ‘A Closer Look at Variation’, containing sections called: ‘Heritable and Non-heritable Characteristics’, ‘Discrete and Continuous variation’, ‘Variation and the Environment’…still no mention of evolution or Darwin. The next chapter is ‘Asexual and Sexual Reproduction’ with special attention given to how sexual reproduction produces variation, and how variation “…helps species survive environmental change.” No ‘Evolution’, no ‘Darwin’.
3. DNA is the inherited material responsible for variation (pg.38) I think this will be my daughter’s favourite section, due to her memories of a Grade 6 project that she did on DNA. The first chapter is DNA: Transmitter of Genetic Code. It mentions Oswald Avery, the Canadian medical researcher best known for his discovery in 1944 with his co-workers Colin MacLeod and Maclyn McCarty that DNA is the material of which genes and chromosomes are made. The second chapter is ‘Cell Division’, and then a chapter called ‘Patterns of Inheritance’. Here much use is made of dogs and cats to discuss dominant and recessive traits and the ideas of pure breeds and hybrids. Chapter headings ‘Other Patterns of Inheritance’ and ‘Environmental Factors’ follow. There is no mention of evolution in this section, although it would have been a good section to introduce evolutionary developmental biology to tie in the previous sections.
4. Human activity affects biological diversity (pg.56). This section again mentions natural selection as part of the chapter on extinction and extirpation: but still no mention of evolution.
What conclusions can I draw from this? Considering that evolution is the over-arching concept that unites all of biology, how can we explain the complete absence of the word in this middle-school textbook?
The requirements for evolution by natural selection are¹:
1. Variation: Individuals in the population must differ with respect to the trait in question. Without this variation, all individuals will have the same trait value and cannot be distinguished with respect to that trait.
2. Heritability: The variation found in the population must (at least partially) be heritable, e.g. transmitted from parent to offspring. If the variation in the trait was due entirely to the environment, for example, changes in the parent population would not affect the characteristics of the offspring population.
3. Differential Mortality: Finally, individuals must have a probability of survival that is a function of the value of the trait in question. If all individuals, regardless of their trait value, had an equal probability of survival and fecundity, no predictable change in the mean value of the population would occur.
This Grade 9 textbook covers all these points: it stops at the natural result of all the evidence it provides – new species formation. Is Evolution a word that dare not be spoken?
How does Science in Action 9 deal with the history of science? This textbook is a general science text. It has units on Biology, Electricity, Chemistry and Astronomy. The Chemistry unit has a history section (ironically called “Evolving Theories of Matter”) that mentions the early contributions of people like Boyle, Lavoisier and many more. The Electricity unit mentions figures like Thales, Tesla and Humphry Davy. The Space Exploration unit speaks of Archimedes, Copernicus and Galileo and more. Yet somehow, the Biology unit, which deals with all the elements required for evolution to take place, fails to actually use the word ‘Evolution’ and fails to mention the first proponents of evolution by natural selection: Darwin and Wallace.
‘Darwin’ and ‘Evolution': words that this Alberta science textbook will not speak.
Has political correctness or religious views interfered with a solid biology education in this province? That question will be considered in a future post.