Section 6: The Book of Nature – The Human Paternity Suit
Genetic Predictions of Special Creation vs Darwin
After that introduction to genetics, it is pertinent to ask: Why are we interested in genes in studying human origins?
You may be aware that DNA, the substance of genes, is used to identify criminals in rape and murder cases. By studying enough sections of DNA and the variations in many different bases and base sequences, an individual can be identified much more surely than by fingerprints. The only people who share the same bases at all sites are identical twins. If you can rule that possibility out, you can confirm with certainty that the DNA on a murder weapon, or in semen, matches the DNA of an accused from just a few sites unique to their DNA.
DNA is also used in paternity suits. It’s not too hard to identify the biological mother who bears a baby. When the question is which man helped conceive a child it is sometimes difficult and disputed. Sequences of DNA bases in a child that match the same sequences in the same parts of a chromosome in a man, and are not present in the mother (or in other men), provide very strong evidence that the man is father to the child. But it is potentially even stronger evidence to show that the child and man share certain gene sequences that are unique to the man’s lineage, and not shared with other people.
How will this help us in our study of human origins?
Although body structure, organs and tissues may be very similar between species, people have argued that God by Special Creation could have separately created each species but using a similar body plan – why not use a formula that works, after all?
But genes are different from the rest of our body parts. They are inherited, and indicate a person’s ancestry. They can be used to identify a person, and to identify their paternity. It doesn’t stop with just one generation though. Just one or two rare and unlikely gene sequences that are identical in two individuals, however far apart those individuals seem to be in body form or in geography, indicate those sequences were inherited from a person who was an ancestor of both individuals (or ‘common ancestor’). Not only that, but as Denis Alexander has pointed out, there are no gaps in the genetic record.55 We have a complete continuum of life forms from the simplest to the most complex, from the oldest forms found in the rocks (bacteria) to the most recent (eg humans), represented in the genes of animals and plants living today.
The most difficult of Darwin’s ideas for Christians to accept is the evolution of humans from non-human primates. Christians have always believed that humans constitute the pinnacle of God’s creation; the only creatures that can communicate with, question and either disobey or love God. There is, for some, a feeling of repugnance about the suggestion that we are physically related to animals. Such a concept also provokes unsettling questions about the meaning of the story of the creation of man and woman, the Fall, and the human soul. That is why I want to address human origins specifically, rather than questions about whether amphibians evolved from fishes, or birds from dinosaurs. Once the question of the origin of humans is settled, the other issues will not seem so pressing and will settle themselves.
Darwin had no genetic evidence because genes and the role of DNA in inheritance would not be discovered for another 100 years (see timeline box).
Timeline of Genetic Discoveries in relation to Darwin
1859 Darwin publishes The Origin of Species.
1866 the augustinian monk Gregor mendel publishes his work on the inheritance of dominant and recessive traits in the pea plant, but his work is largely ignored.
1869 miescher isolates DNa from the cell nucleus but its structure and function are unknown.
1871 Darwin publishes The Descent of Man, outlining his ideas about the relationships between humans, apes, old World monkeys and New World monkeys.
1870s Chromosomes are discovered and in 1888 they are named chromosomes by von Waldeyer.
1882 Charles Darwin dies.
1889 de Vries christens the unit of inheritance a ‘pangen’, later modified to ‘gene’ by Johannsen in the early 1900s.
1902 Chromosomes are shown to be inherited like physical characteristics.
1910 T H Morgan shows that genes reside on chromosomes.
1944 DNA is shown to be associated with genes and chromosomes.
1953 Watson and Crick discover the double helix structure of DNA.
1960s Nirenberg, holley and Khorana decipher the genetic code by which DNA codes for amino acids.
1972 Fiers and colleagues analyse the sequence of bases in a gene (in a microbe) for the first time.
2003 the Human Genome Project, led by Francis Collins, completes its draft sequence of the whole human genome.
We can therefore use Darwin’s assumptions about relatedness between humans and apes or primates, and the assumptions of the idea of the Special Creation of Humankind, to set up a virtual experiment and make predictions from these two views about how human and ape genes will compare. We can then test these predictions by looking at some of the available genetic data, and see which predictions fit the data better. This is a scientific means of comparing the validity of theories, as discussed in Chapter 2.
Am I My Keeper’s Brother? pp 193-195. Order your copy of the book here.Previous Next Section