Evolution can mean change over time or even common ancestry
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very meeting with Prof Asir Ajmal opens new vistas of knowledge for me. He is a psychologist par excellence and holds a PhD from Dartmouth College in the USA, which has an Ivy League status. The debate opened with the contention that the theoretical basis of most scientific knowledge is embedded in human speculation. We went on to uncover various sub-themes in sciences, Asir doing most of the talking.
The discussion boiled down to Darwin’s theory of evolution and its contestation in the American academic sphere. Asir is an ardent advocate of the theory of ‘intelligent design’ vis a vis Darwin’s formulation, which he says does not hold much water. He shared a few write-ups on Dean H Kenyon who is a professor emeritus of biology at the San Francisco State University. Kenyon is one of the instigators of the ‘intelligent design’ movement. He has also authored Biochemical Predestination, a book that won him much critical acclaim.
I will try here to make sense of Darwin’s theorisation in the course of which I will also bring in Lamarck’s thoughts on evolution.
In the later part, I’ll try to summarise the theory of intelligent design. The reader should be mindful that the writer of these lines is not a biologist and wishes to be excused for any lapses.
Charles Darwin (1809-1883) proposed that species can change over time, that new species come from pre-existing species and that all species share a common ancestor. In this model, each species has its own unique set of heritable (genetic) differences from the common ancestor, which have accumulated gradually over a very long time.
For Darwin, five ideas were much more of a unity than they appear to a person who analyses them with modern hindsight. The five theories were: (1) evolution as such; (2) common descent; (3) gradualism; (4) multiplication of species; and (5) natural selection. Darwin and a scientific contemporary of his, Alfred Russel Wallace, proposed that evolution occurs because of a phenomenon called natural selection.
In a five-year expedition, Darwin had collected hydrographic, geologic and meteorologic data from South America and many other regions around the world. Darwin’s own observations on this voyage led to his theory of natural selection. According to the theory of natural selection, most organisms produce more offspring than are able to survive in their environment.
The essence of Darwin’s theory is that natural selection will occur if three conditions are met: a struggle for existence, variation and inheritance. Darwin’s observations that led to his theory of natural selection are: overproduction — all species will produce more offspring than will survive to adulthood; variation — there are variations between members of the same species; adaptation — traits that increase suitability to a specie’s environment will be passed on.
The theory of evolution through the process of natural selection was only gradually accepted because it challenged the idea that God made all animals and plants that live on Earth (creationism). The evidence when the theory was first published was insufficient to convince many scientists. Today, evolution is the unifying concept in biology. This theory documents the change in the genetic makeup of a biological population over time. Evolution helps us understand the development of antibiotic resistance in bacteria and other parasitic organisms.
Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck, often known simply as Lamarck, was a French naturalist, biologist, academic and soldier. He was an early proponent of the idea that biological evolution occurred and proceeded in accordance with natural laws.
Lamarck proposed theories like the inheritance of acquired characters, use and disuse, increase in complexity, etc, whereas Darwin proposed inheritance, different survival, species variation and extinction. Their theories are different because Lamarck thought that organisms changed out of need and after a change in the environment and Darwin thought organisms changed by chance when they were born and before there was a change in the environment.
The crucial difference between the Darwinian and the Lamarckian mechanisms of evolution is that the former emphasises random, undirected variation whereas the latter is based on variation directly caused by an environmental cue and resulting in a specific response to that cue.
‘Intelligent design’ (ID) is a set of concepts based on the notion that life on earth is so complex that it cannot be explained by the theory of evolution and, therefore, must have been designed by a supernatural entity. Phillip Johnson is known as the father of ‘intelligent design’. The idea in its current form appeared in the 1980s and Johnson adopted and developed it with his book, Darwin on Trial in 1991.
In his view, the Darwinian evolution came up short in explaining how all organisms, including humans, came into being. ‘Intelligent design’ theory was then formulated, primarily in the United States, as an explicit refutation of the theory of biological evolution advanced by Darwin.
The basic contention of ‘intelligent design’ is that modern life on earth could not have developed solely through the processes of evolution but instead required the direct intervention of an “intelligent designer” to produce some or most of the species.
‘Intelligent design’ proponents attempt to demonstrate ‘scientifically’ that features, such as irreducible complexity and specified complexity could not arise through natural processes, and therefore, required repeated direct miraculous interventions by a Designer (a reference to the concept of God as provided in religious texts).
‘Intelligent design’ is the idea that certain features of living systems are best explained by a designing intelligence, rather than an undirected process. That is, by studying nature, you can tell something of the effects that an intelligence has had on nature. The theory of ‘intelligent design’ is an inference from biological data, not a deduction from religious authority.
We’re looking at things like the little miniature machines that are being discovered in cells: the rotary engines, the nano technology, the turbines, the sliding clamps, the intricate circuitry. Especially important is the libraries of information that are stored in the DNA molecule in the form of a four-character digital code.
For some people this is the basis of the inference to ‘design’. This is not something one deduces from a religious scripture. Bernd-Olaf Kuppers has made certain revelations in his book, Information and the Origin of Life about the cell that contains vast quantities of biochemical information stored in our DNA in a sequence of nucleotides. No known physical or chemical law dictates the order of the nucleotide bases in our DNA, and the sequences are highly improbable and complex. Moreover, the coding regions of the DNA exhibit sequential arrangements of the bases that are necessary to produce functional proteins.
I will say that the theory of evolution can mean change over time or even common ancestry, which is not contested. What is contested is specifically the Darwinian idea that life is the result of a purely undirected process that merely resembles a designing intelligence: that the appearance of a design is an illusion. Classical Darwinism and modern Darwinism both say that things look like ‘design’ but they’re not really, because natural selection produces that appearance. To a lay person like me, this sounds like a contradiction in terms.
The writer is Professor in the faculty of Liberal Arts at the Beaconhouse National University, Lahore. He can be reached at tahir.kamran@bnu.edu.pk