“Nothing in biology makes sense except in the light of evolution” – Theodosius Dobzhansky

“The absence of evidence is not the evidence of absence” – (Source not accurately known)

The above two quotes are enough to shred into pieces the thought expressed by BJP leader Satyapal Singh at a recent event when he said that Charles Darwin’s theory of evolution (more accurately, the theory of evolution by natural selection) was “scientifically wrong” and that it needed to be taken out of school and college curricula, as our ancestors had not “seen” or “documented” an ape turning into a man (implying that man was ALWAYS man).

While the first half of his statement demands closer scrutiny, the latter half is simply too illogical and can be safely brushed aside as a “brain fade”, to not sound too condescending to the honourable minister.

Expectedly, the internet world reacted with rage and sarcasm in equal measure while the Indian scientific community responded with a strongly-worded dissent note. Almost instantly, the web was flooded with hilarious cartoons, memes and tweets ridiculing the minister’s lack of knowledge on the subject.

Considering the rush-to-the-bottom in our political discourse today and the general lack of scientific vigour or fact-checking among the ruling party’s personnel, this would have been considered at most as a sort of a comedy of errors (in a long continuing one).

Except that it cannot. Primarily because this did not come from a fringe leader trying to stoke communal hatred for electoral gains or talk in the “whataboutery” fashion to divert attention from the inadequacies of the government, but rather from a highly-educated former civil servant and no less than a junior minister at the central ministry of human resources development (MHRD), Dr Satyapal Singh.

His views need to be taken with full seriousness and concern as they come from someone who may be directly able to affect the educational and research priorities of the government. This government has already made significant strides towards pushing an agenda-based science rather than an evidence-driven one. Since the minister very confidently (and arrogantly) refuted Darwin’s (and also the oft-forgotten Alfred Russell Wallace’s) theory outright, it might be prudent to very briefly discuss the broad tenets of the Darwinian theory of natural selection for the minister (if he is willing to listen) and for the purposes of a more informed debate.

But first, let us disentangle the meaning of the word “theory”. While in everyday usage “theory” may pass off as a hunch or speculation (the scientific equivalent is “hypothesis”), the formal scientific definition of the term is slightly different.

A scientific theory is a comprehensive and generally acceptable explanation of some aspect of nature that is supported by a vast body of evidence. In biology, some theories (such as the cell theory, gene theory, theory of homeostasis, and yes, the theory of evolution as well) have, in fact, become so well-established and foundational that no new evidence is likely to alter them in any fundamental way.

Having said that, no scientific theory is sacrosanct and undergoes continuous refinement over time, sometimes is even completely overturned, as new evidences and explanations (primarily by new technologies that enable observations and experiments not possible earlier), previously unexplained by the “old” theory, accumulate and predictions are tested.

In the controversial (at that time) but seminal publication On the Origin of Species in 1859, largely describing his direct observations of the natural world and insights from animal specimen collection during voyages around the globe onboard the HMS Beagle, British naturalist Charles Darwin proposed two key ideas (orhypotheses): evolution, which he defined as “descent with modification”, is the idea that species change over time, give rise to new species, and share a common ancestor; and natural selection as the mechanism that drives this process of evolution, in which heritable traits (which can be passed onto offspring) that help organisms survive and reproduce become more common in a population over several generations, and would have made the population adapt to its environment.

As evidences and voices supporting these ideas began to mount, and the tremendous diversity of life on the planet began to make sense when viewed through the “natural selection” lens, it eventually came to be recognised and accepted as the most well-known theory describing the evolution of life forms on earth (there were and are other competing theories of evolution).

The theory is sometimes misleadingly described as “survival of the fittest”, but “fitness” here does not refer to an organism’s muscular strength or athletic ability (which may help matters), but rather the ability to survive AND reproduce.

Another common misconception of Darwin’s theory of evolution is to view natural selection as unidirectionally moving towards “perfecting” the organism. The fact is that natural selection has no specified goals. After all, natural selection is not a thinking being! It is more accurate to think of it as a mechanistic process in which, given variation, differential reproduction and heredity in populations, it will act on those variations in a very non-random way wherein the variants that aid survival and reproduction of the organism are significantly more likely to become common than variants that do not, resulting in species evolution.

Organisms do not ever “stop” evolving, it’s just that the process is slow enough to not be noticed (although do read about microevolution).

In the mid-20^th century, several decades after Darwin’s original theory was propounded, the “modern evolutionary synthesis” reconciled the gradualist Darwinian view of natural selection with a Mendelian understanding of genetics (proposed in 1865-66, rediscovered in 1900), unifying observations from naturalists, systematists, experimental geneticists, palaeontologists, geologists and developmental biologists.

It is now established that the physical and behavioural changes that make natural selection possible, in fact, happen at the level of DNA and genes (known as “mutations”). New evidences have established that the mechanisms of evolution are diverse and include, apart from natural selection, mutation, migration and genetic drift.

The results of evolution are, in any case, contingent upon the environment that the organism inhabits (a variation at one place may be advantageous while at another disadvantageous) and dependent on the vagaries of history.

In simple words, the modern synthesis theory is a tremendous intellectual achievement of the 20^th century about how evolution works at the level of genes, phenotypes and populations, and greatly strengthens (not diminishes) Darwin’s original theory which was mainly concerned about individuals, organisms and speciation.

While defending the minister’s (scientifically untenable) perspective on a television news debate on NDTV, a BJP spokesperson pointed out that Darwin’s theory had several limitations. While that is true and it sure is important to teach the limitations of the Darwinian theory to students (which many school and other educational boards already do), it is blatantly unscientific (thus unconstitutional even) to suggest that such a widely accepted, well-developed, independently verified and substantiated theory be discredited and taken off the curricula, merely because questions remain on the precise details of evolutionary change.

The basic tenets of the Darwinian theory of evolution by natural selection have withstood the stern test of time and empirical evidence to emerge ever stronger over the last 150 and more years. Removing it or diluting it from the curricula altogether, despite the lack of evidence of it being “wrong”, will not only give further credence to obscurantist ideas but also severely compromise the ability of future Indian evolutionary biologists to contribute to the field in any meaningful manner.

If this happens, India will join the limited list of states that have regressed in the last few years. Such ideas, therefore, must be vehemently opposed should we have any hopes of living in a modern and rationalist Indian society.

The minister’s view, in this context, is dangerous and a significant blow to the (still nascent) development of scientific temper in India. As a member of the scientific community, and in view of my constitutional fundamental duty, I urge the honourable minister to refrain from making such loose and subjective statements, as later advised by his senior minister, or present an objectively verifiable alternative theory.

For a “man of Science” (not Arts, mind you), this should not be a difficult task at all. Until then, let us keep Darwin well and truly alive in our science textbooks.