Do you believe in evolution?

Mikhail Gelfand began his lecture by presenting the results of several surveys conducted at various times in different countries. In the first case, people were asked to agree, disagree with a statement: “Humans have evolved from previously existent species”. In Russia, as well as in USA, a minority of respondents agreed with the statement. In the second case, respondents were asked if they believe in the theory of evolution. But this question is flawed, emphasized Mr. Gelfand, because it is ambiguous.

First of all, belief can be used to discuss religion. Conversely, if  scientists say they believe a certain theory, it means they’ve studied it, examined the author’s evidence and research results, checked if the control studies and computations were conducted properly, considered if anything could be missing, noted the flaws and how it would fit into the rest of scientific knowledge. Secondly, many take the word “theory” to mean something unproven or unfinished. In this case, though, the word “theory” represents a whole section of biology – called evolutionary biology, akin to the theory of relativity being a whole section of physics.

Some also tend to say that Darwin has made several mistakes in his theory and therefore it cannot be relied upon. The first part of that statement is true – the scientist did make mistakes, as he did not know many things that we know now. Some parts of his “On the Origin of Species” contain omissions that he could not explain. For example, Darwin was unable to explain why a “good” trait will, over time, become “watered down” and less prominent in a creature’s descendants. The truth is that he didn’t know that this has to do with genetic variation. Austrian biologist Gregor Mendel, Darwin’s contemporary, is considered the father of genetics, but, unfortunately, he published his studies of pea plants in official publications of Brno’s scientific society instead of a well-known scientific journal. Because of this, his findings on the mechanics of inheritance were discovered too late.

Gregor Mendel. Credit:

“Due to this, there is now a myth stating that Darwin supposedly didn’t open Mendel’s letter in which the latter described his findings. But that’s a lie – no such letter has ever been found. So if you’ve created or discovered something noteworthy – please publish it in a publication that people will actually read” – asked Mikhail Gelfand, half-jokingly.

He also reminded the audience that it is unfair to call Charles Darwin the father of theory of evolution. Many also spoke of evolution before him, but he was the first to describe the principles of natural selection. In that sense he was indeed a true genius. Scientists only went back to studying the mechanics of train inheritance in 20th century when they understood that DNA carries genetic information and gave rise to molecular and systems biology.

Proof of evolution: non-optimality

It is non-optimal forms and vestigial structures, not adaptation, that serve as proof of evolution. Why are all fish elongated? Because it’s the better shape for moving through water. That is the same reason why submarines are that shape. Anything that swims well will be elongated. Why do bees build their “homes” using hexagonal shapes? Because it’s the optimal way to fill out as much available space as possible.

With that rationale, questions begin to arise regarding rudimental traits in various species. For instance, why do cave-dwelling fish still have eyes? Such species live in absolute darkness, yet they possess rudimentary, non-functional, eyes. This is yet another proof of evolution’s handiwork: the fish must have inhabited a better-lit place once and then moved “underground”. Another example is the existence of both flying and non-flying phasmids. This implies that, under certain conditions and relatively recently, some phasmids lost their wings and the system hasn’t fully caught up with the transition.

“The weirdest and impractical design – at least at first glance – is that of the flatfish. The design assignment for this fish seems simple enough: let’s make a fish that’ll live and feed on the seafloor. The qualified designer made a flat “scanner” with a venomous barb, while the s         lacker came up with the flatfish. It was the classic object for creationists to troll evolutionists with. Let’s assume there was a normal fish and then one of its eyes migrated to the other side so that it would be more comfortable with constantly lying on its side. They’d ask: how could it just up and move? Where’s the transitional state? Thankfully, a fossil was found that indeed had an eye slightly moved from its normal position. After all, if you’ve dropped something small on the floor, it’s easier to look along the floor to find it” – said Mr. Gelfand.

Proof of evolution: similar organ structure, different functions

Evolution never invents anything new – it only adjusts what is already there to fit a new set of circumstances. The simplest example of this is a bat’s wing. The wing’s skeleton is an “adjusted” form of a mammal forelimb. Except that the bat’s “pinky” has grown much longer and that other fingers have become webbed. Interestingly enough, all animals that have fingers possess webbing in embryonic state that later degrades. An experiment was done: a regular mouse was injected with the section of bat DNA that regulates the shape and length of the front extremities. And nothing happened. The scientists then injected a different section that is responsible for “turning on” the long extremity gene. Only then did the mice’s front limbs become 15% longer than standard.

Proof of evolution: anthropogenesis

Saying that humans have descended from apes often causes questions and hesitation, notes Mikhail Gelfand. The most common question is: why aren’t chimpanzees turning into humans today? Another question that is just as popular: why do monkeys even exist still if evolution rejects the less adapted species? The answer is that no scientist has ever claimed that humans are descended from any of today’s primates, but that they have a common ancestor. And if we were to find that ancestor, it would be physically very similar to an ape. A common ancestor is a prediction made by Darwin’s theory of evolution. The reason why it’s so difficult to prove it is that we need to build an evolutionary tree composed of the intermediate species that led to the appearance of Homo Sapiens. Even today many of such forms have been found and can be used to track the gradual increase in size of the skull of other primates that serve as our species’ ancestors.

“It’s much harder to prove that the chimpanzee has descended from the monkey since their ancestors lived in jungle climate where humidity and warmth don’t allow bones to preserve well” – noted Mr. Gelfand.

Proof of evolution: observable evolution

Richard Lenski can be called the world’s most patient microbiologist – he has been observing the life of a population of E.coli bacteria for 25 years now. The bacteria have gone through more than 61 thousand generations. The research team takes a sample of each tenth generation and freezes it, ensuring that they have a full history of the organism’s development.


At one point the team studied the various generations and discovered that a new species had emerged through the course of evolution. Its ancestors fed on glucose, while the “newbie” developed an ability to feed on microbial products – the metabolites of its surrounding counterparts. This was a very beneficial evolutionary trait that allowed the new species to avoid competing for glucose with the other bacteria. Then suddenly the new strain began to disappear, baffling the scientists. When placed in a separate Petri dish, it survived without an issue. When they checked the lab journals, it turned out that at some point the lab was left without electricity, which caused the new strain to suddenly drop in numbers. It turned out that the new species was sensitive to change in temperature. Evolutionary traits, therefore, have the cost of having to lose other pre-existent traits, which doesn’t always lead to the formation of a fitter, more perfect species.

Proof of evolution: bacterial resistance to antibiotics

Bacteria are microorganisms that can evolve in front of our eyes, just as the E.coli bacteria did. And they can be very adept at developing the ability to resist threatening substances like antibiotics. Mikhail Gelfand reminded the audience that less than 20 years after the discovery of penicillin, the Staphylococcus aureus developed immunity to the drug. He also demonstrated the results of a Harvard study that shows that, through mutation, bacteria can develop immunity to a one thousandth dose of antibiotics in just 11 days.

“Antibiotics have existed naturally long before humans – the bacteria itself is in a constant state of chemical warfare with one another. They constantly develop methods of offense and defence. There’s a particularly resilient strain of tuberculosis nowadays that can hardly be killed. Pharmaceutic companies lack incentives to develop new antibiotics. It costs a lot and doesn’t bring in much profit, so modern bacteria soon develop a resistance” – stressed the lecturer.

Mikhail Gelfand's open lecture at ITMO university

Oftentimes when a bacteria develops resistance to a particular drug, its method of treatment is changed and a different type of antibiotics is used. The mutated bacteria then evolve again – and this can go on and on. Tougher natural selection breeds tougher species. In the case of cancer cells, this results in new proposed methods of treatment. When higher doses are used in chemical therapy, there is a possibility that new cells could emerge that are impervious to such doses. This gives rise to a theory that it might be more effective not to allow cancer cells to mutate, but instead to keep them at bay with mild doses. Then a “milder” natural selection will occur and the new superresistance trait won’t be present in the next generation of cells.

What to remember if you want to discuss and understand evolution the right way.

  1. Most changes are neutral and do not affect the condition and function of a species. Positive mutations are very few and their effect is minimal
  2. Natural selection is very hard to track. For example, approximately a third of all pregnancies ends in miscarriage at such an early stage that the mother does not notice neither the pregnancy nor the miscarriage.
  3. For any significant genetic change to occur, a great number of factors need to coincide. Most importantly, the new trait should not affect the species’regular way of life while not being entirely useless.
  4. Traits that were previously “harmful” can become useful – and vice-versa. For example, all adult mammals are lactose intolerant due to a genetic trait. This is needed so that grown offspring wouldn’t take away milk from the younger population. With humans, this worked out differently – when they migrated north and began to breed cattle, it once again became useful to digest dairy.

Mikhail Gelfand

“Another example is the human ability to preserve fat. Through the course of evolution, those humans that could store nutritional material in their fat would survive better. But today, when there is enough food for us to eat regularly, it is no longer a favorable trait, as seen with diabetes and sexual selection” – says Mikhail Gelfand.

Dr. Gelfand also added that the next leap in evolutionary biology will occur when we understand how to study the early stages of development of living creatures on a molecular level and compare them with each other. A human is not a chimpanzee because they possess different genes. They are almost the same in composition, but what matters is their sequence. For that purpose we need to look at early development of organisms to understand how these differences emerge.