Is evolution in bacteria different to that in primates?

I got asked a question yesterday on Facebook on whether evolution in bacteria and primates differs. The short answer is no.

The long answer is that the process of evolution itself is so simple in a way that it really doesn’t matter what its object is, i.e. what it operates on. It’s easier to understand this if you think about atoms. The forces governing their behaviour are equal properties in different measures. Mass is mass, whether it’s zero or one hundred units. The slight differences in these properties can lead to huge noticeable differences in final products, just look around.

Natural selection isn’t something that can change depending on what it acts on, be it bacteria or primates. Natural selection is there, and any difference in products is just that. Bacteria and primates are different because of the different evolutionary paths their ancestors took, the different environments and selection pressures that led to their present day evolution.

Another question was whether increasing complexity of species was an inevitable result of evolution. I suppose this is a bit like the question “Can you return a fried egg back to a raw egg?” According to our current knowledge, the answer is no, we can’t undo the burning of an egg or piece of paper. It’s hard to imagine evolution working backwards, because it’s hard to imagine undoing evolution. The matter of fried egg can’t work its way to become a raw egg, it’s an irreversible reaction. In a sense, ancient species had the resources to evolve in certain ways, but that doesn’t mean the subsequent versions of themselves necessarily have the potential to reverse it. If anything, any further evolution that leads to a similarity to previous species would not be a reversal, but merely a continuation of the same evolutionary pathway. Strictly speaking, there is no reason why natural selection on its own couldn’t lead to future species looking more like ancient species rather than more recent past species on the same evolutionary pathway.

An example that springs to mind, although not on an interspecific level, but on an intraspecific level (that is, within one species), is one insect. This insect has switched its wings on and off repeatedly over a long period of time, depending on its environment. Would you call that backwards evolution? I wouldn’t. Evolution evolves one way, regardless of similarity between past and future species. A bit like time.

Comments

4 Reasons Google's Calico Won't "Solve Death"

The on-line world has been taken ablaze by Calico's bid to end ageing, and thus death itself, but is this what they will actually focus on, and will they achieve it? The fact is ageing will be reversed, and death by "natural causes" will go with it. The questions are "When?" and "By whom?". Until recently, not a lot was known about the approach Calico would take in this venture dubbed "moonshot thinking" - a term touted by Google as the source of all considerable human progress throughout history. This we don't doubt, but is this what Calico is all about? CNN's Dan Primack has revealed details about Calico's plan , which hint at a less-than-moonshot thinking approach, and cast a serious question mark on its ability to deliver the punchy TIME headline. Here is why: 1. The man with the idea, Bill Maris, arrived at the conclusion that the root of all death-causing disease is simply ageing itself. Not only is this widely

The evolution of the human body

In order to be able to look at ourselves in the mirror and be able to answer the question "Why do I look like this?", we must look back to our ancestry and their lifestyle, over a very long period of time. For the purpose of this analysis, let's look at the human versus the neanderthal. Recently there have been found neanderthal genes within the human gene pool, but the two species are different enough to compare, yet not too different (human versus fly would be too different). As you can see, the construction of the human pelvis and toes is different, and the human has less hair. This results in humans being able to run easily for long distances, in the detriment of short-distance running which we are worse at. We sweat better, so we can do more long-term effort. This feat is essential to better settlements, as we can discover a larger area with potentially better resources. It might seem counterproductive to not be able to run quickly for a short period, when it come

How do you experience evolutionary selection pressure?

Evolutionary selection permeates the consciousness of members of a species at a level higher than the individuals themselves. Everyone comes into awareness about the selection pressures and adaptations taking place across their population. This happens independently of who they happen to be. Awareness of “life”, being alive, what it takes to survive, exist in each individual even when they lack it in some perceived manner e.g. being unattractive, having low self-esteem, being a failure. Indeed, it’s what enables self-deprecation and sometimes suicide based on some of these beliefs in an individual. Each individual is not out for themselves, with the selection pressure encouraging them to succeed, but rather they are out for the collective they are part of, whether they realise it or not, whether they like it or not. It is detrimental to individuals to feel bad about themselves. However, this is the effect of collective selection. Individuals therefore place themselves

Principles of Evolution

Search This Blog