Curiouser and curiouser!

| June 8, 2022

When we consider alchemists we think of strange men burning substances to transmute base metals into gold or give eternal life to the practitioner. However, through the ages people have produced astounding results for sometimes quite technical problems.

Many plants in Australia possess a high arsenic base and are hence poisonous to mammals. Native animals here have, over time developed a natural immunity to it. However, humans haven’t. This is why we allow arsenic traps to be laid for feral (ie. imported) animals. When the aboriginals arrived they developed a method of removing the poison from the various plants they ate (ie cycads). This involved what we now refer to as ‘retting’ which required soaking in water for about a week, followed by a variety of other activities then grinding the seeds into flour and cooking.

It seems unlikely that this lengthy process could have evolved spontaneously. Some Aboriginal groups have used Austral Indigo as a fish poison, crushing the leaves and roots and adding them to pools of water to stun and disable fish for easy catching. Once again, not a logical step. Through the ages giant leaps forward have been made with little or no intermediary stages.

Many of the things we now take for granted started in a similar way – the Iron Age began when someone decided to heat certain rocks to very high temperatures and collect the melted runoff; the first person to mix two soft metals (copper and tin) to produce bronze, a hard amalgam is another case in point. Glass, created from sand, sodium carbonate and limestone was produced over 2000 years ago from substances which are not transparent. It is difficult to understand the original thinking in its production.

Ancient engineers designed many artefacts, mainly associated with irrigation, the production of food and safe living conditions. These mostly followed logical steps – the study of natural phenomenon and adaptation to suite current needs. However, every so often a genius would arise whose lateral thinking would take knowledge a massive step forward.

Modern science tends to ignore outsiders. But reductionist science is not the only way of knowing things. Naturalists were the forebears of science. Humans once lived much closer to the land and were keen observers who had a deep understanding of nature’s interactions.

Today biology tends to be focused on molecules, and failure to look up from instruments in the lab and actually observe how pieces interact in the natural world sometimes undermines discovery. A clinical focus can lead scientists to miss big-picture connections, such as an emerging understanding that networks may be a more enduring life-form than individuals.

Science over the past two centuries has largely viewed molecules, cells and species as individuals. Symbiosis challenges that notion. Within a lichen, algal cells and fungal cells may experience each other as individuals, but together they form a lichen that the feeding caribou sees as an individual: tasty.

Natural selection happens on both scales simultaneously. Just as light is both a wave and a particle, the fungus and alga are both individuals and parts of a whole. Science’s reductionist focus has made it nearly impossible to fully understand symbiosis. “Ecology was supposed to be the science of natural process and synthesis, but its backbone is severely strained under the mathematics of individuality.”

Even our knowledge of the tree of evolution is now being shown as requiring new ideas. Ever since Darwin published and popularised the idea of evolution, researchers started building evolutionary trees — also called phylogenetic trees — branching diagrams that show the evolutionary relationships between different species that share different characteristics.

It’s a very useful and straightforward tool, except it may be pretty wrong, say the authors of a new study.

Genes don’t lie. If you were a biologist in the 19th or 20th century looking to classify animals, your options were limited. You could study the ecosystem and the animal’s role in it, detail the morphological characteristics of the species, but that was pretty much it — you had to rely a lot on which things looked similar to other things.

But in more recent years, the advent of genetic analysis has opened new doors for classifying species. When rapid genome sequencing became relatively cheap and easily available, researchers had new tools to see which species were related to which, and they started noticing that sometimes, things weren’t as expected.

Sometimes, one species can turn out to be several species, or species thought to be closely related can actually be quite different. Matthew Wills, Professor of Evolutionary Paleobiology at the Milner Centre for Evolution at the University of Bath, says that “it turns out that we’ve got lots of our evolutionary trees wrong.

“For over a hundred years, we’ve been classifying organisms according to how they look and are put together anatomically, but molecular data often tells us a rather different story.”

The problem is that oftentimes, fairly unrelated creatures evolve in a somewhat similar way. For instance, if you’re only looking at flying, you may be tempted to believe that bats and birds are closely related — when that couldn’t be further from the truth.

Of course, any biologist can tell that bats and birds are very different, but sometimes, the differences are more subtle and can be tricky to tell. For instance, many insects show similar mouthparts, despite not being closely related. This is called convergent evolution: the independent evolution of similar features in different groups of animals.

Molecular data show that elephant shrews are more closely related to elephants than to shrews.

In the new study, biologists compared 48 pairs of morphological and molecular data, finding that convergent evolution is more common than previously believed, and as a result, several “traditional” evolutionary trees are not as accurate as previously believed.

The study proves statistically that if you build an evolutionary tree of animals based on their molecular data, it often fits much better with their geographical distribution,” says. Where things live—their biogeography—is an important source of evolutionary evidence that was familiar to Darwin and his contemporaries.

For example, tiny elephant shrews, aardvarks, elephants, golden moles and swimming manatees have all come from the same big branch of mammal evolution—despite the fact that they look completely different from one another (and live in very different ways). Molecular trees have put them all together in a group called Afrotheria, so-called because they all come from the African continent, so the group matches the biogeography.

In addition to helping biologists better understand these biological relationships, this study also shows that we shouldn’t rely on things that seem similar. In addition, it shows that evolution doesn’t always make new things — instead, it seems to tend to produce somewhat similar things over and over again.

Jack Oyston, Research Associate and first author of the paper, concludes: “The idea that biogeography can reflect evolutionary history was a large part of what prompted Darwin to develop his theory of evolution through natural selection, so it’s pretty surprising that it hadn’t really been considered directly as a way of testing the accuracy of evolutionary trees in this way before now.”

“What’s most exciting is that we find strong statistical proof of molecular trees fitting better not just in groups like Afrotheria, but across the tree of life in birds, reptiles, insects and plants too.”

“It being such a widespread pattern makes it much more potentially useful as a general test of different evolutionary trees, but it also shows just how pervasive convergent evolution has been when it comes to misleading us.”

In 1952 Mt Everest was considered an impossible climb, but Edmund Hillary managed to ‘conquer’ it. Since then It has been climbed by thousands of others. In 2021 a woman managed to climb it three times before the end of March. Why was this? It appears that when something has been shown to be possible it is much easier for others to emulate the act.

Science needs more polymaths – people who can see and work outside of the box. It is currently constricted, partly because of the sheer volume of data acquired over the centuries and partly through the activities of senior scientists who have become set in their ways.