Nav: Home

How evolutionary miniaturization in insects influences their organs

May 17, 2017

Scientists from the Faculty of Biology of the Lomonosov Moscow State University have studied out, how organs of microinsects change their sizes in the process of miniaturization -- reduction in sizes of incest bodies in the process of evolution. Looking ahead, principles and regularities of miniaturization, revealed in animals, could be applied in biotechnology and robotization. The researchers have presented their project in Scientific reports journal.

Alexey Polilov, Doctor of Biological Sciences and the article author says: "The project idea was to estimate how different insect organs react on body size changes. We focused on miniaturization -- namely, evolutionary reduction in body sizes up to extremely small sizes. We wanted to study out what happens to the structure of organs when insect body sizes decrease from one centimeter up to tenths of a millimeter. This is necessary to understand what remains the same and what changes in an insect body".

Miniaturization or reduction in body sizes appears to be one of the main tendencies of insect evolution, as a result of which they become the size of unicellular organisms. One of the smallest insects are Coleoptera and Hymenoptera, Mymaridae. Their size is about fractions of a millimeter and it's very difficult to see them with an unaided eye. These insects emerged hundreds of millions years ago and they have been evolving all this time -- up to present day.

Microinsects are around us: they fly in cities, in parks, mountains and forests. They are represented in Moscow, but in low latitudes and tropics there are more of them. These insects have specific wings, made not as a blade like in dragonflies but like a vein with bristles along the edges, looking like a feather.

The biologists have analyzed a vast amount of data, obtained during last ten years, devoted to the studies of structure of tiny insects. The scientists have created 30 complete and 26 partial 3D computer reconstructions for 22 insect species of 11 families¸ belonging to five orders (Thysanura, Psocoptera, Thysanoptera, Coleoptera, and Hymenoptera). Insects of various sizes have been studied -- their body volume differed by a factor of more than 150 000. On the basis on these models the biologists have analyzed relative volumes of insect organs.

Alexey Polilov shares: "We've revealed the fact that the majority insect organ systems demonstrate great opportunities for scaling, namely they constrain constant proportions by multiple changes of body sizes. Organ systems keep structure and some of them -- even constant relative volume, despite multiple reductions in sizes."

The scientists have found out that metabolic systems, tissues of internal environment and tracheal system decrease proportionally to the reduction in body sizes even in the smallest insects. However, reproductive and nervous systems, on the contrary, demonstrate multiple increase in relative volume as the body sizes decrease.

The scientist clarifies: "It seems that these very systems limit minimal body sizes in insects. Our results, being compared together with scientific literature on vertebrate animals, show that at the same allometry scales most organs in vertebrates change non-proportionally. So, we've shown that insect structure is better adapted to scaling and especially, to reduction in body sizes".

In the future the researchers are going to expand a range of studied objects due to covering insects from different orders, for instance, Collembola, Acari and other arthropods.

Lomonosov Moscow State University

Related Evolution Articles:

Prebiotic evolution: Hairpins help each other out
The evolution of cells and organisms is thought to have been preceded by a phase in which informational molecules like DNA could be replicated selectively.
How to be a winner in the game of evolution
A new study by University of Arizona biologists helps explain why different groups of animals differ dramatically in their number of species, and how this is related to differences in their body forms and ways of life.
The galloping evolution in seahorses
A genome project, comprising six evolutionary biologists from Professor Axel Meyer's research team from Konstanz and researchers from China and Singapore, sequenced and analyzed the genome of the tiger tail seahorse.
Fast evolution affects everyone, everywhere
Rapid evolution of other species happens all around us all the time -- and many of the most extreme examples are associated with human influences.
Landscape evolution and hazards
Landscapes are formed by a combination of uplift and erosion.
New insight into enzyme evolution
How enzymes -- the biological proteins that act as catalysts and help complex reactions occur -- are 'tuned' to work at a particular temperature is described in new research from groups in New Zealand and the UK, including the University of Bristol.
The evolution of Dark-fly
On Nov. 11, 1954, Syuiti Mori turned out the lights on a small group of fruit flies.
A look into the evolution of the eye
A team of researchers, among them a zoologist from the University of Cologne, has succeeded in reconstructing a 160 million year old compound eye of a fossil crustacean found in southeastern France visible.
Is evolution more intelligent than we thought?
Evolution may be more intelligent than we thought, according to a University of Southampton professor.
The evolution of antievolution policies
Organized opposition to the teaching of evolution in public schoolsin the United States began in the 1920s, leading to the famous Scopes Monkey trial.

Related Evolution Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Changing The World
What does it take to change the world for the better? This hour, TED speakers explore ideas on activism—what motivates it, why it matters, and how each of us can make a difference. Guests include civil rights activist Ruby Sales, labor leader and civil rights activist Dolores Huerta, author Jeremy Heimans, "craftivist" Sarah Corbett, and designer and futurist Angela Oguntala.
Now Playing: Science for the People

#520 A Closer Look at Objectivism
This week we broach the topic of Objectivism. We'll be speaking with Keith Lockitch, senior fellow at the Ayn Rand Institute, about the philosophy of Objectivism as it's taught through Ayn Rand's writings. Then we'll speak with Denise Cummins, cognitive scientist, author and fellow at the Association for Psychological Science, about the impact of Objectivist ideology on society. Related links: This is what happens when you take Ayn Rand seriously Another Critic Who Doesn’t Care What Rand Thought or Why She Thought It, Only That She’s Wrong Quote is from "A Companion to Ayn Rand"