Gene loss more important in animal kingdom evolution than previously thought

February 27, 2020

Scientists have shown that some key points of animal evolution -- like the ones leading to humans or insects -- were associated with a large loss of genes in the genome. The study, published in Nature Ecology & Evolution, compared over 100 genomes to investigate what happened at the gene level during the evolution of animals after their origin.

During evolution, organisms can gain new genes to perform new functions, lose other genes that are not used anymore, and recycle old ones into new functions. Previous studies have shown that the acquisition of new genes played a major role in the origin of the animal kingdom, and it is assumed that most organisms become more complex by acquiring new genes.

Dr Jordi Paps from the University of Bristol together with PhD student, Cristina Guijarro-Clarke at the University of Essex, and Professor Peter Holland from the University of Oxford, discovered that gene loss has actually been more important during the evolution of the animal kingdom than previously thought.

Animals can be split into major evolutionary lineages. One is deuterostomes: comprising humans and other vertebrates as well as sea stars or sea urchins. Another is ecdysozoans: encompassing the largest group of animals, the arthropods (insects, lobsters, spiders, millipedes), as well as other moulting animals like roundworms. These two lineages include some of the animals considered to be more complex.

However, the research team's analyses has shown that the respective last common ancestors of deuterostomes and ecdysozoans suffered unprecedented levels of gene losses, and that the increase in complexity or diversity of species is not always coupled with a rise in the number of new genes.

Dr Jordi Paps, lead author and Lecturer from Bristol's School of Biological Sciences, explained: "A larger implication is that the evolution of the animal kingdom is not driven by an increase in the number of genes, and in evolution does not invariably mean becoming more complex.

"We are planning to use the same type of approach to study how the genomes of parasitic animals, such as taenia or roundworms, lose and gain genes to see if we can find therapeutic targets to fight the diseases caused by these parasites."

The next step for the research would be to see if this pattern is also seen in other major lineages in the tree of life, other than animals.

'Widespread patterns of gene loss in the evolution of the animal kingdom' by Cristina Guijarro-Clarke, Peter W. H. Holland and Jordi Paps in Nature Ecology & Evolution

University of Bristol

Related Evolution Articles from Brightsurf:

Seeing evolution happening before your eyes
Researchers from the European Molecular Biology Laboratory in Heidelberg established an automated pipeline to create mutations in genomic enhancers that let them watch evolution unfold before their eyes.

A timeline on the evolution of reptiles
A statistical analysis of that vast database is helping scientists better understand the evolution of these cold-blooded vertebrates by contradicting a widely held theory that major transitions in evolution always happened in big, quick (geologically speaking) bursts, triggered by major environmental shifts.

Looking at evolution's genealogy from home
Evolution leaves its traces in particular in genomes. A team headed by Dr.

How boundaries become bridges in evolution
The mechanisms that make organisms locally fit and those responsible for change are distinct and occur sequentially in evolution.

Genome evolution goes digital
Dr. Alan Herbert from InsideOutBio describes ground-breaking research in a paper published online by Royal Society Open Science.

Paleontology: Experiments in evolution
A new find from Patagonia sheds light on the evolution of large predatory dinosaurs.

A window into evolution
The C4 cycle supercharges photosynthesis and evolved independently more than 62 times.

Is evolution predictable?
An international team of scientists working with Heliconius butterflies at the Smithsonian Tropical Research Institute (STRI) in Panama was faced with a mystery: how do pairs of unrelated butterflies from Peru to Costa Rica evolve nearly the same wing-color patterns over and over again?

Predicting evolution
A new method of 're-barcoding' DNA allows scientists to track rapid evolution in yeast.

Insect evolution: Insect evolution
Scientists at Ludwig-Maximilians-Universitaet (LMU) in Munich have shown that the incidence of midge and fly larvae in amber is far higher than previously thought.

Read More: Evolution News and Evolution Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to