Callipterus Cichlid Collecting Shell

ALT: Callipterus Cichlid Collecting Shell

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There is No Consensus on Biological Sex

At this critical moment when misinformation about sex is being applied to policy globally, scientific clarification on the definition of biological sex is valuable. Here, we evaluate the primary appr...

onlinelibrary.wiley.com

Chris Packham, 65, is unrecognisable in exclusive 'prehistoric' Radio Times photoshoot and reveals having "loathed his body" since he was 16

Naturalist, punk, neurodiversity champion, environmental activist, broadcaster and campaigner. How did Chris Packham become the agent provocateur of our age?

radiotimes.com

Unique fingerprint of marine ectotherm body size change during hyperthermal crises | PNAS

The term “Lilliput Effect” describes a substantial decrease in the average body size of fossil assemblages during major environmental perturbations...

doi.org

OU paleontologists make one-in-a-million fossil discovery

Officials say an extraordinarily rare discovery has been made by a University of Oklahoma palentologistBefore the oldest dinosaur, before animals or even plant

okcfox.com

The Tree of Life (A User’s Manual)

Max Telford takes us inside one of science’s greatest quests: reconstructing the web of relationships between all our planet’s species.

eventbrite.co.uk

The influence of reproductive mode on resource competition and diversity patterns in Ediacaran early animal communities - Nature Ecology & Evolution

The appearance of the first animals in the late Ediacaran period was followed by a period of relatively slow diversification. Here the authors show that asexual stoloniferous reproduction would have enabled co-existence of suboptimal interspecific competitors and constrained diversification.

go.nature.com

**Fossils from some of the oldest-known animals on Earth, dating from 574 million years ago (Ediacaran period), suggest that cloning, not competition, dominated the Ediacaran seas, slowing evolution until environmental stress helped drive the rise of sexual reproduction and a burst of biodiversity.** Artist’s reconstruction of the _Fractofusus_ community: the bottom right features a large _Fractofusus_ around which there are 5 to 8 medium specimens clustered; each of the medium specimens also has small specimens clustered around them; the small specimens therefore form an independent double cluster pattern, namely clusters of clusters. Image credit: C.G. Kenchington. After billions of years of microbial life, during the Ediacaran period, between 635 and 539 million years ago, life exploded in size and the first animals appeared. Some of these earliest animals, such as _Fractofusus_, could grow as tall as 2 m (6.6 feet), although most were much smaller. These animals looked more like ferns than any animal we would recognize today: they do not appear to have mouths, organs or means of movement, so they are thought to have absorbed nutrients from the water around them. And like most Ediacaran life forms, they disappeared from the fossil record at the beginning of the Cambrian period 540 million years ago, making it difficult for scientists to link them to any modern life forms. Researchers have previously determined that these early animals reproduced asexually, by sending out clones via stolons or runners, like modern strawberry plants. In the rich waters of the Ediacaran, they thrived. “Life was pretty nice during the Ediacaran, so the need for sex was rather limited,” said Dr. Emily Mitchell, a researcher at the University of Cambridge. “There was relatively little competition, so there was no real pressure to change anything.” Dr. Mitchell and her colleague, University of Cambridge’s Professor Andrea Manica, used a combination of laser scanning, spatial analysis and artificial intelligence to study Ediacaran fossils from Mistaken Point in Newfoundland, Canada. They first showed that asexual, stolon-based reproduction limited competition, then built a computer model to simulate how early animal communities might behave under different reproductive strategies. They ran the model thousands of times while a simple neural network helped narrow down which simulations best matched the diversity patterns seen in the fossil record. This approach, known as Approximate Bayesian Computation, allowed the researchers to work backwards from the real data to estimate how far organisms spread and how strongly they competed for resources. Using this method, they showed that limited dispersal linked to asexual, runner-based reproduction could explain why early animal communities had relatively few species, and why a later shift toward wider dispersal and sexual reproduction coincided with a sudden burst of evolutionary diversity. Competition and stress have been prime drivers of evolution for billions of years, but in the deep waters of the Ediacaran, asexual reproduction meant that competition was limited. “If you’re connected to your neighbor by these runners, then you’re sharing nutrients and you don’t need to compete with them,” Professor Manica said. However, as life in the Ediacaran slowly spread from the deep ocean to shallower waters, early animals faced more pressures: tides, storms, changing temperatures and nutrient levels all would have made life more precarious, leading to increased competition for resources. “If you’re suddenly in an environment where you’re essentially getting killed a couple of times per year, then that changes everything,” Dr. Mitchell said. “Stress essentially leads to sexual reproduction, and when that happens, we can see a massive increase in dispersal distances as animals attempt to colonize new areas due to an increase in competition.” “As these early animals adapted to both a new mode of reproduction and new habitats, there was a corresponding increase in diversification, leading to the Ediacaran ‘second wave’ of animal evolution, a process that accelerated further in the Cambrian, once animals became mobile.” The study was published this week in the journal _Nature Ecology and Evolution_. _____ E.G. Mitchell & A. Manica. The influence of reproductive mode on resource competition and diversity patterns in Ediacaran early animal communities. _Nat Ecol Evol_ , published online June 9, 2026; doi: 10.1038/s41559-026-03094-2

sci.news

The Cambrian Explosion (Evolution 538 MILLION Years Ago)

YouTube video by The Ancients

youtu.be

Sorites orbiculus

Sorites orbiculus from Anse Colas, Bouillante, Guadeloupe on May 1, 2024 at 11:46 AM by Julie Mellinger

inaturalist.org