Latest News Archive

Please select Category, Year, and then Month to display items
Previous Archive
26 April 2018 Photo Supplied
Pretzel-formed fossil of great evolutionary interest
Slab with holotype of Parapsammichnites pretzelifornic from the Urusis Formation, Namibia. Scale bar is 1cm.Picture was taken from Buatois et al., 2018.

The acclaimed scientific journal, Nature, recently published an article about a trace fossil in approximately 543-million-year-old rocks, which elucidates the evolution of the first animals that appeared on Earth and lived in the sea.  

Affiliated Professor in the Department of Geology at the University of the Free State (UFS) Prof Gerard Germs formed part of a team that conducted research with the aim of understanding how the evolution of the first multicellular animals came about and how the Cambrian explosion took place. Prof Germs is of great value to the team for his extended field geological knowledge.

An article which he co-authored was published in the Nature Scientific Reports. The title of the article is: “Sediment disturbance by Ediacaran bulldozers and the roots of the Cambrian explosion”. The international group of writers included authors from Canada, Spain and South Africa. 

Occurrence of the Cambrian explosion
Prof Germs explains the Cambrian explosion: “During the long (4.5-billion-year) history of the Earth, the first life originated and subsequently evolution of plants and animals took place from one-cellular organisms to multicellular vertebrate animals and seed plants. Approximately 573 million years ago the first multicellular animals appeared on the scene. Sometime afterwards, approximately 540 million years ago, a kind of explosion in the origin of many new animal species occurred. This explosion is known as the Cambrian explosion.”

The team studied Earth sediments which are somewhat older than the Cambrian explosion. Such sediments are approximately 573 to 541 million years old and form part of the Ediacaran (late Neoproterozoic) period.

“My discoveries of the past, of among others, the oldest animal with a carbonate skeleton (Cloudina) and of complex horizontal Cambrian-type “worm” tracks (treptichnids) in Ediacaran sediments of Namibia have demonstrated that the Cambrian explosion occurred more gradually than previously thought. This has recently been confirmed in the article that was published in the Nature Scientific Reports.”

Pretzeliformis bulldoze to search for food
According to the article there is evidence that   during the Ediacaran period   worm-like animals such as the Parasammichnites pretzeliformis were already so far developed that they, due to coelom development and size increase, for the first time in the history of the Earth, were able to disturb and bulldoze sediments.  In this way they were able to find a new food source in sea sediments. Bulldozing animals were previously thought to have originated only during and after the Cambrian explosion and not during the older Ediacaran.

“Another major aim of my cooperative research is to improve our knowledge of the geology of the Ediacaran to early Cambrian of South Africa and Namibia. We also intend to establish how the assembly of the supercontinent Gondwana took place. This improved knowledge can be of great future economic interest since large oil, gas and limestone sources occur in Ediacaran-age sediments outside South Africa”.

News Archive

Inaugural lecture: Prof André Pelser
2004-06-04

Tendencies and changes in the South African population structure in future decades.

Within the next five years South Africa will for the first time in the past century enter a period where the death rate will exceed the birth rate, largely due to the impact of HIV / AIDS.

According to sociologist Prof André Pelser, sociologist at the of the University of the Free State’s (UFS) Department of Sociology, the death rate exceeding the birthrate is only one of three demographic trends which will fundamentally change South Africa’s population structure in the following decades.

He was speaking at the UFS in Bloemfontein during his inaugural lecture as professor this week.

Prof Pelser said that according to some models the South African population will decrease within the next five decades by between 10 and 26 percent.

A second important trend which will impact on the population structure is the progressive ageing of the population.

He said the group above 65 years is the only age category in the South African population which will witness sharp increases in the next few decades.

In the next 50 years, the group younger than 15 years will reflect a decrease of 39% and those older than 65 years in South Africa will increase by approximately 110% in the next two decades.

“The systematic “greying” of the South African population will create the same economic and welfare issues as those with which governments in some more developed countries are already grappling,” said Prof Pelser.

A third trend affecting the South African population structure is the constant decrease in life expectancy.

Life expectancy at birth for the total population is projected to decrease from approximately 62 years at the beginning of the 1990’s to 43 years in 2015-2020, with sharp differences between the various population groups.

These tendencies and changes to the South African population structure have serious implications, he said.

For example, he said, the reduction in life expectancy could compromise national development objectives.

“It is estimated that more than a quarter of the economically active population will be infected with HIV by 2006,” said Prof Pelser.

The increase in the population, in age category 65, will place a financial burden on government and the economically active sector.

“Especially worrying is the fact that ever-increasing proportions of the state budget will be allocated to health and welfare services and this at the expense of other priorities like education, infrastructure, criminal justice system and trade and industry, to name but a few,” he said

“A comprehensive and integrated strategy is thus vitally important in addressing the overarching issues caused by changes in the population structure,” said Prof Pelser.

 

We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept