Equine family tree needs a trim, say scientists
Baca Juga
The horse’s position unit of measurement tree should live restructured, according to an international squad of scientists.Ancient deoxyribonucleic acid recovered from extinct Equus caballus species from unopen to the footing has challenged the fossil tape of the Equus caballus family.
Only the modern horse, zebras, wild asses too ass live today, but many other lineages stimulate got larn extinct over the final 50,000 years.
Before the advent of deoxyribonucleic acid analysis, fossils were grouped according to their morphological characteristics.
Now analysis of deoxyribonucleic acid fragments isolated from ancient bones has prompted scientists to reassess the relationships betwixt some of the ancient too modern members of the Equus caballus family.
The report involved an international squad of researchers.
They examined 35 equid fossils from unopen to the footing (South America, Europe, Southwest Asia, too South Africa). Ancient mitochondrial deoxyribonucleic acid (aDNA) was identified inwards 22 of the specimens.
The aDNA samples were extracted, amplified, too sequenced inwards specialist laboratories inwards Lyon too Adelaide.
Professor Alan Cooper, manager of the Australian Centre for Ancient DNA, based at the University of Adelaide, says despite an fantabulous fossil tape of the Equidae, at that spot are nevertheless many gaps inwards our evolutionary knowledge.
“Our results alter both the basic painting exhibit of recent equid evolution, too ideas nearly the issue too nature of extinct species,” he said.
The report used bones from caves to position novel Equus caballus species inwards Eurasia too South America. It also revealed that the Cape zebra, an extinct giant species from South Africa, was but a large variant of the modern Plains zebra.
The Cape zebra weighed upward to 400 kilograms too stood upward to 150 centimetres at the shoulder blades.
“The Plains zebra grouping in i lawsuit included the famous extinct quagga, too thus our results confirm that this grouping was highly variable inwards both coat color too size.”
Lead writer of the paper, Dr Ludovic Orlando, from Ecole Normale Supérieure, of Lyon, says the grouping discovered a novel species of the distinct, small-scale hippidion Equus caballus inwards South America.
“Previous fossil records suggested this grouping was business office of an ancient lineage from North America but the deoxyribonucleic acid showed these odd forms were business office of the modern radiations of equid species,” Dr Orlando says.
A novel species of ass was also detected on the Russian Plains too appears to live related to European fossils dating dorsum to a greater extent than than 1.5 meg years. Carbon dates on the bones discover that this species was live equally lately equally 50,000 years ago.
“Overall, the novel genetic results propose that nosotros stimulate got underestimated how much a unmarried species tin post away vary over fourth dimension too space, too mistakenly assumed to a greater extent than variety with extinct species of megafauna,” Professor Cooper says.
“This has of import implications for our agreement of human evolution, where a large issue of species are currently recognised from a relatively fragmentary fossil record.
“It also implies that the loss of species variety that occurred during the megafaunal extinctions at the terminate of the final Ice Age may non stimulate got been equally extensive equally previously thought.
“In contrast, ancient deoxyribonucleic acid studies stimulate got revealed that the loss of genetic variety inwards many surviving species appears to stimulate got been extremely severe,” Professor Cooper says. “This has serious implications for biodiversity too the hereafter impacts of climate change.”
The report was published inwards the Proceedings of the National Academy of Sciences.
PNAS Dec 22, 2009 vol. 106 no. 51 21754-21759
Published online 27.12.09.
Article commencement published on Horsetalk.co.nz on Dec 29, 2009.
Belum ada Komentar untuk "Equine family tree needs a trim, say scientists"
Posting Komentar