New model IDs primate species with potential to spread Zika in the Americas

Interactive maps can guide surveillance efforts, protect human health

Date:  March 19, 2019

Source:  Cary Institute of Ecosystem Studies

In the Americas, primate species likely to harbor Zika -- and potentially transmit the virus -- are common, abundant, and often live near people. So reports a new study published today in Epidemics. Findings are based on an innovative model developed by a collaborative team of researchers from Cary Institute of Ecosystem Studies and IBM Research through its Science for Social Good initiative.

Lead author Barbara Han, a disease ecologist at Cary Institute, explains: "When modeling disease systems, data gaps can undermine our ability to predict where people are at risk. Globally, only two primate species have been confirmed positive for Zika virus. We were interested in how a marriage of two modeling techniques could help us overcome limited data on primate biology and ecology -- with the goal of identifying surveillance priorities."

The recent Zika epidemic in the Americas was one of the largest outbreaks in modern times, infecting over half a million people. Like other mosquito-borne flaviviruses, Zika circulates in the wild. Primates can serve as disease reservoirs of spillover infection in regions where mosquitoes feed on both primates and people.

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First dogs in the Americas arrived from Siberia, disappeared after European contact

Date:  July 5, 2018

Source:  University of Illinois at Urbana-Champaign

A study reported in the journal Science offers an enhanced view of the origins and ultimate fate of the first dogs in the Americas. The dogs were not domesticated North American wolves, as some have speculated, but likely followed their human counterparts over a land bridge that once connected North Asia and the Americas, the study found.

This is the first comprehensive genomic study of ancient dogs in the Americas to analyze nuclear DNA, which is inherited from both parents, along with mitochondrial DNA, which is passed down only from mothers to their offspring. By comparing genomic signatures from 71 mitochondrial and seven nuclear genomes of ancient North American and Siberian dogs spanning a period of 9,000 years, the research team was able to gain a clearer picture of the history of the first canine inhabitants of the Americas.

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Riverbed discovery places humans in the southeast US 1,500 years earlier than previously thought

MAY 13, 2016

by Susanna Pilny

It was a widely accepted fact since the 1930s: The first people to arrive in the Americas, now known as the Clovis culture, came here about 13,000 years ago.

The first crack in the theory came around in the 1970s, when archaeologists began turning up sites that predated the arrival of the Clovis culture—although acceptance of a pre-Clovis human arrival has been slow.

However, a newly-excavated site in Florida now offers substantial proof for those who doubt, as researchers there have dated human-made tools to 14,550 calendar years before present—and offers up a rare insight into when certain megafauna disappeared from the continent.

The Clovis culture

More than 13,500 years ago, the northern reaches of North America were covered entirely by sheets of ice—which, spanning thousands of miles in solid blocks, hindered the movements of humans and animals looking to move from Bering land bridge southward.

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Ancient DNA reveals evolution of giant bears in the Americas

Date: April 20, 2016

Source: University of Adelaide

The work of University of Adelaide researchers is shedding new light on the evolution of what are believed to be the largest bears that ever walked the Earth.

Dr Kieren Mitchell, from the University's Australian Centre for Ancient DNA, School of Biological Sciences, has a new paper just published in Biology Letters.

He writes: "During the Pleistocene (2.5 million years ago -- 11 thousand years ago) giant bears weighing over 1,000kg roamed both North and South America. These giants belonged to a now practically extinct subfamily of bears -- Tremarctinae -- which is today only represented by the small, herbivorous Andean spectacled bear (Tremarctos ornatus).

"The giant North American bears (Arctodus) and South American bears (Arctotherium) have long been believed to be each others' closest relative. However, by comparing ancient DNA data obtained from representatives of the two extinct genera and comparing them with the living species, we were able to show that Arctotherium is most closely related to Tremarctos and not Arctodus.

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Study of ancient dogs in the Americas yields insights into human, dog migration

Date:

January 7, 2015

Source:

University of Illinois at Urbana-Champaign

Summary:

A new study suggests that dogs may have first successfully migrated to the Americas only about 10,000 years ago, thousands of years after the first human migrants crossed a land bridge from Siberia to North America.

The study looked at the genetic characteristics of 84 individual dogs from more than a dozen sites in North and South America, and is the largest analysis so far of ancient dogs in the Americas. The findings appear in the Journal of Human Evolution.

Unlike their wild wolf predecessors, ancient dogs learned to tolerate human company and generally benefited from the association: They gained access to new food sources, enjoyed the safety of human encampments and, eventually, traveled the world with their two-legged masters. Dogs also were pressed into service as beasts of burden, and sometimes were served as food, particularly on special occasions.

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