How new species arise in the sea

Study sheds new light on a fundamental question in evolutionary biology

Date:  March 4, 2019

Source:  Helmholtz Centre for Ocean Research Kiel (GEOMAR)

For a new species to evolve, two things are essential: a characteristic -- such as a colour -- unique to one species and a mating preference for this characteristic. For example, individuals from a blue fish species prefer blue mates and individuals from a red fish species prefer red mates. If the two species interbreed, the process of sexual recombination is expected to destroy the coupling between colour and mate preferences and form red individuals with a preference for blue mates and vice versa. This will prevent the two species from diverging, and this is one of the reasons why it has been thought for a long time that new species can only evolve in absolute isolation, without interbreeding.

However, the dynamics of this process depend on the exact number and location of genes underlying species characteristics and mate preferences, the strength of natural selection acting on these genes, and the amount of interbreeding between species. In a new study, Professor Oscar Puebla from GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany together with colleagues from the Smithsonian Tropical Research Institute in Panama have found that natural selection can couple the evolution of genes for colour pattern and mate preferences when species still interbreed. The study has been published today in the international journal Nature Ecology and Evolution.

"To address this question, the first challenge was to identify an animal group in which species are still young and interbreed, with clear species characteristics, and in which the bases of reproductive isolation are well understood," Oscar Puebla explains. The hamlets, a group of closely related reef fishes from the wider Caribbean, constitute exactly such a group. The hamlets are extremely close genetically, differ essentially in terms of colour pattern, and are reproductively isolated through strong visually-based mate preferences.

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Hungry moose more tolerant of wolves' presence

Date:  March 13, 2019

Source:  University of Wyoming

Driven by the need for food, moose in western Wyoming are less likely to change their behavior to avoid wolves as winter progresses, according to new research by University of Wyoming scientists.

The findings, published today (March 13) in the journal Ecology, provide new insights into the interactions of the region's apex predators and their prey. The results also highlight the complexity of the relationships between wolves and big-game species, making it difficult to reach general conclusions about whether and how fear of wolves has impacted the ecosystem, the researchers say.

"We have known for some time that hungry animals will tolerate the presence of predators in order to forage and avoid starvation, and that phenomenon, called the 'starvation-predation hypothesis,' is supported by our research," says Brendan Oates, now with the Idaho Department of Fish and Game, who conducted the research as a UW graduate student. "In this case, close proximity of wolves does cause moose to move, but not enough to drive them from their preferred habitats -- especially late in the winter."

Oates is the lead author of the Ecology paper. Co-authors include his UW advisers: Jake Goheen, associate professor in UW's Department of Zoology and Physiology, and Matt Kauffman, a U.S. Geological Survey researcher based at UW. UW's Jerod Merkle, assistant professor in the Department of Zoology and Physiology, also was involved with the research, as were agency personnel from the National Park Service and U.S. Fish and Wildlife Service.

The scientists tracked movements of dozens of GPS-collared moose and wolves in Grand Teton National Park and the Bridger-Teton National Forest over a five-year period, detecting 120 unique encounters among 25 individual moose and six wolf packs. An encounter was defined as when moose and wolves were within about 1,600 yards of each other.

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USDA Fed Cats and Dogs to Kittens, Alarming Watchdog Report Claims

By Jeanna Bryner, Live Science Managing Editor | March 19, 2019 04:50pm ET

The title of the report says it all, "USDA Kitten Cannibalism." It seems hard to believe, but an investigation by a nonprofit watchdog group reveals that the U.S. government purchased hundreds of cats and dogs for stomach-churning research projects — projects that the watchdog group describes as "needless."

The research, carried out at the USDA's Agricultural Research Service's Animal Parasitic Disease Laboratory in Beltsville, Maryland, included feeding the remains of euthanized "meat market" animals to healthy lab cats and injecting the remains of parasite-infected cats into mice, according to NBC News, which acquired an early copy of the reportreleased today (March. 19) by The White Coat Waste Project, a group aimed at ending wasteful animal testing.

According to NBC News, the investigation found that more than 400 dogs from Colombia, Brazil and Vietnam, as well as 100 cats from China and Ethiopia, were euthanized for lab food.

Apparently, the lab also breeds kittens in order to carry out research on the parasite Toxoplasma gondii; cats are the only host animal for the parasite's eggs. These cats were fed brain or muscle tissue from intentionally infected cats. This month, lawmakers announced they would introduce legislation to prevent the lab from infecting cats with the parasite and then later euthanizing and incinerating those cats after researchers collected the parasites from the animals' feces, according to another NBC News report.

The parasite T. gondii causes toxoplasmosis, which the Centers for Disease Control and Prevention (CDC) reports as a leading cause of death attributed to foodborne illness in the United States; humans can become infected after consuming food or water contaminated with infected cat feces or from eating undercooked meat of animals harboring cysts of the parasite in their tissue, according to the CDC.

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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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Short birth intervals associated with higher offspring mortality in primates

March 11, 2019, New York University

Shorter intervals between primate births are associated with higher mortality rates in offspring, finds a new study of macaque monkeys. The results are consistent with previous research on human birth intervals, suggesting that this is a pattern of evolutionary origin.

"Despite the extensive body of research showing a relationship between short birth intervals and high offspring mortality in humans, we have lacked studies outside of humans, especially in non-human primates," observes James Higham, an associate professor in New York University's Department of Anthropology and the senior author of the study, which appears in the journal Proceedings of the National Academy of Sciences. "This new research helps fill the gap by clarifying the biological link between birth intervals and offspring mortality in a general evolutionary framework."

"We provide some of the first such data, from free-ranging rhesus macaques, and show that the risk of a short birth interval to an offspring is contingent on the survival of its older or younger sibling, who may constrain the maternal resources available for the offspring," adds Susie Lee, a doctoral candidate in NYU's anthropology program and one of the paper's co-authors.

The study also included Angelina V. Ruiz-Lambides, associate director of the Cayo Santiago field station of the Caribbean Primate Research Center at the University of Puerto Rico.

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