Ecology & Zoology

At least five mass extinction events have profoundly changed the course of life on Earth - animal life, at least. Plants have been very resilient to those events, finds a new study.

For over 400 million years, plants have played an essential role in almost all terrestrial environments and covered most of the world’s surface. During this long history, many smaller and a few major periods of extinction severely affected Earth’s ecosystems and its biodiversity.
In 2006, there was a large die-off in bees and though their numbers quickly rebounded and have continued upward since, scientists have been looking for ways to make the periodic collapses that occur less dramatic. 

The cause the last time it happened was the same plague that bees have endured for as long as science has been able to study them; parasites. But a new study shows that "nature's medicine cabinet" may be able to smooth out those natural booms and busts.

The Great Lakes have been invaded by more non-native species than any other freshwater ecosystem in the world, and though there have been increasing efforts to stem the tide of invasion threats, they remain vulnerable.

Over the past two centuries, more than 180 non-native species have been recorded in the Great Lakes and the rivers that flow into them. Nearly 20% of these species are considered to be harmful ecologically and economically, posing threats to the Lakes' native biodiversity and multibillion dollar fishery. New threats are emerging because of risks associated with trade in live organisms and climate change,researchers caution in a study in the Journal of Great Lakes Research.

Evolution starts species off on different paths and even if they arrived in one spot from common descent in the past, they can't reproduce. So in modern times an elephant is not hybridizing with a manatee, or a human with a lemur. Tree frogs...well, yes, but who can explain tree frogs? That did happen, two species were able to interbreed after 34 million years, and sunfish who hybridized after nearly 40 million years.

By Tobias Pamminger, University of Sussex

Ants have a reputation of being industrious hard-working animals, sacrificing their own benefit for the good of the colony. They live to serve their queen and take care of all essential tasks including brood care, gathering food and maintaining the nest.

However, not all ant species live up to their reputation. A handful of ant species have figured out a way to outsource all these essential tasks – by exploiting their weaker cousins.

A few years ago, another colony collapse occurred. Though it has happened more times than recorded history has been able to log, the concern was that new pesticides, which replaced the old pesticides blamed for the last colony collapse, might be the cause.

Since then, bees have rebounded nicely. The collapse was limited to one geography, rather than everywhere the newer pesticides - neonicotinoids - were used, so researchers have been scrambling to find out why it happened and therefore make it predictable. 

A new study says it could just be stress - young bees are sometimes pressured to grow up too fast. 

Credit: QMUL
If you own a home, termites are the enemy, but if you want to hold back a desert, their large dirt mounds can be crucial to protecting semi-arid ecosystems and agricultural lands.

That's obviously important for feeding people and insert obligatory global warming reference here, because it means those areas could be a lot more resilient to changing climates than climate scientists believe.

Leigh Cooper,  Inside Science

(Inside Science) – Despite their agility in flight, birds often find themselves unable to escape vehicles – a conundrum that puzzles scientists.

To solve the mystery, a new study brought brown-headed cowbirds (Molothrus ater) into a homemade, bird-sized movie theater where they watched videos of an approaching truck. The cowbirds eyeballed the gap between themselves and the car to evaluate the danger of the approaching vehicle, but they did not take into account how fast the truck closed that distance.

A brilliant-green sea slug can live for months at a time "feeding" on sunlight like a plant and now scientists have the first direct evidence that its chromosomes have some genes that come from the algae it eats. 

Those genes help sustain photosynthetic processes inside the slug that provide it with all the food it needs. 

Importantly, this is one of the only known examples of functional gene transfer from one multicellular species to another, which is the goal of gene therapy to correct genetically based diseases in humans.

Sex or no sex?  If you want to be healthier as a species over time, sexual reproduction is the way to go, according to a new study. 

It's a long-debated topic among biologists - some argue that sexual reproduction is superior because species don't accumulate harmful mutations as easily as in asexual reproduction.

Using various species of the evening primrose (Oenothera) as his model, Dr. Jesse Hollister, assistant professor at Stony Brook University in New York, and colleagues demonstrated strong support for reproducing sexually. "These findings allow us to understand why an enormous diversity of species around the world go through the laborious process of sexual reproduction," says Hollister.