Penguin Genomes Shed Light on Their Evolutionary History and Adaptations

Humans have always been in awe of birds: their beautiful feathers, their graceful flight, and their sweet songs. These are just some of the features that distinguish them from other animals. Birds are extremely diverse—with over 10,000 living species on Earth—and are found in all kinds of environments, from extremely hot and dry deserts, to the frigid Antarctic. 

Penguins are particularly interesting for scientists as they are flightless birds that can swim and have evolved to thrive in the hostile Antarctic environment where few animals can survive. Now, we are a step closer to understanding their evolutionary history, population sizes in response to historical climate change, as well as the genes involved in their ability to adapt to such extreme climates, with an exciting new study published last month in GigaScience, an online open-access BGI-BioMed Central journal.

Ship Noise Makes Young Eels Stressed and Vulnerable to Predation

Noise pollution in the ocean isn’t just a nuisance; it has grave consequences for the survival of some marine organisms. A recent study reveals that ship noises make young eels stressed and when confronted with predators, they are less likely to fend off attacks due to impaired escape behaviors, known as antipredator responses. 

During exposure to harbor ship noise, young eels were less responsive when faced with a looming predator and showed slower escape behaviors than eels exposed to sounds of the harbor only. And when pursued in a simulated predator chase, they were caught faster than eels exposed to harbor-only sounds.

While humans have explored the oceans for centuries, ship traffic now is greater than ever before, largely because of international trade. Commercial shipping activity—transporting the myriad of consumer goods we have become increasingly reliant on—pervades the oceans. Many of the goods transported by ships may make our lives easier, but these unfamiliar man-made noises can pose a threat to marine organisms. In some cases, the effects could mean the difference between life and death.

Two cargo ships in San Francisco
Image: Line0534 by NOAA – California Publication of the National Oceanic & Atmospheric Administration (NOAA), USA via Wikipedia

Rising Ocean Acidity Weakens Hunting Ability in Sharks

Sharks, the ocean’s top predators, renowned for their impressive hunting abilities, rely extensively on their keen sense of smell to hunt prey located miles away—earning themselves the label “swimming noses.” But a new study reveals that high levels of seawater acidity expected due to climate change can diminish their ability to track prey through sensing of odors.

The smooth dogfish, a shark whose range includes the Atlantic Ocean off the eastern United States, could lose their ability to sense the smell of food due to ocean acidification if climate change continues at its current pace.
Credit: Danielle Dixson/Georgia Tech

Developing Countries to Become Major Climate Change Contributors by 2030—Later Than Previous Estimates

Developed nations have dominated global surface temperature change historically, and according to a new study, they will continue to do so until 2030, when developing nations, particularly the two population giants—China and India—will overtake them. 

“This is significant,” said lead author Daniel Ward, a postdoctoral researcher from Cornell University, because most human-induced “climate change will come from developed countries until about the year 2030, whereas previous estimates put this ‘crossover’ year at 2020 or earlier.”