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.
Few organisms can survive in harsh environments, such as extreme cold or dry conditions, but some species equipped with special adaptations can thrive. The Antarctic midge, Belgica Antarctica, the only wingless insect native to Antarctica, has the smallest insect genome among those sequenced, a likely adaptation to the extreme conditions it is exposed to, according to a new study. Led by Professor Joanna Kelley at Washington State University, US, the study is the first to sequence the genome of an insect found in the poles.
Two Antarctica midges
Scientists have known that cleft palate—a birth defect where the baby’s roof of the mouth does not form properly—is caused by certain genes and environmental factors. Maternal smoking during pregnancy has been implicated with cleft palate in babies. Recently, Wu and colleagues discovered two genes from chromosome 4 among Asians—predominantly East Asians—result in a higher risk of nonsyndromic cleft palate when mothers were exposed to tobacco smoke three months prior to pregnancy until the first trimester.
Image: Wikimedia Commons