Tech & Science

Inbreeding contributes to southern resident killer whale’s low population growth: study – BC

A new study finds that high levels of inbreeding among endangered southern killer whales likely contribute to their low population growth.

Study published Monday in peer review Natural ecology and evolution The journal found that the iconic species that lives in the North Pacific has the lowest genetic variation and the highest genetic inbreeding among the five killer whale populations analyzed.

“The big finding from this study is that the more highly inbred individuals are much less likely to survive to old age or survive the reproductive years,” said report co-author Marty Cardos told Global News.

read more:

Research reveals chemical contaminants found in endangered killer whale toilet paper

Using relatively new techniques and archival tissue samples, the researchers sequenced the genomes of 100 southern-dwelling killer whales and 47 other killer whales. Tissue samples ranged in age from the early 20th century to the last decade.

The story continues under the ad

Scientists once thought that individuals with “recent common ancestry” were inbred, but have found at least one example of direct parent-child interbreeding among Southern inhabitants.

Click to play video: 'Gulf Islanders Oppose Increased Freight Traffic'

Gulf Island Residents Oppose Increased Freight Traffic

Kardos said inbreeding appears to affect the “fitness” of the population, limiting its growth for decades.

“It can be associated with an increased risk of getting sick and can affect behavior, neurological function, immune function and metabolism,” explained a geneticist at the Northwest Fisheries Science Center.

“Genomes are large, with tens of thousands of genes in them, any of which can carry deleterious or mutated versions of the gene, and inbreeding really does affect their effects on survival and reproduction. will be exposed to

read more:

Southern killer whales don’t get the thousands of calories they need a day, study finds

The story continues under the ad

Fewer than 80 killer whales remain in the south.

Given that the species has been legally protected for decades, Cardos said scientists wondered why its growth rate did not match that of other groups of killer whales in the region. These protections remain important, he added.

“We’ve known for about a decade or so that the best population models suggest that the population is very likely to decline in the future. This study changes that. Instead, it just provides an explanation.”

© 2023 Global News, a division of Corus Entertainment Inc.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button