wildmanyeah
Crew Member
https://www.forbes.com/sites/michae...-why-but-its-probably-our-fault/#53c4a8611da7
Atlantic Salmon Are Evolving Not To Grow As Big And It's Not Clear Why But It's Probably Our Fault
"We knew from our earlier research that the age at maturity had been decreasing over this period," said Craig Primmer at the University of Helsinki in Finland.
When to spawn is a trade-off: a salmon that waits longer will grow larger and probably have more offspring, but it also risks dying before it can spawn at all. Primmer's team has found that the salmon are spending less time at sea growing, and instead heading back to their rivers to spawn sooner.
"Now we wanted to see if there were signs of this also at the genetic level, that is, whether it was an evolutionary change," said Primmer.
This is normally tricky, because most aspects of an organism's anatomy and behaviour are controlled by multiple genes. But in this case one gene, vgll3, was known to be the major player. The team has found that the version of the gene that causes later maturing has become 18 per cent less common over 36 years.
Atlantic Salmon Are Evolving Not To Grow As Big And It's Not Clear Why But It's Probably Our Fault
"We knew from our earlier research that the age at maturity had been decreasing over this period," said Craig Primmer at the University of Helsinki in Finland.
When to spawn is a trade-off: a salmon that waits longer will grow larger and probably have more offspring, but it also risks dying before it can spawn at all. Primmer's team has found that the salmon are spending less time at sea growing, and instead heading back to their rivers to spawn sooner.
"Now we wanted to see if there were signs of this also at the genetic level, that is, whether it was an evolutionary change," said Primmer.
This is normally tricky, because most aspects of an organism's anatomy and behaviour are controlled by multiple genes. But in this case one gene, vgll3, was known to be the major player. The team has found that the version of the gene that causes later maturing has become 18 per cent less common over 36 years.
