Mr_Wilford
Member
Back in 2003, Beheregaray et al,. (1.) discovered something interesting. It's well known that islands are formed by Volcanic activity, and particularly young islands (those with still active volcanoes) can act as a natural laboratory to study evolution. Beheregaray et al,. looked at the genome of the population of tortoises (Geochelone nigra vandenburghi) on the Island Isabela in the Galapagos, an island with a still active volcano named Alcedo. A large scale survey of their mitochondrial DNA revealed they had an average of three to five times less matrilineal diversity than tortoise populations on other islands. This indicates that at some time in the past, they experienced a genetic bottleneck, a rather large one at that.
By looking at the molecular clocks, they were able to date the genetic bottleneck of the tortoises, giving an age range of about 72,400 to 118,700 years, with a conservative age estimate of around 88,000 years ago. Given this age range, it was obvious what the cause of the bottleneck was. Dating of solidified lavas from the nearby volcano which were from it's most recent eruption using the K-Ar method gave an age range of the eruption between 74,000 and 120,000 years. Thus, the record in the genome of the tortoises actually records the eruption event in a way.
Oh, how I'd love to see the YECs squirm with this. If both the genetic clocks and K-Ar method are so woefully inaccurate, why do these two unrelated methods cross confirm each other?
Citations:
1. http://www.researchgate.net/publication/9066176_Genes_Record_a_Prehistoric_Volcano_Eruption_in_the_Galapagos
By looking at the molecular clocks, they were able to date the genetic bottleneck of the tortoises, giving an age range of about 72,400 to 118,700 years, with a conservative age estimate of around 88,000 years ago. Given this age range, it was obvious what the cause of the bottleneck was. Dating of solidified lavas from the nearby volcano which were from it's most recent eruption using the K-Ar method gave an age range of the eruption between 74,000 and 120,000 years. Thus, the record in the genome of the tortoises actually records the eruption event in a way.
Oh, how I'd love to see the YECs squirm with this. If both the genetic clocks and K-Ar method are so woefully inaccurate, why do these two unrelated methods cross confirm each other?
Citations:
1. http://www.researchgate.net/publication/9066176_Genes_Record_a_Prehistoric_Volcano_Eruption_in_the_Galapagos
