A new study reveals how some sea snakes came to have "shrunken heads".
The slender-necked sea snake (Hydrophis melanocephalus) and the
blue-banded sea snake (Hydrophis cyanocinctus) are pretty different in
terms of looks. Adult slender-necked sea snakes are only half the size
of their blue-banded cousins and possess a much smaller head. But these
differences are only skin-deep - if you were to look at the genes of both species, you'd struggle to tell them apart.
The high genetic similarity between the two species is a good indicator
that they diverged from a common ancestor very recently, and the
researchers believe differences in food and hunting techniques caused
the split. While blue-banded sea snakes hunt spiny fish and gobies, the
small head of the slender-necked snake allows it to invade eel burrows.
"[The genetic similarity] suggested they separated very recently from a
common ancestral species and had rapidly evolved their different
appearances," said Mike Lee (of the South Australian Museum and involved
in the study). "One way this could have happened is if the ancestral
species was large-headed, and a population rapidly evolved small heads
to probe eel burrows - and subsequently stopped interbreeding with the
large-headed forms."
The international team believe that their
results have wider implications than just sea snake biology - they also
highlight the valuable role sea snakes could have in helping us
understand marine speciation and adaptive radiation.
Photo: A slender-necked sea snake. Credit to Yoshitaka Tahara.
http://www.livescience.com/
http://www.adelaide.edu.au/
http://www.wired.co.uk/news/
A new study reveals how some sea snakes came to have "shrunken heads".
The slender-necked sea snake (Hydrophis melanocephalus) and the blue-banded sea snake (Hydrophis cyanocinctus) are pretty different in terms of looks. Adult slender-necked sea snakes are only half the size of their blue-banded cousins and possess a much smaller head. But these differences are only skin-deep - if you were to look at the genes of both species, you'd struggle to tell them apart.
The high genetic similarity between the two species is a good indicator that they diverged from a common ancestor very recently, and the researchers believe differences in food and hunting techniques caused the split. While blue-banded sea snakes hunt spiny fish and gobies, the small head of the slender-necked snake allows it to invade eel burrows.
"[The genetic similarity] suggested they separated very recently from a common ancestral species and had rapidly evolved their different appearances," said Mike Lee (of the South Australian Museum and involved in the study). "One way this could have happened is if the ancestral species was large-headed, and a population rapidly evolved small heads to probe eel burrows - and subsequently stopped interbreeding with the large-headed forms."
The international team believe that their results have wider implications than just sea snake biology - they also highlight the valuable role sea snakes could have in helping us understand marine speciation and adaptive radiation.
Photo: A slender-necked sea snake. Credit to Yoshitaka Tahara.
http://www.livescience.com/
http://www.adelaide.edu.au/
http://www.wired.co.uk/news/
The slender-necked sea snake (Hydrophis melanocephalus) and the blue-banded sea snake (Hydrophis cyanocinctus) are pretty different in terms of looks. Adult slender-necked sea snakes are only half the size of their blue-banded cousins and possess a much smaller head. But these differences are only skin-deep - if you were to look at the genes of both species, you'd struggle to tell them apart.
The high genetic similarity between the two species is a good indicator that they diverged from a common ancestor very recently, and the researchers believe differences in food and hunting techniques caused the split. While blue-banded sea snakes hunt spiny fish and gobies, the small head of the slender-necked snake allows it to invade eel burrows.
"[The genetic similarity] suggested they separated very recently from a common ancestral species and had rapidly evolved their different appearances," said Mike Lee (of the South Australian Museum and involved in the study). "One way this could have happened is if the ancestral species was large-headed, and a population rapidly evolved small heads to probe eel burrows - and subsequently stopped interbreeding with the large-headed forms."
The international team believe that their results have wider implications than just sea snake biology - they also highlight the valuable role sea snakes could have in helping us understand marine speciation and adaptive radiation.
Photo: A slender-necked sea snake. Credit to Yoshitaka Tahara.
http://www.livescience.com/
http://www.adelaide.edu.au/
http://www.wired.co.uk/news/
![A new study reveals how some sea snakes came to have "shrunken heads".
The slender-necked sea snake (Hydrophis melanocephalus) and the blue-banded sea snake (Hydrophis cyanocinctus) are pretty different in terms of looks. Adult slender-necked sea snakes are only half the size of their blue-banded cousins and possess a much smaller head. But these differences are only skin-deep - if you were to look at the genes of both species, you'd struggle to tell them apart.
The high genetic similarity between the two species is a good indicator that they diverged from a common ancestor very recently, and the researchers believe differences in food and hunting techniques caused the split. While blue-banded sea snakes hunt spiny fish and gobies, the small head of the slender-necked snake allows it to invade eel burrows.
"[The genetic similarity] suggested they separated very recently from a common ancestral species and had rapidly evolved their different appearances," said Mike Lee (of the South Australian Museum and involved in the study). "One way this could have happened is if the ancestral species was large-headed, and a population rapidly evolved small heads to probe eel burrows - and subsequently stopped interbreeding with the large-headed forms."
The international team believe that their results have wider implications than just sea snake biology - they also highlight the valuable role sea snakes could have in helping us understand marine speciation and adaptive radiation.
Photo: A slender-necked sea snake. Credit to Yoshitaka Tahara.
http://www.livescience.com/28094-sea-snakes-shrunken-heads.html
http://www.adelaide.edu.au/news/news60142.html
http://www.wired.co.uk/news/archive/2013-03/20/small-headed-sea-snakes](https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-ash3/s480x480/551877_621907841157528_1988937206_n.jpg)
No comments:
Post a Comment