The
late Stephen Jay Gould once argued that if you turned back time on
evolution and let it start over, a completely different outcome would be
produced every time. His reasoning was that even relatively minor
events like droughts or hurricanes could have a magnified effect over
time. The predictability of evolution has been the subject of many
debates for many years. Recent research done on the matter suggests that even if you gave evolution another shot, you’d get pretty much the same thing.
Researcher Luke Mahler used Anole lizards as his test subjects. The
lizards are found on four neighbouring islands; Cuba, Hispaniola,
Jamaica and Puerto Rico. These islands were originally colonized by the
Anoles roughly 40 million years ago. All the islands have similar
climate and ecology. Now, they have diversified.
The scientists
looked at 100 out of 119 lizard species on all four islands.
Measurements of their bodies were taken from both wild and museum
specimens. If evolution were truly unpredictable, a lot of variation
would be seen in the lizards on different islands. However, the
researchers observed an unusual degree of convergence. Lizards that
occupied similar environmental niches on different islands looked very
similar. In the words of Luke Mahler, "The adaptive radiations match on
all four islands -- with few exceptions, each species on an island has a
match on the other islands." As ever, there were some exceptions. The
island of Hispaniola has a leaf-litter specialist, Anolis barbouri
(pictured). None of the other islands have a counterpart.
The
researchers managed to chart their data in the form of adaptive
landscapes for each island. An adaptive landscape is a 3D graph that
displays features and traits. Peaks on an adaptive landscape indicate
combinations of traits that are selected for in that environment, while
valleys represent combinations of traits that are selected against.
All four islands had very similar adaptive landscapes. The researchers
were able to go so far as to look back at the lizards’ evolutionary past
and estimate when a niche was colonized by the lizards.
Read all about it: http://bit.ly/13q0TnH
Also read: http://bit.ly/17oLQeb
Image URL: http://bit.ly/15yzzCF
The
late Stephen Jay Gould once argued that if you turned back time on
evolution and let it start over, a completely different outcome would be
produced every time. His reasoning was that even relatively minor
events like droughts or hurricanes could have a magnified effect over
time. The predictability of evolution has been the subject of many
debates for many years. Recent research done on the matter suggests that even if you gave evolution another shot, you’d get pretty much the same thing.
Researcher Luke Mahler used Anole lizards as his test subjects. The lizards are found on four neighbouring islands; Cuba, Hispaniola, Jamaica and Puerto Rico. These islands were originally colonized by the Anoles roughly 40 million years ago. All the islands have similar climate and ecology. Now, they have diversified.
The scientists looked at 100 out of 119 lizard species on all four islands. Measurements of their bodies were taken from both wild and museum specimens. If evolution were truly unpredictable, a lot of variation would be seen in the lizards on different islands. However, the researchers observed an unusual degree of convergence. Lizards that occupied similar environmental niches on different islands looked very similar. In the words of Luke Mahler, "The adaptive radiations match on all four islands -- with few exceptions, each species on an island has a match on the other islands." As ever, there were some exceptions. The island of Hispaniola has a leaf-litter specialist, Anolis barbouri (pictured). None of the other islands have a counterpart.
The researchers managed to chart their data in the form of adaptive landscapes for each island. An adaptive landscape is a 3D graph that displays features and traits. Peaks on an adaptive landscape indicate combinations of traits that are selected for in that environment, while valleys represent combinations of traits that are selected against.
All four islands had very similar adaptive landscapes. The researchers were able to go so far as to look back at the lizards’ evolutionary past and estimate when a niche was colonized by the lizards.
Read all about it: http://bit.ly/13q0TnH
Also read: http://bit.ly/17oLQeb
Image URL: http://bit.ly/15yzzCF
Researcher Luke Mahler used Anole lizards as his test subjects. The lizards are found on four neighbouring islands; Cuba, Hispaniola, Jamaica and Puerto Rico. These islands were originally colonized by the Anoles roughly 40 million years ago. All the islands have similar climate and ecology. Now, they have diversified.
The scientists looked at 100 out of 119 lizard species on all four islands. Measurements of their bodies were taken from both wild and museum specimens. If evolution were truly unpredictable, a lot of variation would be seen in the lizards on different islands. However, the researchers observed an unusual degree of convergence. Lizards that occupied similar environmental niches on different islands looked very similar. In the words of Luke Mahler, "The adaptive radiations match on all four islands -- with few exceptions, each species on an island has a match on the other islands." As ever, there were some exceptions. The island of Hispaniola has a leaf-litter specialist, Anolis barbouri (pictured). None of the other islands have a counterpart.
The researchers managed to chart their data in the form of adaptive landscapes for each island. An adaptive landscape is a 3D graph that displays features and traits. Peaks on an adaptive landscape indicate combinations of traits that are selected for in that environment, while valleys represent combinations of traits that are selected against.
All four islands had very similar adaptive landscapes. The researchers were able to go so far as to look back at the lizards’ evolutionary past and estimate when a niche was colonized by the lizards.
Read all about it: http://bit.ly/13q0TnH
Also read: http://bit.ly/17oLQeb
Image URL: http://bit.ly/15yzzCF
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