Evolution happens faster in the tropics! Could result in mutations, can form new species
- From: adventurer_guy@xxxxxxxxx
- Date: 7 May 2006 09:33:25 -0700
Report posted on MSNBC, May 1st Science section.
Evolution happens faster in the tropics
Scientists say finding may explain greater biodiversity in rainforests
Plants and animals living in warm, tropical climates evolve faster than
those living in more temperate zones, a new study suggests.
The finding, detailed in Tuesday's issue of the journal for the
Proceedings of the National Academy of Sciences, could help explain why
rainforests have such rich biodiversity compared with other parts of
the planet.
A census of all the plants and animals around the world would reveal
that species richness is uneven: It is highest in the tropics, the
regions of Earth near the equator, and lower the closer one goes toward
the planet's poles.
What's going on
To investigate the reasons for this trend, Shane Wright of the
University of Auckland in New Zealand and colleagues looked at the rate
of molecular evolution for 45 tropical plants and compared it to that
of related species living at more temperate latitudes.
The researchers examined the rate at which DNA bases in the plants'
genetic code are substituted. Like characters in a four-letter
alphabet, bases are DNA molecules arranged to spell out instructions
for building proteins. If one of the letters - A, T, G or C -
become substituted with another, the instructions can change and a
dysfunctional or entirely new and useful protein can be produced.
The researchers found that tropical plants had more than twice the rate
of base substitution compared to their temperate cousins.
How it works
The finding supports a theory put forth by biologist Klaus Rohde in
1992 that climate can have a powerful effect on how fast organisms
evolve and branch off into new species. Scientists think it works like
this:
Warmer temperatures speed up metabolism by allowing chemical reactions
to occur at a faster rate, but this increased efficiency comes at a
price: It produces higher quantities of charged atoms or molecules
called "free radicals," which can damage proteins - including DNA.
Higher metabolism also speeds up DNA replication, which is just another
chemical reaction, and this can increase the number of copying mistakes
that can occur.
Together, damage to DNA by free radicals and replication mistakes could
result in mutations that, over time and through natural selection
pressures, can form new species
© 2006 LiveScience.com. All rights reserved
Ok so now for the questions.????????????
"Could result in mutations"," can form new species?"
Is there any evidence that is 100% that one species has change to
another species?
Not could or can but did?
This seems to be the missing link in the evolution thorey.
Like an ape to a man. Or an alligator to a camen. Or a one type of bird
to another?
Any 100% evidence?
A friend of mine says that there is no evidence that one species has
changed into another on the base DNA level.
I say that phenotype mutations over time in small isolated breeding
populations(like on an island) will mutate base DNA enough to form a
new species.
But is there any solid DNA evidence to back this up?
If not then some scientist needs to find it. That article tip toes
around the issue with words like "Could".
I say there is no could. Just does or does not.
Open for debate.
.
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