Bromeliads

Yesterday I blogged about taxonomy but I did not mention the reasons for it.  One of the benefits of a standardized naming system is that people all over the world can refer to the same organism regardless of the language they speak.  All scientific names are Latinized.  Latin is the language of choice because it is a dead language.  No one speaks it anymore, so it will never change or progress into different meanings.  

Bromeliads massed in a garden bed

 

The binomial system also gives relationship information to scientists about how organisms have evolved.  For example, plants in a Family have diverged back in time from all other families.  Those plants in the family have further divided and evolved different genuses.  All plants in a genus evolve into a particular species which does not usually crossbreed with other species in that Genus.  Species may go on to further specialize due to the forces of geography, time of blooming, or other factors.  The species becomes more and more fit to its environment.  

In the past, botanists used flower anatomy to classify plants into Genus, species, etc.  Now they have another tool.  In the hands of a skilled botanist, even the chromosomes can be counted and studied to shed new light on evolutionary paths.  Some recent studies have revealed surprises that have changed the classification of certain plants. 

Bromeliad

 

The Bromeliad family of plants has had a shake up recently.  It is composed of several subfamilies which we will not go into here.  One of the subfamilies is called Bromelioideae.  Some botanists were looking at the chromosome number of members of the subfamily, Genus Cryptanthus.  Most all other Bromeliads have been found to have 50 chromosomes.  Most of Cryptanthus sp.  have 50 also.  However, a few were found to have either 34 or 36 chromosomes.  This was quite a shock since chromosome number is a very stable and unchanging attribute in most organisms.  A reduction of chromosomes is called aneuploidy and usually causes death or distortion of the organism.  In this genus of Bromeliads, the chromosome number has changed and the plants pass this down to their offspring.  It is a sign that those reduced chromosome plants are evolving into a different group.  How should the botanists react in the name they call these new plants?  Should those species having reduced chromosome number be given a new Genus?  If we are using the naming system the way it is intended, they should probably be named separately.  Bromeliad flower stalks

Bromeliad flower stalks

Article about aneuploidy in Bromeliads:  http://www.bioone.org/doi/abs/10.1043/0363-6445-26.4.722?journalCode=sbot

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